Tebufenozide effects on the reproductive potentials of the mediterranean flour moth, Ephestia kuehniella

The Mediterranean flour moth, Ephestia Kuehniella Zeller (Lepidoptera: Pyralidae), is an important pest in stored products worldwide, and is one of the major pests in flour mills in Algeria. Because of environmental consideration, alternative approaches to neurotoxic insecticides, as well as safe, effective, and sound integrated pest management strategies pest control agents such as the insect growth regulator (IGRs) was developed. Among these IGRs, the bisacylhydrazine derivatives are nonsteroidal ecdysteroid agonists that mimic the action of moulting hormones and induce a precocious and incomplete moult in several insect orders. The reproductive potentials of adult E. kuehniella under laboratory conditions were evaluated using topical bioassays of an ecdysteroid agonist, RH-5992 (Tebufenozide), on pupae of E. kuehniella. This compound reduced the pupae development period witha dose response relationship. Data showed that tebufenozide, topically applied on newly exuvied pupae, significantly affected reproductive parameters in adults such as fecundity, fertility, egg laying periodand embryonic duration of development. In addition, length and width of eggs were also reduced by tebufenozide treatment. Moreover, these parameters were affected more when males treated withpesticide (Tebufenozide) were mated with untreated females or treated males and treated females were mated than when treated females were mated with untreated males and when both males and femaleswere untreated. In a second series of experiment, tebufenozide, topically applied on newly emerged pupae, was evaluated on weight and biochemical composition of gonads of newly emerged adults.Results showed a drastic decrease of gonadic weight and carbohydrate and lipid contents in testicles and ovaries, but, only protein contents of testicles were decreased by tebufenozide treatment. Thus, itseemed that males should be more sensitive than females to tebufenozide treatment