Lufenuron, a chitin-synthesis inhibitor, interrupts development of Drosophila melanogaster

The chitin-synthesis inhibitor lufenuron was administered to Drosophila melanogaster to better understand the effects of chitin-synthesis interruption during the development and reproduction of this insect. When larvae were fed a diet containing a low concentration (< 1 ppm) of lufenuron, mortality was observed during either larval or pupal development, depending on the dose. Survivor adults were unable to fly, probably due to abnormal cuticular development in the wing hinge regions of the thorax. Larvae fed a higher concentration (10 ppm) completed development within that instar, but died during ecdysis to the next instar, presumably due to inadequate cuticle synthesis. Third instar larvae pupariated, but the puparium was abnormal, and pupation did not occur. Adults fed 10 ppm showed normal viability but slightly depressed oogenesis; additionally, although their eggs were fertilized, they failed to hatch. Examination of the embryos showed that they completed development but were unable to perforate the surrounding vitelline membrane, probably due to a weakened chitinous mouth hook assembly that was insufficiently rigid to effect hatching. These results identify stages during D. melanogaster development when chitin synthesis and deposition are critical. This information will be useful for identifying chitin-synthesis mutants of this insect.