Yellow-horned Spongillafly
Sisyra terminalis Curtis, 1854
Order Lacewings (Neuroptera)
Family Spongillaflies (Sisyridae)
Conservation status: in Bulgaria: Critically Endangered CR [B1ab(iii)+2a].
General distribution. Ireland, Great Britain, Sweden, Finland, France, Belgium, the Netherlands, Germany, Switzerland, Italy, Austria, the Czech Republic, Poland, Hungary, Slovenia, Croatia, Bulgaria, Romania, the Ukraine and Russia (in the east to the Far East).
Distribution and abundance in Bulgaria. Reported with certainty on a male specimen only in the Veleka River near the Kovach site, to the south of Zvezdets Village near Malko Tarnovo [1]. The only sure locality in Bulgaria is the southernmost one in the range. In the 1980s in this border part of the range, Sisyra terminalis had a considerably lower abundance than the other three species of the family in Strandzha. Throughout its area, the species has a low population density [2].
Habitats. Flowing waters, mainly large lowland rivers (larvae) and deciduous woody and shrubby vegetation along their banks (adults). The current of the Veleka river near Kovach is comparatively fast.
Biology. The adults are active day and night, with a maximum early in the evening, at twilight. They fly from the end of May to the beginning of September in two generations. Their food consists of pollen of coniferous trees, small dead arthropods, living aphids [3]. They lay about 50 eggs in cracks in the bark of horizontal branches over the water in groups covered with web. The larvae of the three instars parasitize on freshwater sponges (Porifera). The last instar larvae build a cocoon on the riverbanks, in which they turn into prepupa, and then into a pupa. The early hatched larvae of the second generation overwinter as prepupa, and the late hatched ones, as a second instar larva [3].
Similar species. The other three species of the genus in Bulgaria, from which it differs with its two-colour antennae.
Negative factors. Water pollution. Restricted distribution and low density. The water larvae of Sisyra terminalis are strongly vulnerable in cases of pollution of the only river in which they were found with certainty in Bulgaria.
Conservation measures taken. The Veleka river is included in the Strandzha Natural Park.
Conservation measures needed. Maintenance and preservation of the water purity of the Veleka. Monitoring of the population.
References. 1. Popov, 2007a; 2. Aspock et al., 1980; 3. Weissmair, 1994.
Author: Alexi Popov
