Toxicity Evaluation of Selected Plant Water Extracts on a Honey Bee (Apis mellifera L.) Larvae Model

So far, larval rearing in vitro has been an important method in the assessment of bee toxicology, particularly in pesticide risk assessment. However, natural products are increasingly used to control honey bee pathogens or to enhance bee immunity, but their effects on honey bee larvae are mostly unknown. In this study, laboratory studies were conducted to determine the effects of including selected aqueous plant infusions in the diet of honey bee (Apis mellifera L.) larvae in vitro. The toxicity of infusions from three different plant species considered to be medicinal plants was evaluated: tansy (Tanacetum vulgare L.), greater celandine (Chelidonium majus L.), and coriander (Coriandrum sativum L.). The impact of each on the survival of the larvae of honey bees was also evaluated. One-day-old larvae were fed a basal diet consisting of distilled water, sugars (glucose and fructose), yeast extract, and freeze-dried royal jelly or test diets in which distilled water was replaced by plant infusions. The proportion of the diet components was adjusted to the age of the larvae. The larvae were fed twice a day. The experiment lasted seven days. Significant statistical differences in survival rates were found between groups of larvae (exposed or not to the infusions of tansy, greater celandine, and coriander). A significant decrease (p < 0.05) in the survival rate was observed in the group with the addition of a coriander herb infusion compared to the control. These results indicate that plant extracts intended to be used in beekeeping should be tested on all development stages of honey bees.

Effect of a bradykinin potentiating factor separated from honey bee venom on thyroid gland and testis in hypothyroid white rats

Background Animal venoms have been known as a source of drugs beneficial to human health. Accordingly, this study was designed to determine the effect of bradykinin potentiating factor (BPF) separated from honey bee venom, Apis mellifera on histological structure, thyroid and male sex hormones of the thyroid gland and testis in a model of hypothyroid male white rats induced by carbimazole. Results This study includes male rats divided into 6 main and sub-groups (10 rats in each group). Control group, carbimazole group, levothyroxine group, BPF group, carbimazole group treated with levothyroxine and carbimazole group treated with BPF. At the end of experiments (60 days) rats were sacrificed and dissected; the blood was collected for determination of thyroid and male sex hormones. Also, the thyroid gland and testis were taken to histological study. The results indicated that, carbimazole group showed a highly significant decrease in thyroid hormones (T4, T3, Ft4 and Ft3) and male sex hormones (LH, FSH and testosterone), but a significant increase in TSH compared to control group. The results revealed that, treated groups with levothyroxine or BPF have significant increase in thyroid and male sex hormones and significant decreasein TSH. A significant improvement was detected in co-treated groups (hypothyroid groups) with levothyroxine or (BPF). Also, the present study showed a histopathological change in thyroid gland and testis of hypothyroid male rats. Conclusion Treated hypothyroid rats with levothyroxine as a drug and BPF as a natural product showed an improvement of these complications induced by carbimazole in thyroid gland and testis. Therefore, BPF may be benefical in treatment of hypothyroidism.

A honey bee symbiont buffers larvae against nutritional stress through lysine supplementation

Honey bees, the worlds most significant agricultural pollinator, have suffered dramatic losses in the last few decades. These losses are largely due to the synergistic effects of multiple stressors, the most pervasive of which is limited nutrition. The effects of poor nutrition are most damaging in the developing larvae of honey bees, who mature into workers unable to meet the needs of their colony. It is therefore essential that we better understand the nutritional landscape experienced by honey bee larvae. In this study, we characterize the metabolic capabilities of a honey bee larvae-associated bacterium, Bombella apis (formerly Parasaccharibacter apium), and its effects on the nutritional resilience of larvae. We found that B. apis is the only bacterium associated with larvae that can withstand the antimicrobial larval diet. Further, we found that B. apis can synthesize all essential amino acids and significantly alters the amino acid content of synthetic larval diet, largely by increasing the essential amino acid lysine. Analyses of gene gain/loss across the phylogeny suggest that two distinct cationic amino acid transporters were gained by B. apis ancestors, and the transporter LysE is conserved across all sequenced strains of B. apis. This result suggests that amino acid export is a key feature conserved within the Bombella clade. Finally, we tested the impact of B. apis on developing honey bee larvae subjected to nutritional stress and found that larvae supplemented with B. apis are bolstered against mass reduction despite limited nutrition. Together, these data suggest an important role of B. apis as a nutritional mutualist of honey bee larvae.

Diversity and abundance of pollinators in different winter crops at Sher-e-Bangla Agricultural University Campus, Dhaka

The study was conducted at Sher-e-Bangla Agricultural University campus to document the diversity and abundance of pollinators of five commonly grown winter crops, viz., mustard, coriander, niger, black cumin and linseed from October 2020 to February 2021. A total number of fifteen species was identified under eleven genera, nine subfamilies, nine families and seven super families. The study revealed that honey bees, halictids, nymphalids, coccinellids, butterflies and dipterans of genera Apis, Halictus, Lasioglossum, Aglais, Coccinella, Pieris, Eurema, Musca, Syrphid and Calliphora belonging to the families Apidae, Halictidae, Nymphalidae, Coccinellidae, Pieridae, Muscidae, Syrphidae and Calliphoridae, respectively were present in the field. The species diversity was high in mustard with 15 species while it was low in linseed (5 species). The honey bees, Apis sp. and sweat bees, Halictus sp. were common pollinators of all five oilseed crops, while the housefly, Musca domestica was specific to mustard. The honey bee, Apis sp. was predominant among all the insect pollinators in five oilseed crops. The Species Richness (SR), Shannon-Weaver index (H’), Community dominance and Question of similarity indices were applied to determine the diversity and abundance of pollinators. J. Biodivers. Conserv. Bioresour. Manag. 2021, 7(1): 33-42