An Attraction Pheromone from Heads of Worker Vespula germanica Wasps

Vespula germanica is a social wasp that efficiently exploits food resources. Odor cues, derived from substances located in wasp heads, have been proved to be central in conspecific attraction in this species. However, it remains unknown whether this attraction is related to foraging or defense responses. In this study we analyze conspecific attraction under two different contexts: at the nest entrance (defense) and under foraging conditions. We also test wasp response with two dosages of head extract and crosschecked the attractiveness of extracts obtained from different populations. We found no evidence of alarm response to head extracts either at the nest entrance or under foraging conditions. Moreover, no differences in attractiveness were found to both doses tested. Head extracts attract similarly in the same or a different population suggesting that conspecific attraction is not restricted to colony nestmates.     

The Role of Olfactory Cues in Short-Range Mate Finding by the Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)

We investigated the relative importance of olfaction versus vision in the mate-finding behavior of Agrilus planipennis. When coupled in male–female, male–male and female–female pairs, attempts to mate occurred only in the male–female pairs, suggesting that beetles can identify the opposite sex before attempting to mate. In a set of sensory deprivation experiments with male–female pairs, we evaluated whether males could find females when deprived of their sense of olfaction, vision or both. Males whose antennae were blocked with model paint took significantly longer to find females and spent less time in copula compared to untreated males. Males whose eyes were similarly blocked did not differ in their mate finding capacity compared to untreated males. In a third experiment that compared both olfaction and vision, olfactorily impaired beetles never mated whereas the mate finding potential of visually impaired beetles did not differ from that of untreated beetles. Our results indicate that males can identify females before coming into physical contact with them, and that at short range (≤5 cm), volatile cues detected by olfaction are involved in mate finding by A. planipennis.     

Differential expression of SNMP-1 and SNMP-2 proteins in pheromone-sensitive hairs of moths

In moths the detection of female-released sex pheromones involves hairlike structures on the male antenna. These long sensilla trichodea usually contain 2-3 chemosensory neurons accompanied by several supporting cells. Previous studies have shown that the pheromone-specific neurons are characterized by a "sensory neuron membrane protein" (SNMP) which is homologous to the CD36 family and localized in the dendrite membrane. By employing the SNMP-2 sequence from Manduca sexta we have isolated cDNAs that encode SNMP-2 proteins from Heliothis virescens (HvirSNMP-2) and Antheraea polyphemus (ApolSNMP-2). To elucidate the topographic and cell type-specific expression of these SNMP subtypes, 2-color in situ hybridization experiments were performed with tissue sections through the male antennae. For H. virescens, a specific probe for the pheromone receptor HR13 was used to identify pheromone-responsive neurons. It was found that HvirSNMP-1 and HR13 were coexpressed in the same cells; in contrast, HvirSNMP-2 was not expressed in HR13 cells but rather in cells that surrounded the HR13 neurons, apparently the supporting cells. A corresponding expression pattern was also found for ApolSNMP-1 and ApolSNMP-2 on the antenna of male A. polyphemus. Our results indicate that SNMP-1s and SNMP-2s are differentially expressed in cells of pheromone-sensitive sensilla and suggest distinct functions for the 2 SNMP subtypes in the olfactory system.     

昆虫聚集信息素

昆虫聚集信息素是昆虫重要的信息化学物质之一,对昆虫的聚集行为有重要意义。近三十年来,国外鉴定了多种昆虫聚集信息素,主要成分为一些烃、醇、醛、酮、酯、酸、酸酐、胺以及腈类化合物,但其在有害生物可持续治理中的应用潜能尚未充分利用;昆虫聚集信息素的来源多样,除蛹外,多个虫态均有聚集信息素释放,有些学者甚至把一些寄主释放的挥发物作为聚集信息素的组分;同种昆虫,不同生理状态,其聚集信息素可以完全不同或同一信息化学物质的功能不同;但是,并非所有昆虫的聚集行为均为聚集信息素调节,利他素、性信息素以及报警信息素等其它信息化学物质均能导致一些昆虫的聚集。本文综述了5目17科55种昆虫的聚集信息素。     

Neural mechanisms of alarm pheromone signaling

Alarm pheromones are important semiochemicals used by many animal species to alert conspecifics or other related species of impending danger. In this review, we describe recent developments in our understanding of the neural mechanisms underlying the ability of fruit flies, zebrafish and mice to mediate the detection of alarm pheromones. Specifically, alarm pheromones are detected in these species through specialized olfactory subsystems that are unique to the chemosensitive receptors, second messenger-signaling and physiology. Thus, the alarm pheromones appears to be detected by signaling mechanisms that are distinct from those seen in the canonical olfactory system.     

