Population Structure and Climate Effects on Geckobia Infestation in Ptyodactylus Geckos from Israel and West Bank, with Descriptions of G. parva sp. nov. and G. inermis sp. nov.

Scale mites of the genus Geckobia (Pterygosomatidae) are highly specialized permanent parasites of geckos, but their diversity and ecology in arid environments remain poorly understood. We examined 1135 museum specimens of Ptyodactylus geckos collected from 1965 to 1991 across Israel and the West Bank's Mediterranean-desert climate gradient to investigate environmental effects on Geckobia mite distributions and population structure. We analyzed prevalence, intensity, population structure, and seasonal patterns across three climate zones using standard parasitological methods and Köppen-Geiger climate classification. We describe two new species, Geckobia inermis sp. nov. and G. parva sp. nov., from Ptyodactylus puiseuxi and provide the first descriptions of previously unknown life stages: the male and nymphchrysalis of G. squameum and the imagochrysalis and larva of G. bochkovi. We report P. oudrii as a new host for G. synthesys and address taxonomic confusion regarding northern Israeli host populations following recent phylogenetic revisions of Ptyodactylus. Only 37 hosts were infected (3.26% prevalence), with a significant female bias in G. squameum populations. Most mites (94.6%) concentrated in the tympanum, where we documented a "double skin plug", closing the ear opening and creating favorable microenvironments for mite survival. The results demonstrate climate as the primary factor structuring mite distributions: environmental filtering showed systematic prevalence decline from Mediterranean zones (4.3%) to desert-edge areas (1.1%), representing a 3.9-fold gradient that exceeded host species effects by 5.2-fold. Populations exhibited phenological plasticity, with Mediterranean mites peaking in winter versus spring activity in semi-arid zones. These findings reveal how climate constrains ectoparasite persistence in arid systems, with implications for understanding parasite responses to environmental change.