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GC of females Glossina (Glossina) cuticular alkanes: (A) G. morsitans centralis; (B) G. m. submorsitans; (C) G. swynnertoni; (D) G. longipalpalis.
Source publication
The cuticular methyl-branched alkanes of tsetse flies of the subgenera Glossina (sensu stricto, formerly morsitans) and Nemorhina (formerly palpalis) were identified and quantified by capillary gas-liquid chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Males of Glossina (Nemorhina) are differentiated from G. (Glossina) by domi...
Contexts in source publication
Context 1
... n-alkanes and methylalkanes identified by GC-MS from G. morsitans centralis, G. m. submorsitans, G. longipalpis, and G. swynnertoni of the subgenus Glossina and G. caliginea, G. fuscipes martinii, G. pallicera palli- cera, and G. p. newsteadi of the subgenus Nemorhina are presented in Tables 1 and 2 for females and males, respectively. The GC profiles for males and females of each of the taxa are shown in Figures 1-4 and the major peak areas tabulated in Tables 3 and 4. The surface alkanes of these species of tsetse flies were comprised of long-chain methyl-branched alkanes with n-alkanes present as minor components. The dominant methylalkanes common to males and females in both subgenera consisted of an odd-carbon-number backbone series of 2-methylalkanes having modes at 29 or 31 carbons, and a homologous even- carbon-number backbone series with a mode at 30 carbons. Internally branched monomethylalkanes were present at relatively low levels with the 15-, 13-, and 11-isomers coeluting at Kovats index (Kovats, 1965) KI XX78-XX33, where XX refers to the first two digits of the KI number, and internal branching refers to branch positions near the center of the carbon chain. There was no un- ambiguous evidence for the presence of 3-or 4-methylalkanes in any of the taxa using either the 30-m or 50-m column, the latter producing about 300,000 theoretical plates. Adult females were characterized by the presence of relatively large quan- tities of internally branched di-and/or trimethylalkanes in addition to the 2-methylalkanes. These compounds were present in the males, if detected, in significantly smaller quantities. Internally branched tetramethylalkanes were also present albeit at relatively low ...
Context 2
... m. submorsitans were essentially identical ( Figure 1 and did not necessarily indicate the presence of additional isomers. This frag- mentation pattern was consistent with 15,19,23-trimethylheptatriacontane, hav- ing a pattern of methylene interruptions (/) between the branch points of the form / = 3,3-Both El mass spectra and KI were found to be identical with both the synthetic and the natural compound originally identified from G. mor- sitans morsitans (Carlson et al., 1978). The [M-15]+ fragment at m/z 547 was not identifiable in the El spectra but CI-MS confirmed the presence of 40 car- bons. Homologs of 15,19,23-trimethylheptatriacontane were also present with backbone carbon numbers of 38 and 39. In addition, smaller quantities of other trimethylalkane isomers were present with methyl branching ranging from 3,x,y- to 9,x,y-and I3,x,y-to 14,jc, y-, where x refers to the position of the second methyl group, and y refers to the position of the third methyl group. The 3,x,y- the l,x,y-isomers were the predominant trimethylalkanes at backbone carbon numbers below 35, with much less of the even backbone homologs. Dimeth- ylalkanes were present at relatively low levels with methyl branching from 5,*- to 17,x-. The internally branched isomers, 11,jc-to 17,x-, coeluted, forming a homologous series of peaks at KI XX55 and were quantitatively correlated with the 15,19,23-series. The CI-MS confirmed the presence of small quantities of tetramethylalkanes at KI XX90 with the mode at KI 3790, and the El spectra for the compound at KI 3790 was consistent with a single isomer, 11,15,19,23- tetramethy ...
Context 3
... males and females of G. swynnertoni also exhibited methylalkane patterns within the range of variation seen in the G. morsitans subspecies (Fig- ures 1 and 2). El mass spectra of the predominant peak in adult females (27.4%) at KI 3770 showed major fragments as above for 15,19,23-trimethylheptatria- contane. Hydrocarbon patterns and composition of adult males of G. sywnner- toni were essentially identical with G. morsitans ...
