Infestation of humans and non-human primates with <i>Cordylobia rodhaini</i> (Diptera: Calliphoridae) in a ‘hotspot’ of furuncular myiasis

Lund's fly, <i>Cordylobia rodhaini</i> (Calliphoridae), is an African blowfly considered to be an uncommon cause of furuncular myiasis. Far less is known about <i>C. rodhaini</i> than about the more frequently reported tumbu fly, <i>Cordylobia anthropophaga</i>. From 2011 to 2020, fly larvae were collected and analysed from 11 independent infestations of wild non-human primates and 10 independent infestations of humans (including 1 from this author) in Kibale National Park, Uganda. All 21 larvae were identified morphologically and genetically as <i>C. rodhaini</i>. Larvae from non-human primates were on average 4·5 times larger than larvae from humans. Non-human primates had empty furuncles, indicating recent egress of mature third instar larvae and completion of the larval stage of the lifecycle; however, eastern chimpanzees (<i>Pan troglodytes schweinfurthii</i>) were photographed removing larvae from furuncles of grooming partners. A total of 4 closely related mitochondrial haplotypes were identified, 2 of which were shared by larvae from humans and non-human primates. Genetic variation within <i>C. rodhaini</i> from this single location was comparable to that within other calliphorid species. Non-human primates may play a larger role in the maintenance of <i>C. rodhaini</i> than previously known, and in certain forested locations <i>C. rodhaini</i> may be the predominant cause of furuncular myiasis. The sylvatic lifecycle of <i>C. rodhaini</i> may explain its differentiation from <i>Cordylobia anthropophaga</i>, which has a peridomestic lifecycle. In general, these findings shed new light on how myiasis-causing flies can adapt to different ecological settings and be regionally rare but locally abundant.