Analysis Of Cuticular Hydrocarbons Research Articles

Highly diverse cuticular hydrocarbon profiles but no evidence for aggression towards non-kin in the ambrosia beetle Xyleborinus saxesenii.

Animal societies use nestmate recognition to protect against social cheaters and parasites. In most social insect societies, individuals recognize and exclude any non-nestmates and the roles of cuticular hydrocarbons as recognition cues are well documented. Some ambrosia beetles live in cooperatively breeding societies with farmed fungus cultures that are challenging to establish, but of very high value once established. Hence, social cheaters that sneak into a nest without paying the costs of nest foundation may be selected. Therefore, nestmate recognition is also expected to exist in ambrosia beetles, but so far nobody has investigated this behavior and its underlying mechanisms. Here we studied the ability for nestmate recognition in the cooperatively breeding ambrosia beetle Xyleborinus saxesenii, combining behavioural observations and cuticular hydrocarbon analyses. Laboratory nests of X. saxesenii were exposed to foreign adult females from the same population, another population and another species. Survival as well as the behaviours of the foreign female were observed. The behaviours of the receiving individuals were also observed. We expected that increasing genetic distance would cause increasing distance in chemical profiles and increasing levels of behavioural exclusion and possibly mortality. Chemical profiles differed between populations and appeared as variable as in other highly social insects. However, we found only very little evidence for the behavioural exclusion of foreign individuals. Interpopulation donors left nests at a higher rate than control donors, but neither their behaviours nor the behaviours of receiver individuals within the nest showed any response to the foreign individual in either of the treatments. These results suggest that cuticular hydrocarbon profiles might be used for communication and nestmate recognition, but that behavioural exclusion of non-nestmates is either absent in X. saxesenii or that agonistic encounters are so rare or subtle that they could not be detected by our method. Additional studies are needed to investigate this further.

Discrimination of Diptera order insects based on their saturated cuticular hydrocarbon content using a new microextraction procedure and chromatographic analysis.

The nature and proportions of hydrocarbons in the cuticle of insects are characteristic of the species and age. Chemical analysis of cuticular hydrocarbons allows species discrimination, which is of great interest in the forensic field, where insects play a crucial role in estimating the minimum post-mortem interval. The objective of this work was the differentiation of Diptera order insects through their saturated cuticular hydrocarbon compositions (SCHCs). For this, specimens fixed in 70 : 30 ethanol : water, as recommended by the European Association for Forensic Entomology, were submitted to solid-liquid extraction followed by dispersive liquid-liquid microextraction, providing preconcentration factors up to 76 for the SCHCs. The final organic extract was analysed by gas chromatography coupled with flame ionization detection (GC-FID), and GC coupled with mass spectrometry was applied to confirm the identity of the SCHCs. The analysed samples contained linear alkanes with the number of carbon atoms in the C9-C15 and C18-C36 ranges with concentrations between 0.1 and 125 ng g-1. Chrysomya albiceps (in its larval stage) showed the highest number of analytes detected, with 21 compounds, while Lucilia sericata and Calliphora vicina the lowest, with only 3 alkanes. Non-supervised principal component analysis and supervised orthogonal partial least squares discriminant analysis were performed and an optimal model to differentiate specimens according to their species was obtained. In addition, statistically significant differences were observed in the concentrations of certain SCHCs within the same species depending on the stage of development or the growth pattern of the insect.

Cuticular Hydrocarbon Profiling of Australian Gonipterini Weevils

Cuticular hydrocarbon (CHC) profiling shows promise as a chemotaxonomic tool for identifying and discriminating between closely related insect species. However, there have been limited studies using CHC profiling to differentiate between weevil species (Coleoptera: Curculionidae). This proof-of-concept study investigated the use of CHC and volatile profiling to discriminate between five weevil species from three genera in the Gonipterini tribe. A total of 56 CHCs and 41 other volatile compounds were found across the five species, with 83 of the compounds being identified through their mass fragmentation patterns. The number of CHCs from each species ranged from 20 to 43, while the proportion of CHCs unique to each species varied between 0% and 19%. The most abundant CHCs were nonacosane, 7-methylheptacosane, heptacosane, and hexacosane. Principal component analysis of the centred log-ratio transformed data revealed broad differences in CHC profiles between the two Oxyops species, with Bryachus squamicollis demonstrating the greatest divergence from the other Gonipterini species. The results suggest that CHC analysis could be used to support established taxonomic methods, including morphological features and genetic sequencing results.

