Microscopic morphology and distribution of the antennal sensilla in the double-spined bark beetle, Ips duplicatus (Coleoptera: Curculionidae).

The double-spined spruce bark beetle, Ips duplicatus, has become an infamous secondary pest of Norway spruce, causing extensive ecological and economic destruction in many Central European countries. Antennae are the primary olfactory organs that play a fundamental role in insect-host chemical communication; therefore, understanding morphology is crucial before conducting electrophysiological investigations. Here, we present our analysis of sensilla types on the antennal surface of I.

Identification of a queen primer pheromone in higher termites.

It is long established that queens of social insects, including termites, maintain their reproductive dominance with queen primer pheromones (QPPs). Yet, the QPP chemistry has only been elucidated in a single species of lower termites. By contrast, the most diversified termite family Termitidae (higher termites), comprising over 70% of termite species, has so far resisted all attempts at QPP identification.

Anti-attractant activity of (+)-trans-4-thujanol for Eurasian spruce bark beetle Ips typographus: Novel potency for females.

Background: Eurasian spruce bark beetles (Ips typographus) use both attractant and anti-attractant semiochemicals to find suitable mature host trees. Trans-4-thujanol is abundant in young, unsuitable spruce trees. Electrophysiological studies have demonstrated its high activity levels, but field data are lacking.

Metabolomics and transcriptomics of pheromone biosynthesis in an aggressive forest pest Ips typographus.

Eurasian spruce bark beetle, Ips typographus, is a destructive pest in spruce forests. The ability of I. typographus to colonise host trees depends on its massive aggregation behaviour mediated by aggregation pheromones, consisting of 2-methyl-3-buten-2-ol and cis-verbenol.

Interactions among Norway spruce, the bark beetle and its fungal symbionts in times of drought.

Resilience and functionality of European Norway spruce forests are increasingly threatened by mass outbreaks of the bark beetle promoted by heat, wind throw and drought. Here, we review current knowledge on Norway spruce and interactions from the perspective of drought-stressed trees, host selection, colonisation behaviour of beetles, with multi-level effects of symbiotic ophiostomatoid fungi. By including chemo-ecological, molecular and behavioural perspectives, we provide a comprehensive picture on this complex, multitrophic system in the light of climate change.

Stereochemistry of two pheromonal components of the bumblebee wax moth, Aphomia sociella.

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees. In this species, males produce sexual pheromone to attract females, while females produce an aphrodisiac pheromone that initiates male courtship. Both pheromones contain 6,10,14-trimethylpentadecan-2-one (TMPD-one) and the corresponding alcohol, 6,10,14-trimethylpentadecan-2-ol (TMPD-ol) in sex specific quantities.

(3R,6E)-nerolidol, a fertility-related volatile secreted by the queens of higher termites (Termitidae: Syntermitinae).

The queens of advanced social insects maintain their reproductive monopoly by using exocrine chemicals. The chemistry of these "queen pheromones" in termites is poorly known. We show that primary queens of four higher termites from the subfamily Syntermitinae (Embiratermes neotenicus, Silvestritermes heyeri, Labiotermes labralis, and Cyrilliotermes angulariceps) emit significant amounts of the sesquiterpene alcohol (E)-nerolidol.

Sex-Pairing Pheromones in Three Sympatric Neotropical Termite Species (Termitidae: Syntermitinae).

Termite colonies are almost always founded by a pair of winged dispersers, in spite of the high costs and low success rates inherent in independent colony foundation. The dispersal flights of imagoes from natal colonies are followed by mate search, mediated by sex-pairing pheromones. Here, we studied the chemistry of sex-pairing pheromones and the related aspects of mate search in winged imagoes of two facultatively parthenogenetic species, Embiratermes neotenicus and Silvestritermes minutus, and an additional species from the same subfamily, Silvestritermes heyeri.

Epicuticular chemistry reinforces the new taxonomic classification of the Bactrocera dorsalis species complex (Diptera: Tephritidae, Dacinae).

Bactrocera invadens Drew, Tsuruta & White, Bactrocera papayae Drew & Hancock, and Bactrocera philippinensis Drew & Hancock, key pest species within the Bactrocera dorsalis species complex, have been recently synonymized under the name Bactrocera dorsalis (Hendel). The closely related Bactrocera carambolae Drew & Hancock remains as a discrete taxonomic entity. Although the synonymizations have been accepted by most researchers, debate about the species limits remains.

Smells Like Home: Chemically Mediated Co-Habitation of Two Termite Species in a Single Nest.

Termite nests often are referred to as the most elaborate constructions of animals. However, some termite species do not build a nest at all and instead found colonies inside the nests of other termites. Since these so-called inquilines do not need to be in direct contact with the host population, the two colonies usually live in separate parts of the nest.

An integrative approach to unravel the Ceratitis FAR (Diptera, Tephritidae) cryptic species complex: a review.

This paper reviews all information gathered from different disciplines and studies to resolve the species status within the Ceratitis FAR (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa) complex, a group of polyphagous fruit fly pest species (Diptera, Tephritidae) from Africa. It includes information on larval and adult morphology, wing morphometrics, cuticular hydrocarbons, pheromones, microsatellites, developmental physiology and geographic distribution. The general consensus is that the FAR complex comprises Ceratitis anonae, two species within Ceratitis rosa (so-called R1 and R2) and two putatitve species under Ceratitis fasciventris.

Analyses of volatiles produced by the African fruit fly species complex (Diptera, Tephritidae).

Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from the African continent. The taxonomy of this group (the so-called Ceratitis FAR complex) is unclear. To clarify the taxonomic relationships, male and female-produced volatiles presumably involved in pre-mating communication were studied using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) followed by multivariate analysis, and gas chromatography combined with electroantennographic detection (GC-EAD).

Evaluating mating compatibility within fruit fly cryptic species complexes and the potential role of sex pheromones in pre-mating isolation.

The study of sexual behavior and the identification of the signals involved in mate recognition between con-specifics are key components that can shed some light, as part of an integrative taxonomic approach, in delimitating species within species complexes. In the Tephritidae family several species complexes have received particular attention as they include important agricultural pests such as the Ceratitis fasciventris (Bezzi), Ceratitis anonae (Graham) and Ceratitis rosa Karsch (FAR) complex, the Bactrocera dorsalis (Hendel) complex and the Anastrepha fraterculus (Wiedemann) complex. Here the value and usefulness of a methodology that uses walk-in field cages with host trees to assess, under semi-natural conditions, mating compatibility within these complexes is reviewed, and the same methodology to study the role of chemical communication in pre-mating isolation among Anastrepha fraterculus populations is used.

Reproductive Isolation of Ips nitidus and I. shangrila in Mountain Forests of Western China: Responses to Chiral and Achiral Candidate Pheromone Components.

Eastern Palearctic conifers are subject to frequent bark beetle outbreaks. However, neither the species responsible nor the semiochemicals guiding these attacks are well understood. Two high-mountain Ips species on Qinghai spruce, Picea crassifolia, I.

Total synthesis, proof of absolute configuration, and biosynthetic origin of stylopsal, the first isolated sex pheromone of strepsiptera.

The asymmetric total synthesis of the diastereomers of stylopsal establishes the absolute configuration of the first reported sex pheromone of the twisted-wing parasite Stylops muelleri as (3R,5R,9R)-trimethyldodecanal. The key steps for the diastereo- and enantiodivergent introduction of the methyl groups are two different types of asymmetric conjugate addition reactions of organocopper reagents to α,β-unsaturated esters, whereas the dodecanal skeleton is assembled by Wittig reactions. The structure of the natural product was confirmed by chiral gas chromatography (GC) techniques, GC/MS and GC/electroantennography (EAD) as well as field tests.

Stylopsal: the first identified female-produced sex pheromone of strepsiptera.

A female-produced sex pheromone of Stylops muelleri was identified as an unusually branched saturated aldehyde (9R)-3,5-syn-3,5,9-trimethyldodecanal. We named it stylopsal. Its structure was established by using mass spectrometry, infrared spectroscopy, and organic synthesis of candidate compounds.

Cuticular hydrocarbons of the South American fruit fly Anastrepha fraterculus: variability with sex and age.

Insect cuticular hydrocarbons are usually species-specific mixtures and may serve for species and gender recognition. They are, therefore, widely used in the chemotaxonomy and zoogeography of various insect taxa. In order to provide a basic study for further comparative analyses of cuticular hydrocarbon (CHC) profiles of cryptic species hidden within the South American fruit fly Anastrepha fraterculus complex (Diptera: Tephritidae), we analyzed the composition of the CHCs and their production with respect to age and sex in a laboratory population from Tucuman, Argentina.

Are the wild and laboratory insect populations different in semiochemical emission? The case of the medfly sex pheromone.

The medfly (Ceratitis capitata) is one of the major agricultural pests controlled through sterile insect technique (SIT) programs. We studied the chemical composition of the volatiles released by calling males from one laboratory and two wild C. capitata populations using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC/TOFMS) and gas chromatography with electroantennographic detection (GC-EAD).

Females of the bumblebee parasite, Aphomia sociella, excite males using a courtship pheromone.

Aphomia sociella (Lepidoptera: Pyralidae: Galleriinae) is a parasitic moth of bumblebees. Behavioral experiments show that A. sociella females emit semiochemicals that influence male pre-mating behavior and serve as a courtship pheromone.

Male moth songs tempt females to accept mating: the role of acoustic and pheromonal communication in the reproductive behaviour of Aphomia sociella.

Background: Members of the subfamily Galleriinae have adapted to different selective environmental pressures by devising a unique mating process. Galleriinae males initiate mating by attracting females with either chemical or acoustic signals (or a combination of both modalities). Six compounds considered candidates for the sex pheromone have recently been identified in the wing gland extracts of Aphomia sociella males.

Nonadecadienone, a new termite trail-following pheromone identified in Glossotermes oculatus (Serritermitidae).

Within the multitude of chemical signals used by termites, the trail marking by means of pheromones is ubiquitous. Chemistry and biology of the trail-following communication have been described in more than 60 species from all families except for the Neotropical Serritermitidae. The chemical ecology of Serritermitidae is of special interest not only as a missing piece of knowledge on the diversity and evolution of isopteran pheromones but also because it may contribute to the debate on the phylogenetic position of this family, which is still unresolved.

Sex pheromone and trail pheromone of the sand termite Psammotermes hybostoma.

Within the complex network of chemical signals used by termites, trail pheromones and sex pheromones are among the best known. Numerous recent papers map the chemical identity and glandular origin of these pheromones in nearly all major isopteran taxa. In this study, we aimed to describe the sex pheromone and the trail pheromone of a poorly known sand termite, Psammotermes hybostoma.

Comparison of age-dependent quantitative changes in the male labial gland secretion of Bombus terrestris and Bombus lucorum.

Age-related changes of antennal-active components of male labial gland extracts were studied in two closely related bumblebee species, Bombus terrestris and B. lucorum. In B.