At least 2500 species of mites from 40 families are closely associated with birds, occupying all conceivable habitats in the nests and on the bodies of their hosts. No avian is free from a mite. Bird mites can be divided into those that dwell primarily in, or near, the nest and those that reside mainly on the body of the host. The best studied nest-dwelling mites are blood feeders from the genera Dermanyssus and Ornithonyssus (shown here is a micrograph of a female Ornithonyssus bursa, a common nest parasite of passerines. These mites have short generation times and can rapidly build-up huge populations. For example, half a million northern fowl mites have been extracted from a single nest. Blood-feeding nest mites can reduce the reproductive success of their hosts by slowing development or even killing chicks.
Blow fly biology varies among the 1100 species and with environmental conditions so the following information is general.
Each female blow fly deposits thousands of eggs over her 2- to 8-week life span. Egg masses may consist of 1500 to 2,000 eggs, but the larger masses are usually the result of several females depositing eggs at the same location. Hatching usually occurs in less than 24 hours when conditions are warm and humid.The larvae feed by night and move downward into the nesting material during the day. This fascinating adaptation has, no doubt, evolved over many centuries of a close association of blowflies with cavity nesting birds. The larva avoids being eaten by the adult bird during the day, and feeds only after dark, when the helpless nestlings are easy prey. Blood is usually drawn from the feet or legs, often from between the toes. Depending on the temperature maggots usually complete development in 4 days. At the end of this period, larvae typically burrow in the nesting material and pupate for 5 to 7 days which the adult flies emerge. About a week later, females begin to deposit eggs and the life cycle is repeated. Blow flies usually develop from egg to adult in only 10 to 25 days and complete 4 to 8 generations each year.
Read more about the Blowfly at http://www.no-pest.com/Blowfly.htm
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