SURVIVAL AND REPRODUCTIVE OUTPUT OF CHIRONOMUS-TENTANS (DIPTERA, CHIRONOMIDAE) IN RESPONSE TO PARASITISM BY LARVAL UNIONICOLA-FOILI (ACARI,UNIONICOLIDAE)

Parasitic associations between larval Unionicola foili and the diptera n Chironomus tentans were established in the laboratory, and the effec ts of these water mite larvae on survival and reproduction of C. tenta ns were determined. Longevity of parasitized insects was not significa ntly different from those that were unparasitized. Furthermore, there was no significant difference in the onset of oviposition between para sitized and unparasitized female chironomids. However, infected female s oviposited significantly more eggs compared to uninfected controls. This study contradicts others indicating that water mite larvae severe ly reduce the survivorship and reproductive output of insects. The res ults are consistent with analyses indicating that degree of parasitism is not correlated with either duration of the parasitic phase or long evity of larvae following their parasitic association with chironomids . Larval U. foili apparently secure sufficient nutritional resources t o complete their development, yet their hosts still exhibit fitness co mponents expected for unparasitized individuals. Extreme site specific ity exhibited by larval U. foili may limit the degree of parasitism on host insects and in doing so preclude larval mites from achieving inf ection levels that could negatively impact host survival and reproduct ion.