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Habitually used hibernation sites of paper wasps are marked with venom and cuticular peptides
... The increasing attention given in the last decades to hydrocarbons of social insects and the striking evidence of their involvement in communication, boosted by the exponential development of more sensitive analytical techniques, could have masked the potential role of additional cuticular compounds as recognition pheromones. Peptides and proteins, for example, have been detected on the bodies of various insects , such as locusts, honeybees, cockroaches, paper wasps, and termites (Zupko et al. 1993; Korchi et al. 1998; Cornette et al. 2002; Turillazzi, Mastrobuoni, et al. 2006; Hanus et al. 2010), and they have been reported to play a possible role as pheromones in some insects (Kubli 1992; Cornette et al. 2002 Cornette et al. , 2003 Turillazzi, Dapporto, et al. 2006). In the social wasps of the Polistes genus, this cuticular blend of polar substances, analogously to the cuticular hydrocarbons (CHCs), is formed by numerous compounds (ranging between 900 and 3000 Da) highly variable among species (Turillazzi et al. 2007). ...
... In the social wasps of the Polistes genus, this cuticular blend of polar substances, analogously to the cuticular hydrocarbons (CHCs), is formed by numerous compounds (ranging between 900 and 3000 Da) highly variable among species (Turillazzi et al. 2007). Moreover, this blend, once passively deposited on the substrate by congeneric individuals , can be detected by young mated Polistes foundresses of the following season and used to locate suitable hibernation sites (Turillazzi, Dapporto, et al. 2006). Due to the presence of this detectable and variable mixture of polar compounds on the cuticle of paper wasps, their putative role as semiochemicals in other contexts of the colonial life seems reasonable. ...
... Epicuticular fractions extracts of foreign workers versus solvents-only experiment. Finally, as we know that CPs are semiochemicals during the overwintering period (Turillazzi, Dapporto, et al. 2006), in order to assess whether the sole CPs extract of an alien individual (worker) evokes any aggressive response in a colony context, we presented it simultaneously with the solvent only (water) to a P. dominulus colony (n = 29). The same procedure was performed to each colony for the pure CHCs fraction of an alien individual (worker) versus pentane. ...
A colony of social insects is like a fortress where access is allowed only to colony members. The epicuticular mixture of hydrocarbons has been widely reported to be involved in nestmate recognition in insects. However, recent studies have shown that polar compounds (mainly peptides) are also present, mixed with hydrocarbons, on the cuticle of various insects, including the paper wasps of the genus Polistes. As these polar compounds are variable among Polistes species and are perceived by the wasps, this cuticular fraction could also be involved in nestmate recognition. Through MALDI-TOF (Matrix-Assisted Laser Desorption Ionization Time of Flight) mass spectrometry analysis, we assessed, for the first time, the intercolonial variability of the cuticular polar fraction of Polistes dominulus in order to evaluate its reliability as source of nestmate recognition cues. We then tested through behavioral assays the importance of the 2 isolated fractions (apolar and polar) in nestmate recognition by presenting them separately to colonies of P. dominulus. Our results showed that the cuticular polar compounds are not colony specific and they are not used by paper wasps to discriminate nestmates from non-colony members. On the contrary, we confirmed that the isolated cuticular hydrocarbons are the chemical mediators prompting nestmate recognition in paper wasps.
... Moreover the peptidic spectral profiles of the venom can change according to the caste or age, or colony of a given individual. In Polistes dominulus two venom peptides called Dominulin A and B (both of 17 residues), which can be included in Mastoparans with a biological action similar to that of Melittin, have a strong antimicrobial activity and can be found on the cuticle of the wasps, probably smeared on the body by self cleaning movements (Turillazzi et al., 2006b). The same compounds demonstrated also to have a communicative function as they can be used as cues for the ...
... All rights reserved. finding of suitable hibernation sites by future spring foundresses when they search for a place where to spend the winter (Turillazzi et al., 2006a). The second aim of the present was research to ascertain if, similarly to what happens in Polistes, peptides of venom origin can be found on the cuticle of honeybees, and provide MALDI reference spectra also for the peptidic fraction (950–4000 Da) of the cuticle. ...
... To ascertain that the use of a pincer did not determine a release and the passage of the venom on the insects cuticle we also gently attracted and trap some of the bees in a jar. We sampled different parts of the body of the bees using a method described by Turillazzi et al. (2006b) ...
The fraction between 950 and 4000Da of the venom of Apis mellifera has been analyzed with MALDI-TOF mass spectrometry and statistical facilities of the ClinProTools software. Consistent differences in the composition of this venom fraction were observed between queens and workers while younger and older workers (nurses and guards as well as foragers) differ for the relative percentages of two well known cytolytic peptides, namely Melittin and Apamin. Total in situ body methanol extracts and methanol micro-extractions on the cuticle of various parts of the body of drones and females confirmed that venom peptides are smeared on the body surface of females in a not yet clarified way. The observation that venom peptides have been found also on comb wax rises the hypothesis that the use of venom as antimicrobial agent makes part of the social immunity system of A. mellifera.
... Moreover, Turillazzi et al. (2006a) found that antibacterial peptides of the mastoparan class (denominated as Dominulins) are present on the cuticle and in the venom of females of Polistes dominulus. They also showed that wasps actually perceive these compounds and probably use them to locate shelters, previously used by congeneric individuals, in which they then spend the winter (Turillazzi et al., 2006b). This is evidence for the communicative use of peptides in terrestrial insects. ...
... This technique requires a very low amount of substance, allowing us to perform analyses of the cuticle of single insects. The data were statistically analysed with multivariate techniques originally developed for proteome analyses and individuation of disease markers, but which has recently also been used for comparisons of secretions (mainly venoms) produced by different species for systematic and applicative purposes (Serrao Wermelinger et al., 2005; Turillazzi et al., 2006b). ...
