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Chemical communication in insect communities: A guide to insect pheromones with special emphasis on social insects
Abstract
Chemical communication plays an important part in the lives of insects, and particularly in lives of those that live in groups or social organizations.
Chemicals which are used in communication in the general sense are called semiochemicals, and there are a number of subdivisions recognized under this title.
Pheromones are a category of semiochemicals which are used for communication between individuals of the same species.
Pheromones are in turn subdivided into primer and releaser pheromones. The former produce a relatively long‐lasting physiological change in the receiver, and the latter stimulate the receiver to some immediate behavioural response.
Far more is known about releaser pheromones at present because they are easier to study.
Nine categories of releaser pheromone are recognized here, used by both social and non‐social insects.
Sex pheromones are widely used to bring the sexes together for mating, and they have been extensively studied in Lepidoptera.
Invitation pheromones, encouraging the species to feed or oviposit at an explored site, are not extensively known.
Aggregation pheromones are designed to bring individuals together into groups which may be temporary in sub‐social insects, or permanent in social insects.
Dispersal or spacing pheromones are used by other species to reduce intraspecific competition for scarce resources.
Alarm pheromones are a broad and sometimes unclearly defined group which communicate alarm or attack, chiefly in colonial species.
Trail pheromones, applied to a surface by an individual, to be followed by another, are confined to Hymenoptera, Isoptera and a few Lepidoptera as far as is known.
Territorial and home range pheromones may be widely distributed, but as yet few of them have been recognized.
Surface and funeral pheromones are even less well known. Surface pheromones may play a large part in species or colony recognition.
We can expect the number and complexity of pheromones to be much greater in social insects, a part of the subject which until now has received relatively less attention.
As our understanding of the subject grows we may expect other categories to be added to this list.
... Mass trapping technique is particularly successful against Coleopteran pests wherein the aggregation type of pheromones is employed for trapping both sexes of target pests. Aggregation pheromone is similar to sex pheromone but attractive to both sexes and thus help in locating food sources, hibernation sites, oviposition and also to some extent mating as it causes con specifics to gather at one site (Ali and Morgan 1990). Aggregation pheromones offer excellent potential for direct control in pest management when incorporated into traps along with host plant volatiles and currently being used to control forest pests (Macaulay et al., 1985;Kogan, 1998). ...
Insect Sex Pheromones in IPM
... Chemical communication is widespread among insects and exploited to adjust their behavior, such as food and habitat seeking and preferences, recruitment, defense, and mate attraction [1]. During the communication process, semiochemicals, such as pheromones and allelochemicals, may be released into the water or air, transported by currents, adhered to food or plants, or transferred through direct contact, e.g., trophallaxis [2], and eventually recognized by insect chemoreceptors, thereby triggering attractive or repellent behavior in insects. Chemoreception, an essential process in the perception and analysis of chemical information from the environment [3], is described as the physiological response to a chemical signal. ...
Chemical communication is widespread among insects and exploited to adjust their behavior, such as food and habitat seeking and preferences, recruitment, defense, and mate attraction. Recently, many studies have revealed that microbial symbionts could regulate host chemical communication by affecting the synthesis and perception of insect semiochemicals. In this paper, we review recent studies of the influence of microbial symbionts on insect chemoreception. Microbial symbionts may influence insect sensitivity to semiochemicals by regulating the synthesis of odorant-binding proteins or chemosensory proteins and olfactory or gustatory receptors and regulating host neurotransmission, thereby adjusting insect behavior. The manipulation of insect chemosensory behavior by microbial symbionts is conducive to their proliferation and dispersal and provides the impetus for insects to change their feeding habits and aggregation and dispersal behavior, which contributes to population differentiation in insects. Future research is necessary to reveal the material and information exchange between both partners to improve our comprehension of the evolution of chemoreception in insects. Manipulating insect chemoreception physiology by inoculating them with microbes could be utilized as a potential approach to managing insect populations.
... A good example of cooperative odour-based navigation can be observed in foraging ants (Stuart & Moffett, 1994;Ali & Morgan, 1990). An individual ant releases a pheromone to indicate its path to a food source. ...
This thesis presents an investigation of odour source localisation using multiple cooperating robots. A cooperative strategy has been implemented for the control of multi-robot teams in order to demonstrate their advantages together with the improvements in carrying out cooperative search tasks.
The odour source localisation experiments that are presented in this thesis are carried out in two types of chemical fields and the results are obtained both via simulation studies as well as via experiments using real mobile robots. The fundamental search strategies are biologically inspired and single robot searches are used to demonstrate for the first time their relative merits under different experimental conditions in order to assess the search performance of these strategies.
