scholarly journals Comparative Morphology of the Mouthparts in Three Predatory Stink Bugs (Heteroptera: Asopinae) Reveals Feeding Specialization of Stylets and Sensilla

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 762
Author(s):  
Yan Wang ◽  
Jolanta Brożek ◽  
Wu Dai

Mouthpart structures were observed in three species of Asopinae using scanning electron microscopy to investigate their morphological disparity. The examined species attack mainly slow-moving, soft-bodied insects, primarily larval forms of the Lepidoptera, and are the natural enemies of many pests. This is the first detailed description of their external mouthparts. The triangular and elongated labrum and four-segmented tube-like labium are longer in Picromerus species (Picromerus bidens (Linnaeus, 1758) and Picromerus lewisi Scott, 1874 than in Cazira bhoutanica Schouteden, 1907. The labrum of P. lewisi and C. bhoutanica appear to be equipped with olfactory sensilla basiconica Sb3, a special type of sensilla with nanopores. The labium surface in all studied species bears 14 types of sensilla (St1–St4, Sb1–7, Sst, Sca1–2). A new characteristic of sensilla trichodea is represented in sensillum St1; in both Picromerus species, it is classified as an olfactory sensillum with nanopores. The tripartite apex of the labium consists of two lateral lobes and a central membranous lobe having microtrichial extensions. Each lobe has one sensory field, including sensilla basiconica (Sb7), sensilla styloconica (Sst), and sensilla trichodea (St4). In the three studied predatory stink bugs, each mandibular stylet tip has five irregular teeth and three long, pointed hooks. The two opposing maxillae, which are held together by a tongue-and-groove system, form a food canal and a salivary canal. The apices of the right maxilla have small teeth and few short barbs along the edge of the food canal. In P. bidens and P. lewisi, there are 5 teeth, while in C. bhoutanica there are 2. Based on structural differences, we inferred that the hook-shaped mandibular teeth, right maxilla with small teeth, and few short barbs along edge of the food canal are more adapted for a predatory lifestyle. Predatory stink bugs use sharp recurved hooks and irregular teeth penetrating, tearing, or filing devices that aid in the mechanical disruption of host tissue. Stiff bristles in the food canal may indicate their possible adaptation to feeding on insect larvae. The evolution of mouthpart morphology and the putative functional significance of sensilla are discussed, providing insight into the sensory mechanism.


2021 ◽  
Vol 15 ◽  
Author(s):  
Wan-Ying Dong ◽  
Bing Wang ◽  
Gui-Rong Wang

The olfactory sensing system of the syrphid fly Eupeodes corollae is essential in pollination and prey localization, but little is known about the ultrastructural organization of their olfactory organs. In this study, the morphology, distribution, and ultrastructural organization of antennal sensilla of E. corollae in both sexes were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Neuronal responses of a subtype of sensilla basiconica to floral scent compounds were recorded by single sensillum recording (SSR). Ten morphological types, including Böhm bristles, sensilla chaetica, microtrichiae, sensilla trichodea, sensilla basiconica, sensilla clavate, sensilla coeloconica, sensilla styloconica, sensilla placodea, and sensory pit, were identified. Except for Böhm bristles and sensilla chaetica, which were distributed on the scape and pedicel of E. corollae antennae, innervated sensilla were densely distributed on the flagellum, a vital sensory organ. Further, observing ultrastructural organization showed that the sensilla trichodea, basiconica, and clavate are single-walled with multiple nanoscale pores perforating the cuticle. Sensilla coeloconica are double-walled and have no wall pores, but instead, have longitudinal grooves along with the pegs. Sensilla chaetica, Böhm bristles, and microtrichiae did not have wall pores on the cuticle or sensory cells at the base. The SSR results indicated that neuron B housed in the subtype of sensilla basiconica I (SBI) mainly responded to methyl eugenol and other aromatic compounds. Overall, our results provide valuable information to understand the morphology and ultrastructure of antennal sensilla from E. corollae. These findings are beneficial for the studies of the neuronal function map of olfactory sensilla and for determining evolutionary relationships in Diptera.



Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 143 ◽  
Author(s):  
Yan Wang ◽  
Lingfei Li ◽  
Wu Dai

To obtain a better understanding of feeding adaptations, the fine structure of the mouthparts in adults of Cheilocapsus nigrescens Liu and Wang, including the sculpture and interlocking mechanisms of the stylets and distribution and abundance of sensilla located on the labium, were studied using scanning electron microscopy. The mouthparts are similar to those of previously studied mirid species in most aspects and composed of a cone-shaped labrum, a tube-like, four-segmented labium with a deep groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets. Each mandibular stylet tip has about 6–8 indistinctive notches, which help in penetrating the leaf surface. A series of transverse squamous textures are present on the adaxial surface of the mandibular stylets. The maxillary stylets interlock to form a food canal and a salivary canal, equipped with an external longitudinal process that engages grooves in the mandibular stylets. Three kinds of sensilla, including four types of sensilla basiconica (I, II, III, and IV), four types of sensilla trichodea (I, II, III, and IV), and one type of sensillum campaniformium, occur at different locations on the labium. Among them, sensilla trichodea I and II are the most abundant; sensilla basiconica II occurs between the first segment and second segment, and between the third and fourth segment. The tripartite apex of the labium consists of two lateral lobes and an apical plate. Each lateral lobe possesses a field of 11 sensilla basiconica IV and 1 sensillum trichodeum IV. The morphology of the mouthparts and the distribution of sensilla located on the labium in C. nigrescens are discussed with respect to their possible taxonomic and functional significance. In particular, the indistinct notches of the mandibular stylet and smooth inner surface of the right maxillary stylets are suited primarily for phytophagy.



1990 ◽  
Vol 68 (7) ◽  
pp. 1443-1453 ◽  
Author(s):  
J. F. Sutcliffe ◽  
E. G. Kokko ◽  
J. L. Shipp

The innervation and internal ultrastructure of the antennal flagellar sensilla of female Simulium arcticum (cytotypes IIL-3 and IIS-10.11) are described from transmission electron micrographs. Two types of contact chemosensilla and at least four types of olfactory sensilla (sensilla trichodea, two or more types of sensilla basiconica, grooved pegs) were found. These correspond to sensillar types previously described from scanning electron micrographs of the antennae of these species. In addition, possible thermo- and hygro-receptive sensilla coeloconica are described from the antennal tip. The sensory complement of the simuliid antenna is compared with those of certain other dipterans, and possible roles of these sensilla in host location and other behaviours are discussed.



Author(s):  
R. Aruna ◽  
S. Jeyarani ◽  
S. Mohankumar ◽  
C. Durairaj

The studies with SEM clearly depicted that the antenna of female was longer than male antenna. Five types of sensilla namely trichodea, chaetica, styloconica, coeloconica and auricillica, and scales were observed on the flagellum of both sexes. Sensilla trichodea were distributed randomly on all segments and were the most frequent type. Six sensilla chaetica were observed on each flagellar segment in both sexes, except in the apical segment. A sensillum styloconicum was always found at the upper-middle region of each flagellar subsegment. This sensillum had a smooth petiole and a conic extremity with one to three apical structures. Sensilla coeloconica were situated from middle to the distal portion of segment. Sensilla auricillica were found among the scales and had the typical shape of rabbit’s ear. Sensilla squamiformia were present on dorsal part of the antenna among scales. They were shorter and finer than scales and were embedded in a socket and point distally. Sensilla basiconica were smaller and least abundant of all sensilla.



2021 ◽  
Vol 56 (1) ◽  
pp. 1-11
Author(s):  
Shu Z. Yang ◽  
Mei H. Yang ◽  
Yun Xu ◽  
Jin T. Zhang

Abstract Chrysis shanghalensis Smith (Hymenoptera: Chrysididae) is an ectoparasitoid and important natural enemy of Monema flavescens Walker (Lepidoptera: Limacodidae), a serious defoliator of a number of tree species. The external morphology of the antennal sensilla of this parasitoid was examined by scanning electron microscopy, and types and distribution of sensilla were recorded. The antennae of C. shanghalensis were geniculate in shape and composed of a scape with radicula, a pedicel, and a flagellum divided into 11 flagellomeres in males and females. Cuticular pore and 14 types of sensilla were identified on the antennae of both sexes. These included aporous Böhm's bristles, sensilla trichodea 1, 2, and 3 (nonporous), sensilla trichodea 4 (multiporous), two types of sensilla chaetica (nonporous), four morphological types of sensilla basiconica (multiporous), two morphological types of sensilla coeloconica (multiporous), and one type of sensillum campaniforme (nonporous).



