Benzoyl(phenyl)urea insecticides (such as triflumuron and diflubenzuron) are insect growth regulators commonly used in agrochemical products and as animal ectoparasiticides. These compounds, which interfere with chitin synthesis (Tunaz and Uygun, 2004) are taken up more by insect ingestion than by contact. Chitin synthesis inhibition disrupts cuticle formation. Therefore, benzoylurea compounds act primarily as larvicides or nymphicides by rupturing the malformed cuticle or causing death by starvation. The precise mode of action of benzoylurea insecticides is not known, but they are believed to act by blocking transport across epithelial membranes of UDP-N-acetylglucosamine, the base polymer unit of chitin (Tunaz and Uygun, 2004).