The ultrastructural basis of abnormal development of Brugia pahangi in refractory Aedes aegypti.

Cuticular abnormalities in larval Brugia pahangi at c. 12 hours post blood meal are the first signs of abnormal worm development in refractory Aedes aegypti. Normally developing B. pahangi undertakes large scale cuticular reorganization during the first larval stage, screting new cuticle to nearly six times the original volume. The inability of the first stage larva to carry out this cuticular reorganization in refractory A. aegypti is the basis of developmental abnormality. It is concluded that this failure on the part of the worm is caused by an alteration in the physiological environment of the flight muscle cells of refractory A. aegypti from that of susceptible A. aegypti.