Combined neonicotinoid pesticide and parasite stress alter honeybee queens’ physiology and survival

Abstract

Honeybee colony survival strongly relies on the queen to overcome worker losses exposed to combined stressors like pesticides and parasites. Queen’s capacity to withstand these stressors is however very little known. The effects of the common neonicotinoid pesticide imidacloprid in a chronic and sublethal exposure together with the wide distributed parasite Nosema ceranae have therefore been investigated on queen’s physiology and survivorship in laboratory and field conditions. Early physiological changes were observed on queens, particularly the increase of enzyme activities (catalase [CAT] and glutathione-S-transferase [GST] in the heads) related to protective responses to xenobiotics and oxidative stress against pesticide and parasite alone or combined. Stressors also alter the activity of two other enzymes (carboxylesterase alpha [CaE α] and carboxylesterase para [CaE p] in the midguts) involved in metabolic and detoxification functions. Furthermore, single and combined effects of pesticide and parasite decrease survivorship of queens introduced into mating hives for three months. Because colony demographic regulation relies on queen’s fertility, the compromise of its physiology and life can seriously menace colony survival under pressure of combined stressors.

Perspectives of studying causes and consequences of the mass death of honeybees

“…Коли швидкість утворення АФО переважає над швидкістю їх детоксикації, відбувається пошко-дження клітинних структур. За вираженого або тривалого стресу концентрація АФО у клітині може підвищуватися і тоді мобілізація захис-них систем клітини слабшає, у результаті чого активуються процеси, які спричиняють апоптоз або некроз [2,6,8,9,33]. Зумовити розвиток оксидативного стресу в організмі медоносної бджоли можуть вищезгадані чинники.…”

Chemical manipulation of honey bee behavior

“…Studies have found that neonicotinoids have detrimental effects on bee navigation, motivation to forage, and social communication . They additionally negatively affect bee immunocompetence, gland and respiratory system development, reduce the survival of queens with Nosema infection, and reduce sperm viability in queens (Hatjina et al 2013, Chaimanee et al 2016, Dussaubat et al 2016). The fungicide chlorothalonil has been shown to alter the compilation of bee gut flora, potentially altering functionality resulting in decreased vigor (Kakumanu et al 2016).…”

“…Adult bee exposure to imidacloprid, during the first two weeks after emergence, negatively affects development of the hypopharyngeal glands and respiratory system (Hatjina et al 2013). Imidacloprid has also been shown to decrease the survival of queen honey bees that have Nosema ceranae infections (Dussaubat et al 2016). …”

“…Exposure to these miticides can have negative effects associated with olfactory learning, immune gene suppression, and decreased locomotor activity in bees , Teeters et al 2012, Cizelj et al 2016. Several pesticides in the neonicotinoid class negatively affect immunocompetence, gland and respiratory development in bees, as well as reducing the survivability of queens exposed to other stressors (Hatjina et al 2013, Chaimanee et al 2016, Dussaubat et al 2016. Methods to reduce the interaction times of pollinators and pesticides are needed to help in reducing the stress on managed bee colonies.…”

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 1: new molecules, metabolism, fate, and transport

“…In this context, it should be mentioned that Nicodemo et al (2014) showed that fipronil and imidacloprid impair energy production in mitochondria. Dussaubat et al (2016) studied sublethal effects of imidacloprid together with the widely distributed microsporidian parasite Nosema ceranae on queen's physiology and survivorship, both under laboratory and field conditions. The study showed that combined neonicotinoid pesticide and parasite stress alter honeybee queens' physiology and survival.…”