COMPARATIVE ECOLOGY OF BLOODSUCKING DIPTERA
Abstract
Distilled water introduced into the body cavity of the horsefly in large quantity (no less than half of body weight) lowers hemolymph osmotic pressure and causes necrosis of the organs and rapid death of a substantial number of individuals. Liquid which has entered directly into the body cavity is quickly excreted by the Malpighian vessels. Horseflies with parenterally administered Ringer's solution die from loss of water at the same time as control flies (by the end of two days). In the experiment the horseflies die of desiccation somewhat more rapidly than do mosquitoes and in somewhat larger percentage with the same loss of water. Horseflies withstand fluctuations in osmotic pressure of the hemolymph more poorly than do mosquitoes. This is apparently associated with their vital pattern (greater mobility providing the opportunity for more frequently drinking water and the associated adaptation to more stable osmotic conditions in the internal medium). The crop (ingluvies) in horseflies has, in addition to its role in double feeding, great significance in providing the organism with water. Water from the crop passes gradually into the stomach in small amounts, which eliminates the possibility of an abrupt drop in hemolymph osmotic pressure fatal to the organism and on the other hand ensures economical use of the water imbibed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 17, 1967
- Accession Number
- AD0675733
Entities
People
- Z. M. Denisova
Organizations
- United States Army Biological Warfare Laboratories