Sensilla on the mouthparts and antennae of the elephant louse,Haematomyzus elephantis piaget (Phthiraptera: Haematomyzidae)

The labial palpus of the elephant louse Haematomyzus elephantis has six sensilla that represent three different types: trichoid, basiconic, and styloconic. Two rows of basiconic sensilla are situated on the dorsal and ventral surfaces of the rostrum, and each row consists of three sensilla. Male and female antennae have 15–17 trichoid sensilla situated on the scape, pedicel, and three antennal annuli. Both sexes have two sensilla basiconica on the dorsal surface of the pedicel near the junction of the scape and pedicel. Two coeloconic (tuft) sensilla are situated on the antennae of both sexes, one sensillum on each of the last two annuli. There are three plate organs, two on the last annulus and one on the penultimate annulus of the male and female antennae. Sexual dimorphism is exhibited in the male and female antennae, in that the male has about twice as many sensilla basiconica on the apex of the last annulus as does the female. The total number of sensilla basiconica on the apex of the male antennae is at least two times the number that is known to be present in any other species of lice. © 1992 Wiley-Liss, Inc.     

Scanning Electron Microscopy Studies of the Antennal Sensilla of Metaphycus parasaissetiae Zhang & Huang (Hymenoptera: Encyrtidae)

Metaphycus parasaissetiae Zhang & Huang (Hymenoptera: Encyrtidae) is an important adult parasitoid of Parasaissetia nigra Nietner (Hemiptera: Coccoidea). The external morphology of the antennal sensilla of male and female M. parasaissetiae was examined using scanning electron microscopy. The geniculate antennae of male and female M. parasaissetiae were composed of a scape with a basal radicula, a barrel-shaped pedicel, and a long flagellum. Twelve morphologically distinct types of sensilla were identified, including multiporous placoid sensilla, campaniform sensilla, finger-like sensilla, multiporous basiconic sensilla (BS-1), three aporous types of basiconic sensilla (BS-2, BS-3, and BS-4), two types of aporous trichoid sensilla (TS-1 and TS-3), a type of multiporous trichoid sensilla (TS-2), and two types of sensilla chaetica (CH-1 and CH-2). Sex dimorphism in the sensilla composition of M. parasaissetiae is also observed. Major differences between the sexes were found in the number, distribution, shape, structure, and size of the identified sensilla. We also discuss on the functional aspects of these sensilla to elucidate the mechanisms involved in host searching and courtship behavior of M. parasaissetiae.     

External morphology of antennal sensilla of trichogramma australicum girault (Hymenoptera : Trichogrammatidae)

External morphology of antennal sensilla on female and male Trichogramma australicum (Hymenoptera : Trichogrammatidae) was examined using scanning electron microscopy. Antennae show strong sexual dimorphism in structure and types of sensilla. The female antenna displays 14 types of sensilla: basiconic capitate peg sensilla (types 1 and 2), campaniform sensilla, chaetica sensilla (types 1–3), coeloconic sensilla, falcate sensilla, placoid sensilla (types 1 and 2), styloconic sensilla and trichoid sensilla (types 1–3). The male antenna displays 12 types of sensilla: basiconic capitate peg sensilla (type 2), campaniform sensilla, chaetica sensilla (types 1–5), coeloconic sensilla, placoid sensilla (type 1), and trichoid sensilla (types 3–5). Falcate and styloconic sensilla occur only on the female antenna. Both sensilla probably are associated with host examination, host discrimination and oviposition behaviour. Male antennal trichoid sensilla types 4 and 5 are probably associated with courtship behaviour, because these types occur only on the male. We propose the term “falcate sensilla” for a unique female antennal sensilla; the number of falcate sensilla may be used for identification of Trichogramma spp. In addition, we report the presence of placoid sensilla type 2 and difference in structure of coeloconic sensilla in T. australicum. Variation in structure and position of antennal sensilla are discussed.     

