SOME ASPECTS OF SEX IN THE EUROPEAN RED MITE, PANONYCHUS ULMI

Abstract

AbstractThe proportion of females of the European red mite, Panonychus ulmi (Koch), reared from periodic samples of larvae and nymphs from a peach orchard averaged about 75% with little seasonal variation. A male can copulate at least 11 times in 2 hr, and inseminate at least 26 females during its life span, but many later copulations inseminate the females incompletely or not at all. Some females copulate at least three times but one copulation with a young male enables a female to lay the usual proportion of fertilized (female) eggs, which exceeds that of unfertilized (male) eggs. No evidence of males with only one nymphal instar, as reported in Europe, was found in mites reared at 15°, 22°, or 30 °C. Males disperse much more rapidly than females.