Cuticular hydrocarbons as weathering biomarkers of empty puparia of the forensically important blowfly Calliphora vicina Robineau-Desvoidy, 1830 (Diptera: Calliphoridae) in soil v/s under room conditions

Forensic entomology uses the age of insects, such as blow flies, to determine a minimum post-mortem interval (PMImin). Recent research has focused on using the analysis of specific cuticular hydrocarbons (CHCs) in adult insects and their empty puparia to estimate their age, as it has been shown that their profile changes are consistent with age. The current work is based on the weathering of five CHCs from empty puparia of Calliphora vicina that were stored in soil (field/outdoor) and non-soil (room/indoor conditions) based pupariation media for a total of six months. The experiment was conducted in a controlled environment chamber at a constant temperature of 25 ± 2 °C under constant darkness. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the cuticular hydrocarbons after they were extracted in n-Hexane. n-Pentacosane, n-Hexacosane, n-Heptacosane, n-Octacosane, and n-Nonacosane were the five CHCs investigated. Results showed that CHCs weathered more quickly in the soil than in the non-soil environment. It was also found that the abundance of Heptacosane increased in the samples during the fifth month when stored in a non-soil medium, while the abundances of all five CHCs were not detected after eight weeks onwards in soil pupation medium.

A new host for a new Rossomyrmex minuchae population

Social parasites usually rely on chemical cues (cuticular hydrocarbons) to successfully invade and coexist with their hosts. Most ants that are obligate social parasites (slave-makers) can parasitize several related host species with different levels of chemical similarity although there are few exceptions where there is only a single host species. An example of the latter is Rossomyrmex minuchae, which was known to be only associated with Proformica longiseta. However, a recent discovery of a new R. minuchae population revealed that it can parasitize P. nasuta, a species with a separate distribution to P. longiseta. Chemical analyses of cuticular hydrocarbons show local adaptation of the parasite to its host in this new population, being more similar to P. nasuta than to other R. minuchae populations. In addition, genetic analyses evidence differences from the other known populations, from which it split 1.21 Mya during glacial and interglacial periods of the Pleistocene and remained separated to the present day. This historical genetic isolation and the chemical differences found between parasite populations may evidence a speciation process and support the local host–parasite coevolution.

Unique venom proteins from Solenopsis invicta x Solenopsis richteri hybrid fire ants.

The Solenopsis venom protein 2 transcript was amplified, sequenced, probed, and analyzed from Solenopsis invicta x Solenopsis richteri hybrid ant colonies (hybrids) collected from across Tennessee to determine the extent of introgression of each parent allele (Solenopsis invicta venom protein 2 [Soli2] and Solenopsis richteri venom protein 2 [Solr2]). Chemotaxonomic analyses of venom alkaloids and cuticular hydrocarbons were used to categorize hybrid colonies and their relative relatedness to each parent species. Hybrid colonies were chosen randomly from each chemotaxonomic hybridization category, including “very near S. richteri,” “near S. richteri,” “near S. invicta,” and “very near S. invicta.” Lateral flow immunoassays for detection of the Soli2 and Solr2 venom proteins were largely in agreement with the chemotaxonomic analyses for the very near S. richteri (100% Solr2) and very near S. invicta (80% Soli2, 20% Soli2 + Solr2 detected in the sample) groups, while Soli2 and Solr2 were reported in 60% and 40% in the near S. invicta and near S. richteri chemotaxonomic groups. Analysis of transcripts from the hybrid colonies revealed a sequence with 100% identity to Soli2 (GenBank Accession L09560) and three unique sequences, which we identify as Solenopsis hybrid venom protein 2 (Solh2; GenBank Accession MT150127), Solenopsis hybrid truncated venom protein 2 (Solh2Tr97; Genbank Accession MT150129), and Solenopsis richteri venom protein 2, D to A change at position 69 (Solr2A69; GenBank Accession MT150128). The predicted open reading frame for Solh2 and Solh2Tr97 revealed sequences unique to hybrid ants, with Solh2Tr97an alternatively spliced form. A third unique sequence, Solr2A69, is likely the correct sequence for Solr2, which appears to have been published previously with a sequencing error (GenBank Accession P35776).