Antennal sensilla of the click beetle,Melanotus villosus (Geoffroy) (Coleoptera: Elateridae)

The typology, number and placement of antennal sensilla of the click beetle Melanotus villosus (Geoffroy) (Coleoptera: Elateridae) were studied using scanning electron microscopy. On both the males and females the antennae are made up of the scape, pedicel and nine flagellomeres. Two types of basiconic sensilla, three types of trichoid sensilla, one type of styloconic sensilla, one type of chetoid sensilla, dome-shaped sensilla, grooved pegs, and Böhm sensilla all appear on the antennae of the beetles of both sexes, with the exception of trichoid sensilla type II, whose large number (average of 1635 hairs per antenna) was found only in male beetles. Sensilla trichodea type II evidently respond to the sex pheromone produced by the female beetle. Unlike the other two click beetles, studied up till now, Agriotes obscurus and Limonius aeruginosus, the trichoid and basiconic sensilla of M. villosus, whose proven or assumed function is olfactory, are located predominantly on the flagellomeres ventral extensions. It is assumed that the placement of the olfactory sensilla, mainly on the ventral side of M. villosuss antennae, and their more or less even distribution on the flagellomeres, can be seen as morphological adaptation of this species of insect, whose specific behavioural reaction of olfactory searching is flying, both before and after contact with an odour plume.     

Analysis of immunocytochemical staining patterns in the antennal system of Drosophila melanogaster

By immunizing mice with homogenized brains, heads, or a mixture of heads and antennae of D. melanogaster, we obtained six monoclonal antibodies (mabs) that bind to the olfactory system of Drosophila with various degrees of specificity. They can be divided into three groups with respect to their staining pattern: (1) The antibodies ca51/2, na21/2, and nb230 label both in the third (olfactory) antennal segment and in the visual ganglia. All of them bind to antennal structures that can be correlated with basiconic sensilla. The antibody ca51/2 labels sensory neurons of these sensilla. In the antenna of the lozenge ³ mutant, which lacks basiconic sensilla, no labeling is present. In Western blots ca51/2 recognizes in the antenna an antigen of 43.5 kDa, which is expressed in the antenna only in the presence of basiconic sensilla. The antibody na21/2 binds to basiconic and coeloconic sensilla, most likely to the apical part of sheath cells. In immunoblots it recognizes in the antenna two antigens of 42.2 kDa and 46.7 kDa. The latter appears to be correlated in the antenna with the presence of basiconic sensilla. (2) The staining pattern of antibody nc10 is associated with the sheath cells of basiconic and coeloconic sensilla. Moreover, nc10 binds to a subset of glomeruli in the antennal lobe. (3) The staining pattern of the antibodies VG2 and I24B5 is restricted to the antenna. I24B5 recognizes coeloconic sensilla and VG2 recognizes both coeloconic and basiconic sensilla. Staining patterns in both cases include sheath cells.     

Description of the antennal sensilla of <Emphasis Type="Italic">Habrobracon Hebetor</Emphasis>

The morphology of the antennal sensilla of both male and female Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is described using Scanning Electron Microscopy complemented with Transmission Electron Microscopy. Five types of innervated sensilla as well as uninnervated microtrichia were found. These types are: sensilla trichodea; s. chaetica; s. basiconica; s. coeloconica; and s. placodea. No differences in shape, basic structure, and types of antennal sensilla were found between males and females. The types of sensilla of both sexes of H. hebetor were compared with what has been described in other parasitic Hymenoptera, and their putative functions are discussed with reference to their morphology, distribution and ultrastructure.     

Variation in antennal sensory system in different phenotypes of large fruit-tree tortrix Archips podana scop. (Lepidoptera: Tortricidae)

Quantitative composition of antennal sensilla was studied in different phenotypes of large fruit-tree tortrix imago. Changes in the number of sensilla were observed in individuals reared on lilac: male phenotypes AB and B differed by the number of chaetoid, coeloconic, auriculate, and basiconic sensilla; female offspring of males with AB and B phenotypes differed by the number of short trichoid sensilla and auriculate sensilla of the first type. The relationship between male phenotype and the number of sensilla as well as the impact of parental male genotype on the variation in antennal sensory system in female offspring are discussed.     

Antennal sensilla and sexual dimorphism of the adult ladybird beetle Semiadalia undecimnotata Schn. (Coleoptera: Coccinellidae)

The antennal receptors of the adult male and female ladybird beetle, Semiadalia undecimnotata (Coleoptera: Coccinellidae), were examined by scanning and transmission electron microscopy. Twelve types of receptors were characterized and grouped into 5 morphological classes: Böhm, trichoid, coeloconic, basiconic, and chetiform sensilla. Sensory function was determined on the basis of sensillar ultrastructure and electrophysiological response. Olfactory sensilla are confined in both sexes to the 2 terminal antennal segments. In contrast, gustatory and mechanosensitive organs are present along the entire length of the antennae. Sexual dimorphism of antennal receptors is limited to the latter 2 functional classes. The principal characteristics of this dimorphism are the following: a) males possess 540 sensilla (all types), while females possess only 500; b) males exhibit 2 types of taste receptors not present in females; c) females exhibit one type of mechanoreceptor absent in males; d) the 3 sex-specific types of sensilla, which occupy the same position in males and females, are confined to the inner side of the antennae. The possible role of male-specific sensilla in intersexual communication is discussed.     

