Genome of the small hive beetle (Aethina tumida, Coleoptera: Nitidulidae), a worldwide parasite of social bee colonies, provides insights into detoxification and herbivory

Abstract

BackgroundThe small hive beetle (Aethina tumida; ATUMI) is an invasive parasite of bee colonies. ATUMI feeds on both fruits and bee nest products, facilitating its spread and increasing its impact on honey bees and other pollinators. We have sequenced and annotated the ATUMI genome, providing the first genomic resources for this species and for the Nitidulidae, a beetle family that is closely related to the extraordinarily species-rich clade of beetles known as the Phytophaga. ATUMI thus provides a contrasting view as a neighbor for one of the most successful known animal groups.ResultsWe present a robust genome assembly and a gene set possessing 97.5% of the core proteins known from the holometabolous insects. The ATUMI genome encodes fewer enzymes for plant digestion than the genomes of wood-feeding beetles but nonetheless shows signs of broad metabolic plasticity. Gustatory receptors are few in number compared to other beetles, especially receptors with known sensitivity (in other beetles) to bitter substances. In contrast, several gene families implicated in detoxification of insecticides and adaptation to diverse dietary resources show increased copy numbers. The presence and diversity of homologs involved in detoxification differ substantially from the bee hosts of ATUMI.ConclusionsOur results provide new insights into the genomic basis for local adaption and invasiveness in ATUMI and a blueprint for control strategies that target this pest without harming their honey bee hosts. A minimal set of gustatory receptors is consistent with the observation that, once a host colony is invaded, food resources are predictable. Unique detoxification pathways and pathway members can help identify which treatments might control this species even in the presence of honey bees, which are notoriously sensitive to pesticides.

The draft genome of the specialist flea beetle Altica viridicyanea (Coleoptera: Chrysomelidae) provides insight into host plant specialization

“…Furthermore, meta-analyses have established that the size of the P450, CCE and GST gene families are correlated with insect diet breadth [66,67,74]. Consistent with these ideas, in A. viridicyanea, the number of detoxifying genes is larger than that of the closely-related oligophagous Leptinotarsa decemlineata (197 genes) [21,67], but smaller than that of the seed feeding T. castaneum (275 genes) [26,75].…”

“…Consequently, the genome for A. viridicyanea will add to our genomic resources for a monophagous member of the Chrysomelidae. Furthermore, this assembly will also expand our knowledge of beetles in general as we currently have only 21 published beetle genome assemblies [22,[24][25][26][27][28][29][30][31][32][33] (Table S1) which is a comparably small number for a diverse insect group with nearly 400,000 described species [34][35][36]. Finally, the high-quality genome assembled here will provide an important resource for further studies on host plant adaptation and functionally a liated genes.…”

In silico identification and assessment of insecticide target sites in the genome of the small hive beetle, Aethina tumida

“…Over-reliance on insecticides will undoubtedly select for insecticide resistance and reduce the effectiveness of these tools for SHB control. The insecticide target sites in the SHB genome described here and elsewhere [17] provide a susceptible benchmark for designing molecular diagnostic tools to identify and monitor changes in resistance alleles. As more reports of insecticide sensitivity are made available, potential differences in toxicity between SHB and honey bees may be explained by differences in target sites.…”

“…Understanding the genetic basis of insecticide resistance is the foundation for designing an accurate, effective, and enduring resistance management strategy. A description of the SHB acetylcholinesterases (Ace1 and Ace2) and voltagegated sodium channel (Na v1 ) have appeared in recent publications of the SHB genome [17] and transcriptome [18]. Ace and Na v1 are the target sites of organophosphate and pyrethroid insecticides, respectively, which are the only two classes of insecticide registered for SHB control in the USA.…”

Draft Genome of a Blister Beetle Mylabris aulica

“…Then, this model was used in Augustus (Burge and Karlin, 1997) and SNAP (http://korflab.ucdavis.edu/) (Goodswen et al, 2012) for ab initio prediction. For the homology-based method, we downloaded the gene sets of H. cichorii (Wu et al, 2018), H. phaleratus, Aethina tumida (Evans et al, 2018), Anoplophora glabripennis (Mckenna et al, 2016), Tribolium castaneum (Richards et al, 2008), Dendroctonus ponderosae (Keeling et al, 2013), Leptinotarsa decemlineata (Schoville et al, 2018), Diabrotica virgifera virgifera (Coates et al, 2012), and Bombyx mori from the GenBank database. These homologous protein sequences were concatenated and imported into GeneWise (Trapnell et al, 2012) to search for genes.…”