Cuticular hydrocarbons of Gonipterus weevils: are there species differences?

Gonipterus weevils have been a taxonomic challenge for many years, with implications on our understanding of invasive species, host plant relationships and natural enemies. We assessed cuticular hydrocarbon (CHC) analysis as a tool for discrimination of some of the many species of Gonipterus occurring in Australia. Weevils were collected across several localities and kept under identical conditions prior to a whole-body wash for extraction of CHCs in hexane. Weevil identifications were confirmed using morphology and molecular tools. CHC extracts were analyzed by gas chromatography–mass spectrometry (GC–MS) and the relative peak areas in profiles were compared; compounds were identified according to MS fragmentation and retention indices. CHC profiles of the seven species of Gonipterus analyzed differed from each other, and from another weevil genus (Oxyops), used as an outgroup. The compounds that contributed most to species differences were alkanes, alkenes and methyl branched alkanes. Within some species, locality of collection affected CHC profiles. Our study presents CHC analysis as a promising tool for distinction of Gonipterus species.

Cuticular Hydrocarbon Profile Analyses Help Clarify the Species Identity of Dry-Mounted Cuckoo Wasps (Hymenoptera: Chrysididae), Including Type Material, and Reveal Evidence for a Cryptic Species

Abstract Cuckoo wasps of the Chrysis ignita species group are difficult to identify at the species level, and the taxonomic status of various taxa has consequently been controversial. COI barcoding has helped clarify some of the taxonomic problems in this group, but also revealed cryptic diversity at the genetic level that remained difficult to interpret taxonomically. Here we show that analysis of cuticular hydrocarbons (CHCs) clarifies the taxonomic status of cuckoo wasp samples with distinct COI haplotypes. The advantages of studying CHCs in insects for taxonomic purposes reside on the fact that CHC profiles evolve quickly and that all proteins required for CHC biosynthesis are encoded by nuclear genes. Using Chrysis pseudobrevitarsis as an example, we show that COI barcoding in combination with analysis of CHCs extracted from freshly collected and from dry-mounted museum specimens (including the lectotype of C. pseudobrevitarsis) provides clear evidence for a separate taxon among samples which were previously considered to be conspecific with C. pseudobrevitarsis. We describe this taxon as Chrysis parabrevitarsis n. sp. and present characters for distinguishing it chemically, genetically, and morphologically (females only) from C. pseudobrevitarsis. CHC profile comparison suggests females of C. pseudobrevitarsis may chemically mimic females of the vespid wasp Euodynerus notatus. Our study demonstrates the value of CHC analyses for supporting taxonomic inferences based on COI barcodes. It additionally underlines the value of dry-mounted collection specimens for chemical analyses and the potential of CHCs for inferring the identity of museum specimens, including type material, in a morphologically noninvasive manner.

Mitochondrial DNA and cuticular hydrocarbon analyses of Lethe diana (Lepidoptera, Nymphalidae, Satyrinae) inhabiting Mikura Island, Japan

Mitochondrial DNA and cuticular hydrocarbon analyses of Lethe diana (Lepidoptera, Nymphalidae, Satyrinae) inhabiting Mikura Island, Japan

Cuticular Hydrocarbon Analysis in Forensic Entomology: A Review

Blowflies are the first inhabitants of decomposing remains and are therefore of forensic relevance for post mortem interval estimations. Forensic entomology is becoming widely accepted as a branch of forensic science and is being utilised more within forensic casework. This wider use has driven an increase in research being carried out within the field, in particular, in less “classical” techniques such as DNA and chemical analysis in the form of cuticular hydrocarbon analysis. This short review will examine the research currently being studied in the area of cuticular hydrocarbon analysis of forensically important Diptera for species identification and ageing.

