Scanning electron microscopy studies of antennal sensilla of Ooencyrtus phongi (Hymenoptera: Encyrtidae)

Abstract

Ooencyrtus phongi (Hymenoptera: Encyrtidae) is an important egg parasitoid of the litchi stink bug, Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae). Antennae of parasitic Hymenoptera are important sensory organs and play an important role in host location, host discrimination, courtship, and mating behavior. In this article, we examined the external morphology of the antennal sensilla of female and male of O. phongi using scanning electron microscopy. Twelve morphological sensillar types were recognized in both sexes, including the placoid sensilla, basiconic sensilla, two types of sensilla trichodea, and eight types of sensilla chaetica. Major differences were found between the sexes, in number, distribution, shape, structure, and size of the identified sensilla. These results are discussed in relation to the possible role of these sensilla in the host location behavior of O. phongi.

Diverse Filters to Sense: Great Variability of Antennal Morphology and Sensillar Equipment in Gall-Wasps (Hymenoptera: Cynipidae)

“…Sensilla trichoidea type C were observed in our study in all taxa, and represent the more numerous sensillar type on the cynipoid antennae, as also reported for other non-Aculeata lineages [55]. These sensilla resemble the “SCh-7” of O. phongi (Chalcidoidea: Encyrtidae) [71] and the aporous mechanosensory hairs reported for different parasitoid lineages [55]. Sensilla trichoidea type D, which were rare in Cynipoidea, having being detected in only 12 taxa, resemble the “ChS-1” of C. solmsi marchali [72].…”

“…Also the number of SP per row seems to be higher in most Cynipoidea (>5 in 33 of the studied species) than in the other Proctotrupomorpha and in Ichneumonoidea (apparently no more than 4) [22], [26], [71]–[75], [80], which results in Cynipoidea having often SP narrowly or closely spaced in a row.…”

“…In Ichneumonoidea, SCa were observed in few Braconidae [74], though in most analysed species of this family it seems to be absent [18], [23], [25]–[27], [71], [75], [92]. Within Proctotrupomorpha excluding Cynipoidea, this sensilla type was observed in Scelioninae (Platygastroidea), Trichogrammatidae and Eupelmidae (Chalcidoidea) [22], [55], [88], [93], but is apparently absent in many other chalcidoid families such as Aphelinidae, Agaonidae, Pteromalidae, Eulophidae and Mymaridae [11], [29], [72], [76], [87].…”

Peer Review #2 of "Between extreme simplification and ideal optimization: antennal sensilla morphology of miniaturized Megaphragma wasps (Hymenoptera: Trichogrammatidae) (v0.1)"

“…By contrast, Ooencyrtus phongi Trjapitzin, Myartseva & Kostjukov, 1977 (Hymenoptera: Encyrtidae), Metaphycus parasaissetiae Zhang and Huang, 2007 (Hymenoptera: Encyrtidae), Trichogramma dendrolimi Matsumura, 1926 andT. australicum Girault, 1912 (Hymenoptera: Trichogrammatidae) have a single club segment in males, which is separated into flagellomeres in females (Amornsak, Cribb & Gordh, 1998;Xi et al, 2011;Zhang et al, 2012;Zhou et al, 2013b). In the case of M. caribea, both sexes have a fused club, which is uncommon.…”

“…Within-species variations of sensillum sizes, numbers of sensilla, and their morphology is often described, and were thoroughly studied in Trichogramma evanescens Westwood, 1833 (Hymenoptera: Trichogrammatidae) (van der Woude & Smid, 2016). Most of the studies treat Braconidae (Xi et al, 2010;Zhou et al, 2011) and Chalcidoidea, with special emphasis on Trichogrammatidae, Scelionidae and Platygastridae (Cave & Gaylor, 1987;Olson & Andow, 1993;Amornsak, Cribb & Gordh, 1998;Isidoro, Romani & Bin, 2001;Zhang et al, 2012). Some studies covered the biology and behavior associated with the antennal sensilla in parasitoid wasps, making it possible to predict the functions of some types of sensilla (Norton & Vinson, 1974;Schmidt & Smith, 1986).…”