Types Of Basiconic Sensilla Research Articles

Sensillar Ultrastructure of the Antennae and Maxillary Palps of the Warble Fly Oestromyia leporina (Pallas, 1778) (Diptera: Oestridae).

Despite the development of molecular techniques, morphological phylogeny still remains integral in underpinning the relationship between some clades of Calyptratae, especially the ones with fast radiation, such as those in Oestridae (Diptera: Brachycera), yet few synapomorphy has been proposed for adults in this family. Using scanning electron microscopy, we investigated the morphological structure and ultrastructure of the antennae and maxillary palps of adult Oestromyia leporina (Hypodermatinae, Oestridae). One type of trichoid sensillum (Tr), three types of basiconic sensilla (Ba I, Ba II, and Ba III), one type of coeloconic sensillum (Co I), and one type of clavate sensillum (Cl) were found on the antennal postpedicel. Surprisingly, this species has the most complex types of sensilla on the maxillary palps that have been reported in Calyptratae so far, with two types of coeloconic sensilla (Co II and Co III) and two types of mechanoreceptors. We then identified three common characteristics on the arista of Oestridae (Hypodermatinae, Oestrinae, Gasterophilinae and Cuterebrinae) that are potential synapomorphies. These characteristics indicate the value of the morphology of maxillary palps and aristae in taxonomy studies of Calyptratae.

Morphological Effect of Gamma Radiation on the Antennal Sensory Structure of Peach Fruit Fly, Bactrocera zonata, Using Electron Microscopy

External morphology of antennal sensilla of both sexes of irradiated with sterilizing and substerilizing doses and unirradiated peach fruit fly, Bactrocera zonata were studied with scanning electron microscopy. The antenna of this fly consists of 3 segments: Basal scape, pedicel and funiculus. The antennal segments of males tended to be longer and more elongated than those of females. Eight distinct morphological types of sensilla belong to four groups. These sensilla are: trichoid sensilla type I and II, chaetica sensilla type I and II, basiconic sensilla type I, II, III and campaniform sensilla (in the pedicel of female). The changes which occurred to the antennae and their associated sensilla due to the sterilizing dose (90Gy for male and 50Gy for female) were investigated; distribution, size and position are also described.

Antennal sensilla of phytophagous and predatory pentatomids (Hemiptera: Pentatomidae): a comparative study of four genera

Antennal sensilla of four genera of Pentatomidae (Hemiptera: Heteroptera) belonging to two subfamilies viz., Pentatominae and Asopinae were examined using scanning electron microscopy. The representatives selected from the subfamily Pentatominae (phytophagous)—Dolycoris indicus (Stål) and Plautia crossota (Dallas), and from the subfamily Asopinae (predatory)—Perillus bioculatus (Fabricius) and Eocanthecona furcellata (Wolff). They were studied in order to morphologically differentiate the sensilla present on the antennae. This study indicated the presence of six types of sensilla, most of which were found on the flagellar segments rather than on the scape or pedicel. Sensilla campaniformia were recorded on the flagellar segments as well as the scape and pedicel. Phytophagous species (D. indicus and P. crossota) showed a higher number of sensilla trichodea, basiconica and chaetica whereas sensilla coeloconica were restricted to the predatory species studied (E. furcellata and P. bioculatus). These differences may be related to their evolutionary history. The presence of multiporous chemo-sensilla as basiconic sensilla type and sensilla placoidea reflect the ability of the antennae to perceive chemical stimuli. A relatively higher abundance of mechanoreceptors could be considered as potential detectors for various mechanical functions and these appeared to be correlated with the genus and type of feeding but not with the sex of the studied species.

Sensilla on the antenna of blow fly, Triceratopyga calliphoroides Rohdendorf (Diptera: Calliphoridae).

