Tropilaelaps mercedesae parasitism changes behavior and gene expression in honey bee workers

Abstract

Tropilaelaps mercedesae is one of the most problematic honey bee parasites and has become more threatening to the beekeeping industry. Tropilaelaps can easily parasitize immature honey bees (larvae and pupae) and have both lethal and sublethal effects on the individual worker bees. Our study for the first time experimentally assessed the effects of T. mercedesae on olfactory learning, flight ability, homing ability as well as transcriptional changes in parasitized adult honey bees. T. mercedesae infestation had negative impacts on olfactory associated function, flight ability, and homing rate. The volume of the mushroom body significantly increased in infested honey bees, which may be correlated to the lower sucrose responsiveness as well as lower learning ability in the infested bees. The gene expression involved in immune systems and carbohydrate transport and metabolism were significantly different between infested bees and non-infested bees. Moreover, genes function in cell adhesion play an essential role in olfactory sensory in honey bees. Our findings provide a comprehensive understanding of European honey bees in response to T. mercedesae infestation, and could be used to further investigate the complex molecular mechanisms in honey bees under parasitic stress.

Tropilaelaps mercedesae Infestation Is Correlated with Injury Numbers on the Brood and the Population Size of Honey Bee Apis mellifera

“…An increase in mite infestation rates can be expected where the presence of injuries on honey bees caused by parasitic mites is relatively high because these mites have rapid locomotion and reproductive rates [ 12 , 23 ]. Indeed, a previous study has reported that increased numbers of injuries are positively correlated with increased numbers of actively feeding mites [ 8 ].…”

“…Tropilaelaps mite infestations showed a negative effect on the olfactory learning, flight ability, and homing ability of A . mellifera [ 12 ]. Gao et al [ 12 ] reported that mushroom bodies of Tropilaelaps mite-infested honey bees significantly increased when compared with uninfested honey bees, which may be related to a lower learning ability in the infested honey bees.…”

“…mellifera [ 12 ]. Gao et al [ 12 ] reported that mushroom bodies of Tropilaelaps mite-infested honey bees significantly increased when compared with uninfested honey bees, which may be related to a lower learning ability in the infested honey bees. In general, the mushroom body of insect brains is associated with antennal lobes containing primary olfactory neuropils [ 53 ].…”

“…Parasite infestation is one of the most critical factors that have led to bee population decline worldwide [ 5 , 6 ]. Previous studies have postulated that parasitic mites in the genus Tropilaelaps and Varroa are the main factors that severely damage honey bee colonies in the continent of Asia [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

Identification and pathogen detection of a Neocypholaelaps species (Acari: Mesostigmata: Ameroseiidae) from beehives in the Republic of Korea

“…These mites have co-evolved with their hosts, developing an intimate dependence on honeybees for survival. While Varroa mites primarily parasitize bees in their brood cells [6,13], Euvarroa and Tropilaelaps demonstrate host specificity towards Dwarf honeybees (Apis florea) and giant honeybees (Apis dorsata), respectively [7,[14][15][16][17]. The most pathogenic species within the genus Acarapis primarily parasitize A. mellifera but have also been found in Asian honeybee species [18][19][20][21][22].…”