Toxicity of Insecticides with Different Modes of Action to Apis Mellifera Larvae (Hymenoptera, Apidae)

Pesticides are one of the elements that lead to the decline in honeybee populations. Honey bee while foraging collect nectar and pollen from various crops, can be exposed to pesticide residues, which may be transported into their colonies and consumed by the larvae. The objective of this study was to evaluate acute toxicity of fipronil and lambda-cyhalothrin, two commonly detected pesticides within beehives, on the larvae of Apis mellifera. The testes chemicals were given to three-day old larvae. Treatments were administered using a micropipette at the bottom of each chosen comb cell. Each treatment included sixty larvae per dosage and the experiment was repeated three times. Larvae were given only acetone in the control treatment. Fipronil and lambda-cyhalothrin were toxic to the larvae of A. mellifera with LD₅₀ values of 0.163 and 0.83 μg/larvae, respectively after seven days of exposure. The maximum mortality of 81.35% was recorded with a dose of 0.38 μg/larvae in Fipronil, whereas in lambda-cyhalothrin, it was 94.23% with a dose of 1.70 μg/larvae.