Burrowing byrsinus
Byrsinus fossor (Mulsant et Rey, 1865)
Order True bugs (Heteroptera)
Family Burrowing bugs (Cydnidae)
Conservation status: in Bulgaria: Extinct EX.
General distribution. Spain, France, Hungary, Romania, Bulgaria, the Ukraine (the Crimea), Southern Russia (the Black Sea coast and the Caspian Sea coast of Northern Caucasus), Armenia, Azerbaijan (the Caspian coast), Kazakhstan (the Caspian coast), Turkmenistan (the Caspian coast), Afghanistan, China (Xinjiang).
Distribution and abundance in Bulgaria. Found once in 1888 near Nesebar [1]. It has not been recorded for the second time in spite of the intensive studies of the heteropterous fauna along the Black Sea coast and of the family Cydnidae in Bulgaria [2, 3].
Habitats. Shore and continental sand dunes.
Biology. A psammophilous species. It overwinters as adult or rarely as last instar nymph around the roots of the plants, under various vegetation remains, or in sand at a depth of up to 10 cm. The overwintered specimens become active after the middle of March. Mating takes place in April. Egg laying begins in April and continues until July. The nymphs hatch in June, those of the eggs laid later occur until November. The adult of the new generation emerges in July. The adults and the nymphs live in the upper layer of the sand at a depth of 2-10 cm and feed on the roots and the root parts of the stems of different cereals: Leymus racemosus, Digitaria ischaemum, Carex arenaria, Elymus elongatus [3, 4].
Similar species. The remaining species of the genus in Bulgaria, Byrsinus balcanicus, B. flavicornis and B. pilosulus [5], live in similar habitats with B. fossor and have a similar biology [3, 4]. The latter species can easily be distinguished from them by the presence of thin and long hairs on the scutellum and on the whole surface of the chitinized part of the forewings.
Negative factors. Change of the habitats and the increase of the tourist flow near its single locality are the reasons for its extinction in Bulgaria. The sand dunes near Nesebar, where it occured, are practically destroyed, and the other dune complexes along the Black Sea coast are exposed to an enormous anthropogenic pressure.
Conservation measures taken. None.
References. 1. Puton, 1888; 2. Josifov, 1974; 3. Josifov, 1981; 4. Putshkov, 1961; 5. Lis, 1999.
Authors: Michail Josifov, Nikolay Simov
