Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 1996
Publication Date: N/A
Interpretive Summary: Developing environmentally compatible insect pest control strategies to reduce pesticide use requires new knowledge of the biochemical and endocrine mechanisms regulating pest growth and development. Interference with the feeding or egg maturation process in the stable fly, Stomoxys calcitrans, would provide relief from this blood-feeding, livestock insect pest. We have identified a novel steroid hormone cycling mechanism in this multiple blood-feeding pest, further analysis of which could identify points of intervention for blocking egg maturation and blood feeding. Such information will be useful in generating control agents that selectively disrupt development of this, and possibly other, livestock pests.
The effect of blood-feeding on total and specific immunoreactive ecdysteroids in Stomoxys calcitrans adult females was examined following the 4th and 5th blood meals when total whole body and hemolymph ecdysteroids showed a dramatic increase in titer. In general, for both total and specific immunoreactive ecdysteroids that included highly polar material, 20,26-dihydroxyecdysone, 20- hydroxyecdysone and ecdysone, there were clear differences between the effects of the 4th and 5th meals. Following the 5th meal, the titers rose sooner, reached higher levels and remained high longer than those following the 4th meal. This is the first examination of the effects of back-to-back blood meals on total and specific ecdysteroid levels in an intermittent, blood-feeding fly. These results suggest that both rates of synthesis and degradation are affected by blood feeding and that the number and possibly quantity of blood ingested affect the biochemical mechanisms that regulate ecdysteroid titers in S. calcitrans.