Sexual dimorphism in neuronal projections from the antennae of silk moths (Bombyx mori,Antheraea polyphemus) and the gypsy moth (Lymantria dispar)

Summary The antennal lobe of both sexes of the silk moth Bombyx mori contains 55–60 ventrally located antennal glomeruli; in addition, that of the male contains a dorsal macroglomerular complex (MGC). A group of identifiable glomeruli consisting of two lateral large glomeruli (LLG) and four medial small glomeruli (MSG) is present in both sexes, but the LLG are greatly enlarged in the female. A MGC is also present in the male gypsy moth Lymantria dispar and male giant silk moth Antheraea polyphemus. The MGC in all of these species is organized into 3–4 distinct levels of glomeruli. Antennal sensory fibers were stained by cobalt backfills in B. mori, A. polyphemus, and L. dispar. Most fibers stained from cut long hairs (sensilla trichodea) projected to MGC in males and LLG in both sexes of B. mori. The distribution of fibers in the MGC of B. mori was topographically biased in that a majority of fibers from anterior branches projected medially in MGC while most fibers from posterior branches projected laterally or anteriorly. Terminal arborizations of single fibers were each restricted to a single glomerular level of the MGC. Fibers projecting to the posterior antennal center were frequently stained in cut-hair and control preparations, apparently by uptake of cobalt through intact sensilla on flagellar branches.     

管氏肿腿蜂触角感器的扫描电镜观察

扫描电镜观察表明 ,管氏肿腿蜂SclerodermaguaniXiaoetWu触角上存在 1 3种感器 ,其中毛形感器Ⅰ型、Ⅱ型、刺形感器、锥形感器、鳞形感器、栓锥形感器、钟形感器和坛形感器雌雄均有 ,仅数量和分布存在差异 ;板形感器、柱形感器Ⅰ型、Ⅱ型、长锥形感器和耳形感器只在雌蜂触角上存在。感器的种类、数量和分布在性别间的差异 ,为研究该蜂寻找生境和寄生行为提供了形态学依据。     

Morphological and functional heterogeneity in olfactory perception between antennae and maxillary palps in the pumpkin fruit fly,Bactrocera depressa

The morphology and ultrastructure of the olfactory sensilla on the antennae and maxillary palps were investigated through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and their responses to five volatile compounds were measured using electroantenogram (EAG) and electropalpogram (EPG) techniques in the pumpkin fruit fly, Bactrocera depressa (Shiraki; Diptera: Tephritidae). Male and female B. depressa displayed distinct morphological types of olfactory sensilla in the antennae and maxillary palps, with predominant populations of trichoid, basiconic, and coeloconic sensilla. Basiconic sensilla, the most abundant type of olfactory sensilla in the antennae, could be further classified into two different types. In contrast, the maxillary palps exhibited predominant populations of a single type of curved basiconic sensilla. High‐resolution SEM observation revealed the presence of multiple nanoscale wall‐pores on the cuticular surface of trichoid and basiconic sensilla, indicating that their primary function is olfactory. In contrast, coeloconic sensilla displayed several longitudinal grooves around the sensillum peg. The TEM observation of individual antennal olfactory sensilla indicates that the basiconic sensilla are thin‐walled, while the trichoid sensilla are thick‐walled. The profile of EAG responses of male B. depressa was different from their EPG response profile, indicating that the olfactory function of maxillary palps is different from that of antennae in this species. The structural and functional variation in the olfactory sensilla between antennae and maxillary palps suggests that each plays an independent role in the perception of olfactory signals in B. depressa.     