... However, the presence of cuticular peptides and proteins was demonstrated in honeybees (Zupko et al., 1993), cockroaches (Cornette et al., 2002) and Polistes wasps (Turillazzi et al., 2006a, b) but little is known about their function. The occurrence of a diversification among foundresses and workers in this group of substances and the perception of such compounds as demonstrated by Turillazzi et al. (2006b) for Dominulin A and B (the two most abundant peptides on P. dominulus cuticle) is not sufficient to affirm that caste recognition is made on the basis of these compounds. However, our finding is the first evidence demonstrating a clear diversification according to caste membership. ...
Several studies have shown that differences in the relative abundance of cuticular hydrocarbons occur between reproductives and non-reproductives in many social insects. These differences also exist between Polistes dominulus foundresses and their first emerged daughters (usually indicated as workers), but they gradually disappear when workers from orphaned colonies develop their ovaries and assume a reproductive role in the colony. However, hydrocarbons are not the exclusive components of cuticular layer of wasps. Mass-spectrometry analysis of cuticular methanol extracts from Polistes paper wasps showed a complex pattern of polar substances, partly or totally proteinaceous in nature. We found that these compounds, ranging from 918 to 2679 Da, showed a clear caste differentiation between foundresses and their first emerged daughters (usually indicated as "workers"), both in queen-right and in orphaned colonies. Conversely to hydrocarbons, workers from orphaned colonies maintain a significant difference from foundresses in the pattern of the medium molecular weight (MW) polar compounds obtained by MALDI-TOF. On the basis of such results we hypothesize that a reliable cue to identify foundresses from daughters, and not only their reproductive status, may exist in Polistes wasps. Although the great majority of previous work on social insect communication has focused on cuticular hydrocarbons, our findings suggest that the medium MW component of cuticular substances may be involved in recognition.
... We also performed an internal calibration using the flex analysis software by Bruker Daltonics, Bremer, Germany, as we had the exact mass of two peptides (1854 and 1909 Da) identified in the venom of the paper wasp Polistes dominulus. Calibrated spectra were imported into the clinprotools Ô (cpt) software (Bruker Daltonics, Bremen, Germany) and processed with a procedure suggested by the software manual and similar to that used by Zhang et al. (2004) for profiling potential biomarkers in the plasma of asthma patients and to that of a previous study in our laboratory on cuticular and venom peptides (Turillazzi et al. 2006). The program calculates the areas of the most important peaks that may account for statistical differences between various species. ...
... At present, we have no information about the chemical nature of the detected compounds and their source. Preliminary analyses performed on the venom of some species indicated that most of the compounds found on the cuticle and extracted in methanol came from that secretion, as occurs in Polistes wasps (Turillazzi et al. 2006). ...
The Stenogastrinae wasps have been proposed as a key group for an understanding of social evolution in insects, but the phylogeny of the group is still under discussion. The use of chemical characters, in particular cuticular hydrocarbons, for insect taxonomy is relatively recent and only a few studies have been conducted on the cuticular polar substances. In this work, we ascertain, by the matrix-assisted laser desorption ionization-time of flight mass spectrometry technique, that different species of primitively eusocial hover wasps have different compositions of the epicuticular polar compounds ranging from 900 to 3600 Da. General linear model analysis and discriminant analysis showed that the average spectral profiles of this fraction can be diagnostic for identification of the species. Moreover, for the first time we show population diversification in the medium MW polar cuticular mixtures in insects. In conclusion, the results demonstrate that the chemical characters are consistent with the physical characters and the study support the importance of medium MW polar substances as powerful tools for systematics (chemosystematics) and chemical ecology (fertility signal and population characterization) in a primitively social insect taxon.
... Recently, however, the paradigm of an exclusive role of CHCs in social insect communication has been challenged by the discovery of several proteinaceous and peptidic compounds on the insect cuticle ( Korchi et al., 1998;Cornette et al., 2002;Turillazzi et al., 2006a;Hanus et al., 2010). Moreover, their role as semiochemicals has in some cases been demonstrated (Kubli, 1992;Cornette et al., 2002;Cornette et al., 2003;Turillazzi et al., 2006b). However, virtually nothing is known about the importance that cuticular polar compounds (CPCs) may have in the different contexts of host-parasite interactions. ...
... The presence of HCs ( ) and PCs ( Turillazzi et al., 2006a) on both the body and the comb surface has been demonstrated in the host species. Moreover, it has been shown that hosts are able to perceive and use these PCs in specific contexts ( Turillazzi et al., 2006b). However, while CHCs have received extensive attention during the last few decades as cues for recognition processes [for social wasps see review ( Bruschini et al., 2010)], CPCs have only recently been investigated ). ...
Insect social life is governed by chemicals. A great number of studies have demonstrated that the blend of hydrocarbons present on the cuticle (CHCs) plays a pivotal role in intra- and inter-specific communication. It is not surprising, therefore, that social parasites, specialized in exploiting the costly parental care provided by host workers, exploit the host chemical communication system too. Throughout their life cycle, social parasites intercept and break this CHC-based code. Recently, however, several polar compounds (mainly peptides) have been found in addition to CHCs both on the cuticle and on the comb surface of social insects, and their semiochemical role has been demonstrated in some circumstances. In the present study, we used the paper wasp social parasite-host system Polistes sulcifer (Zimmerman)-Polistes dominulus (Christ) to evaluate the relative importance of the CHCs and polar compounds in two different steps of the host exploitation process: host nest detection by the pre-usurping parasite and parasite chemical integration into the host colony. After separating the polar and apolar fractions of the host nest as well as those of pre- and post-usurpation parasites, we carried out laboratory assays based on the binary choice model. Our results show that nest polar compounds neither are used by the parasite to detect the host's nest nor play a role in parasite chemical integration into the host colony. In contrast, we demonstrate that CHCs are fundamental in both steps, thus confirming their primary role in social insect life and consequently in social parasite-host interactions.
... For proteins, this is a credible explanation as they would be susceptible to proteolysis by regurgitated gastric enzymes. On the other hand, some compounds may be long-lived: Turillazzi et al. reported long-lasting peptides on the cuticle and in the venom of Polistes: dominulin A (1854 Da) and dominulin B (1909 Da) 40 . It is possible that CPCs must be deposited repeatedly on substrates to maintain their effect, or that the cuticle is needed as a stabilizing carrier. ...