Citations
... O dimorfismo sexual químico em termos quantitativos e qualitativos dos hidrocarbonetos cuticulares foi reportada por autores nos últimos anos para algumas representantes de ordens de insetos, as quais incluem espécies de dípteros (Nelson et al., 1986, Cobb & Ferveur, 1995Sutton et al., 1997), besouros (Ginzel et al., 2003), abelhas (Abdalla et al., 2003;Borges et al., 2012;Ferreira-Caliman et al., 2013) e vespas (Howard, 1992;Howard & Liang, 1993). Dessa forma, as particularidades encontradas para perfis de machos e fêmeas da espécie M. cerberus podem servir como reforço para sustentar a hipótese de uma correspondência sexo-específica relacionada aos padrões de hidrocarbonetos. ...
A via de comunicação através de compostos químicos tem sido amplamente
estudada dentro do grupo dos insetos, os quais são responsáveis por mediar diversas
interações. O arranjo colonial dos insetos que vivem em sociedades, pode ter contribuído para que compostos químicos de alto peso molecular (hidrocarbonetos cuticulares), que a priori funcionam como uma barreira protetora contra dessecação, tenham sido co-adaptados para uma função comunicativa, tal qual, contribui em linhas gerais para manutenção da coesão entre os indivíduos. As variações em termos quantitativos e qualitativos desses compostos podem contribuir para mediar interações de caráter intraespecífico e interespecífico. Contudo, embora muito conhecimento tenha sido acumulado ao longo dos últimos anos acerca do papel dos hidrocarbonetos na vida em sociedade para diversas espécies de abelhas, formigas e vespas, alguns grupos são ainda negligenciados, como é o caso das vespas do gênero Mischocyttarus. As peculiaridades biológicas dessas vespas as tornam bons modelos para
investigação da possível conexão existente entre a expressão de hidrocarbonetos e contextos sociais atrelados. Dessa maneira, o presente trabalho teve por objetivo primário descrever os hidrocarbonetos da espécie M. cerberus e investigar a conexão desses compostos a caráter intersexual, intraespecífico e interespecífico, e em segundo instante, o possível vínculo dos hidrocarbonetos com a dinâmica social da espécie. Para tal, diversas abordagens e técnicas foram utilizadas, as quais envolveram coleta de material, consulta bibliográfica, videografia, dissecções e técnicas de ecologia química. De acordo com os resultados encontrados, os alcanos ramificados (alcanos metilados e dimetilados) se destacam como os principais constituintes da superfície cuticular da espécie M. cerberus (para fêmeas e machos), além disso, as fêmeas possuem uma maior riqueza de compostos se comparadas aos machos (duas vezes mais). Por outro lado, quando comparadas de forma geral, fêmeas provenientes de diferentes locais de coleta não se distinguiram com base nos hidrocarbonetos comparados. A partir da comparação realizada entre o perfil químico da espécie M. cerberus e outras cinco do
mesmo gênero, encontrou-se apenas 12 hidrocarbonetos cuticulares comuns à todas (oito alcanos lineares e quatro alcanos ramificados), dos 251 compostos encontrados, resultados que sugerem a existência de um perfi espécie-específico para todas as espécies comparadas. Ainda, os hidrocarbonetos cuticulares pareceram relacionar-se à posição hierárquica e estado reprodutivo das fêmeas, visto que as vespas ocupantes da primeira posição da hierarquia de dominância, em diferentes contextos, sempre se diferenciaram quando comparadas aos demais grupos. Com base nas informações encontradas, é possível sugerir que provavelmente esses compostos cuticulares contribuam para a dinâmica colonial da espécie M. cerberus, e ainda abrem espaço para que novas hipóteses sejam criadas acerca do possível uso dos hidrocarbonetos enquanto via de comunicação de vespas do gênero Mischocyttarus, as quais são normalmente conhecidas por regularem sua dinâmica social através de agressões físicas.
... Wing morphometrics can distinguish between species and subpopulations of tsetse flies and reportedly has the advantage of simplicity of data acquisition and low cost (Rohlf and Marcus, 1993;Solano et al., 1999;Patterson and Schofield, 2005;Camara et al., 2006;Leak et al., 2008;Getahun et al, 2014). For cuticular hydrocarbons identification method, the examination of the potentially stimulating methylalkanes [(via gas chromatography (GC) patterns)] provide reasons for the reproductive isolation of closely related species from each other (Sutton and Carlson, 1997;Getahun et al, 2014) and is used in classification and population studies. While, the phylogenetics method is expected to give greater accuracy when fully developed, a combination of identification methods is expected to give more accurate identification than the single methods. ...
