Physiological and Behavioral Changes in Honey Bees (Apis mellifera) Induced by Nosema ceranae Infection

Abstract

Persistent exposure to mite pests, poor nutrition, pesticides, and pathogens threaten honey bee survival. In healthy colonies, the interaction of the yolk precursor protein, vitellogenin (Vg), and endocrine factor, juvenile hormone (JH), functions as a pacemaker driving the sequence of behaviors that workers perform throughout their lives. Young bees perform nursing duties within the hive and have high Vg and low JH; as older bees transition to foraging, this trend reverses. Pathogens and parasites can alter this regulatory network. For example, infection with the microsporidian, Nosema apis, has been shown to advance behavioral maturation in workers. We investigated the effects of infection with a recent honey bee pathogen on physiological factors underlying the division of labor in workers. Bees infected with N. ceranae were nearly twice as likely to engage in precocious foraging and lived 9 days less, on average, compared to controls. We also show that Vg transcript was low, while JH titer spiked, in infected nurse-aged bees in cages. This pattern of expression is atypical and the reverse of what would be expected for healthy, non-infected bees. Disruption of the basic underpinnings of temporal polyethism due to infection may be a contributing factor to recent high colony mortality, as workers may lose flexibility in their response to colony demands.

Interaction betweenVarroa destructorand imidacloprid reduces flight capacity of honeybees

“…There is evidence that precocious foragers are indeed heavier and less efficient flyers than older foragers [43]. This precocious foraging due to parasite infestation was previously observed in bees exposed to Nosema ceranae infestation [44].…”

Long term effects of a food supplement HiveAlive™ on honey bee colony strength and Nosema ceranae spore counts

“…It is known that N. apis affects the epithelial cells lining the midgut of the adult bees (Bailey, 1955) and shortens the life span of both queens and adult bees (Wang & Moeller, 1970;Webster, 1994). Recent studies (Huang, Solter, Aronstein, & Huang, 2015;Natsopoulou, Doublet, & Paxton, 2015) suggest that N. ceranae is not more virulent than N. apis, in disagreement with older studies which suggested that it was associating it with colony depopulation and collapse (Hatjina et al, 2010;Higes et al, 2008;Paxton, 2010;Paxton et al, 2007) as well as colony losses in general, in particular in southern European countries (Botías, Martín-Hernández, Barrios, Meana, & Higes, 2013;Dussaubat et al, 2013;Globlirsch, Huang, & Spivak, 2013;Hatjina et al, 2011;Higes, Martín-Hernandez, & Meana, 2010, 2006Higes et al, 2005Higes et al, , 2008Soroker et al, 2011;Villa, Bourgeois, & Danka, 2013).…”

Chronic neonicotinoid pesticide exposure and parasite stress differentially affects learning in honeybees and bumblebees

“…Both neonicotinoid insecticides and parasites alter associative learning and cognitive functions of bees [5][6][7][8][9]. Acting as nicotinic acetylcholine receptor (nAChR) agonists [10], exposure to very low levels of neonicotinoids can disrupt normal function of neurons in the bee brain [11,12] and lead to disruptions in learning and memory [8,13].…”