1463-6395 10.1111/j.1463-6395.2008.00341.xWillemart, R. H., Farine, J.-P. and Gnaspini, P. 2008. Sensory biology of Phalangida harvestmen (Arachnida, Opiliones): a review, with new morphological data on 18 species. 2014Acta Zoologica (Stockholm) 90: 2092013227 Phalangida includes three of the four suborders of Opiliones (Arachnida): Eupnoi, Dyspnoi and Laniatores. We review the literature on the sensory structures and capabilities of Phalangida, provide new morphological data for 18 species and discuss the 11 sensory structures that have been described in the group. Based on the published data encompassing both behaviour and morphology, three conclusions are apparent: (1) species of Phalangida appear to have limited abilities to detect stimuli at a distance; (2) close range olfaction probably helps to find foods with strong odours, but (3) they appear to be highly dependent on contact chemoreception to detect live prey, predators and mates. We also highlight the fact that legs I in the three suborders and pedipalps in Dyspnoi and Eupnoi are very important sensory appendages, thus legs II should not be called the 'sensory appendages' of harvestmen. In conclusion, we highlight the fact that the sensory capabilities, diet, prey capturing and handling ability, and foraging behaviour of species of Phalangida seem to be different from those of most other arachnids. Finally, we suggest future directions for studies in the field of the sensory system of the group

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In various animal species, male sexual dimorphic characters may be used during intrasexual contests as ornaments to attract females, or to hold them before, during, or after copulation. In the well-known harvestman, Phalangium opilio L., 1758, the behavioral functions of these male sexually dimorphic structures have never been studied in detail. Therefore, in addition to a morphometric study, 21 male contests and 43 sexual interactions were analyzed. Our observations revealed that during contests, the male cheliceral horns form a surface by which the contestants use to push each other face-to-face while rapidly tapping their long pedipalps against the pedipalps of the opponent, occasionally twisting the opponent's pedipalp. Scanning electron micrographs revealed contact mechanoreceptors on the pedipalp that would detect the intensity–frequency of contact with the contender's pedipalp. Larger males won almost all contests, whereas the loser rapidly fled. During sexual interactions, the longer pedipalps of the male held legs IV of the female, whereas males with shorter pedipalps held the female by legs III. No contact with the male pedipalps and chelicerae by the females was visible before, during, or after copulation. Soon after copulating, males typically bent over the female, positioning their cheliceral horns against the females's dorsum. Consequently, our data show that the cheliceral horns and the longer pedipalps of the male seem to play an important role, during both intersexual and intrasexual encountering. Résumé : Chez de nombreuses espèces animales, les ornementations sexuellement dimorphiques des mâles peuvent être utilisées lors des combats rituels entre mâles ou comme signal afin d'attirer les femelles ou les retenir avant, pendant et après l'accouplement. Chez l'opilion Phalangium opilio L., 1758, le rôle précis joué par ces structures n'a jamais été mis en évidence. Au cours de ce travail, outre une étude morphométrique, nous avons analysé, grâce à des enregistrements vidéo, 21 combats entre mâles et 43 accouplements. Nous avons pu montrer que, lors des combats, les mâles utilisent les cornes portées par les chélicères pour se repousser lorsqu'ils sont face-à-face, tout en se tapant mutuellement à l'aide de leurs longs pédipalpes, voire en les enroulant avec ceux de l'adversaire. Des micrographies réalisées au microscope électronique à balayage révèlent l'existence de mécanorécepteurs sur les pédipalpes qui pourraient permettre au mâle de détecter la fréquence et l'intensité des contacts des pédipalpes de son adversaire. Les mâles les plus grands gagnent presque tous les combats, le perdant fuyant rapidement. Au cours du comportement sexuel, les mâles à grands pédipalpes les utilisent pour agripper les pattes IV de la femelle, alors que les mâles à pédipalpes plus courts les retiennent par les pattes III. Il n'y a aucun contact tactile de la part des femelles avec les pédipalpes et les chélicères des mâles avant, pendant et après l'accouplement. Juste après l'accouplement, le mâle s'appui...

Sexually dimorphic glands often release sexual pheromones both in vertebrates and invertebrates. Species of Laniatores (Arachnida, Opiliones) seem to depend on chemical communication but few studies have addressed this topic. In this study, we review the literature for the Phalangida and present new data for 23 species of Laniatores. In 16 taxa, we found previously undescribed sexually dimorphic glandular openings on the femur, patella, metatarsus, and tarsus of legs I and metatarsus of legs III and IV. For the other species, we provide scanning electron micrographs of previously undescribed sexually dimorphic setae and pegs located on swollen regions of the legs. We also list additional species in which males have swollen regions on the legs, including the tibia, metatarsus, and tarsus of legs I, trochanter and tibia of legs II, femur, metatarsus, and tarsus of legs III, and metatarsus and tarsus of legs IV. The function and biological role of the secretions released by these glands are discussed.