Tsetse fly (Diptera: Glossinidae) anti-vector measures are reliant upon accurate identification of species
and their subpopulations. Two species were studied, Glossina palpalis palpalis and Glossina morsitans
submorsitans using two mitochondrial DNA: cytochrome oxidase subunit II (COII) and cytochrome b
(CytB). Sequencing data were used to perform phylogenetic analysis of the two reared species together
with other Glossina species’ sequences from the DNA data base. For each gene, members of the same
species group, palpalis or morsitans demonstrated a common ancestry and closer relatedness by
belonging to one cluster. Within each species group members of the same species clustered together,
an indication of common ancestry and relatedness too. Inspite of the few mixed clusters, the pattern
produced in the phylogenetic trees can provide a good guide to support any other method of Glossina
identification. It was recommended that evaluations be made to validate other genetic markers that can
produce better resolutions to identify tsetse fly species using phylogenetic tree.
... One species (the Caribbean fruit fly) contains a high proportion of 2-methyloctacosane (2-MeC 28 ) and the other (Mediterranean fruit fly) contains a high proportion of 2-methyltriacontane (2-MeC 30 ). Methylalkanes have therefore been shown to be good chemotaxonomic species markers in ants ( Dahbi et al., 1996; this study), flies ( Caputo et al., 2007;Horne and Priestman, 2002;Sutton and Carlson, 1997;Ye et al., 2007), beetles ( Page et al., 1990) and grasshoppers ( Chapman et al., 1995). There were also stable species-specific differences within the pentacosene isomers, with M. sabuleti predominantly having Z12C 25:1 and M. scabrinodis Z9-C 25:1. ...
... Pheromones are composed of internally branched di-, tri-and tetra-alkanes or -alkenes on the female cuticle, which act by contact on specific males (Table 3). There are also species and subspecies differences in male cuticular hydrocarbons (Sutton and Carlson, 1997) but their role on female behavior has not been much studied. In the male tsetse fly, G. morsitans morsitans, the major alkene, 19,23-dimethyltritriacont-1-ene is transferred to the female preparatory or during mating and apparently acts as an anti-aphrodisiac (Carlson and Schlein, 1991). ...
Sex pheromones are known for many dipteran species and play an important role in courtship behavior, together with visual, tactile, acoustic and other factors. Pheromones for a number of dipterans have been recently identified. This survey covers a number of species in all the families that have been studied. The review discusses diverse courtship behaviors in Diptera, with a special focus on the sex pheromones involved. In the Nematocera suborder, pheromones are volatile components, which act at a distance. They are derived from short-chain alkanes with acetoxy groups (Cecidomyidae) or terpenes (Psychodidae). In the Cyclorrhapha, pheromones may be volatile, derived from alkanes (Tephritidae) or terpenes (Agromyzidae), or non-volatile, unsaturated or methyl-branched hydrocarbons, which act by contact (the other subgenera). The behavioral roles and regulation of these pheromones are described, and their importance in species recognition is discussed.
... Epicuticular HC have been applied for taxonomic purposes in several orders of insects; they were used for caste discrimination in social insects (Haverty et al., 1988), and to study species of agronomic relevance (Page et al., 1990). They have also been employed in differentiating species within blood-sucking insect complexes, such as mosquitoes and flies (Milligan et al., 1986;Carlson et al., 1993;Sutton and Carlson, 1997). In triatomines, the HC pattern was early used to differentiate a variety of species within the genus Triatoma (Juárez and Brenner, 1986). ...
Triatomine insects (Hemiptera) are the vectors of Chagas disease. Their cuticular surface is covered by a thin layer of lipids, mainly hydrocarbons, wax esters, fatty alcohols, and free or esterified fatty acids. These lipids play a major role in preventing a lethal desiccation, altering the absorption of chemicals and microorganism penetration, they also participate in chemical communication events. Lipid components are biosynthetically related, the synthesis of long chain and very long chain fatty acids was first shown in the integument of Triatoma infestans through the concerted action of fatty acid synthases (FAS's) and fatty acyl-CoA elongases. A final decarboxylation step produces the corresponding hydrocarbon. Capillary gas chromatography coupled to mass spectrometry analyses showed that cuticular hydrocarbons of Triatominae comprise saturated straight and methyl-branched chains, from 18 to more than 43 carbon atoms. Odd-chain hydrocarbons, mostly from 27 to 33 carbons, are the major straight chains. Different isomers of mono, di, tri, and tetramethylcomponents, mostly from 29 to 39 atoms in the carbon skeleton, account for the major methyl-branched hydrocarbons. The presence, absence, and relative quantities of these hydrocarbons represent characters for their chemical phenotype, and are useful for differentiating genera, species and populations. In this review, we will discuss the metabolic pathways involved in hydrocarbon formation, and their structure, together with their role in insect survival. We will also review the utility of cuticular hydrocarbon fingerprints in chemotaxonomy.