Proteins are known to be social interaction signals in many species in the animal kingdom. Common mediators in mammals and aquatic species, they have seldom been identified as such in insects' behaviors. Yet, they could represent an important component to support social signals in social insects, as the numerous physical contacts between individuals would tend to favor the use of contact compounds in their interactions. However, their role in social interactions is largely unexplored: are they rare or simply underestimated? In this preliminary study, we show that, in the termite Reticulitermes flavipes, polar extracts from reproductives trigger body-shaking of workers (a vibratory behavior involved in reproductives recognition) while extracts from workers do not. Molecular profiling of these cuticular extracts using MALDI-TOF mass spectrometry reveals higher protein diversity in reproductives than in workers and a sex-specific composition exclusive to reproductives. While the effects observed with extracts are not as strong as with live termites, these results open up the intriguing possibility that social signaling may not be limited to cuticular hydrocarbons or other non-polar, volatile chemicals as classically accepted. Our results suggest that polar compounds, in particular some of the Cuticular Protein Compounds (CPCs) shown here by MALDI to be specific to reproductives, could play a significant role in insect societies. While this study is preliminary and further comprehensive molecular characterization is needed to correlate the body-shaking triggering effects with a given set of polar compounds, this exploratory study opens new perspectives for understanding the role of polar compounds such as proteins in caste discrimination, fertility signaling, or interspecific insect communication.
... It is well known that many wasps die until spring (Gibo, 1972;Pratte, 1982;Starks, 2001;Gamboa et al., 2004). Identifying appropriate winter quarters is likely to be essential for survival, and wasps often overwinter in the same shelters year after year (Dapporto & Palagi, 2006;Turillazzi et al., 2006). Additionally, nourishment and resource storage during the pre-overwintering phase seem to play an important role in the survival of gynes during the winter (Strassman, 1979;González et al., 2002;Hunt et al., 2003;Dapporto et al., 2005). ...
Winter in climatic regions with low temperatures is a challenge for overwintering insects. They are exposed to temperature extremes, which directly cause mortality or lead to energy depletion. The winter hibernaculum of paper wasp gynes protects from predators and rain, but only poorly from ambient temperature. In order to detect physiological adaptations to differing climates, we compared the respiratory metabolism of overwintering gynes of two polistine species from the Mediterranean climate in Italy (Polistes dominula and Polistes gallicus), and of one species from the temperate climate in Austria (Polistes dominula). The wasps' CO2 emission was measured with stop‐flow respirometry in a temperature range from 2.5 to 20 °C. The mass‐specific standard (resting) metabolic rate, the main type of metabolism of the dormant insects during overwintering, increased exponentially with ambient temperature but was suppressed in comparison to individuals measured in the summer, which conserves the energy stores. In addition, it was lower in the Mediterranean species (P. dominula and P. gallicus) in comparison to the temperate species (P. dominula), especially at higher temperatures. The active metabolic rate was suppressed to a similar amount. The suppressed metabolism of the overwintering Mediterranean gynes could be an adaptation to the higher winter temperatures to prevent a premature depletion of the energy resources. Dormant polistine wasps suppress metabolic rate during overwintering in comparison to summer individuals, which conserves their energy stores. Winter metabolism is lower in Mediterranean than in temperate wasps. Together, metabolic and microclimate measurements suggest a similar vulnerability of Mediterranean and temperate species to global warming.
... This can be achieved easily by fractionating complete CL extracts on silica gel columns. In addition, recent studies have shown that more polar lipids (Yasui et al., 2003;Eliyahu et al., 2008;Kühbandner et al., 2012;Salerno et al., 2012;Stökl et al., 2014;Keppner et al., 2017) and even peptides (Turillazzi et al., 2006) can elicit behavioral responses in insects and are likely used as contact sex pheromones far more often than previously thought. ...
The use of chemical cues and signals is essential for communication in insects. Wasps of the genus Nasonia (Hymenoptera, Pteromalidae) are gregarious parasitoids that lay their eggs into puparia of cyclorrhaphous flies. During their life cycle, various kinds of semiochemicals are used: (1) a male abdominal sex pheromone that attracts females and induces site fidelity in males, (2) a female-derived contact sex pheromone eliciting courtship behavior in males, (3) an oral male aphrodisiac eliciting receptivity signaling in females and causing a switch in the females' olfactory preferences, (4) chemicals derived from host habitat and host puparia used in olfactory host finding by female wasps, and (5) chemicals used by females to assess the quality and parasitization status of potential hosts. We review the literature on the chemical ecology of Nasonia spp. following the wasps' life cycle from emergence to oviposition. We depict biosynthetic pathways where available, discuss ecological implications, highlight differences among Nasonia species, summarize insights into their olfactory perception and associative learning abilities, and point out gaps in our understanding of the chemical ecology of these parasitoids to be addressed in future studies.
... Paper wasps hibernate in particular safe locations that can be used by subsequent generations of foundresses. Turillazzi et al. (2006) experimentally showed that these hibernation sites are marked with venom secretions and cuticular peptides. A proteinaceous pheromone has also been recently identified as having a role in termite egg recognition (Matsuura et al. 2007). ...
... Although we have not yet obtained unequivocal observations of the mating behavior or number of breeding males and females in P. olivaceus, female philopatry could potentially arise in this species: after successful copulation, P. olivaceus gynes may start a nest foundation or alight to hibernacula where they spend the winter season (Alam 1958), whereas males might disperse farther to encounter other gynes. As observed in other Polistes wasps, closely related gynes cluster at the same hibernacula year after year using recognition cues (Turillazzi et al. 2006), and even before establishing new colonies, they display pronounced philopatry (Klahn 1979). These phenomena may also occur in P. olivaceus gynes to confine them within a narrow dispersal range across years, resulting in natal philopatry. ...