The performance of the single robot searches is compared to that of a multi-robot system in non-cooperative multi-robot experiments. It is shown that the search efficiency and robustness are significantly improved even though frequent spatial interactions between the robots hinder the search. The effects of such interactions for the multi-robot system are quantified. Finally, a new cooperation strategy is proposed in order to further improve the search performance. The cooperative multi-robot searching experiments demonstrate that the robots are carrying out the odour source localisation task more efficiently as a result of sharing local information and knowledge concerning the chemical field to achieve a good global cooperation strategy.
... Surgical removal of the antennae eliminated the response, suggesting that the response relied on the olfactory system (Fig. 3D). In insect chemical ecology, compounds are described as arrestants, aphrodisiacs, and/or attractants (37), based on the elicited behavior. Compounds can belong to more than one category. ...
Tsetse flies transmit trypanosomes-parasites that cause devastating diseases in humans and livestock-across much of sub-Saharan Africa. Chemical communication through volatile pheromones is common among insects; however, it remains unknown if and how such chemical communication occurs in tsetse flies. We identified methyl palmitoleate (MPO), methyl oleate, and methyl palmitate as compounds that are produced by the tsetse fly Glossina morsitans and elicit strong behavioral responses. MPO evoked a behavioral response in male-but not virgin female-G. morsitans. G. morsitans males mounted females of another species, Glossina fuscipes, when they were treated with MPO. We further identified a subpopulation of olfactory neurons in G. morsitans that increase their firing rate in response to MPO and showed that infecting flies with African trypanosomes alters the flies' chemical profile and mating behavior. The identification of volatile attractants in tsetse flies may be useful for reducing disease spread.
Semiochemicals, such as sex pheromones or predator kairomones, trigger inter- and intraspecific interactions among animals. With more than 7500 species, frogs (Anura) are a highly diverse group with complex life cycles and adaptations to aquatic and terrestrial habitats. In this review we give a comprehensive and numerical overview about the research conducted concerning semiochemical use in different anuran live stages. Analysing more than 300 studies, we found that chemical communication and kairomone recognition are best studied in tadpoles. Tadpoles of different species are well known to react for example to damage-released alarm substances or predator kairomones. This knowledge has been used in some species to elope more complex research questions about learning mechanisms or the impact of chemical pollution. But also juvenile frogs and adults have been in the focus of semiochemical research, e.g., analysing the recognition of predator kairomones, conspecific semiochemicals, substances involved in parental care, or potential courtship pheromones. However, compared to tadpoles the research efforts in these life stages are still scarce. Furthermore, the species studied regarding semiochemical use do not remotely reflect the diversity of anuran species known today. Future studies of anuran chemical communication should provide additional insight to the role of semiochemicals across different life stages and species.
In the recent years, increasing labour cost and shortage of labour being
the major constraints to follow cotton manual harvesting in staggered
manner. Further, it is very expensive and they would like to increasingly opt
for mechanical harvesting. In this context, it was suggested that research
should focus to reduce cost of cultivation substantially by promoting the use
of synchronized maturity varieties in cotton and use of defoliants to
encourage mechanical harvesting. In agriculture, defoliants are used to
eliminate the leaves of a crop plant so they will not interfere with the
harvesting by machinery. Early harvesting with good boll opening can also
be achieved by use of defoliants. The use of defoliants also reduces the trash
content in picked cotton which will also help in improving the quality of
cotton. There is an urgent need to identify suitable defoliant with suitable
dose and time of application so as to facilitate mechanical harvesting in
rainfed cotton, Some of the successful defoliants for uniform boll bursting
and higher yield of cotton such as Ethrel, Ethepon, Mepiquat chloride (MC),
Sodium salt and DU (Dropp Ultra) are the hormonal defoliants and TDZ
Thidiazuron Butifos, merphos, tribufos and tribute are the herbicidal
defoliants. The best combination of Thidiazuron + diuron (DCMU),
pyraflufen ethyl, thidiazuron + diuron cellular isozyme, Ethephon +
AMADS, Ethephon + cyclanilide Ethephon + tribufos Mepiquat chloride
(MC) + cyclanilide.
