Comparative Studies on the Karyotypes of Leptotrombidium deliense, L. fletcheri, and L. arenicola (Acari: Trombiculidae)

摘要

Cytogenetic data are available for some mites in the suborders Mesostigmata, Astigmata, Cryptostigmata, and Prostigmata but no information is available for mites of the family Trombiculidae. Included in this family is the genus leptotrombidium, which contains the vectors of scrub typhus, a febrile illness widely distributed in the Asiatic-Pacific region. In Malaysia, the 3 principal vectors are Leptotrombidium deliense, L. fletcheri and L. arenicola. We studied the colonies of these 3 species in our laboratory to determine 1) whether any cytotaxonomic difference might exist between these related species; and 2) whether any genetic mechanisms, such as sex determination, contribute to the various mite dynamics. The mitotic chromosomes of L. deliense and L. fletcheri showed 2n = 14, while those of L. arenicola showed 2n = 28. Chromosomes were generally small and dotlike, with lengths ranging from 1.1 to 1.9 micrometers. The best preparations were obtained from the testes of 2-day-old adults.