Dispersal triggers gene flow, which in turn strongly affects the ensuing genetic population structure of a species. Using nuclear microsatellite loci and mitochondrial DNA (mtDNA), we estimated the genetic population structure of the wasp Polistes olivaceus throughout Bangladesh. The level of population differentiation using nuclear markers (F
ST) appeared to be much lower than that estimated using mtDNA haplotype sequences (ФST), even after correcting for effective population size differences between the two markers. These results suggest a philopatric tendency, in which gynes disperse less than males. We observed no isolation by distance among the study populations at either the nuclear or mtDNA level, suggesting nonequilibrium between gene flow and drift as a result of very frequent interpopulation movement. For the nuclear markers, an individual assignment test showed no genetically and geographically distinct groups. Instead, phylogenetic analyses as well as a minimum spanning network using mtDNA haplotypes consistently revealed two distinct lineages. The distribution of haplotypes indicated western populations with a single lineage and offered clear evidence for restricted gene flow across the Jamuna–Padma–Upper Meghna river system. Mismatch distributions exhibited a unimodal distribution, which along with a starlike haplotype network, suggested a population expansion in lineage I but not in lineage II. Overall, these results suggest that gene flow among populations of P. olivaceus was affected by both female philopatry and a major river system across Bangladesh.
... Howard and Blomquist, 2005;Turillazzi et al., 2006a;Benoit, 2010), but different compositions of the mixtures are also perceived by insects and are used to interact at both the inter-and intra-specific level (e.g. Howard, 1993;Turillazzi et al., 2006b). Indeed, cuticular substances can convey cues used to adjust responses in prey-predator and sexual recognition, and in social insects they also provide complex information about individual status (Howard and Blomquist, 2005). ...
... obs.). Recently, Turillazzi et al. (2006) strongly suggested that antibiotic cuticular peptides are cues involved in the identification of previously used hibernacula (Turillazzi et al. 2006aTurillazzi et al. , 2006b). In addition, nourishment and resource storage during the pre-hibernating stage seem to play an important role in the survival of gynes during the winter (Strassmann 1979, Hunt et al. 2003, Gonzalez et al. 2002, Dapporto et al. 2005a). ...
Dapporto, L. & Palagi, E. 2006: Wasps in the shadow: Looking at the pre-hibernating clusters of Polistes dominulus. — Ann. Zool. Fennici 43: 583–594. In some Polistes species, hibernation begins with the formation of clusters. Pre-hiber-nating aggregations may be evolutionarily favoured because they provide a dilution effect, better active defence from predators, and insulation from cold and/or dryness. Many authors have suggested that the pre-hibernating phase represents a socially inac-tive period for wasps. This paradigm strongly influenced the direction of research; in fact, most studies on Polistes behaviour focus on the nesting phase. It has been demonstrated, however, that many social interactions occur in aggregations, and that a division of labour is also present in these aggregations. Here, we evaluate the influence of cluster formation and social networks on the main aspects of wasp social behaviour, such as the consequences on kin-assortment (philopatry and tolerance level), variation in chemical recognition, division of labour, and helping behaviour.
... The case of P. dominulus demonstrates that venom can be used for individual and colony protection against enemies other than vertebrates or invertebrates. A further function of the dominulins has been reported by Turillazzi et al. (2006b) who found that these substances are within the suite of chemical cues used by future P. dominulus foundresses to assess the suitability of places to hibernate. In fact, large quantities of these peptides are deposited year after year by hibernating wasps in habitually used hibernacula. ...
Turillazzi, S. 2006: Polistes venom: a multifunctional secretion. — Ann. Zool. Fennici 43: 488–499. Polistes venom is a complex secretion that has several functions in the social organiza-tion of a colony. The defensive function as an allomone against vertebrate and inverte-brate enemies is enhanced with antimicrobial properties. Its role in chemical commu-nication is multi-faceted as it contains both alarm and sexual pheromones, but can also have cues which are important both for nestmate and caste recognition, as well as for hibernacula marking. Research on venom chemistry is extremely important for both the establishment of specific immunotherapy for allergic patients and for the discovery of new molecules with pharmacological activity. Venom composition can also provide important characters for taxonomical and phylogenetical studies.
... It may be noted that the rub abdomen behaviour shown by the R. marginata queen is reminiscent of the abdominal stroking behaviour reported for Polistes queens, and which is believed to be used for applying recognition odors on the nest (Dani et al. 1992; Van Hooser et al. 2002). Since the queen pheromone in R. marginata may be non-volatile, the use of proteinaceous pheromones (Klobuchar and Deslippe 2002; Turillazzi et al. 2006) is a possibility that deviates from the usual CHC-based pheromones commonly believed to be used in other species. Besides, CHC's do not appear to function as fertility signals in Ropalidia opifex (Dapporto et al. 2006). ...
Queens of primitively eusocial wasps generally have active and behaviourally dominant queens who use physical aggression to
suppress worker reproduction. Although a Ropalidia marginata queen is strikingly docile and behaviourally non-dominant, she is completely successful in maintaining reproductive monopoly.
R. marginata queens must achieve such reproductive monopoly by some means other than overt physical aggression. Upon loss or removal of
the queen, one of the workers (referred to as the potential queen) becomes extremely aggressive and will eventually go on
to become the next queen of the colony, if the original queen is not returned. The fact that potential queens are not discernible
in the presence of the queen but become obvious within minutes after removal of the queen raises the question of how workers
in general and the potential queens in particular, perceive the presence or absence of their queens. Here, we have conducted
experiments in which we separate half of the workers from their queen by a wire mesh screen and study their behavioural response
to such separation. We demonstrate that the presence of the queen is not perceived across the wire mesh screen, which suggests
that if the queen uses a pheromone to signal her presence, then that pheromone is not very volatile.
... Because the number of candidate compounds available to regulate multiple systems may be biosynthetically finite, strong selection favors the use of single natural products for many purposes. Secondary use of chemical compounds that have evolved for other primary functions occurs in various social insects (Blum and Brand, 1972;Turillazzi et al., 2006;Cremer et al., 2007). Identification of the termite egg-recognition pheromone elucidated such evolutionary parsimony ). ...
