Population genomics of the invasive Northern Giant Hornet Vespa mandarinia in North America and across its native range.

The northern giant hornet Vespa mandarinia (NGH) is a voracious predator of other insect species, including honey bees. NGH's native range spans subtropical and temperate regions across much of east and southeast Asia and, in 2019, exotic populations of the species were discovered in North America. Despite this broad range and invasive potential, investigation of the population genomic structure of NGH across its native and introduced ranges has thus far been limited to a small number of mitochondrial samples. Here, we present analyses of genomic data from NGH individuals collected across the species' native range and from exotic individuals collected in North America. We provide the first survey of whole-genome population variation for any hornet species, covering this species' native and invasive ranges, and in doing so confirm likely origins in Japan and South Korea for the two introductions. We additionally show that, while this introduced population exhibited strongly elevated levels of inbreeding, these signatures of inbreeding are also present in some long-standing native populations, which may indicate that inbreeding depression alone is insufficient to prevent the persistence of NGH populations. As well as highlighting the importance of ongoing monitoring and eradication efforts to limit the spread of this species outside of its natural range, our data will serve as a foundational database for future genomic studies into introduced hornet populations.

Mediating a host cell signaling pathway linked to overwinter mortality offers a promising therapeutic approach for improving bee health.

INTRODUCTION: Honey bees provides valuable pollination services for world food crops and wild flowering plants which are habitats of many animal species and remove carbon dioxide from the atmosphere, a powerful tool in the fight against climate change. Nevertheless, the honey bee population has been declining and the majority of colony losses occur during the winter. OBJECTIVES: The goal of this study was to understand the mechanisms underlying overwinter colony losses and develop novel therapeutic strategies for improving bee health. METHODS: First, pathogen prevalence in overwintering bees were screened between 2015 and 2018. Second, RNA sequencing (RNA-Seq) for transcriptional profiling of overwintering honey bees was conducted and qRT-PCR was performed to confirm the results of the differential expression of selected genes. Lastly, laboratory bioassays were conducted to measure the effects of cold challenges on bee survivorship and stress responses and to assess the effect of a novel medication for alleviating cold stress in honey bees. RESULTS: We identified that sirtuin signaling pathway is the most significantly enriched pathway among the down-regulated differentially expressed genes (DEGs) in overwintering diseased bees. Moreover, we showed that the expression of SIRT1 gene, a major sirtuin that regulates energy and immune metabolism, was significantly downregulated in bees merely exposed to cold challenges, linking cold stress with altered gene expression of SIRT1. Furthermore, we demonstrated that activation of SIRT1 gene expression by SRT1720, an activator of SIRT1 expression, could improve the physiology and extend the lifespan of cold-stressed bees. CONCLUSION: Our study suggests that increased energy consumption of overwintering bees for maintaining hive temperature reduces the allocation of energy toward immune functions, thus making the overwintering bees more susceptible to disease infections and leading to high winter colony losses. The novel information gained from this study provides a promising avenue for the development of therapeutic strategies for mitigating colony losses, both overwinter and annually.

Two new species of Neocorynura from Guatemala (Hymenoptera: Halictidae: Augochlorini) with a key to the species known from the country.

This paper describes two new species of bees of the genus Neocorynura Schrottky from Guatemala. A taxonomic key to all five known species of the genus in Guatemala is provided and the male of N. centroamericana is described for the first time.

Abejas Chilicola (Hylaeosoma) Ashmead (Colletidae: Xeromelissinae) del grupo megalostigma: una especie nueva de Colombia y clave para las especies / Chilicola (Hylaeosoma) Ashmead bees (Colletidae, Xeromelissinae) of the megalostigma group: a new species from Colombia and a key to species

We describe a new species of Chilicola (Hylaeosoma) of the megalostigma group from southern Colombia and present an identification key to species. Chilicola muruimuinane sp. nov. resembles Chilicola yanezae Hinojosa-Díaz & Michener, 2005, from Mexico, but it differs from it in its body color, shape of basal tarsomeres of female fore legs, and characters of the seventh and eighth sterna of the male.

Describimos una nueva especie de Chilicola (Hylaeosoma) del grupo megalostigma del sur de Colombia y presentamos una clave para las especies. Chilicola muruimuinane sp. nov. es semejante a Chilicola yanezae Hinojosa-Díaz & Michener, 2005, de Méjico, pero se diferencia por el color del cuerpo, la forma de los tarsómeros basales de las patas anteriores de la hembra, y caracteres de los esternos siete y ocho del macho.

[Chilicola (Hylaeosoma) Ashmead bees (Colletidae, Xeromelissinae) of the megalostigma group: a new species from Colombia and a key to species]. / Abejas Chilicola (Hylaeosoma) Ashmead (Colletidae: Xeromelissinae) del grupo megalostigma: una especie nueva de Colombia y clave para las especies.

We describe a new species of Chilicola (Hylaeosoma) of the megalostigma group from southern Colombia and present an identification key to species. Chilicola muruimuinane sp. nov. resembles Chilicola yanezae Hinojosa-Díaz & Michener, 2005, from Mexico, but it differs from it in its body color, shape of basal tarsomeres of female fore legs, and characters of the seventh and eighth sterna of the male.

Phylogeny of finescale shiners of the genus Lythrurus (Cypriniformes: Cyprinidae) inferred from four mitochondrial genes.

We infer the phylogenetic relationships of finescale shiners of the genus Lythrurus, a group of 11 species of freshwater minnows widely distributed in eastern North America, using DNA sequences from the ND2 (1047 bp), ATPase8 and 6 (823 bp), and ND3 (421 bp) mitochondrial protein-coding genes. The topologies resulting from maximum parsimony, Bayesian, and maximum likelihood tree building methods are broadly congruent, with two distinct clades within the genus: the L. umbratilis clade (L. umbratilis + L. lirus + (L. fasciolaris + (L. ardens, L. matutinus))) and the L. bellus clade (L. fumeus + L. snelsoni + (L. roseipinnis + (L. atrapiculus + (L. bellus, L. algenotus)))). Support is weak at the base of several clades, but strongly supported nodes differ significantly from prior investigations. In particular, our results confirm and extend earlier studies recovering two clades within Lythrurus corresponding to groups with largely "northern" and "southern" geographic distributions. Several species in this genus are listed in the United States as threatened or of special concern due to habitat degradation or limited geographic ranges. In this study, populations assigned to L. roseipinnis show significant genetic divergence suggesting that there is greater genetic diversity within this species than its current taxonomy reflects. A full accounting of the biodiversity of the genus awaits further study.