... A sex pheromone that released copulatory activity in male G. tachinoides (Westwood) was isolated from extracted female hydrocarbons. Bioactivity was observed in two natural dimethylalkane 37 carbon-chain isomers (Nelson et al., 1988). Bioassays of both synthetic stereoisomeric mixtures showed slightly more activity in the 11,23-than the 13,25-dimethyl isomer (Carlson et al., 1998). ...
... The assignment of KI narrows the range of possible methyl-branch configurations in cases of overlapping peaks or insufficient EI spectra (Carlson et al., 1998). The identification of methylalkanes followed the interpretations established previously for EI mass spectra (Nelson & Carlson, 1986; Nelson et al., 1988). ...
Copulatory responses of male Glossina austeni (Newstead) (Diptera: Glossinidae), that were elicited after contact with frozen female tsetse, were not observed after solvent washing of cuticular lipids. Chromatographic analysis of extracts from laboratory-reared and field-collected G. austeni females yielded natural hydrocarbons that were highly stimulatory to males. Most of this activity was produced by compounds in the alkene fraction. Gas chromatograms (GC) contained five natural alkenes; these were separated by preparative GC for bioassays conducted in Tanzania. The two major alkenes were identified using gas chromatography-mass spectrometry (GC-MS) to be 13,17-dimethyltritriacont-1-ene and 13,17-dimethylpentatriacont-1-ene, after the samples had undergone derivatization using dimethyl disulphide and saturation with deuterium. These alkenes and natural alkanes were quantified from G. austeni of both sexes from laboratory and field samples to confirm that their presence was consistent in this species. Trials of synthetic samples resulted in the order of biological activity for the stereoisomers of 13,17-dimethyltritriacont-1-ene as follows: S,R-33:1 > R,S- 33:1 > S,S-33:1 > R,R-33:1. Dose-response data showed an ED(50) at 5 microg per treated, solvent-washed male decoy. Of the four stereoisomers of 13,17-dimethylpentatriacont-1-ene, R,R-35:1 showed the most activity. This is the first report of alkene-induced sexual activity in males of the genus Glossina.
... Previous studies have clearly established the utility of using hydrocarbon patterns for separations between widely or closely related species of insects with subsequent use of gas chromatography and GC-MS to confirm the identities of compounds detected. Insects studied include Blattella germanica and closely related species (Carlson andBrenner, 1988, Brenner et al., 1993), 26 species and sub-species of tsetse flies (Carlson et al., 1993, Sutton andCarlson, 1997a), and tabanids (Sutton and Carlson, 1997b). Unfortunately, there was only one useful set of museum specimens of H. aenescens found at the Florida State Collection of Arthropods, as the only other specimens were in a collection from the 1950s and these flies had been dipped in solvent, probably xylene (B.D. Sutton, personal communication). ...
Hydrotaea aenescens (Wiedemann), the black dump fly, is a potential biological control agent originally from the western hemisphere, now found in many parts of the Palearctic region except for the United Kingdom, where it cannot be imported for any reason. A complication of classical biological control is the problem of strain identification, as one must be able to somehow mark or follow a particular strain that has been introduced into the field or is contemplated for release. Gas chromatographic analysis of the surface hydrocarbons of pooled and individual dump fly adults resulted in reproducible hydrocarbon patterns that differentiated widely distributed strains of H. aenescens and showed similarities between strains that were related. Sexual dimorphism was observed in the surface hydrocarbons. Conspecific similarities included identities of the hydrocarbons found in colony material collected worldwide, with differences being found in the quantities of compounds present.
