The horned passalus, Odontotaenius disjunctus (Illiger), is host to a variety of parasites, including a little-studied nematode, Chondronema passali (Leidy), that can number in the thousands in a single beetle. We attempted to determine the effects of this parasite on two measures of host fitness, physical strength and body size of adult beetles collected from hardwood logs at two sites in Georgia, USA. For a subset of the beetles, we measured their individual pulling strength using a dynamometer and data-logging apparatus. We also recorded the live weight of all beetles and from another subset a composite measure of body size based on digital images. Beetles were dissected and nematode infection status was assessed for all beetles. Of all beetles examined in this study (49 females, 44 males), we detected C. passali in 63 (67.7%) individuals. Prevalence in males did not differ from females. Infections ranged from 10 to over 1,000 individual nematode larvae per beetle. There was no significant effect of infection on maximum pulling force after accounting for body size and gender. Beetles with nematode infections weighed significantly more than those without nematodes and were significantly larger in body size. These results suggest the effects of this parasite are minimal to the host, and infections may even confer an advantage via the increase in size. Based on a review of the relevant literature, this appears to be a rare phenomenon among the many insect-nematode parasite relationships.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 67 • No. 2