Eylaidae Leach, 1815

Gerecke, Reinhard, 2020, The early derivative water mites (Acari: Hydrachnidia, superfamilies Eylaoidea, Hydrachnoidea and Hydryphantoidea) of Madagascar, Zootaxa 4727 (1), pp. 1-77 : 8

Family Eylaidae Leach, 1815

The only known genus of the family, Eylais , is distributed worldwide, but the documentation of its diversity is at a preliminary stage. In the northern hemisphere, until the mid-20 th century, high numbers of species were described on the base of small differences in the shape of the frontal eye sclerite. Recently, many were synonymized when the high intraspecific variability of many character states was detected. Studies of B.P. Smith (1986) demonstrated the existence of species easily distinguishable at the larval stage, but not displaying remarkable differences as adults. Therefore, future taxonomic work should concentrate on all developmental stages, and at best include also molecular analyses.

As far as data are available, Eylais larvae are parasites of adult water beetles belonging to at least 6 different families (e.g., Zawal 2004). The fact that many of these host insects are highly active and have extensive flight ranges, probably explains why many Eylais species have an extended distribution area and are able to colonize isolated habitats in arid areas or remote oceanic islands. The eylaid fauna of Madagascar is still strongly underdocumented. In addition to two species with a wide distribution over several continents, for two further, possibly endemic, but uncertain species, we are provided with single records only. The new records given here are based on the very old, probably outdated systematics of Koenike (1898).