Platypygius crassus (Karny, 1907)
Order Grasshoppers and crickets (Orthoptera)
Family Short-horned grasshoppers (Acrididae)
Conservation status: in Bulgaria: Critically endangered CR [B2ab(ii)c(ii)].
General distribution. The Aegean Sea coast of Northern Greece; the Black Sea coast of Bulgaria, the Ukraine and Russia; Moldova and the Caspian Sea coast of Russia to the delta of the Volga river.
Distribution and abundance in Bulgaria. Found in a locality restricted in its area near the mouth of the Ropotamo River (1958, 1961, 1962, 1963 and 1967) [1, 2, 3]. Later it was not found. Considerable fluctuations in the population abundance were observed, with tendencies for a decline: high in 1958, very low in 1961, low in 1962-1967 [2, 3].
Habitats. A halophylic mesohygrobiotic and euryhygrophilic species. It inhabits sunlit, entirely open salty sandy terrains, partly flooded by sea water, without herbaceous vegetation or with a low one, very thinned, with a predomination of Artemisia santonicum along the low riverbanks near the sea shore .
Biology. In Bulgaria, adults are found in July and August but in other parts of the range they have been recorded from June to September . The eggs overwinter in soil, laid in groups in "cocoons", and hatch at the end of April or in May. Because of the strong requirements of the species of salty soils along the sea shore, its food mainly contains herbaceous halophilic plants. It keeps to the soil. In 1958, the only year when a high abundance of the population was observed, the specimens moved in groups displaying a gregarious behaviour .
Similar species. None.
Negative factors. Tourist infrastructure and intensive development of tourism in the region between Sozopol and Primorsko are the major factors restricting the area of the typical habitat of Platypygius crassus.
Conservation measures taken. The habitat is included in the Ropotamo Reserve.
Conservation measures needed. Study of the current state of the population, aimed at determining concrete measures for conservation. Ban on activities around the mouth of Ropotamo that disturb the normal ecological parameters of the habitat.
References. 1. Pesev, 1962a; 2. Pesev, 1971; 3. Peshev, Djingova, 1974; 4. Harz, 1975.
Authors: Dragan Chobanov, Alexi Popov