A receptor and binding protein interplay in the detection of a distinct pheromone component in the silkmoth Antheraea polyphemus

Male moths respond to conspecific female-released pheromones with remarkable sensitivity and specificity, due to highly specialized chemosensory neurons in their antennae. In Antheraea silkmoths, three types of sensory neurons have been described, each responsive to one of three pheromone components. Since also three different pheromone binding proteins (PBPs) have been identified, the antenna of Antheraea seems to provide a unique model system for detailed analyzes of the interplay between the various elements underlying pheromone reception. Efforts to identify pheromone receptors of Antheraea polyphemus have led to the identification of a candidate pheromone receptor (ApolOR1). This receptor was found predominantly expressed in male antennae, specifically in neurons located beneath pheromone-sensitive sensilla trichodea. The ApolOR1-expressing cells were found to be surrounded by supporting cells co-expressing all three ApolPBPs. The response spectrum of ApolOR1 was assessed by means of calcium imaging using HEK293-cells stably expressing the receptor. It was found that at nanomolar concentrations ApolOR1-cells responded to all three pheromones when the compounds were solubilized by DMSO and also when DMSO was substituted by one of the three PBPs. However, at picomolar concentrations, cells responded only in the presence of the subtype ApolPBP2 and the pheromone (E,Z)-6,11-hexadecadienal. These results are indicative of a specific interplay of a distinct pheromone component with an appropriate binding protein and its related receptor subtype, which may be considered as basis for the remarkable sensitivity and specificity of the pheromone detection system.     

Functional organization of the macroglomerular complex related to behaviourally expressed olfactory redundancy in male cabbage looper moths

Abstract. The neurophysiological bases for behaviourally expressed olfactory redundancy in the sex pheromone communication system of the cabbage looper moth, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae), were examined by coupling the cut-sensillum extracellular recording technique with a highly specific neuronal marking method for moth peripheral receptors. In seventy-two antennal sensilla, axonal pathways of cobalt-stained neurones could be traced into the male-specific macroglomerular complex in the antennal lobe. In T. ni males this comprises five glomeruli, two of which are subdivided into morphologically, and in some instances functionally identifiable, regions. Axonal arborizations of forty-eight neurones (single stainings) showed high fidelity (98%) for containment within a specific glomerulus or glomerular subdivision, and the neuropil targeted seemed to be related to the specificity of a neurone to a particular female-emitted sex pheromone component (27-12:Ac, Z7-14:Ac, Z9-14:Ac, 12:Ac, 11–12:Ac, Z5-12:Ac), or to a behavioural antagonist (Z7-12:OH). Double (twenty-one) and multiple stainings (three) showed axons projecting into two or more glomeruli, respectively, with 100% fidelity for the component-specific glomerulus or glomerular subdivision to be targeted. We suggest that the potential for a single minor component to cross-stimulate two or more neurones within a sensillum may enable partial blends to continue to provide sensory input into all of the pheromone-processing glomeruli of the complex. Our interpretation is that redundancy occurs at the receptor level on neighbouring dendrites, and thus allows various four-component partial blends to evoke full pheromone-mediated behaviour.     

Pheromone receptor cells in the male moth Manduca sexta

Three types of pheromone receptor cells have been identified by electrophysiological recording from single antennal sensilla trichodea of the male sphinx moth Manduca sexta. These cells responded best to the pheromone components (E,Z)-10,12-hexadecadienal (type A receptor cell), (E,E,Z)-10,12,14-hexadecatrienal (type B), and (E,E,E)-10,12,14-hexadecatrienal (type C). Cell type B also responded to (E,Z)-11,13-pentadecadienal, which has been used experimentally as a pheromone substitute. In recordings from 20 trichoid hairs, 17 were found to be innervated by one cell of type A and one of type B; 3 trichoid hairs had cell types A and C.     