Pheromones are likely involved in all social activities of social insects including foraging, sexual behavior, defense, nestmate recognition, and caste regulation. Regulation of the number of fertile queens requires communication between reproductive and non-reproductive individuals. Queen-produced pheromones have long been believed to be the main factor inhibiting the differentiation of new reproductive individuals. However, since the discovery more than 50 years ago of the queen honeybee substance that inhibits the queen-rearing behavior of workers, little progress has been made in the chemical identification of inhibitory queen pheromones in other social insects. The recent identification of a termite queen pheromone and subsequent studies have elucidated the multifaceted roles of volatile pheromones, including functions such as a fertility signal, worker attractant, queen-queen communication signal, and antimicrobial agent. The proximate origin and evolutionary parsimony of the termite queen pheromone also are discussed.
... Alternatively, the glandular epithelium may be involved in the synthesis of compounds with another chemical nature and perhaps no detected by our histochemical analysis, which could be involved in the queen recognition mechanism, like suggested to P. analis and D. lucida [39,40]. Indeed, other non-CHC cuticular substances, such as proteins, might also be used as chemical recognition cues as it was demonstrated in the paper wasp, Polistes dominulus, in the shelter (hibernacula) marking phenomenon [66]. Recently it was also showed in this same species that the foundresses can be distinguished from the workers on the basis of the pattern of cuticular polar peptide compounds, revealing thus the implication of substances other than CHCs as reliable cue to signal the foundresses, although no link with fertility status was found [67]. ...
The wax layer covering the insect's cuticle plays an important protective role, as for example, uncontrolled water loss. In social insects, wax production is well-known in some bees that use it for nest building. Curiously, mated-fertile queens of the ant Ectatomma tuberculatum produce an uncommon extra-wax coat and, consequently queens (mated-fertile females) are matte due to such extra cuticular hydrocarbon (CHC) coat that covers the cuticle and masks the brightness of the queens' cuticle while gynes (virgin-infertile queens) are shiny. In this study, histological analysis showed differences in the epidermis between fertile (i.e., queens or gynes with highly ovarian activity) and infertile females (gynes or workers with non developed ovaries). In fertile females the epidermis is a single layer of cubic cells found in all body segments whereas in infertile females it is a thin layer of flattened cells. Ultrastructural features showed active secretory tissue from fertile females similar to the glandular epithelium of wax-producing bees (type I gland). Different hypotheses related to the functions of the glandular epithelium exclusive to the E. tuberculatum fertile queens are discussed.
... Namely, the function of polar substances of peptidic (proteinaceous ) origin in insect communication is unexplored, although their presence on the cuticular surface has been documented in various insects (Zupko et al. 1993; Korchi et al. 1998; Cornette et al. 2002; Turillazzi et al. 2006a). They may act as antibacterial agents (Turillazzi et al. 2006a), but experiments have also indicated their role in signalling (Cornette et al. 2002Cornette et al. , 2003 Turillazzi et al. 2006b). Recently, distinct patterns of peptides were found in paper wasp females with different social status, suggesting that these compounds might be, beside CHCs, involved in caste and status signalling (Dapporto et al. 2008 ). ...
In 1959, P. Karlson and M. Lüscher introduced the term 'pheromone', broadly used nowadays for various chemicals involved in intraspecific communication. To demonstrate the term, they depicted the situation in termite societies, where king and queen inhibit the reproduction of nest-mates by an unknown chemical substance. Paradoxically, half a century later, neither the source nor the chemical identity of this 'royal' pheromone is known. In this study, we report for the first time the secretion of polar compounds of proteinaceous origin by functional reproductives in three termite species, Prorhinotermes simplex, Reticulitermes santonensis and Kalotermes flavicollis. Aqueous washes of functional reproductives contained sex-specific proteinaceous compounds, virtually absent in non-reproducing stages. Moreover, the presence of these compounds was clearly correlated with the age of reproductives and their reproductive status. We discuss the putative function of these substances in termite caste recognition and regulation.
... b-glucosidase in termite eggs might still have any practical function (e.g., egg shell formation) because b-glucosidase is an essential enzyme for oothecal formation in other dictyopteran insects including mantis [23]. Secondary use of chemical compounds that have evolved for other primary functions can be seen in various social insects [24,25]. It is notable that both lysozyme and b-glucosidase are enzymes that hydrolyze b-1,4 glycosidic linkages. ...
Insects and fungi share a long history of association in various habitats, including the wood-decomposition niche. Fungal mimicry of termite eggs is one of the most striking evolutionary consequences of insect-fungus association. Termites of the genus Reticulitermes often harbor fungal sclerotia, called "termite balls," along with eggs in nursery chambers, whereby the fungus gains a competitor-free habitat in termite nests. Sophisticated morphological and chemical camouflage are needed for the fungus to mimic termite eggs. However, the mechanism of chemical egg mimicry by the fungus is unknown. Here, we show that the fungus mimics termite eggs chemically by producing the cellulose-digesting enzyme beta-glucosidase. We found that the termite egg-recognition pheromone consists of beta-glucosidase and lysozyme. Both enzymes are major salivary compounds in termites and are also produced in termite eggs. Termite balls were tended by termites only when the fungus produced beta-glucosidase. Our results demonstrated that the overlap of the cellulose digestion niche between termites and the fungus sharing the same chemicals provided the opportunity for the origin of termite egg mimicry by the fungus. This suggests that pheromone compounds might have originally evolved within other life history contexts, only later gaining function in chemical communication.
... Our group has recently shown that the medium volatile fraction of the venom (peptides) is species specific (Turillazzi et al., 2007) and caste specific (Dapporto et al., 2008). Furthermore, these compounds can be perceived by the wasps (Turillazzi et al., 2006) indicating that peptides could be involved in communication. Future experiments on Polistes dominulus are needed to assess the role of the venom in sexual behaviour and subsequently to investigate which fraction of the venom functions as a sex pheromone. ...
