Distributional range expansion of the parasitic wasp Lirata batesella (Westwood, 1874) (Hymenoptera, Eucharitidae)

This study is focused on the expansion of the distributional range of Lirata batesella (Westwood, 1874) (Hymenoptera, Eucharitidae) and based on a single female specimen deposited at Coleção Entomológica do Laboratório de Sistemática e Bioecologia de Predadores e Parasitoides of the Instituto Biológico, in Ribeirão Preto, São Paulo state, Brazil. Santarém, in Pará state, Brazil, the type locality, is the only known distribution record for the species. Here, we provide a new distribution record for L. batesella, in Luiz Antônio, São Paulo state, about 2,200 km south of the type locality, which represents a significant increase in its distribution range. A map showing the geographical distribution of L. batesella based on the new record and literature is provided.

How to cease the ‘succession’ of anthropogenic environmental problems using the knowledge on their interconnected nature?

Some man-made environmental problems are in a succession. Usually this happens due to the establishment of unsustainable solutions to the identified man-made environmental crisis. When the human driven solutions to the environmental problem also become a threat, the chain continues as a succession of man-made environmental crises until a permanent sustainable or regenerative solution is achieved. For instance, in early 1950s, Dayak people suffered from malaria. World Health Organization (WHO) had permitted to spray huge amount of DDT to kill mosquitoes. The attempt was a success and vector borne disease malaria was mitigated, however, their houses began to fall down on their heads. This is because application of DDT also killed the parasitic wasp that had previously controlled thatch eating caterpillars. In this scenario the worst event is DDT poisoned insects were eaten by geckos, which were eaten by cats, the cats died (biomagnification of DDT) and the rat population increased. The people were affected by sylvatic plague and typhus. To find solution to this WHO was obliged to parachute 14,000 live cats into Borneo. Thus, to prevent this succession of man-made environmental crises a need for clear understanding on all man-made environmental issues and their causes and effects is required. This article reviews the previously published research paper “Keystone Links of Anthropogenic Environmental Problems and Emergence of Interconnected Man-made Environmental crises” on this journal. In that study 40 identified man-made environmental crises were mapped by their interconnections as causes and effects. And established concept map could be used in problem mitigation, or identifying most promising solution to the man-made environmental crises. Qualitative content analysis method was applied in that study, and 252 links between man-made environmental crises were identified and supported by real-world examples in the elaborated thesis.

Bracoviruses recruit host integrases for their integration into caterpillar’s genome

Some DNA viruses infect host animals usually by integrating their DNAs into the host genome. However, the mechanisms for integration remain largely unknown. Here, we find that Cotesia vestalis bracovirus (CvBV), a polydnavirus of the parasitic wasp C. vestalis (Haliday), integrates its DNA circles into host Plutella xylostella (L.) genome by two distinct strategies, conservatively and randomly, through high-throughput sequencing analysis. We confirmed that the conservatively integrating circles contain an essential “8+5” nucleotides motif which is required for integration. Then we find CvBV circles are integrated into the caterpillar’s genome in three temporal patterns, the early, mid and late stage-integration. We further identify that three CvBV-encoded integrases are responsible for some, but not all of the virus circle integrations, indeed they mainly participate in the processes of early stage-integration. Strikingly, we find two P. xylostella integrases (PxIN1 and PxIN2) are highly induced upon wasp parasitism, and PxIN1 is crucial for integration of some other early-integrated CvBV circles, such as CvBV_04, CvBV_12 and CvBV_24, while PxIN2 is important for integration of a late-integrated CvBV circle, CvBV_21. Our data uncover a novel mechanism in which CvBV integrates into the infected host genome, not only by utilizing its own integrases, but also by recruiting host enzymes. These findings will strongly deepen our understanding of how bracoviruses regulate and integrate into their hosts.

Ovigeny strategy of the parasitic wasp Cosmocomoidea annulicornis (Hymenoptera: Mymaridae): effect of female age, feeding and host availability on reproductive traits

The reproductive traits of the mymarid wasp Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) attacking eggs of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae) were evaluated under laboratory conditions. Bioassays were carried out to estimate the realized fecundity and egg load of females. The ovigeny index was calculated and different biological traits, such as body size, oöcyte length, gaster length and wing length, were analysed to assess significant associations between these traits and the species fitness. In addition, the effect of host availability and feeding on longevity and potential fecundity throughout life and the effect of female age on egg maturation dynamics were assessed. The results showed that C. annulicornis is a strongly synovigenic species. A positive correlation was found between fecundity and longevity of the females and between body size and oöcyte length. Contrary to expected, body size was not related to fecundity and longevity. Females lived significantly longer in the presence of hosts and honey than when they were host-deprived and honey-fed or both host and honey deprived. Host availability had a significant effect on the amount of eggs laid by C. annulicornis females. Female age was negatively associated with oöcyte length. Furthermore, females were able to mature additional eggs as they aged, nevertheless, when host-deprived, senescent females presented significantly less mature eggs than younger ones, suggesting a possible egg oosorption. These results might contribute to a better understanding of the reproductive potential of this species as a biocontrol agent.

Biological relevance unites, semantics divides: a comment on Ruther et al (2021)

Ruther et al (2021) evaluated fatty acid synthesis in several parasitic wasp species to test if the general finding that lipogenesis in parasitoids is lacking is upheld (Visser et al 2010 PNAS). As proposed by Visser & Ellers (2008), parasitoids can readily assimilate the triglyceride stores produced by their host. When large triglyceride stores are carried over from larval feeding into adulthood (i.e., up to 30 to 40% of the parasitoid’s dry body weight; Visser et al., 2018, 2021), de novo lipid synthesis from adult feeding is either unnecessary or too costly to maintain, leading to trait loss (Ellers et al., 2012). To test the hypothesis that many parasitoids do not synthesize substantial quantities of fat stores as adults, a previous study used feeding experiments on a wide taxonomic range of insects, including parasitoid wasps, parasitoid flies, a parasitoid beetle, and 65 non-parasitoid species (Visser et al., 2010 and references therein). What is striking is that when compared to non-parasitoid insects, 24 out of 29 evolutionarily distinct parasitoid lineages (Coleoptera, Diptera and Hymenoptera; Visser et al., 2010) did not accumulate significant lipid quantities in adulthood even when fed surplus carbohydrates. When little to no lipids are synthesized de novo by adult parasitoid wasps, this can lead to significant constraints on energy allocation toward key adult functions, such as maintenance, dispersal, and reproduction (Jervis et al., 2008). To our minds, the most important question is ‘why don’t parasitoids accumulate substantial quantities of fat as adults like other insects do, and what does this mean for their life histories?’