This report is a review of pertinent scientific literature on the chemical communication of the Miridae (Order Hemiptera; Suborder Heteroptera), with a focus on the sympatric species Eccritotarsus catarinensis Carvhalho and Eccritotarsus eichhorniae Henry. Both species have been deployed as biological control agents of water hyacinth, Pontederia (Eichhornia) crassipes (Martius) Solms-Laubach, in over 30 sites in South Africa. Our aim in this review was to gather and assimilate information on the chemical communication and chemical ecology of mirids, with an ultimate goal of enhancing the effectiveness of biological control agents of water hyacinth, particularly E. catarinensis and E. eichhorniae. Many hemipterans have highly developed metathoracic scent glands (MTGs), Brindley’s glands, and secretory setae that store and emit chemicals that may act as
allomones, kairomones, or pheromones. The preponderance of the available literature dealt with sex pheromones. Hexyl butyrate, (E)-4-oxo-2-hexenal, and (E)-2-hexenyl butyrate are reported to be sex pheromones in many mirids: for example, Adelphocoris fasciaticollis Reuter, Apolygus spinolae Meyer-Du¨r, Liocoris tripustulatus F., Lygocoris pabulinus L., several Lygus spp. (Lygus hesperus Knight, Lygus lineolaris Beauvois, Lygus elisus van
Duzee, Lygus pratensis L., and Lygus rugulipennis Poppius), and Stenotus rubrovittatus Matsumura. Hexyl butyrate is the most prevalent sex pheromone in Miridae, while (E)-4-oxo-2-hexenal is the most prevalent sex pheromone in Heteroptera. Both pheromones co-occur in some species and exhibit many functionalities. The constancy of sex pheromones linked to
behavioral patterns in Miridae suggest a punctuated equilibrium pattern of evolution (dating back to the Triassic), similar to morphological characters of many insects.
Mucus is applied to substrates as snails move and when they rest. Beyond the use of mucus in movement and adhesion, the wide array of chemicals in mucus allows for supplemental use in communication. This communication is apparent in trail‐following behavior. This study addresses the potential communication via mucus in selecting resting sites in a laboratory assay. In a series of six experiments, individuals of Cornu aspersum (which often rest on above‐ground surfaces) were placed into lidded plastic containers with three or four sections swabbed with water (the control) or mucus, which included the test snail's own mucus, mucus from conspecifics from the same or a different container holding snails from the same lab colony, or from a different colony, and mucus from three additional snail species. The resting location was recorded on the following day. In two additional experiments, the facultative predator Rumina decollata was tested against conspecific and other snails' mucus. Individuals of C. aspersum preferentially rested in areas with the mucus of familiar conspecifics over mucus of unfamiliar conspecifics, a behavior that may contribute to homing and aggregation behaviors. There was evidence that juveniles may be less selective than adults. The mucus of only one of the three other species was avoided by individuals of C. aspersum . Unlike individuals of C. aspersum , individuals of the predator R. decollata avoided the mucus of conspecifics, which may be associated with less need for mate‐finding in this self‐fertilizing species. Individuals of R. decollata did not select among potential prey species.
В статті розглядається захисна поведінка соціальних комах за допомогою групових дій така як «атака», яка вимагає максимальної узгодженості дій великої кількості членів соціальної групи. Розглянуто особливості атакуючої захисної поведінки з використанням хімічних комунікаторів, жала, укусів або затискань щелепами. Аналіз літературних даних дозволив зробити висновок, що хімічні комунікатори комах – це фізіологічно активні речовини, які виробляються секреторними залозами у відповідь на небезпеку. Маючи різну хімічну будову, міжвидову, внутрішньовидову та популяційну специфічність, спільним для них є наявність двох типів фракцій: 1 – захисна (атакуюча), до якої можна віднести клейову частина спрею термітів та мурашину кислоту захисного секрету мурах; 2 – комунікаційна (інформуюча), до якої відносяться феромони тривоги, завдяки яким можлива «атака» організованої групи комах. Ще однією важливою спільною особливістю хімічних комунікаторів є обов’язкове заспокоєння після високо рівня збудження під час «атаки». Своєчасне блокування сигналу тривогиє життєво важливим для комах і забезпечується різними шляхами: 1 – високою летючістю, відповідно, швидким зменшенням концентрації збуджуючих речовин; 2 – наявністю у вмісті хімічних комунікаторів заспокійливих речовин, які мають низьку летючість і проявляють свою активність після збудження; 3 – механічно, укриттям джерела збудження. Підсумовано, що використання жала це ефективна групова атакуюча тактика медоносних бджіл, яка має популяційні відмінності, і є генетично обумовленою. Процес жаління умовно можна поділити на комунікаційну (інформуючу) складову, яка полягає в залученні особин за допомогою феромонів сигналізації до жаління та власне захисну (атакуючу), яка полягає у використанні жала. Розглянуто атакуючу групову тактику кусання, яку використовують бджоли без жала для захисту. Відмічено, що даній атакуючій дії передує застосування пасивного захисту, а саме накопичення на кутикулі речовин рослинного походження, які відлякують комахи-хижаків, водночас, ці речовини є аломонами заспокоєння. Під час кусання бджоли застосовують комплекс захисних заходів, які умовно можна поділити на захисні (атакуючі), які полягають у використанні смолоподібних клейових речовин для знерухомлення нападника та власне кусанні, тобто фізичному знешкодженні нападника, а також комунікаційні (інформуючі), які за допомогою феромонів забезпечують залучення до активного захисту максимальної кількості особин. Проведений аналіз зарубіжних літературних публікацій стосовно особливостей захисної поведінки соціальних комах типу «атака» дозволив узагальнити наукові дані з подальшим включенням їх у зміст авторського курсу «Соціальна поведінка тварин».
