Bat-Infesting Chiggers (Trombiculidae) in Indonesia: Current Review, Distribution, and Hosts with Three New Records and their Morphometric Data.

Purpose: Even though the taxonomy of bat-infesting chiggers has been studied extensively, information about the distribution and morphological variability of many species is still lacking. In fact, the only available distribution records for several species are their type localities. The purpose of this paper is to broaden the knowledge of the Indonesian group.

Methods: Hosts and chiggers were captured from April 2018 to March 2020 in Bali and Nusa Penida Islands in Indonesia by using standard bat-capturing and parasite-collecting methods. A list of bat-infesting chiggers in Indonesia was compiled by searching the public databases using specific keywords.

Results: When compared with already published data on type specimens, the physical measurements and morphology of Whartonia diosi, W. maai and Grandjeana sinensis revealed only minor differences that fell within intraspecific variability of the mentioned species. Two species (W. diosi and G. sinensis) are recorded here for the first time outside of their type localities (Panay Island in the Philippines and China) and, in both cases, represent the first records for Indonesia. The checklist summarizes all 16 species in 9 genera of bat-infesting chiggers collected from 12 bat species belonging to 5 families all collected on 8 Indonesian islands.

Conclusion: Indonesia comprises more than 17,000 islands, is home to over 200 bat species, and harbors hundreds of still undiscovered caves. With such a huge potential for chigger diversity and endemism, it is likely that our results document only a fraction of the actual diversity.