Morphological analysis of sensilla on different organs in Pachyneuron aphidis, a hyperparasitoid of Myzus persicae

Abstract

Aphidius gifuensis is the main enemy of Myzus persieae. While its parasitic rate can be influenced by the hyperparasitoid, Pachyneuron aphidis. As important parts of insects to sense odors from various environments, study of sensilla can lay the foundation of the further study about the parasitic mechanisms, reduce the hyperparasitic rate, and make the most effect usage of A. gifuensis. Here, we give a fundamental study about the morphology of the sensilla on the whole body of male and female P. aphidis. We observed seven main types of sensilla on them totally by using scanning electron microscopy. Including Böhm bristle (BB), chaetica sensilla (ChS), basiconic sensilla (BS), trichoid sensilla (TS), and placodea sensilla (PS), coeleoconica sensilla (CoS), basiconic capitate peg sensilla (BCPS). In addition, TS on antennae can be divided into four subtypes, on wings can be divided into two subtypes. Sensilla were most abundant on the antennae. We observed all types of sensilla on antennae. TS4 was uniporous and PS was multiporous. The other sensilla were nonporous. We did not find sexual dimorphism with regards to sensilla on the antennae except for the location of CoS. In male, CoS situated on the fourth subsegment of flagellum, but on the eighth subsegment in female. In other organs, TS has the largest number. We also found BS on compound eyes and ovipositor, BB on thoracic legs. The possible roles of these sensilla played in life activities are discussed. Our study makes a contribution of the parasitic mechanism of hyperparasitoids.

Morphology and Distribution of Antennal Sensilla in an Egg Parasitoid Wasp,Anastatus disparis(Hymenoptera: Eupelmidae)

“…We identified the sensilla structures on each antenna and calculated their frequencies and distributions. Sensillum types were classified as described in Altner and Prillinger (1980) , Schneider (1964) , and Zacharuk (1980) , with reference to more recent literature on Hymenopteran antennal sensilla ( Zhang et al 2015 , Zheng et al 2016 , Shen et al 2019 , Sevarika et al 2021 ).…”

“…Numerous studies have investigated antennal sensillum morphology and function in various insects, particularly Hymenoptera ( Olson and Andow 1993 , Onagbola and Fadamiro 2008 , Zhang et al 2015 , Zheng et al 2016 , Shen et al 2019 , Sevarika et al 2021 ), but to date, no reports have described the antennal sensilla of A. disparis . A thorough understanding of the insect olfactory system is essential for developing effective semiochemical-based control strategies.…”

The Ecology of Hyperparasitoids

“…Nevertheless, fundamental research on the sensory systems of hyperparasitoids remains scarce. Scanning electron microscopy was used to describe the sensory cells on antennae for Cheiloneurus noxius (131), for male and female Alloxysta consobrina and A. victrix (92), and different types of external sensilla across the entire bodies of male and female Pachyneuron aphidis (101). Eight different types of sensilla have been discovered on hyperparasitoid antennae, including porous sensilla that are thought to play a role in olfaction (85), such as the abundant multiporous placoidea sensilla on the antennae of Alloxysta spp.…”