Analysis of immunocytochemical staining patterns in the antennal system of Drosophila melanogaster

By immunizing mice with homogenized brains, heads, or a mixture of heads and antennae of D. melanogaster, we obtained six monoclonal antibodies (mabs) that bind to the olfactory system of Drosophila with various degrees of specificity. They can be divided into three groups with respect to their staining pattern: (1) The antibodies ca51/2, na21/2, and nb230 label both in the third (olfactory) antennal segment and in the visual ganglia. All of them bind to antennal structures that can be correlated with basiconic sensilla. The antibody ca51/2 labels sensory neurons of these sensilla. In the antenna of the lozenge ³ mutant, which lacks basiconic sensilla, no labeling is present. In Western blots ca51/2 recognizes in the antenna an antigen of 43.5 kDa, which is expressed in the antenna only in the presence of basiconic sensilla. The antibody na21/2 binds to basiconic and coeloconic sensilla, most likely to the apical part of sheath cells. In immunoblots it recognizes in the antenna two antigens of 42.2 kDa and 46.7 kDa. The latter appears to be correlated in the antenna with the presence of basiconic sensilla. (2) The staining pattern of antibody nc10 is associated with the sheath cells of basiconic and coeloconic sensilla. Moreover, nc10 binds to a subset of glomeruli in the antennal lobe. (3) The staining pattern of the antibodies VG2 and I24B5 is restricted to the antenna. I24B5 recognizes coeloconic sensilla and VG2 recognizes both coeloconic and basiconic sensilla. Staining patterns in both cases include sheath cells.     

Sexual dimorphism of antennal and ovipositor sensilla of Tetrastichus sp. (Hymenoptera: Eulophidae)

Tetrastichus sp. (Hymenoptera: Eulophidae) is a primary parasitoid of the Metisa plana (Lepidoptera: Psychidae), an oil palm bagworm. The sensilla on the surface of the antenna and ovipositor of Tetrastichus sp. were examined using a scanning electron microscope. The antennae of both male and female Tetrastichus sp. are geniculate in shape and hinged at the scape-pedicel joint. The female antenna is about 200 µm longer than the male antenna. However, the male antenna has an additional flagellomere compared to the female antenna. In total, eight different types of antennal sensilla were observed on the antenna of Tetrastichus sp.: trichoid sensilla type 1, 2, 3, 4, placoid sensilla type 1 and 2, basiconic sensilla, and campaniform sensilla. The antenna of the female Tetrastichus sp. lacks placoid sensilla type 2 and campaniform sensilla. The distribution and abundance of the antennal sensilla were compared between the male and female Tetrastichus sp. and discussed. On the ovipositor stylet of Tetrastichus sp., coeloconic sensilla, styloconic sensilla and campaniform sensilla were observed. Trichoid sensilla were observed at the medial part of the distal extremity of the ovipositor.     

Morphology of the antennal sensilla of the cabbage root fly,Delia radicum L. (Diptera : Anthomyiidae)

The antennal sensilla of Delia radicum L. (Diptera : Anthomyiidae) were studied by scanning electron microscopy. On the scape and pedicel, grooved socketed bristles and setiferous plaques were found. There are 4 types of surface sensilla on the funicle: trichoid, basiconic, clavate, and grooved. Their numbers and distribution are described. There are 3–4 single-chambered pits on the dorsal surface of the funicle of both sexes and these contain basiconic sensilla. On the ventral surface, there is one multi-chambered pit, which contains 5 types of sensilla: grooved s., smooth-walled conical s., smooth-walled tapered s., striated s. and a novel type, flattened sensilla. These results are compared with previously published studies on several other fly species.     

Morphological and ultrastructural characterization of olfactory sensilla in Drosophila suzukii: Scanning and transmission electron microscopy

Drosophila suzukii is a serious horticultural and quarantine pest, damaging various berry crops. Although the active use of olfactory communication in D. suzukii is well-known, their olfactory sensory system has not been comprehensively reported. Therefore, the present study was carried out to understand the morphology, distribution and ultrastructure of olfactory sensilla present in the antennae and maxillary palps of D. suzukii, through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The olfactory sensilla on the antennae of D. suzukii in both sexes could be classified into three major morphological types, basiconic, trichoid and coeloconic sensilla, according to their shapes. The antennal basiconic sensilla were further divided into three subtypes and the antennal trichoid sensilla into two subtypes, respectively, according to the size of individual sensillum. In contrast to the antennal olfactory sensilla showing diverse morphology, basiconic sensilla was the only type of olfactory sensilla in the maxillary palps of D. suzukii. The basiconic sensilla in the maxillary palps could be further classified into three subtypes, based on their size. Our SEM and TEM observations indicated that multiple nanoscale pores are present on the surface of all types of olfactory sensilla in the antennae and maxillary palps, except coeloconic sensilla. The difference in the morphological types and the distribution of olfactory sensilla suggests that their olfactory functions are different between antennae and maxillary palps in D. suzukii. The results of this study provide useful information for further studies to determine the function of olfactory sensilla in D. suzukii and to understand their chemical communication system.     

