Honeybees, Apis mellifera, are important pollinators of many economically important crops. However, one of the reasons for their decline is pathogenic infection. Nosema disease and American foulbrood (AFB) disease are the most common bee pathogens that propagate in the gut of honeybees. This study investigated the impact of gut-propagating pathogens, including Nosema ceranae and Paenibacillus larvae, on bacterial communities in the gut of A. mellifera using 454-pyrosequencing. Pyrosequencing results showed that N. ceranae was implicated in the elimination of Serratia and the dramatic increase in Snodgrassella and Bartonella in adult bees’ guts, while bacterial communities of P. larvae-infected larvae were not affected by the infection. The results indicated that only N. ceranae had an impact on some core bacteria in the gut of A. mellifera through increasing core gut bacteria, therefore leading to the induction of dysbiosis in the bees’ gut.

Bumblebees (tribe Bombini, genus Bombus Latreille) play a pivotal role as pollinators in mountain regions for both native plants and for agricultural systems. In our survey of northern Thailand, four species of bumblebees (Bombus (Megabombus) montivagus Smith, B. (Alpigenobombus) breviceps Smith, B. (Orientalibombus) haemorrhoidalis Smith and B. (Melanobombus) eximius Smith), were present in 11 localities in 4 provinces (Chiang Mai, Mae Hong Son, Chiang Rai and Nan). We collected and screened 280 foraging worker bumblebees for microsporidia (Nosema spp.) and trypanosomes (Crithidia spp.). Our study is the first to demonstrate the parasite infection in bumblebees in northern Thailand. We found N. ceranae in B. montivagus (5.35%), B. haemorrhoidalis (4.76%), and B. breviceps (14.28%) and N. bombi in B. montivagus (14.28%), B. haemorrhoidalis (11.64%), and B. breviceps (28.257%).

This study was carried out to assess the impact of pollen feeding from common floral sources in Thailand (e.g., tea, coffee, and bitter bush) on royal jelly (RJ) properties (i.e., protein pattern, (E)-9-hydroxydec-2-enoic acid (9-HDA), and (E)-10-hydroxy-2-decenoic acid (10-HDA) contents and antibacterial activity). The protein patterns from three different pollen were different, while RJ samples derived from bee colonies fed by different pollen, exhibited similar protein patterns. RJ samples from bee colonies fed by pollen from bitter bush and coffee possessed the higher 10-HDA levels than RJ collected from bee colonies fed by tea pollen. The 9-HDA was found in lower amount than 10-HDA in every sample. Even though the antibacterial activities of pollen were varied, however, RJ samples exhibited similar antibacterial properties. This is the first report showing that different pollen feeding affected 10-HDA contents, but not affected overall protein content and antibacterial properties.

Honey bees are economically important insects for crop pollination. They play a significant role as pollinators of wild plants and agricultural crops and produce economical products, such as honey, royal jelly, wax, pollen, propolis, and venom. Despite their ecological and economical importance, the global honey bee population is in decline due to factors including pathogens, parasites, intensive agriculture, and pesticides. Moreover, these factors may be interlinked and exacerbate the loss of honey bees. This study aimed to investigate the interaction between a pesticide, thiamethoxam, and deformed wing virus type A (DWV-A) to honey bees and the effects on survival rate, wing characteristics, and expression of immune and apoptosis genes in Apis mellifera. We described the potential interaction between thiamethoxam and DWV-A on honey bee wing characteristics, DWV-A loads, and the expressions of immune (defensin, abaecin, and hymenoptaecin) and apoptosis genes (buffy, apaf1, caspase3-like, caspase8-like, and caspase9-like). Honey bee larvae were fed with three different thiamethoxam doses (0.001, 1.4, and 14.3 ng/µL of the diet). Then, thiamethoxam-treated white-eyed pupae were injected with 10⁷ copy numbers/honey bee of the DWV-A genome. The interaction between thiamethoxam and DWV-A caused a high mortality rate, crippled wings in newly emerged adult honey bees (100%), and resulted in induced expression of hymenoptaecin gene compared to the control group, while downregulation of caspase8-like, caspase9-like genes compared to the DWV injection group. Therefore, the potential interaction between thiamethoxam and DWV-A might have a deleterious effect on honey bee lifespan. The results from this study could be used as a tool to combat DWV-A infection and mitigate pesticide usage to alleviate the decrease in the honey bee population.