TAXONOMIC STUDIES ON TWO TEPHRITID SPECIES (ORDER: DIPTERA), BACTROCERA OLEAE AND B. ZONATA, USING THE CUTICULAR HYDROCARBONS PROFILE

The outer surface of insects (cuticle) is sheltered by a complex mixture of cuticular hydrocarbons (CHCs) play an important role in avoiding desiccation and defend the insects against diseases infestation. Identification and chemical analyses of insect cuticular hydrocarbons are vital practice toward insect control. The obtained results indicated the two studied species obviously differ in CHCs components (35 and 29 components characterized B. oleae and B. zonata respectively) and shared twelve components. All these components can be used (quantitatively and qualitatively) to identify and taxonomically separate them.The objective of this paper is to evaluate the using of cuticular hydrocarbons as taxonomic tools in two dipteran species, Bactrocera oleae and B. zonata.

Lock-picks: fungal infection facilitates the intrusion of strangers into ant colonies

Studies investigating host-parasite systems rarely deal with multispecies interactions, and mostly explore impacts on hosts as individuals. Much less is known about the effects at colony level, when parasitism involves host organisms that form societies. We surveyed the effect of an ectoparasitic fungus, Rickia wasmannii, on kin-discrimination abilities of its host ant, Myrmica scabrinodis, identifying potential consequences at social level and subsequent changes in colony infiltration success of other organisms. Analyses of cuticular hydrocarbons (CHCs), known to be involved in insects’ discrimination processes, revealed variations in chemical profiles correlated with the infection status of the ants, that could not be explained by genetic variation tested by microsatellites. In behavioural assays, fungus-infected workers were less aggressive towards both non-nestmates and unrelated queens, enhancing the probability of polygyny. Likewise, parasitic larvae of Maculinea butterflies had a higher chance of adoption by infected colonies. Our study indicates that pathogens can modify host recognition abilities, making the society more prone to accept both conspecific and allospecific organisms.

Subterranean termite phylogeography reveals multiple postglacial colonization events in southwestern Europe.

A long‐standing goal of evolutionary biology is to understand how paleoclimatic and geological events shape the geographical distribution and genetic structure within and among species. Using a diverse set of markers (cuticular hydrocarbons, mitochondrial and nuclear gene sequences, microsatellite loci), we studied Reticulitermes grassei and R. banyulensis, two closely related termite species in southwestern Europe. We sought to clarify the current genetic structure of populations that formed following postglacial dispersal from refugia in southern Spain and characterize the gene flow between the two lineages over the last several million years. Each marker type separately provided a fragmented picture of the evolutionary history at different timescales. Chemical analyses of cuticular hydrocarbons and phylogenetic analyses of mitochondrial and nuclear genes showed clear separation between the species, suggesting they diverged following vicariance events in the Late Miocene. However, the presence of intermediate chemical profiles and mtDNA introgression in some Spanish colonies suggests ongoing gene flow. The current genetic structure of Iberian populations is consistent with alternating isolation and dispersal events during Quaternary glacial periods. Analyses of population genetic structure revealed postglacial colonization routes from southern Spain to France, where populations underwent strong genetic bottlenecks after traversing the Pyrenees resulting in parapatric speciation.

Resolving cryptic species complexes of major tephritid pests.

