Phoretic Behavior of Four Species of Alkali Bee Mites as Influenced by Season and Host Sex

The phoretic relationships of four species of mites [Caloglyphus boharti Cross, Glyphanoetus nomiensis Cross, Imparipes americanus (Banks), and Trochometrid ium tribulatum Cross] to both immature and adult stages of the alkali bee, Nomia melanderi Cockerell, were investigated during the summers of 1955-1956 and 1965? 1966. Degree and incidence of infestation of these mites were analyzed in time, space, and by host sex. Each species occurred in specific location(s) on adult Nomia. Two species, C. boharti and G. nomiensis, located differentially according to bee sex. The same mite species attached in different locations on different bee species. At least two, and probably all, of the species studied were distributed on adult hosts in approximately bilaterally symmetrical fashion. All four of the species used the adult host only for transportation. There was no evidence that phoresy, per se, was responsible for bee mortality. The phoretic population of each species followed a unique pattern in time which was at least partly dependent upon bee sex. In /. americana, both bee sexes appeared to be infested equally at emergence, but new males apparently lost mites much more rapidly than new females. Hypopi of C. boharti infested a higher percentage of, and occurred in greater numbers on, male bees.