Foundresses and workers of Polistes paper wasps show slight morphological and physiological differences. However, after the emergence of the workers, the castes can be readily discriminated by their behaviour: the dominant foundress is the principal egg-layer, whereas workers perform different tasks linked to colony development. Previous studies have demonstrated in this genus that defence of the colony by the workers is more effectively carried out by a collective response elicited by venom volatiles used as alarm pheromones. In the present study, gas chromatography-mass spectrometry analyses of the venom volatiles of foundresses and workers of Polistes dominulus (Christ) show predominantly quantitative differences. Spiroacetals, mainly (E,E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, are significantly higher in the venom volatiles fraction of workers, whereas the amount of N-(3-methylbutyl)acetamide is almost double in foundresses. On the basis of the chemical results, behavioural assays were performed on fifteen field colonies to test the alarm response of the resident wasps to venom extracts from foundresses and workers. Our behavioural results suggest that worker venom has a stronger alarm effect on the colonies than that of the foundresses, which seems unable to elicit the complete alarm response ending with a final attack and sting. The venom volatiles of P. dominulus workers serve mainly to alarm the colony whilst those of foundresses may also be linked to additional functions related to conspecific interactions.
Polistes paper wasps in the Fuscopolistes subgenus (Hymenoptera: Vespidae) can be serious pests when they swarm at tall man-made structures. Chemical attractants may be useful to trap such paper wasps when they achieve pest status. Polistes venom has been shown to elicit a variety of behavioral responses in congeneric wasps, making it a source for potential chemical attractants. The compound N-(3-methylbutyl)acetamide is a principal volatile component in the venom of many female vespid wasps, including numerous Polistes species. We report the presence of N-(3-methylbutyl)acetamide in autumn gynes of Polistes metricus Say, Polistes bellicosus Cresson, and Polistes dorsalis (F.), as well as workers of Polistes aurifer (Saussure), P. bellicosus, P. metricus, and P. dorsalis. In field tests conducted in Florida, Georgia, South Carolina, and Washington, N-(3-methylbutyl)acetamide attracted male and female P. aurifer and P. metricus, as well as male P. dorsalis and P. bellicosus. Thus, N-(3-methylbutyl)acetamide may be a useful lure for trapping these paper wasps in pest situations.
Molecules of keystone significance are vital in structuring ecological communities. Select bioactive compounds can cause disproportionately large effects by connecting such seemingly disparate processes as microbial loop dynamics and apex predation. Here, we develop a general theory and propose mechanisms that could lead to the evolution of keystone molecules. Introduced into a respective community by one, or only a few, autotrophic or microbial species, these compounds often originate as chemical defenses. When co-opted by resistant consumer species, however, they are used either in chemical defense against higher-order predators or as chemosensory cues that elicit courtship and mating, alarm, and predatory search. Requisite to these multifunctional properties, biosynthetic capacity evolves along with mechanisms for resistance and/or toxin storage in primary producers. Subsequently, consumers acquire resistances or tolerances, and the toxins are transferred through food webs via trophic interactions. In consumers, mechanisms eventually evolve for recognizing toxins as feeding cues and, ultimately, as signals or pheromones in chemical communication within or between species. One, or a few, active compounds can thus mediate a vast array of physiological traits, expressed differentially across many species in a given community. Through convergent evolution, molecules of keystone significance provide critical information to phylogenetically diverse species, initiate major trophic cascades, and structure communities within terrestrial, freshwater, coastal-ocean and open-ocean habitats.
As the most species-rich and biologically eclectic of all social insects, ants present considerable challenges to the process of cataloguing and understanding their remarkable diversity. Substantial progress has been made in recent years, however, in identifying the major clades of ants and in clarifying their evolutionary history. We now have a higher classification of ants in which most of the subfamilies and tribes appear to be monophyletic and well diagnosed, with a few notable exceptions. Uncertainty persists regarding the phylogenetic relationships among old lineages at the base of the ant tree and concerning the time frame of ant evolution. The specieslevel taxonomy of ants has advanced more fitfully, and ant ecologists have an extensive but far-from-complete set of resources for identifying ant species. Ongoing and sustained effort is needed in the area of species discovery and delimitation, and in the delivery of this information to potential users.
From scorching, barren deserts to humid tropical forests, from deep in the soil, to high in the tree canopies, ants are everywhere! Comprising a substantial part of living biomass on earth, ants are integral to the functioning of terrestrial ecosystems. More than 12,000 species have been described to date, and it is estimated that perhaps as many still await classification. Their social structure provides a rich ground for exploring how division of labour affects the acquisition of resources, foraging and defensive behaviours, and coevolution with the flora and fauna with which they interact. The study of ants has led to significant advances in our understanding of insect evolution, global diversity patterns, competitive interactions, mutualisms, ecosystem's responses to change, and biological invasions. Ant Ecology explores these and other key ecological issues and new developments in myrmecology across a range of scales. The book begins with a global perspective on species diversity in time and space and explores interactions at the community level before describing the population ecology of these social insects. The final section covers the recent ecological phenomenon of invasive ants: how they move across the globe, invade, affect ecosystems, and are managed by humans. Each chapter links ant ecology to broader ecological principles, provides a succinct summary, and discusses future research directions. The Synthesis and Perspectives highlights contributions of ant ecology to ecology more broadly, and outlines promising areas for future research.
The present-day distribution of ants reflects the influence of geography, geology, and climate on the origin, diversification, and spread of a lineage. Though the process is complex and often difficult to reconstruct for a given taxon, two important overall patterns emerge: taxa are neither randomly nor uniformly distributed across the earth, and endemic taxa are clustered in particular regions. The greatest ant diversity and endemicity are found in the tropics and the Gondwanaland fragments of South America, Africa, and Australia. Lines of inquiry that combine exhaustive inventories, taxonomic revisions, and phylogenetics will enable a more rigorous approach to the study of biogeography. Islands offer a model system to explore these questions. Due to their range in size, origin, degree of isolation, and habitat types, the south-west Indian Ocean islands are an ideal model system to explore the relative impact of biogeographic factors on species diversity.
