Host Range Difference and Reproductive Incompatibility among Five Populations of the Citrus Red Mite, Panonychus citri(McGregor)(Acari: Tetranychidae).

Abstract

The developmental success of the citrus red mite, Panonychus citri (McGregor) and its oviposition on47species of plant were studied for five populations collected from the satsuma mandarin, Japanese holly, Japanese yew, orange osman and fortunes osmanthus. The host ranges for three populations (citrus type) that developed on citrus trees but not on any of the oleaceous plants, were similar to one another, and were different from those of the other two populations (oleaceous type) that normally developed on oleaceous plants, although five plants (sour orange, trifoliate orange, pear, fig and kudzu vine) were the common hosts of all five populations. In intrapopulation crosses, all populations produced both female and male progeny. Inter-population crosses between the three populations of the citrus type and between the two populations of the oleaceous type produced both sexes, showing that populations belonging to the same type were compatible each other. Mites of the oleaceous type produced F1 females when mated with the mites of the citrus type. However, these F1 females failed to lay eggs and/or failed to produce fertile F2 females, even if the F1 females mated with the males from the parental populations . This trend indicates that the oleaceous type is reproductively incompatible with the citrus type. This study indicates that P. citri contains at least two different biological entities, which show not only differences in host ranges but also a lack of reproductive compatibility with one another.