Interneurons sensitive to female pheromone in the deutocerebrum of the male silkworm moth, Bombyx mori

ABSTRACT. In response to minute quantities of female sex pheromone, the male silkworm moth, Bombyx mori L., walks upwind to locate the odour source. The axons of antennal receptors specific for the two known components of the pheromone terminate in the deutocerebrum. In this study, single interneurons were recorded extracellularly in the deutocerebrum of the male silkworm moth. Responses were characterized as the antennae were presented with puffs of clean air, or air containing either or both components of the female pheromone, bombykol and bombykal. An apparatus is described which added bombykol or bombykal to a constant air stream flowing over the antenna. Most units (87%) showed qualitatively different responses to bombykol and bombykal. A majority of the pheromone-sensitive units (65%) also showed mechanosensory responses to air puffs. Two units were recorded which were slightly inhibited by either bombykol or bombykal alone, but were excited by a mixture of the two.     

雄性白杨透翅蛾单个嗅觉感受细胞对性信息素的反应(英文)

电生理学记录表明,雄性白杨透翅蛾触角的一个毛形感器中,存在两类性信息素感受细胞。A型感受细胞对性信息素的主要组分E_3,Z_(13)-18:OH发放大振幅的神经脉冲;B型感受细胞对次要组分的侯选化合物Z_3,Z_(13)-18:Ac发放小振幅的神经脉冲,尚需作野外试验和行为反应试验证明其为性信息素的次要组分;选择性适应试验证明A型和B型感受细胞互不适应:Z_3,Z_(13)-18:Ac和E_3,E_(13)-18:Ac是兴奋同种类型的感受细胞,E_3,Z_(13)-18:Ac是一种性信息素组分类似物。     

Specificity of odorant-evoked inhibition in lobster olfactory receptor neurons

Lobster olfactory receptor neurons, like those of many animals, use two modes of olfactory signaling, excitation and inhibition to code olfactory information. Inhibition appears to act through two distinct ionic mechanisms. Here we show that neither ionic mechanism is odor-specific, providing further support for the emerging understanding that there are no inhibitory odorants per se, but rather that the action of a particular odorant is inherent in the olfactory receptor cell on which an odorant acts.     

RESPONSES OF SINGLE OLFACTORY RECEPTOR CELL TO SEX PHEROMONES IN MALE MOTH PARANTHRENE TABANZFORMIS

Abstract Electrophysiological recording showed two types of pheromone receptor cell in one sensillum trichodeum of the male Paranthrene tabani formis . Type A receptor cell fired larger nerve impulse to the major pheromone component E₃, Z₁₃,-18:OH; type B receptor cell fired smaller nerve impulse to the candidate compound of minor pheromone component Z₃, Z₁₃-18:Ac. Pheromonal effect should be tested still in field and behavior response. The selective adaptation demonstrated that Z₃, Z₁₃,-18:Ac and E₃, Z₁₃-18: Ac excited the same receptor cell. E₃, Z₁₃-18:Ac was an analog of pheromone.     

Pheromonal dominance and the selection of a socially parasitic honeybee worker lineage (Apis mellifera capensis Esch.)

The recent invasion by self-replicating socially parasitic Cape honeybee workers, Apis mellifera capensis, of colonies of the neighbouring African subspecies Apis mellifera scutellata represents an opportunity to study evolution of intraspecific parasitism in real time. As honeybee workers compete pheromonally for reproductive dominance, and as A. m. capensis workers readily produce queen-like pheromones, we hypothesized that these semiochemicals promoted the evolution of intraspecific social parasitism. Remarkably, the offspring of a single worker became established as a parasite in A. m. scutellata's range. This could have resulted from extreme selection among different clonal parasitic worker lineages. Using pheromonal contest experiments, we show that the selected parasitic lineage dominates in the production of mandibular gland pheromones over all other competitors to which it is exposed. Our results suggest that mandibular gland pheromones played a key role in the evolution of intraspecific social parasitism in the honeybee and in the selection of a single genotype of parasitic workers.