The macroparasite Xenos vesparum affects both the behaviour and the physical traits of its host, the social wasp Polistes dominulus. Female wasps, if parasitized, do not perform any social tasks and desert the colony to gather at specific sites, where the parasite mates; at the end of summer they form prehibernating clusters joined by healthy future queens to overwinter. Parasitized wasps become highly gregarious. In April, healthy wasps leave the aggregations to found new colonies, while parasitized wasps remain in overwintering groups and release parasites to infect wasp larvae only later in the season. We studied the prolonged gregarious behaviour of parasitized wasps and analysed the morphology of parasitized and healthy wasps in aggregations collected over a 7-year period to determine whether the parasite affects host size, wing symmetry, ovarian development and lipid stores. All parasitized wasps were smaller and had undeveloped ovaries and more wing fluctuating asymmetry than unparasitized wasps, irrespective of time of year, parasite load and parasite sex. If infected only by one or two X. vesparum females, the wasps had large fat bodies, which could facilitate their overwintering. In contrast, wasps infected by at least one male parasite had little lipid and died at the end of the summer. Thus, X. vesparum, may play a role in the fate of its host, by exploiting wasps' tendency to form aggregations outside the colony and by altering its caste system, nutrient allocation, diapause timing and life span to achieve its own reproduction and dispersal.
Molecules of keystone significance are vital in structuring ecological communities. Select bioactive compounds can cause disproportionately large effects by connecting such seemingly disparate processes as microbial loop dynamics and apex predation. Here, we develop a general theory and propose mechanisms that could lead to the evolution of keystone molecules. Introduced into a respective community by one, or only a few, autotrophic or microbial species, these compounds often originate as chemical defenses. When co-opted by resistant consumer species, however, they are used either in chemical defense against higher-order predators or as chemosensory cues that elicit courtship and mating, alarm, and predatory search. Requisite to these multifunctional properties, biosynthetic capacity evolves along with mechanisms for resistance and/or toxin storage in primary producers. Subsequently, consumers acquire resistances or tolerances, and the toxins are transferred through food webs via trophic interactions. In consumers, mechanisms eventually evolve for recognizing toxins as feeding cues and, ultimately, as signals or pheromones in chemical communication within or between species. One, or a few, active compounds can thus mediate a vast array of physiological traits, expressed differentially across many species in a given community. Through convergent evolution, molecules of keystone significance provide critical information to phylogenetically diverse species, initiate major trophic cascades, and structure communities within terrestrial, freshwater, coastal-ocean and open-ocean habitats.
The theory of kin selection (Hamilton 1964a, b) explains the evolution of helping behavior among relatives (see Chap. 3),
but it also predicts several conflicts among relatives. First, individuals belonging to the same generation compete over resources.
For example, several foundresses can compete with one another upon colony founding. Second, queen(s) and daughter workers
belonging to different generations compete over the sex ratio. Third, queen(s) and workers compete over male parentage. The
second and third conflicts are expected when the relatedness between interacting providers and recipients of altruism differs
among kin groups.
Social wasps need an efficient communication system to coordinate their members in the numerous activities of the colony. In this regard, the chemical channel is the most utilized by social wasps to transfer information in intraspecific (pheromones) and interspecific (allomones) communication. In this chapter, we reviewed the main chemical substances which mediate recognition between colony members and coordinate nest defense, alarm and recruitment. Due to their central role in the colonial life, the majority of pheromones have been identified and their functions have been deeply investigated in many species. On the contrary, sex pheromones which are the most studied in insects, have been quite neglected in social wasps.
Many colonies of the North American ant Crematogaster smithi contain a "third female caste" in addition to queens and workers. These "intermorphs" are morphological intermediate of queens and workers and have well-developed ovaries but lack a spermatheca for the storage of sperm. They are specialised for laying large numbers of unfertilised, viable eggs, most of which serve as food for larvae and adults, though a few may eventually develop into males. Based on the assumption that cuticular hydrocarbons (CHCs) in social insects honestly signal the reproductive status of an individual we investigated the CHC of mated mature queens, virgin queens, intermorphs and workers. We expected intermorphs to show chemical profiles intermediate between those of mated queens and non-reproductive workers. A discriminant analysis of the chemical profiles reliably separated queens, virgin queens, and workers, but failed to distinguish between queens and intermorphs even though workers were apparently capable of doing so.
Surfaces on which the cypris larvae of barnacles do not settle readily were treated with aqueous extracts of whole barnacles. Cyprids then settled on the treated surfaces as readily as they do on surfaces bearing adult barnacles, thus simulating the gregarious response to their own species. It is inferred that a settling factor, present in barnacle tissues, was transferred to a neutral surface rendering it favourable for settlement. The settling factor was shown to be non-dialyzable and stable to boiling in aqueous solution. When attached to a surface, it resisted severe physical and chemical treatments. The settling factor evoked a greater response from cyprids of the species used in preparing the extract than from cyprids of other species. Extracts made from other cirripedes and from all other arthropods tested, promoted settlement, but were less effective than extracts made from the same species of cirripede. The settling factor was found to be located mainly in the integument of arthropods and was present in greater amount in newly moulted individuals. It is suggested that the settling factor to which the cyprid responds may be the arthropodins of its own species, and that arthropodins of related species evoke a similar response. No evidence was found for chemotaxis, the cyprids responding to the settling factor only after alighting on the treated surface. It is thought likely that cyprids, in common with the larvae of many other sedentary marine organisms, may not be capable of detecting or responding to such chemical releasers in the sea unless they are in contact with the surface on which the chemical is adsorbed or from which it is diffusing.
We are told in the text-books that in temperate reglOns Polistes hibernate as adults. The story goes that at the close of snmmer the queens and the males are born, and with the approach of cold all but the fertilized females succumb and that these queens hide in nooks and crannies during the winter and come forth in the following spring, when each one builds a nest independently. In a general way this is correct for Polistes as a genus, but when one takes the species separately and studies their hibernation in relation to their dissemination, each will be found to have unique details of its own to tell, and mayhap the story of each species will show sufficient variety to throw some light upon the relationships of the members of this genus. I make only a meagre offering, for I can throw light on the habits of only one species of Polistes, P. annularis, and give some incomplete notes on a few other species, which, however, show certain tendencies.