The presence and use of a stridulatory organ (SO) to produce vibrational signals is highly variable and structured within the ants. The file and scraper that make up the SO are specialized morphological features not used for functions other than stridulation (a vibratory signal production mechanism) and not found in non-stridulating species. It has been hypothesized and generally accepted that the stridulatory organ first evolved to alert nest mates of burial and need for rescue. Based on this premise, arboreal species are expected to exhibit a reduction of use of vibrational signals when compared to terrestrial species. Using ancestral state reconstruction, we have mapped the presence of the SO on a molecular phylogeny of the ants and found support for the hypothesis that the SO evolved multiple times in the ants. We quantitatively tested the hypothesis that stridulation evolved initially to signal burial/rescue by comparing the presence of the SO to general foraging and nesting preferences for 76 genera evenly spread throughout the currently accepted ant phylogeny. We found that a greater proportion of genera that are considered primarily arboreal possess a SO, as opposed to the ground nesting genera, and none of the five entirely subterranean genera included in this study possess a SO. We therefore reject the previous hypothesis regarding burial/rescue signaling.
Insects as a group occupy a middle ground in the biosphere between bacteria and viruses at one extreme, amphibians and mammals at the other. The size and general nature of insects present special problems to the student of entomology. For example, many commercially available instruments are geared to measure in grams, while the forces commonly encountered in studying insects are in the milligram range. Therefore, techniques developed in the study of insects or in those fields concerned with the control of insect pests are often unique. Methods for measuring things are common to all sciences. Advances sometimes depend more on how something was done than on what was measured; indeed a given field often progresses from one technique to another as new methods are discovered, developed, and modified. Just as often, some of these techniques find their way into the classroom when the problems involved have been suffi ciently ironed out to permit students to master the manipulations in a few lab oratory periods. Many specialized techniques are confined to one specific research laboratory. Although methods may be considered commonplace where they are used, in another context even the simplest procedures may save considerable time. It is the purpose of this series (1) to report new developments in methodology, (2) to reveal sources of groups who have dealt with and solved particular entomo logical problems, and (3) to describe experiments which may be applicable for use in biology laboratory co~rses.
Both behavioral and chemical analyses demonstrated that in the ant Camponotus vagus the colony recognition signal is strongly correlated with the composition of cuticular hydrocarbons. Variation of relative proportions of dimethylalkanes characterize the chemical signatures in different colonies.
Possible pheromonal components identified from the sting apparatus, mandibular gland and Nasonov gland of worker honeybees (Apis mellifera) were tested in an attempt to elucidate their function. Other chemicals known to affect behaviour were also tested. The components iso-pentyl acetate and n-octyl acetate from the sting, and 2-heptanone from the mandibular glands, repelled bees and diminished Nasonov gland exposure (scenting); 1-pentanol and (Z)-11-eicosen-1-ol from the sting diminished scenting; iso-pentyl acetate, n-butyl acetate, 2-nonanol and 1-pentanol, all from the sting, and 2-heptanone, released stinging. The alarm pheromones 2-heptanol and 3-octanone (from certain stingless bees and ants) inhibited scenting, and the former also repelled bees and released aggression. The chemicals iso-butyl acetate, sec-butyl acetate and n-pentyl acetate diminished scenting, and the insect repellents dimethyl phthalate and diethyl toluamide diminished stinging. Many of the chemicals from the honeybee sting apparatus failed to elicit a response, and their function remains unknown.