An FAO/IAEA Co-ordinated Research Project (CRP) on “Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade” was conducted from 2010 to 2015. As captured in the CRP title, the objective was to undertake targeted research into the systematics and diagnostics of taxonomically challenging fruit fly groups of economic importance. The scientific output was the accurate alignment of biological species with taxonomic names; which led to the applied outcome of assisting FAO and IAEA Member States in overcoming technical constraints to the application of the Sterile Insect Technique (SIT) against pest fruit flies and the facilitation of international agricultural trade. Close to 50 researchers from over 20 countries participated in the CRP, using coordinated, multidisciplinary research to address, within an integrative taxonomic framework, cryptic species complexes of major tephritid pests. The following progress was made for the four complexes selected and studied:Anastrepha fraterculus complex – Eight morphotypes and their geographic and ecological distributions in Latin America were defined. The morphotypes can be considered as distinct biological species on the basis of differences in karyotype, sexual incompatibility, post-mating isolation, cuticular hydrocarbon, pheromone, and molecular analyses. Discriminative taxonomic tools using linear and geometric morphometrics of both adult and larval morphology were developed for this complex.Bactrocera dorsalis complex – Based on genetic, cytogenetic, pheromonal, morphometric, and behavioural data, which showed no or only minor variation between the Asian/African pest fruit flies Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens, the latter three species were synonymized with Bactrocera dorsalis. Of the five target pest taxa studied, only Bactrocera dorsalis and Bactrocera carambolae remain as scientifically valid names. Molecular and pheromone markers are now available to distinguish Bactrocera dorsalis from Bactrocera carambolae.Ceratitis FAR Complex (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa) – Morphology, morphometry, genetic, genomic, pheromone, cuticular hydrocarbon, ecology, behaviour, and developmental physiology data provide evidence for the existence of five different entities within this fruit fly complex from the African region. These are currently recognised as Ceratitis anonae, Ceratitis fasciventris (F1 and F2), Ceratitis rosa and a new species related to Ceratitis rosa (R2). The biological limits within Ceratitis fasciventris (i.e. F1 and F2) are not fully resolved. Microsatellites markers and morphological identification tools for the adult males of the five different FAR entities were developed based on male leg structures.Zeugodacus cucurbitae (formerly Bactrocera (Zeugodacus) cucurbitae) – Genetic variability was studied among melon fly populations throughout its geographic range in Africa and the Asia/Pacific region and found to be limited. Cross-mating studies indicated no incompatibility or sexual isolation. Host preference and genetic studies showed no evidence for the existence of host races. It was concluded that the melon fly does not represent a cryptic species complex, neither with regard to geographic distribution nor to host range. Nevertheless, the higher taxonomic classification under which this species had been placed, by the time the CRP was started, was found to be paraphyletic; as a result the subgenus Zeugodacus was elevated to genus level.

Various chemical strategies to deceive ants in three Arhopala species (lepidoptera: Lycaenidae) exploiting Macaranga myrmecophytes.

Macaranga myrmecophytes (ant-plants) are generally well protected from herbivore attacks by their symbiotic ants (plant-ants). However, larvae of Arhopala (Lepidoptera: Lycaenidae) species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies.

Identifying 1st instar larvae for three forensically important blowfly species using “fingerprint” cuticular hydrocarbon analysis

Calliphoridae are known to be the most forensically important insects when it comes to establishing the minimum post mortem interval (PMImin) in criminal investigations. The first step in calculating the PMImin is to identify the larvae present to species level. Accurate identification which is conventionally carried out by morphological analysis is crucial because different insects have different life stage timings. Rapid identification in the immature larvae stages would drastically cut time in criminal investigations as it would eliminate the need to rear larvae to adult flies to determine the species. Cuticular hydrocarbon analysis on 1st instar larvae has been applied to three forensically important blowflies; Lucilia sericata, Calliphora vicina and Calliphora vomitoria, using gas chromatography–mass spectrometry (GC–MS) and principal component analysis (PCA). The results show that each species holds a distinct “fingerprint” hydrocarbon profile, allowing for accurate identification to be established in 1-day old larvae, when it can be challenging to apply morphological criteria. Consequently, this GC–MS based technique could accelerate and strengthen the identification process, not only for forensically important species, but also for other entomological samples which are hard to identify using morphological features.

Ovarian development of Agrilus planipennis: effects of age and mating status and influence on attraction to host volatiles

AbstractEmerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a major pest of ash trees, Fraxinus spp. (Oleaceae), in North America. This study investigated the timing of reproductive development in female beetles and the influence of female reproductive maturity on attraction to host volatiles. Based on dissections of females of increasing age, females with access to males for mating, and thus presumed mated, developed mature eggs only after 18–24 days. In contrast, female beetles reared without access to males, and thus unmated, did not develop mature eggs at any age. Chemical analysis of cuticular hydrocarbons detected the contact sex pheromone, 9‐methyl‐pentacosane, in cohorts of females which were 8–9 days old and older, supporting previous research that this compound signals sexual maturity to males. Results from field‐trapping bioassays demonstrated that stage of female reproductive maturity influenced their attraction to host volatiles: females caught on traps baited with foliar volatiles contained eggs and ovarioles that were significantly less developed than those on traps baited with bark sesquiterpenes. However, our results revealed that females with immature stages of ovarioles and undeveloped eggs, such as those observed in unmated females, were rarely ever caught on traps baited with either of the host volatile lures. Further research on host compounds attractive to immature females is critical for early detection and possible control of A. planipennis populations during the extended pre‐oviposition period.

