Biology of <I>Tyrophagus pacificus</I> Fan & Zhang (Acari: Acaridae) Infesting Gold Cordyceps

Abstract

Gold cordyceps, Cordyceps militaris (L.) Link, is a medical important mushroom due to its medicinal properties resulted in having a high price. Thus, a number of cultivators try to culture this mushroom in laboratory but some are occasionally infested by mite, Tyrophagus pacificus Fan & Zhang. There was no study report dealing with T. pacificus in Thailand. The biology of T. pacificus was investigated and revealed that the dominant morphological characteristics of the adult female was spermathecal sac which was narrow from copulatory opening and flat at base. For adult male, the aedeagus was very long, with two obvious curves and distal half reversely curved, tapering from base to tip. Biological study of T. pacificus was conducted using 15 day-old C. militaris on PDA as food under the laboratory conditions at 19.89 ± 0.44 °C and with relative humidity of 82.52 ± 5.01%. The result showed that the development of T. pacificus consisted of 5 stages; egg, larva, protonymph, deutonymph and adult, with the average durations of 7.13 ± 2.07, 0.96 ± 0.00, 1.97 ± 0.02, 3.87 ± 0.37 and 14.34 ± 1.48 days, respectively. Due to the life cycle of T. pacificus was short so the mite could increase its population so rapidly. Thus, T. pacificus trended to be the promising pest of C. militaris.  The data on life history can be used as a database for predicting the damage and controlling T. pacificus on C. militaris culture.