Blow fly, Triceratopyga calliphoroides Rohdendorf, is a common and synanthropic species of medical and forensic significance in eastern Asia. Field monitoring studies have indicated that olfaction system plays an important role in guiding the behavior of insect species. To further our understanding of fly olfaction, scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) are applied to examine the sensillar morphology of adults, with an emphasis on sensory pit and sacculus. Both microtrichiae and several mechanoreceptors are detected on antennal scape and pedicel. Except for these two structures, pedicellar buttons are also found in antennal pedicellar depression after the separation of antennal pedicel and funiculus. Eight types of antennal sensilla are observed on external surface of antennal funiculus (one type of trichoid sensilla, three types of basiconic sensilla, three types of coeloconic sensilla, and one type of clavate-like sensilla), while two types (one type of basiconic sensilla and one type of coeloconic-like sensilla) are detected at the inner surface of sensory pits or sacculus. As the first to investigate cuticular invaginations of blow flies via paraffin section, the internal structure of abundant sensory pits and an excessively complex sacculus on antennal funiculus are revealed. After comparison to other species previously studied, this phenomenon is proved to be the most unique feature of T. calliphoroides, armed with a discussion on its morphology, function, and possible evolutionary implications.

Ultrastructure and distribution of sensilla on the antennae of female fig wasp Eupristina sp. (Hymenoptera: Agaonidae)

AbstractIn the species‐specific and obligate mutualism between the fig (Moraceae: Ficus spp.) and its pollinator (Hymenoptera: Agaonidae), the continuity of lifecycle of both partners completely depends on the female pollinator's ability to detect receptive figs. To better understand the chemical location mechanism, we examined the antennae and their sensilla of the female fig pollinator Eupristina sp. using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The antennae of female Eupristina sp. are geniculated, and in total, there were seven types of sensilla found on the antennae: two types of multiporous placoid sensilla (type 1 is sausage‐like and type 2 is rounded), sensilla trichodea (ST), basiconic sensilla (BS), chaetica sensilla (ChS), coeloconic sensilla (CoS), and one specialized sensillum classified as sensillum obscurum (SO). We described external morphology, abundance, distribution, ultrastructure and discussed putative functions. We inferred from their ultrastructures as chemoreceptors that two types of multiporous placoid sensilla, BS and CoS, were innervated by sensory neurons. The aporous type ST, ChS, and SO were not innervated by dendrites which may function as mechanoreceptor/proprioceptor. These results were also discussed in relation to the interaction between Eupristina sp. and its host fig.

Olfactory sensilla on antennae and maxillary palps of Fannia hirticeps (Stein, 1892) (Diptera: Fanniidae)

The Fanniidae is one of four families in the superfamily Muscoidea (Diptera), including some important medical and hygienic flies. There is a paucity of reports on the ultrastructure of olfactory sensilla for the fanniid species. To provide more information on the morphology of the antennal and palpal sensilla of fanniid fly, Fannia hirticeps (Stein, 1892) has been studied using scanning electron microscopy. The first two antennal segments, scape and pedicel, are covered by microtrichiae and several chaetic sensilla. Six distinct morphological types of sensilla are recorded on the antennal funiculus, including one trichoid, two basiconic, two coeloconic sensilla, and one clavate sensilla. The measurement and density of each sensilla type are also provided. The trichoid sensilla tend to be longer and denser toward the apex of antennal funiculus. Basiconic sensilla spread all over the funicular surface. F. hirticeps bears two types of coeloconic sensilla, type 2 coeloconic sensilla distributed on the distal part of the anterior surface, whereas type 1 distributed on the rest of the funiculus. Clavate sensilla are found on the base of antennal funiculus. Only one large sensory pit is located on the posterior surface. Maxillary palps bear one type of basiconic sensilla. These results are compared with eight other muscid flies. Our findings provide a morphological basis for future investigations on olfactory-mediated behavior of this group.