... carbon equivalents for each additional methyl branch when the carbon backbone was held constant (Nelson and Sukkestad, 1970;Nelson et al., 1972), with internal methylene bridges of three carbons being most common. Useful examples are found in the alkanes of the tsetse fly Glossina morsitans morsitans that have series of internally substituted di-, tri-, and tetramethylalkanes of 25-39 carbons in which the major components had three methylene interruptions only (Nelson and Carlson, 1986), but were later shown to include dimethylalkanes having longer interruptions (Sutton and Carlson, 1997a). Tsetse flies of other species, G. pallidipes and G. tachinoides, showed dimethylalkanes with larger interruptions of 7, 9, and 11 methylenes, and a later study of G. palpalis describes "terminal" trimethylalkanes . ...
... Lange et al. (1989) primarily described methylalkanes and only a few dimethylalkanes. We describe herein representative retention times on nonpolar columns for several rather complete series of di-, tri-, and tetramethylalkanes found in tsetse flies Sutton and Carlson, 1997a) and extended data for internal monomethyl alkanes to 60 carbons found in grasshoppers (Sutton et al., 1996). We include data from the literature covering most of the homologous methylalkanes from insects, where detailed retention data were included. ...
... However, peaks also containing the internally branched series with higher interruptions are split (I = 9, 11), because the latter isomers eluted considerably later than those with 1 = 3, typically by 8 KI units at 35, 36, and 37 carbons. This was seen in hydrocarbons from Melanoplus grasshoppers (Sutton et al., 1996) and tsetse flies (Sutton and Carlson, 1997a). ...
A common and confusing problem in analyses of insect hydrocarbons is in making sense of complicated gas chromatograms and interpreting mass spectra since branched chain compounds differing by one or two carbons in backbone or chain length may elute from the column at nearly the same time. To address this confusing situation, relative gas chromatography (GC) retention times are presented for typical mono-, di-, tri-, and tetramethylalkanes comprising most of the commonly appearing series of homologous methyl-branched alkanes up to 53 carbons that are found in insect cuticular hydrocarbons. Typical insect-derived methylalkanes with backbones of 33 carbons were characterized by Kovats indices (KI); monomethyl alkanes elute between KI 3328 and 3374, dimethylalkanes elute between KI 3340 and 3410, trimethylalkanes elute between KI 3378 and 3437, and tetramethylalkanes elute between KI 3409 and 3459, depending upon the positions of substituents. A protocol is described for identification of methyl-branched hydrocarbons eluted from nonpolar polysiloxane DB-1 capillary GC columns. In this protocol, retention indices (KI values) are assigned to peaks, then the patterns in GC peaks that probably contain homologs are marked to assist subsequent GC-mass spectrometric (GC-MS) interpretation. Use of the KI allows assignment of likely structures and the elimination of others, with demonstrative consistency, as there are no known exceptions. Interpretation of electron ionization mass spectra can then proceed within narrowed structural possibilities without the necessity of chemical ionization GC-MS analysis. Also included are specific examples of insect hydrocarbons that were assembled from 30 years of the literature, and these are intended to help with confirmation of confusing or contradictory structures.
Comparative chemistry is an old discipline originally designed to “use chemistry to name and classify plants”. The first reports appeared in 1960, and there has been a steady stream ever since (see Reynolds, 2007 for review). Although plants have been the most studied chemotaxonomy, many researchers have applied the same approach to invertebrates, especially insects. One of the most widely studied chemotaxonomic characters in insects has been cuticular hydrocarbons (CHCs). The earliest descriptive papers on CHCs were by Jackson (1970), Jackson and Bayer (1970), Jackson and Blomquist (1976), Lockey (1976), and Lange et al. (1989). Carlson and collaborators (Carlson and Service 1979, 1980; Carlson et al., 1978; Carlson, 1988) were the first to recognize the special role of CHCs in chemical taxonomy. Since then, numerous reviews have devoted sections to CHCs (Lockey, 1980, 1988; Howard and Blomquist, 1982, 2005; Blomquist and Dillwith, 1985; Blomquist et al., 1987; Kaib et al., 1991; Singer, 1998; Howard, 1993). Since the introduction of molecular techniques, the number of insect chemotaxonomy papers about hydrocarbons has dropped, but there are still many submissions and publications. Explanations for this continued interest in insect CHCs include not only their importance as chemical cues in recognition processes, but also the fact that insects are excellent bioindicators of nature conservation, and inversely, pests to control.