Behavioral and electroantennogram analysis of olfactory stimulation inlozenge: ADrosophila mutant lacking antennal basiconic sensilla (Diptera: Drosophilidae)

Two alleles of the mutant lozengeof Drosophila melanogaster, lzand lz³,lack basiconic sensilla on the antennal funiculus. To elucidate the role of these sensilla for the perception of food odors, we studied the locomotor behavior and the electroantennogram (EAG) activity of lozenge flies in response to olfactory stimuli. The significance of basiconic sensilla on the maxillary palps was assessed by testing the locomotion of flies surgically deprived of their palps. The behavioral data suggest that antennal and maxillary basiconic sensilla may be important receptors for short chain alcohols and organic acids but less crucial receptors for acetates, aldehydes, and ketones. In agreement with this interpretation, EAG responses to alcohols (but not to esters) were found to be markedly lower in lozengethan in the wild type.     

稻虱红螯蜂触角感受器的扫描电镜观察

扫描电镜观察表明,稻虱红螯蜂Haplogonatopus japonicus Esaki et Hashimoto触角上存在6种感受器,其中刺形感器、锥形感器Ⅳ型、柱形感器Ⅱ型和Bhm氏鬃毛雌、雄都有,仅数量和分布上存在差异;毛形感器Ⅱ型、Ⅲ型,锥形感器Ⅰ型、Ⅱ型、Ⅲ型,柱形感器Ⅰ和锥形乳头状感器仅分布于雌蜂触角;而毛形感器Ⅰ型,锥形感器Ⅴ型仅见于雄蜂触角。对触角感受器的形态进行了描述,并对部分感器功能进行了讨论。     

草地贪夜蛾成虫触角感器超微结构观察

[目的]草地贪夜蛾是一种严重危害农业生产的迁飞性害虫,本研究旨在了解草地贪夜蛾成虫触角感器的类型、超微结构和分布.[方法]采用扫描电镜对其雌雄成虫触角感器类型及分布进行观察.[结果]草地贪夜蛾雌雄成虫触角由柄节、梗节及鞭节3部分组成,雄蛾触角稍长于雌蛾,且触角表面覆有大量鳞片.共观察到7种类型的感受器,分别为B?hm氏...     

Antenna morphology and sensilla microstructure of the male and female scarab beetle,Lepidiota mansueta Burmeister (Coleoptera: Scarabaeidae)

Studies on Lepidiota mansueta Burmeister were conducted to describe and compare the external morphology of the antenna and its sensilla of male and females. Distinct variations were observed in antennal segments between the sexes with males possessing longer scape, pedicel, flagellum and lamellar club segments. Variation was also seen in the antennal sensilla, with males possessing three different types of sensilla while the females possessed seven types of sensilla. Sensilla trichodea (TRS), sensilla placodea (PLAS) type I and sensilla placodea (PLAS) type II were common in both sexes while sensilla chaetica (CHS), sensilla auricilica (AUS) type I, sensilla auricilica (AUS) type II and sensilla auricilica (AUS) type III were found only in females.     

The fine structure of the antennal sensilla of the pine saw flyNeodiprion sertifer (Insecta: Hymenoptera)

Summary There is a considerable sexual dimorphism as regards the development of the antenna inNeodiprion sertifer. In the male this is manifested in a larger antennal surface area and the possession of a great number of long single-walled sensilla (SW 1), which are located on the antennal branches. In the female the antennal branches are vestigial, and the single-walled sensilla, of a second type (SW 2), are shorter and present in lower numbers. Both sexes have in addition four types of sensilla in common:viz. a third type of single-walled sensilla (SW 3), terminal pore sensilla, double-walled sensilla, and poreless sensilla. These four sensillar types are characterized not only by their external appearance but also by their internal morphology. Especially the cells enveloping the sensory cells vary in number and appearance.Supported by joint grants from the Swedish Council for Planning and Coordination of Research, the Swedish Natural Science Research Council, and the Swedish Council for Forestry and Agricultural Research.