The exocrine glandular system of the nymphs and the adults of Dysdercus cingulatus were studied. The D. cingulatus nymphs present 3 dorso-abdominal glands (lying under the 3rd, 4th, and 5th abdominal terga) and a pair of dorso-lateral pygidial glands on the pygidium (tergum 8). Histological and ultrastructural studies show that the upper and lower walls of the dorso-abdominal glands differ in structure; 3 types of cells were described: epidermal cells, unicellular secretory cells, and multicellular secretory units. Each of these exocrine glands plays an important part in the behavior of the nymphs (gregariousness, alarm, defense). The morphology of the various glands is discussed, and the chemistry of their secretions and their biological functions are considered.

The scent apparatus of male Eldana saccharina is a glandular complex on the costal area of the forewing. It consists of two parts; glandular complex 1 is composed of five kinds of cells (epidermal cells, scale cells, glandular cells, supporting cells, duct cells); glandular complex 2 also shows five types of cells (epidermal cells, scale cells, glandular cells, duct cells, trichogen cells). The secretory products of the two parts are discharged into separate ducts which converge before opening onto the lower side of the wing. The male also has two prominent hair-pencils borne on the coremata and large secretory trichogen cells on the genital valves. Each of these exocrine gland components plays an important part in formation of the chemically complex pheromones utilized in the precopulatory behavior of the male.The sugar-cane borer is one of the principal ravagers of sugar cane in Africa. Zagatti ('81a) demonstrated the complexity of sexual behavior in this species. This paper is intended to complement his experiments by a morphological study of the male exocrine glandular system (Diagram 1A) which plays a decisive role in precopulatory behavior. Whereas numerous monographs are devoted to the transmitter substances functioning in the sexual attraction of lepidoptera (Dahm et al., '71; Finn and Payne, '77; Zagatti, '81a,b), few detailed morphological studies of the exocrine glands excreting these substances exist.Among sugar-cane borers, it is the male which gives off the aphrodisiaclike pheromone. After coming to a standstill on the tip of a stem, the male raises its abdominal end and begins to vibrate its wings while progressively extruding the two hair-pencil tufts carried by the coremata (eversible tubular invaginations of the intersegmental membrane arising between abdominal segment 8 and 9). Zagatti ('81b) showed that the females are attracted at a distance by the secretion of the alar glands and that the kinds of aphrodisiac pheromones produced at the level of the coremata lead to the mating position.This study is an examination of the morphology of the alar glandular system which secretes the male pheromone and of the hairpencils (or androconial) system borne on the coremata. MATERIALS AND METHODS MaterialsThe insects, furnished by the Laboratoire des mediateurs chimiques de Brouessy (INRA), were raised in an artificial environment '77). Photoperiod was of the extended-day character (18 hours of daylight, 6 hours of darkness). The temperature was 25°C with approximately 75% relative humidity. HistologyThe insects were fixed upon emergence using alcoholic Bouin's. Stains used were Masson's trichrome, a variant of Goldner, or Heidenhain's azan (Martoja and MartojaPierson, '67). UltrastructureAfter dissection, the glands were fixed overnight in a solution of 5% glutaraldehyde in 0.05 M cacodylate buffer (pH 7.2-7.3) with 2% sucrose and 0.01 M calcium chloride. Rinsing was carried out in the same buffer and followed by postfixation for 1 hour at 4°C using 2% osmium tetroxide in the cacodylate buffer....

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The most studied pheromone in Drosophila melanogaster, cis-Vaccenyl Acetate (cVA), is synthesized in the male ejaculatory bulb and transferred to the female during copulation. Combined with other chemicals cVA can modulate fly aggregation, courtship, mating and fighting. We explored the mechanisms underlying both cVA biosynthesis and emission in males of two wild types and a pheromonal mutant line. The effects of ageing, adult social interaction, and maternally-transmitted cVA and microbes — both associated with the egg chorion — on cVA biosynthesis and emission were measured. While ageing and genotype changed both biosynthesis and emission in similar ways, early developmental exposure to maternally-transmitted cVA and microbes strongly decreased cVA emission but not the biosynthesis of this molecule. This indicates that the release — but not the biosynthesis — of this sex pheromone strongly depends on early developmental context. The mechanism by which the preimaginal effects occur is unknown but reinforces the significance of development in determining adult physiology and behaviour.