THE HYPOPUS OF HEMISARCOPTES COCCOPHAGUS - DISTRIBUTION AND APOLYSIS

Hypopodes (deutonymphs) of Hemisarcoptes coccophagus Meyer (Astigmata Hemisarcoptidae), a parasite of armored scale insects (Homoptera Diasp ididae), had a contagious distribution while dispersing on their vecto r, Chilocorus bipustulatus (L.) (Coleoptera : Coccinellidae). When app earing in low numbers, most deutonymphs aggregated on one of the beetl e's elytra, whereas when occurring in higher numbers they were evenly distributed on both elytra. The hypopodes strongly preferred the subel ytral margins (especially their anterior-lateral parts) for attachment . These areas lack microsetae which are dense at the elytras' center. Deutonymphs were unable to complete their ontogenesis without staying a minimum of 48 hours under the vectors' elytra. Optimal contact-time with the beetles was 4-6 days, a period which induced ca 30% hypopodia l moltings. Host scales were not essential for apolysis, but their pre sence increased deutonymphal molting success. The significance of thes e results for enhancing the effectiveness of mite releases in the fiel d is discussed.