Adverse Effects of Diatomaceous Earth on Immature Duration, Mortality, Adult Deformity and Salivary Gland Morphometrics in Musca domestica L

Larvicidal bioassays against the third-instar larvae of the housefly Musca domestica were used to determine an LC50 of 0.6636 mg diatomaceous earth (DE) 100 mL-1 larval food medium. The lethal concentration thus estimated was then used to assess the effects of the DE on immature durations and mortalities, along with adult deformities of the houseflies from parental through F2 generations under laboratory conditions. Results show that the DE product not only lingered larval and pupal durations significantly (P<0.001), but it also killed significantly greater number of larvae and pupae (P<0.001) and induced significant adult deformities (P<0.001) in three successive generations. Moreover, the immature growth inhibitions following DE treatments were highly significant compared to the controls (P<0.001). All these DE-induced alterations could be interpreted in terms of the drastic changes in the morphometrics of the larval salivary glands of the insects. The present findings therefore have practical implications in relevance to the control strategies of this vector species of public health and veterinary importance