Morphological characterization of the antennal sensilla of t he earwig Anisolabis maritima (Dermaptera: Carcinophoridae) with reference to their probable functions

The earwig, Anisolabis maritima (Dermaptera: Carcinophoridae), is one of the most significant insects in KSA because, it was recorded in Saudi Arabia as a beneficial predator on eggs and newly hatched larvae of the red palm weevil, Rhyncophorus ferrugineus. We examined the external morphology of the antennal sensilla of males and females of A. maritima using scanning electron microscopy (SEM). The filiform antennae of A. maritima were of the conventional type comprising a basal scape, pedicle and a long, thread-like flagellum, which was composed of 12 flagellomeres of males and 16 flagellomeres of females. Six morphologically unique sensillar types were found and described on the antennae of males and females of A. maritima. Of those identified, there were three types of porous trichoid sensilla (long, curved and arcuate), and two types of basiconic sensilla (short and curved), and one type of aporous trichoid sensilla. The shape, external morphology and array of sensilla on the antennae of males and females of A. maritima were similar.

Antennal Morphology of Two Specialist Predators of Hemlock Woolly Adelgid, <I>Adelges tsugae</I> Annand (Homoptera: Adelgidae)

We used scanning and transmission electron microscopy in a morphological examina- tion of the antennae of two specialist predators of the exotic hemlock woolly adelgid, Adelges tsugae Annand, as an initial step toward understanding the potential importance of olfaction in host-Þnding behavior. Laricobius nigrinus Fender (Coleoptera: Derodontidae) possesses six types of sensilla on a relatively long antennae comprised of scape, pedicel, and nine annuli. Two types of basiconic sensilla contained numerous wall pores with branching pore kettles and were located on the terminal three annuli. The terminal annulus contained a placoid-like sensillum, and the penultimate and antepen- ultimate annuli contained a coeloconic-type sensillum forming a ring around the distal portion. Two types of sensilla chaetica were located along much of the length of the antennae. Pseudoscymnus tsugae Sasaji and McClure (Coleoptera: Coccinellidae) was found to possess Þve types of sensilla on an extremely short antenna, which is characteristic of the tribe Scymnini, consisting of scape, pedicel, and seven annuli. Three of the annuli were void of sensilla. Two types of sensilla chaetica were located on the scape and pedicel, as well as the terminal annuli. Three types of basiconic sensilla, one of which contained numerous wall pores, were identiÞed on the terminal two annuli. No sexual dimorphism was detected on either predator species. Our results suggest that olfaction is a more important sensory modality in L. nigrinus than P. tsugae, and that trap-based sampling methods incorporating olfactory cues are more likely to be successful for L. nigrinus than P. tsugae.

Fine structure of antennal sensilla basiconica and their detection of plant volatiles in the eucalyptus woodborer, Phoracantha semipunctata Fabricius (Coleoptera: Cerambycidae)

The ultrastructure and distribution pattern of two types of basiconic sensilla (I and II) on the antennal flagellum of both sexes of Phoracantha semipunctata (Coleoptera: Cerambycidae) was investigated by scanning and transmission electron microscope. Both types are thin-walled multiporous sensilla and occur mostly along the anterior border of the Fl1–Fl6 flagellomeres, while on the distal flagellomeres (Fl7–Fl9) they are more evenly distributed on both surfaces. Clusters of sensilla basiconica II are found on the distal half of the anterior border of the Fl1–Fl6 flagellomeres. Sensilla basiconica I have one bipolar sensory cell with a branched distal dendrite, whereas the sensilla basiconica II contain two bipolar sensory cells with branched distal dendrites. No sexual dimorphism was found in the fine structure and distribution pattern of both types of sensilla basiconica. Responses from single sensory cells to host and non-host plant odors were examined, using gas chromatography linked with electrophysiological recordings. Most cells associated with each sensillum type were narrowly tuned, each specialized for the detection of one or two chemically related compounds. No clear functional distinction between the two morphological types of sensilla was found, although the few cells that responded specifically to non-host volatiles were associated with sensilla basiconica II.

