Trogulus megaligrava is an endemic harvestman species, recorded only from the Megali Grava cave on Corfu, Greece. It has an area of occupancy (AOO) and extent of occurrence (EOO) both estimated at 4 km². The species' habitat is threatened by the high rate of tourist visits annually, while tourist recreational plans in the cave will likely affect the habitat tremendously. Therefore, the species is assessed as Critically Endangered under criterion B (CR B1ab(iii)+2ab(iii)). A conservation plan for the cave and more research in species' distribution, ecology and its possible threats are needed.

The species is only known from the type locality, which is the Cave Megali Grava in Corfu, Greece (Schönhofer et al. 2013).

There are no population data for the species.

Trogulus megaligrava is only known from the Megali Grava cave on Corfu island. The species is a possible troglophile, though this needs verification. According to Schönhofer et al. (2013), the species is often hidden in the very scarce vegetation of the cave, where many juveniles have been spotted. Large snails, which are abundant in the cave, could be a possible food source for the species.

The Megali Grava cave has many visitors each year, who trample the cave floor, posing a severe threat to the cave population. The sparse vegetation where the species has been found is easily accessible by the visitors. Touristic development (e.g., touristic facilities, illumination constructions, etc.) of the cave is certainly a plausible future threat to the species (K. Paragamian pers. comm. 2023).

There are no ongoing conservation actions for the species. A conservation plan is definitely needed for the proper management of the touristic development of the cave.