Aggregation of blue mussels (Mytilus edulis) is stimulated by environmental chemical stimuli. Experiments carried out in a basin with a one-way current showed that individual mussels were attracted to upstream mussel concentrations and moved actively in their direction. The involvement of a tripeptide in this migration was implicated by experiments demonstrating that individual mussels were effectively attracted and moved actively towards a source of glycine–glycine–arginine at concentrations of 0.56–3.7810–10M. A distinct seasonal difference in the extent of movement towards mussel concentrations was found. From the beginning of autumn, movement decreases linearly towards zero movement in winter.
We have characterized a glycosylated, 31 amino-acid peptide of 4932 Da isolated from Drosophila melanogaster males. The mature peptide contains a sugar moiety of 1184 Da at a NDT consensus glycosylation site and a disulfide bond. It is synthesized in the male ejaculatory duct via a 54 amino-acid precursor containing an N-terminal signal peptide and Arg-Lys at the C-terminus which is cleaved off during maturation. The gene contains an intron of 53 bp and is localized in the cytological region 99B of the D. melanogaster genome. The peptide is therefore named DUP99B (for ductus ejaculatorius peptide, cytological localization 99B). The C-terminal parts of mature DUP99B and D. melanogaster sex-peptide (ACP70A) are highly homologous. Injected into virgin females, DUP99B elicits the same postmating responses as sex-peptide (increased oviposition, reduced receptivity). These effects are also induced by de-glycosylated native peptide or synthetic DUP99B lacking the sugar moiety. Presence of the glycosyl group, however, decreases the amount needed to elicit the postmating responses. Homologies in the coding regions of the two exons of DUP99B and sex-peptide, respectively, suggest that the two genes have evolved by gene duplication. Thus, we consider these two genes to be members of the new sex-peptide gene family.
We conducted five bioassays to study how queens control the execution of sexual larvae by workers in colonies of the red imported fire ant, Solenopsis invicta. In each assay, subset colonies were made from many large polygyne colonies, and the 20 sexual larvae they contained were monitored over time. Sexual larvae mostly survived in queenless colonies, but were mostly killed in colonies with a single dealated queen, regardless of whether or not the queen was fertilized. The larvae were also killed when fresh corpses of queens were added to queenless colonies. Whereas acetone extracts of queens did not produce a significant increase in killings, extracts in buffered saline induced workers to execute most sexual larvae, indicating successful extraction of an execution pheromone. We identified the probable storage location of the chemical as the poison sac, and found both fresh (1 day) and old (21 day) extracts of poison sacs to be equally effective in inducing executions. The pheromone is stable at room temperature, perhaps because venom alkaloids also present in the extracts keep the pheromone from degrading. It is apparently either proteinaceous or associated with a proteinaceous molecule, a novel finding, as no queen pheromone of a proteinaceous nature has been previously demonstrated in ants.
The epicuticular surface protein Lma-p54 is imbedded in the "cuticular waxes" which cover the abdominal surface of the adult Leucophaea maderae. Natural Lma-p54 was purified and the complete cDNA sequence was determined by RT-PCR using primers based on Edman degradation fragments. Northern blot and in situ hybridization analyses showed that Lma-p54 was expressed in the adult abdominal epidermis and in the chemical sense organs of both sexes. Sequence alignment indicates that Lma-p54 is closely related to aspartic proteases (EC 3.4.23). However, there are critical amino acid substitutions at the level of the active site and, since no proteolytic activity was detected in the abdominal secretion, the protein is likely inactive. As an inactive aspartic protease, Lma-p54 is related to pregnancy-associated glycoproteins (PAGs) which still present a peptide-binding ability. According to recent experiments using whole tergal protein secretions, a role in intraspecific contact recognition was proposed for this surface protein.
Individual recognition is an important component of behaviors, such as mate choice and maternal bonding that are vital for reproductive success. This article highlights recent developments in our understanding of the chemosensory cues and the neural pathways involved in individuality discrimination in rodents. There appear to be several types of chemosensory signal of individuality that are influenced by the highly polymorphic families of major histocompatibility complex (MHC) proteins or major urinary proteins (MUPs). Both have the capability of binding small molecules and may influence the individual profile of these chemosignals in biological fluids such as urine, skin secretions, or saliva. Moreover, these proteins, or peptides associated with them, can be taken up into the vomeronasal organ (VNO) where they can potentially interact directly with the vomeronasal receptors. This is particularly interesting given the expression of major histocompatibility complex Ib proteins by the V2R class of vomeronasal receptor and the highly selective responses of accessory olfactory bulb (AOB) mitral cells to strain identity. These findings are consistent with the role of the vomeronasal system in mediating individual discrimination that allows mate recognition in the context of the pregnancy block effect. This is hypothesized to involve a selective increase in the inhibitory control of mitral cells in the accessory olfactory bulb at the first level of processing of the vomeronasal stimulus.
Two new antibacterial peptides, denominated as Dominulin A and B, have been found on the cuticle and in the venom of females of the social paper wasp Polistes dominulus. The amino acidic sequence of the two peptides, determined by mass spectrometry, is INWKKIAE VGGKIL SSL for Dominulin A (MW = 1854 Da) and INWKKIAEIGKQVL SAL (MW = 1909 Da) for Dominulin B. Their presence on the cuticle was confirmed using MALDI-TOF by means of micro-extractions and direct analyses on body parts. The presence in the venom and the primary structure of the dominulins suggest their classification in the mastoparans, a class of peptides found in the venom of other Aculeate hymenoptera. Their antimicrobial action against Gram+ and Gram- bacteria fits in the range of the best natural antimicrobial peptides. Dominulins can represent an important defense of the colony of Polistes dominulus against microbial pathogens.