The emergence of ecotypes in a parasitoid wasp: a case of incipient sympatric speciation in Hymenoptera?

The Prevalence of Self-Reported Systemic Allergic Reaction to Hymenoptera Venom in Beekeepers Worldwide: A Systematic Literature Review and Meta-Analysis

Background

Beekeepers represent a high-allergic risk population group due to their unavoidable seasonal or persistent exposure to the elicitors of Hymenoptera venom allergy, bees in particular. A systematic literature review and meta-analysis aimed to estimate the prevalence of self-reported systemic allergic reaction to Hymenoptera venom among beekeepers worldwide.

Methods

We rigorously reviewed and conducted meta-analysis on observational studies retrieved from seven electronic databases (MEDLINE via PubMed, Web of Science Core Collection, Scopus, Academic Search Complete, ScienceDirect, Cumulative Index to Nursing and Allied Health Literature, Zoological Record), spanning data from inception to August 1, 2023. The Joanna Briggs Institute Prevalence Critical Appraisal Tool was employed to assess the risk of bias. A meta-analysis was conducted to synthesize evidence.

Results

Out of 468 studies, eight original articles met the inclusion criteria. The estimated overall lifetime and one-year prevalence of self-reported systemic allergic reaction to bee venom were 23.7% (95% CI: 7.7-53.4) and 7.3% (95% CI: 5.8-9.2), respectively. The estimated lifetime prevalence of self-reported systemic allergic reaction to bee venom for grades III-IV (severe systemic allergic reaction) was 6.0% (95% CI: 3.0-11.7). In general, substantial heterogeneity and a high risk of bias were observed across the majority of studies. The impact of geographical location and climate differences on the estimated lifetime prevalence is suggestive for severe systemic allergic reaction.

Conclusions

Future observational cross-sectional studies should employ rigorous study designs, using validated questionnaires, and thoroughly report the observed health outcomes, verified by physicians.

Ecological determinants of prevalence of the male-killing bacterium Arsenophonus nasoniae

Male-killing bacteria are found in a broad range of arthropods. Arsenophonus nasoniae is a male-killing bacterium, causing a 80% reduction of the male progeny in infected Nasonia vitripennis wasps. Although the discovery of A. nasoniae dates from the early 80's, knowledge about the biology and ecology of this endosymbiont is still scarce. One of these poorly studied features is the ecological factors underlying A. nasoniae incidence on its Nasonia spp. hosts in different geographical locations. Here, we studied the prevalence of A. nasoniae in Iberian wild populations of its host N. vitripennis. This wasp species is a common parasitoid of the blowfly Protocalliphora azurea pupae, which in turn is a parasite of hole-nesting birds, such as the blue tit (Cyanistes caeruleus). We also examined the effects of bird rearing conditions on the prevalence of A. nasoniae through a brood size manipulation experiment (creating enlarged, control and reduced broods). Both the wasp and bacterium presence were tested through PCR assays in blowfly pupae. We found A. nasoniae in almost half (47%) of nests containing blowflies parasitized by N. vitripennis. The prevalence of A. nasoniae was similar in the two geographical areas examined (central Portugal and southeastern Spain) and the probability of infection by A. nasoniae was independent of the number of blowfly pupae in the nest. Experimental manipulation of brood size did not affect the prevalence of A. nasoniae nor the prevalence of its host, N. vitripennis. These results suggest that the incidence of A. nasoniae in natural populations of N. vitripennis is high in the Iberian Peninsula, and the infestation frequency of nests by N. vitripennis carrying A. nasoniae is spatially stable in this geographical region independently of bird rearing conditions.

The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps

Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the "Angiosperm Terrestrial Revolution". Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3-180.5 Ma) and a crown age of 162.2 Ma (153.9-169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history.