Do chemical signals mediate reproductive behavior of Trupanea vicina, an emerging pest of ornamental marigold production in California?

AbstractA variety of signals mediate reproductive behaviors of Tephritidae, and studies of such behaviors have focused predominantly on economically important tephritid pest species. Trupanea vicina (Wulp) (Diptera: Tephritidae: Tephritinae), an Asteraceae‐feeding fruit fly, was not considered a pest until recently, when large populations developed on marigolds in California (USA) nurseries. Understanding courtship behavior and the signals that mediate mating behavior in T. vicina could produce leads for new methods of controlling this emerging pest species. Most of the sexual behaviors observed in T. vicina were expressed by males and reflected the general characteristics of known reproductive behaviors in the genus Trupanea. Analyses of headspace volatiles indicated the presence of almost exclusively one male‐specific compound, 1‐nonanol. Age‐related changes were observed in the amount but not in the composition of the male‐produced volatiles. Aerations of males showed no diel periodicity in 1‐nonanol production, but an increase after mating. Solid‐phase microextraction wipe samples from various body parts of male T. vicina showed that 1‐nonanol was concentrated on the abdomens of males exhibiting pleural distension. Laboratory bioassays failed to detect any strong attraction of either sex to synthetic 1‐nonanol. Although the functional role of 1‐nonanol in T. vicina's biology is not yet clear, we suggest that it must have some role in the life history of this species, given the relatively large amounts in which it is produced, and the specialized structures used in its production and release. Analysis of cuticular hydrocarbons extracted from males and females showed pronounced sexual dimorphism in the cuticular lipid profiles, suggesting that these compounds may have a role as short‐range and contact pheromones.

Delineating species boundaries using an iterative taxonomic approach: The case of soldierless termites (Isoptera, Termitidae, Apicotermitinae)

Species boundaries are traditionally inferred using morphological characters, although morphology sometimes fails to correctly delineate species. To overcome this limitation, researchers have widely taken advantage of alternative methods such as DNA barcoding or analysis of cuticular hydrocarbons (CHs) profiles, but rarely use them simultaneously in an iterative taxonomic approach. Here, we follow such an approach using morphology, DNA barcoding and CHs profiles to precisely discriminate species of soldierless termites, a diversified clade constituting about one-third of the Neotropical termite species richness, but poorly resolved taxonomically due to the paucity of useful characters. We sampled soldierless termites in various forest types of the Nouragues Nature Reserve, French Guiana. Our results show that morphological species determination generally matches DNA barcoding, which only suggests the existence of three cryptic species in the 31 morphological species. Among them, Longustitermes manni is the only species whose splitting is corroborated by ecological data, other widely distributed species being supported by DNA barcoding. On the contrary, although CHs profiles provide a certain taxonomic signal, they often suggest inconsistent groupings which are not supported by other methods. Overall, our data support DNA barcoding and morphology as two efficient methods to distinguish soldierless termite species.

Evidence for antiseptic behaviour towards sick adult bees in honey bee colonies

Social life is generally associated with an increased risk of disease transmission, but at the same time it allows behavioural defence at both the individual and collective level. Bees infected with deformed-wing virus were introduced into observation hives; through behavioural observations and chemical analysis of cuticular hydrocarbons from healthy and infected bees, we offer the first evidence that honeybee colonies can detect and remove infected adult bees, probably by recognising the cuticular hydrocarbon profiles of sick individuals. We also found that health-compromised colonies were less efficient at defending themselves against infected bees, thus facing an ever increasing risk of epidemics. This work reveals a new antiseptic behaviour that can only be interpreted as an adaptation at colony level and one which should be considered an element of the social immunity system of the beehive, re-enforcing the view of a colony as an integrated organism.