Apomictic parthenogenesis in a parasitoid waspMeteorus pulchricornis, uncommon in the haplodiploid order Hymenoptera

Abstract

Although apomixis is the most common form of parthenogenesis in diplodiploid arthropods, it is uncommon in the haplodiploid insect order Hymenoptera. We found a new type of spontaneous apomixis in the Hymenoptera, completely lacking meiosis and the expulsion of polar bodies in egg maturation division, on the thelytokous strain of a parasitoid wasp Meteorus pulchricornis (Wesmael) (Braconidae, Euphorinae) on pest lepidopteran larvae Spodoptera litura (Fabricius) (Noctuidae). The absence of the meiotic process was consistent with a non-segregation pattern in the offspring of heterozygous females, and no positive evidence was obtained for the induction of thelytoky by any bacterial symbionts. We discuss the conditions that enable the occurrence of such rare cases of apomictic thelytoky in the Hymenoptera, suggesting the significance of fixed heterosis caused by hybridization or polyploidization, symbiosis with bacterial agents, and occasional sex. Our finding will encourage further genetic studies on parasitoid wasps to use asexual lines more wisely for biological control.

Novel microsatellite markers suggest the mechanism of parthenogenesis in Extatosoma tiaratum is automixis with terminal fusion

“…Studies in various organisms report correlations between loss of heterozygosity and reduced fitness (Chapman et al ., ). Such fitness costs may explain why most obligate or cyclic parthenogenetic species reproduce by apomixis (e.g., Johnson & Leefe, ; Mark Welch & Meselson, ; Delmotte et al ., ; Vavre et al ., ; Tsutsui et al ., ) while automixis is mainly observed among facultative or geographic (only in certain populations) parthenogens (e.g., Matsuura et al ., ; Pearcy et al ., ; Sekiné & Tojo, ; Kellner & Heinze, ). Apomictic populations may persist over a greater number of generations while avoiding inbreeding depression, whereas automictic populations would quickly become inbred (Schwander & Crespi, ).…”

No evidence of parthenogenesis‐inducing bacteria involved in Thripoctenus javae thelytoky: an unusual finding in Chalcidoidea

“…We cannot exclude an allelic origin of thelytoky, originated by a spontaneous mutation, or by the integration of one (or more) bacterial gene(s) in the parasitoid genome, in every case leading to a non-revertible parthenogenesis (Kondo et al, 2002;Lattorff et al, 2005). In parasitic Hymenoptera, a genetic basis of thelytoky has been hypothesized for the braconids Meteorus pulchricornis (Wesmael) (Tsutsui et al, 2014) and Lysiphlebus fabarum (Marshall), the latter being the only case where the alleles involved have been identified (Sandrock & Vorburger, 2011), and the ichneumonid Venturia canescens (Gravenhorst) (Beukeboom & Pijnacker, 2000). It is also conceivable that an ancient bacterial infection occurred in T. javae, followed by the transfer of genetic material from the endosymbionts to the wasp nucleus.…”

Polyphagous koinobiosis: the biology and biocontrol potential of a braconid endoparasitoid of exophytic caterpillars

“…Certain microgastroid braconids and some ophioniform ichneumonids are oligophagous probably because they regulate host-specific immunity with symbiotic polydnaviruses (Edson et al 1981;Pennacchio and Strand 2006;Quicke 2015). In contrast, M. pulchricornis causes rapid and extensive apoptosis of host granulocytes by the co-injection of virus-like particles (VLPs) from its venom glands (Suzuki and Tanaka 2006;Suzuki et al 2008Suzuki et al , 2009Yokoi et al 2017) (Table 2) The first instar larva of M. pulchricornis has a pair of sharp mandibles to fight against conspecific competitors (Chau and Maeto 2008). These mandibles may also be used to subdue multiparasitic competitors such as unarmed gregarious parasitoids (Magdaraog et al 2012).…”

“…Meteorus pulchricornis is a solitary koinobiont endoparasitoid of lepidopteran larvae. Its general bionomics (Askari et al 1977;Fuester et al 1993; Suzuki and Tanaka 2007;Takashino et al 2001), adult diet (Wu et al 2008), circadian activity (Nishimura et al 2015), courtship and mating behavior (Askari and Coppel 1978), oviposition behavior (Chau and Maeto 2009; Kageyama and Sugiura 2016;Sheng et al 2015;Yamamoto et al 2009;Zhou et al 2017), adaptive melanism (Abe et al 2013), superparasitism Maeto 2008, 2009;Zhang et al 2014), immune suppression mechanism (Suzuki and Tanaka 2006;Suzuki et al 2009), mitochondrial genome (Wei et al 2010), and modes of reproduction (Tsutsui et al 2014) have been studied.…”