美国食品与农业研究基金会展会观感

2020年2月5日,我们参加了在华盛顿特区由美国食品与农业研究基金会组织举办的主题为"孕育未来"的会议和活动。美国食品与农业研究基金会全称是Foundation of Food and Agriculture Research,简称FFAR。它是2014年7月23日由美国农业部(USDA)牵头成立的一个研究基金会。根据当年国会通过的《农场法案(Farm Act)》财政拨2亿美元,每期5年,同时接受企业或财团等的捐赠。

Comparative susceptibility and immune responses of Asian and European honey bees to the American foulbrood pathogen, Paenibacillus larvae

American foulbrood (AFB) disease is caused by Paenibacillus larvae. Currently, this pathogen is widespread in the European honey bee— Apis mellifera. However, little is known about infectivity and pathogenicity of P. lan'ae in the Asiatic cavity-nesting honey bees, Apis cerana. Moreover, comparative knowledge of P. larvae infectivity and pathogenicity between both honey bee species is scarce. In this study, we examined susceptibility, larval mortality, survival rate and expression of genes encoding antimicrobial peptides (AMPs) including defensin, apidaecin, abaecin, and hymenoptaecin in A. mellifera and A. cerana when infected with P. larvae. Our results showed similar effects of P. larvae on the survival rate and patterns of AMP gene expression in both honey bee species when bee larvae are infected with spores at the median lethal concentration (LC5 0 ) for A. mellifera. All AMPs of infected bee larvae showed significant upregulation compared with noninfected bee larvae in both honey bee species. However, larvae of A. cerana were more susceptible than A. mellifera when the same larval ages and spore concentration of P. larvae were used. It also appears that A. cerana showed higher levels of AMP expression than A. mellifera. This research provides the first evidence of survival rate, LC50 and immune response profiles of Asian honey bees, A. cerana, when infected by P. larvae in comparison with the European honey bee, A. mellifera.

Effects of Imidacloprid and Varroa destructor on survival and health of European honey bees, Apis mellifera

There has been growing concern over declines in populations of honey bees and other pollinators which are a vital part to our food security. It is imperative to identify factors responsible for accelerated declines in bee populations and develop solutions for reversing bee losses. While exact causes of colony losses remain elusive, risk factors thought to play key roles are ectoparasitic mites Varroa destructor and neonicotinoid pesticides. The present study aims to investigate effects of a neonicotinoid pesticide Imidacloprid and Varroa mites individually on survivorship, growth, physiology, virus dynamics and immunity of honey bee workers. Our study provides clear evidence that the exposure to sublethal doses of Imidacloprid could exert a significantly negative effect on health and survival of honey bees. We observed a significant reduction in the titer ofvitellogenin （Vg）, an egg yolk precursor that regulates the honey bees development and behavior and often are linked to energy homeostasis, in bees exposed to lmidacloprid. This result indicates that sublethal exposure to neonicotinoid could lead to increased energy usage in honey bees as detoxification is a energy-consuming metabolic process and suggests that Vg could be a useful biomarker for measuring levels of energy stress and sublethal effects of pesticides on honey bees. Measurement of the quantitative effects of different levels of Varroa mite infestation on the replication dynamic of Deformed wing virus （DWV）, an RNA virus associated with Varroa infestation, and expression level of immune genes yields unique insights into how honey bees respond to stressors under laboratory conditions.