Surface skin lipids of birds--a proper host kairomone and feeding inducer in the poultry red mite, Dermanyssus gallinae.

A factor in bird skin responsible for D. gallinae feeding on its natural hosts was investigated. Both skin and plumage of chickens contained substance(s) attractive to mites which was easily dissolved in benzene derivates, amyl acetate or ethyl acetate, thermostabile up to 100 degrees C, nonvolatile, alkaline hydrolysable, and susceptible to oxidation. Components of surface skin lipids were ascertained to be the host-markers when using chromatographic separation and consecutive in vitro feeding technique for testing the isolates. Purified specific fowl diol esters of fatty acids prepared from the secretion of uropygial (preen) glands of hens were at least as effective a feeding stimulant for the mites as the natural extract of surface lipids of birds.