2014 ◽  
Vol 71 (8) ◽  
pp. 777-779 ◽  
Author(s):  
Vladimir Biocanin ◽  
Ljubomir Todorovic

Introduction. Intentional partial odontectomy or coronectomy is primarily advocated in situations with intimate relationships between the roots of the tooth indicated for extraction and the inferior alveolar nerve (IAN). The aim of this report was to present a patient with two neighbouring infraoccluded teeth in the right mandible indicated for extraction prior to prosthetic rehabilitation, which were coronectomied as to prevent injuring of the IAN and causing iatrogenic fracture of the mandibular body. Case report. Coronectomy of both teeth was performed as recommended in the literature. The patient had no special discomfort after the operation or deficit in sensitive nerve function, and the wound healed uneventfully. The patient was followed regularly during a 2- year period. Conclusion. The presented case suggests coronectomy as quite beneficial solution for avoiding serious problems (injuring of the IAN and possible fracture of the mandible) and making feasible forthcoming prosthetic rehabilitation.



Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 386 ◽  
Author(s):  
Yan Wang ◽  
Junru Zhang ◽  
Wanshan Wang ◽  
Jolanta Brożek ◽  
Wu Dai

Millipede assassin bugs are a diverse group of specialized millipede predators. However, the feeding behavior of Ectrichodiinae remains poorly known, especially how the mouthpart structures relate to various functions in feeding. In this study, fine morphology of the mouthparts and feeding performance of Haematoloecha nigrorufa (Stål, 1867) was observed and described in detail for the first time. The triangular labrum is divided by a conspicuous transverse membrane into a strongly sclerotized basilabrum and a less sclerotized distilabrum. Fifteen types of sensilla are distributed on the mouthparts. Each mandibular stylet has an expanded spatulate apex and about 150 approximately transverse ridges on the external middle side; these help in penetrating the ventral trunk area and the intersegmental membranes of millipede prey. The right maxilla is tapered. On the internal surface are a row dorsal short bristles near the apex and a row of ventral bristles preapically. A longitudinal row of long lamellate structures extend proximate for a considerable distance, lie entirely within the food canal, and bear several short spines and short bristles. There is no obvious difference between males and females in the distribution, number, and types of sensilla on mouthparts. The adult feeding process involves several steps, including searching and capturing prey, paralyzing prey, a resting phase, and a feeding phase. The evolution of the mouthpart morphology and the putative functional significance of their sensilla are discussed, providing insight into the structure and function of the mouthparts adapted for millipede feeding.



PROTOPLASMA ◽  
2017 ◽  
Vol 254 (5) ◽  
pp. 1965-1972 ◽  
Author(s):  
Luis Carlos Martínez ◽  
Angelica Plata-Rueda ◽  
José Cola Zanuncio ◽  
Wagner de Souza Tavares ◽  
José Eduardo Serrão


Parasitology ◽  
1939 ◽  
Vol 31 (2) ◽  
pp. 212-242 ◽  
Author(s):  
G. G. Robinson

1. Vogel's (1920) assertion that the labral canal is closed ventrally by apposition of the edges of the labral groove is fully confirmed. The hypopharynx plays no part in the ventral closure of the food canal except at its base. The somewhat popular term “labrum-epipharynx” is dispensed with in favour of “labrum”.2. The mandibular teeth vary in number round about 40. The mandibular suspension is fully described.3. Evidence from musculature is put forward for the existence of a small maxillary palpifer not present in other Diptera.4. Snodgrass (1935) criticizes Crampton's (1925) homologizing of the labella with labial palps because “the lobes of the fly labium have usually each only one muscle inserted directly upon it”, whereas palpi usually have antagonistic muscles. Vogel for Culex and this paper for Anopheles maculipennis show that the labial lobes of these insects have antagonistic muscles like typical palpi.



2019 ◽  
Vol 25 (4) ◽  
pp. 186-198 ◽  
Author(s):  
Jian Zhang ◽  
Xiaojun Zhang ◽  
Chunyu Liu ◽  
Lipeng Meng ◽  
Yulin Zhou

Scanning electron microscopy was used to examine the morphology, ultrastructure, and distribution of antennal sensilla of the stink bug Arma chinensis. Two types of sensilla trichodea (ST1–2), four types of sensilla basiconica (SB 1– 4), one type of sensilla chaetica (SCH), one type of sensilla cavity (SCA) and one type of sensilla coeloconica (SCO) were distinguished on the antennae in both sexes. ST1 and ST2 were absent from the scape and pedicel. SB1 were absent from the scape. SB2 were distributed throughout the antennae. SB3 were located on the second pedicel and the two flagellomeres. SB4 were absent from the second flagellomere. SCH was observed on the second pedicel and the two flagellomeres. SCA and SCO occurred only on the second flagellomere. SB1 clusters occurred on the distal part of the second flagellomere. We compared the morphology and structure of these sensilla to other Heteroptera and discuss their possible functions.



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