Ovipositor of the braconid wasp Habrobracon hebetor: structural and functional aspects

Abstract

The Braconidae are a megadiverse and ecologically highly important group of insects. The vast majority of braconid wasps are parasitoids of other insects, usually attacking the egg or larval stages of their hosts. The ovipositor plays a crucial role in the assessment of the potential host and precise egg laying. We used light- and electron-microscopic techniques to investigate all inherent cuticular elements of the ovipositor (the female 9th abdominal tergum, two pairs of valvifers, and three pairs of valvulae) of the braconid Habrobracon hebetor (Say, 1836) in detail with respect to their morphological structure and microsculpture. Based on serial sections, we reconstructed the terebra in 3D with all its inherent structures and the ligaments connecting it to the 2nd valvifers. We examined the exact position of the paired valvilli, which are bilateral concave structures that protrude into the egg canal. In H. hebetor, these structures putatively divert the egg ventrally between the 1st valvulae for oviposition. We discuss further mechanical and functional aspects of the ovipositor in order to increase the understanding of this putative key feature in the evolution of braconids and of parasitoid wasps in general.

Natural variability in bee brain size and symmetry revealed by micro-CT imaging and deep learning

“…Indeed, recent studies showed Biomedisa is suitable for many types of volumetric image data other than micro-CT scans, e.g. from confocal laser scanning microscopy (CLSM), focused ion beam scanning electron microscopy (FIB-SEM), histological imaging [ 63 ], or magnetic resonance imaging (MRI) [ 64 ], which offer the opportunity for a wide range of studies in biology, ecology and evolution to perform large-scale, cost-effective and time-efficient analyses.…”

Exploration for Asian longhorned beetle parasitoids in Korea using an improved sentinel log trap

“…Decisively, the pupa has distinctly visible ovipositor sheaths that generally appear in some Chalcidoidea families [ 8 – 10 , 30 ]. In contrast, in Platygastroidea, ovipositor sheaths are inside the metasoma [ 1 ], and in Ichneumonoidea, visible ovipositor sheaths start at the basal margin of the metasoma [ 12 , 14 ]. The aforementioned morphological characteristics combination suggests that the unidentified parasitoid is most likely a Chalcidoidea.…”

“…One parasitoid species was found with only two individuals at the larval stage during the 2019 survey, and both died before imago during rearing. Therefore, identification of the larvae and pupae of this species was carried out using external morphology and molecular analysis by referring to [ 1 , 6 – 10 , 12 , 14 , 19 , 20 , 29 , 38 ].…”

Natural variability in bee brain size and symmetry revealed by micro-CT imaging and deep learning

“…Indeed, recent studies showed Biomedisa is suitable for many types of volumetric image data other than micro-CT scans, e.g. from confocal laser scanning microscopy (CLSM), focused ion beam scanning electron microscopy (FIB-SEM), histological imaging [61], or magnetic resonance imaging (MRI) [62], which offer the opportunity for a wide range of studies in biology, ecology and evolution to perform large-scale, cost-effective and timeefficient analyses.…”