A scientific note on detection of honeybee viruses in the darkling beetle (Alphitobius diaperinus, Coleoptera: Tenebrionidae), a new pest in Apis cerana cerana colonies

Abstract

viruses / Apis cerana / Alphitobius diaperinus / honeybeesThe darkling beetle, also known as the lesser mealworm (Alphitobius diaperinus Panzer, Coleoptera: Tenebrionidae), exhibits a cosmopolitan distribution in poultry houses and piggeries (McAllister et al. 1995). A. diaperinus originates from sub-Saharan Africa, and this species has adapted to moist and warm poultry facilities (Geden and Hogsette 1994). A. diaperinus is a nocturnal omnivore considered as a serious pest of poultry facilities; low light environments, such as poultry houses and piggeries, provide an optimum habitat for A. diaperinus (Esquivel et al. 2012). Larvae and adults can damage poultry houses by tunnelling into insulation materials (Esquivel et al. 2012). The lesser mealworm beetle can also act as a reservoir of poultry pathogens, including viruses, bacteria and fungi (McAllister et al. 1995;Esquivel et al. 2012). Our study described the lesser mealworm inhabiting honeybee (Apis cerana cerana ) hives.A. diaperinus beetles were first found in our experimental apiary during our hive inspection in daytime twice a week. We further surveyed two more apiaries to further confirm that A. diaperinus is a new pest in A. c. cerana colonies. The three honeybee (A. c. cerana ) apiaries were located in Fuzhou, Fujian Province, Southeast China (latitude N26°08', longitude E119°28'). The honeybees were kept in a four-frame hive with Langstroth frames, and all of the colonies examined in the study were queenright and strong in population. A. diaperinus beetles were seen inhabiting the surface area of the solid bottom boards of hives, the cracks and joints of the bottom boards and the frames (top and bottom bars) of combs. Two to eighteen beetles were found in each inhabited hive. The number of beetles inhabiting the three different apiaries significantly differed, as revealed by nonparametric Kruskal-Wallis test (P < 0.05). The beetle parasitism rates in the three different apiaries were 34.5 % (10/29), 30.8 % (4/13) and 36.7 % (11/30), respectively. The beetle larvae were also observed in the cracks and crevices of the bottom boards of the hives. Some beetles were resting inside the empty cells of the combs. Other beetles were distributed in clusters in the shadow of the hives. They tended to avoid light and rested underneath the fallen hive debris when the inner cover of the hive was opened. However, beetle eggs were not observed in the hives.The adult lesser mealworms collected from A. c. cerana colonies were further used to examine whether they can act as reservoirs of common honeybee viruses. The adult lesser mealworms were individually surfacesterilised with 10 % sodium hypochlorite for 10 min and then used for RNA extraction with TRIzol (Invitrogen) in accordance with the manufacturer's instructions.Electronic supplementary material The online version of this article

A scientific note on the association of black fungus beetles (Alphitobius laevigatus, Coleoptera: Tenebrionidae) with Eastern honey bee colonies (Apis cerana)

“…The adults of A. laevigatus share a considerable similarity to those of the lesser mealworm, A. diaperinus (Panzer, 1796), which has recently been reported to inhabit A. cerana colonies (Li et al 2016). These two species can be separated from each other by the structure of their eyes (Rees 2004) and pronotum (Schawaller & Grimm 2014).…”

“…Since none of the involved beekeepers reported any BFB-associated damage, A. laevigatus appears to be a rather harmless associate of A. cerana colonies. Nevertheless, the BFB may carry bee pathogens such as viruses similar to A. diaperinus in A. cerana colonies (Li et al 2016) and effects on colonies may be seasonal and/or not obvious during visual inspections. Further detailed studies on A. laevigatus and other beetle associates will shed light on the underlying mechanisms enabling certain species, but not others, to exploit the usually well-defended social bee colonies as food sources and/or shelter.…”

Prevalence and behavioral bioassays of Platybolium alvearium (Coleoptera: Tenebrionidae) in colonies of honeybees (Apis: Hymenoptera: Apidae) in northern Vietnam

“…We additionally found that contrary to many bee pests, P. alvearium is more abundant in stronger, not weaker, honeybee colonies, although this result may reflect the general scarcity of the beetles at the time of our hive surveys. Our observations, coupled with the highly contrasting results of P. alvearium in northeastern India (Pande et al 2015) and reports of two Alphitobius beetle species associated with Apis cerana in Asia (Li et al 2016, Maitip et al 2016, suggest that additional investigations in Asia may alter our understanding of beetle symbionts of honeybees.…”

“…P. alvearium was also detected in surveys of bee hives in Himachal Pradesh, northern India (Chandra and Mattu 2017). Li et al (2016) described instances of Alphitobius diaperinus Panzer in Ap. cerana colonies in southeast China.…”

“…These beetles were found over a narrow geographic range but consistently occurred in high numbers in infested hives. While there is no evidence that they harm the bee colonies, Li et al (2016) showed that Al. diaperinus can act as a reservoir of bee diseases and thus this species may be of concern to beekeepers.…”