Antennal sensilla of the ground beetle Platynus dorsalis (Pontoppidan, 1763) (Coleoptera, Carabidae).

The typology, number, and distribution pattern of antennal sensilla of the ground beetle Platynus dorsalis (Pontoppidan) (Coleoptera, Carabidae) were studied using scanning electron microscopy. The 4.3-4.6-mm-long filiform antennae of the beetles consist of the scape, pedicel, and nine flagellomeres. In both sexes, four subtypes of sensilla chaetica, five subtypes of sensilla basiconica, sensilla trichodea, two subtypes of sensilla campaniformia, sensilla auricillica, and sensilla coeloconica were distinguished. The possible function of the sensilla was discussed and three types of sensilla were considered as olfactory, sensilla trichodea and sensilla basiconica types 1 and 2. Olfactory sensilla form two separate, dorsal and ventral, fields of sensilla on the flagellomeres, which seems to be common in ground beetles. The total numbers of olfactory trichoid (approximately 1,000 hairs) and basiconic sensilla type 1 (1,700-1,800 pegs) on the antennae of P. dorsalis are 5-7 times higher than on the antennae of the ground beetle Bembidion lampros, suggesting that nocturnally active P. dorsalis is much more sensitive to odours perceived by these sensilla than B. lampros with diurnal activity and hunting predominantly by sight. No remarkable sexual differences in the types, numbers, and distribution of antennal sensilla were found in P. dorsalis.

Fine structure of antennal sensilla of the female sphinx moth, Manduca sexta (Lepidoptera: Sphingidae). I. Trichoid and basiconic sensilla

Olfaction is the principal sensory modality through which insects locate their food sources, mates, and oviposition sites. Insects offer certain advantages as experimental models for the study of mechanisms of olfaction, and a thorough knowledge of the antennal olfactory sensory cells is essential for such studies. While the sphinx moth, Manduca sexta, has proved to be an especially favorable experimental model in studies of pheromone processing in males, little is known about the female olfactory system, including the antennal olfactory sensilla. In this and another paper in this series, we present the first thorough investigation of the structure, innervation, number, and distribution of sensilla on the antennal flagellum of female M. sexta. The flagellum of the female moth bears eight morphological types of sensilla: two trichoid, two basiconic, one auriculate, two coeloconic, and one styliform complex. In this paper, we describe the two types of trichoid and two types of basiconic sensilla. The first type of trichoid sensillum, a long hairlike sensillum averaging 34 µm in length, is innervated by two bipolar sensory cells, and the second type, a shorter hairlike sensillum averaging 26 µm in length, is innervated by either one or three bipolar sensory cells. The first type of basiconic sensillum is a long peg, averaging 22 µm in length, and the second is a shorter peg, averaging 15 µm in length. Both types of basiconic sensilla are innervated by three bipolar sensory cells. These trichoid and basiconic sensilla have structural features characteristic of insect olfactory sensilla.

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.

SEXUAL DIMORPHISM IN THE ADULT ANTENNAE OF ANTITROGUS PARVULUS BRITTON AND LEPIDIOTA NEGATORIA BLACKBURN (COLEOPTERA: SCARABAEIDAE: MELOLONTHINAE)

AbstractAntennae of both sexes of adults of Antitrogus parvulus and Lepidiota negatoria were examined using scanning electron microscopy following critical‐point drying. Males of A. parvulus have 7 large lamellae, the inner surfaces of which have ca 150,000 cup‐shaped placoid sensilla. Females have fewer and smaller lamellae, no placoid sensilla and few basiconic sensilla. Both sexes of L. negatoria have similar 3‐lamellate antennae with placoid sensilla and 2 types of basiconic sensilla. Sensilla differences suggest that male A. parvulus use pheromones to locate distant females, whilst in L. negatoria the antennal sensilla are used to locate host trees and proximate females.