Butozania bulgarica ( Kantardzhieva-Minkova, 1953 )

Butozania bulgarica ( Kantardzhieva-Minkova, 1953) View in CoL

New records: Bulgaria: Radomir Valley , N Chervena Mogila Vill., 42°31.354’N 23°00.219’E, 700 m, 05.v.2018, field margins, arable fields (cereals and sunflower), 4 ♂♂, 2 ♀♀, at flight and on the ground (5:50–6: 50 p. m.), YP & DG leg. ( Fig. 1 View Fig ) GoogleMaps ; idem, 04.v.2019, 7 ♀♀, on the ground, feeding obs. (4:00–5:00 p.m.), YP & DG leg GoogleMaps .; idem, 17.v.2020, 3 ♂♂, 12 ♀♀, on the ground (7:45–8: 10 p. m.), YP & DG leg GoogleMaps .; idem, 16.iv.2022, 5 ♂♂, 11 ♀♀, on the ground, feeding obs. (6:10–6: 20 p. m.), YP & DG leg. [numerous specimens obs.] GoogleMaps ; idem, 24.v.2022, 5 ♀♀, on the ground, feeding obs. (6:30–7:00 p.m.), YP & DG leg GoogleMaps .; idem, 19.iii.2023, 9 ♂♂, 1 ♀ (3:10–3: 50 p. m.), YP & DG leg GoogleMaps .; idem, 26.iii.2023, 4 ♂♂, 5 ♀♀, on the ground (6:10–6: 30 p. m.), YP & DG leg GoogleMaps .; idem, 23.iv.2023, 5 ♂♂, 3 ♀♀, on the ground, feeding obs. (6:30–6: 50 p. m.), YP & DG leg. [numerous specimens obs.]; Radomir Valley , N Chervena Mogila Vill., 42°31.136’N 23°00.053’E, 685 m, grasslands, 04.v.2019, 3 ♀♀, on the ground, feeding obs. (4:00–5:00 p.m.), DG leg GoogleMaps .; idem, 23.iv.2023, about ten specimens, flight, feeding and mating, DG obs. (6:00–6: 10 p. m.); Radomir Valley , N Chervena Mogila Vill., 42°31.160’N 23°00.135’E, 685 m, field margins, arable fields (cereals and sunflower), 23.iv.2023, 13 ♂♂, 6 ♀♀, at flight and on the ground, feeding and mating obs. (5:40–6: 30 p. m.), YP & DG leg. [hundreds of specimens obs.] GoogleMaps ; idem, 11.vi.2023, 2 ♀♀, in soil (1: 50 p. m.), YP & DG leg.; Radomir Valley , N Vladimir Vill., 42°27.930’N 23°05.084’E, 680 m a. s. l., grasslands, 05.v.2018, 2 ♂♂, on the ground (8:00 p.m.), YP & DG leg.; Radomir Valley, N Vladimir Vill., 42°27.890’N 23°05.017’E, 675 m, field margins, arable fields, 20.v.2018, 1 ♀, on the ground (8:00 p.m.), DG leg GoogleMaps .; idem, 23.iv.2023, 2 ♂♂, at flight (5: 15 p. m.), DG leg.; Radomir Valley , NE Stefanovo Vill., 42°29.673’N 23°02.288’E, 670 m, 05.v.2018, field margins, arable fields, 1 ♀, on the ground (7: 15 p. m.), YP & DG leg GoogleMaps .; idem, 24.v.2022, 1 ♂, 4 ♀♀, DG leg.; Radomir Valley , N Stefanovo Vill., 42°30.251’N 23°01.419’E, 675 m, 23.iv.2023, field margins, 1 ♂, at flight (5: 35 p. m.), DG leg.; Radomir Valley, SE Chervena Mogila Vill., 42°30.679’N 23°00.738’E, 670 m, 24.v.2022, field margins, arable fields (sunflower), 1 ♀, on the ground (6: 30 p. m.), YP & DG leg.; Radomir Valley, Drugan Vill., 42°29.125’N 23°03.135’E, 670 m, 23.iv.2023, roadside verges, field margins, 1 ♂, on the road (5: 30 p. m.), YP & DG leg GoogleMaps .

During the present study B. bulgarica has been found in wheat ( Triticum aestivum ), barley ( Hordeum vulgare ) and sunflower ( Helianthus annuus ) fields, as well as in the adjacent field margins ( Fig. 2A, B View Fig ). At Chervena mogila and north of Vladimir village the species has been found also in seminatural dry grasslands at a distance of 60–80 m from the field ( Fig. 2C View Fig ). Within the fields, the beetles are much more abundant at the field edge where the cultures are mixed with wild herbaceous species.

In the studied habitats the adults fed preferably on leaves of wild herbs, most frequently bindweed ( Convolvulus arvensis ), yarrow ( Achillea sp. ) and mullein ( Verbascum sp. ), which were close to the ground and easily accessible ( Fig. 2E–G View Fig ). Feeding on leaves of wheat and barley ( Fig. 2D View Fig ), speedwell ( Veronica sp. ), poppy ( Papaver sp. ), wild strawberry ( Fragaria vesca ) has also been recorded. On one occasion we observed feeding on leaves of freshly fallen branch of cherry plum ( Prunus cerasifera ) ( Fig. 2H View Fig ). Evidently the adults are polyphagous, but clearly prefer young and tender leaves of their food plants.

The adults have been observed from the second half of March to the first half of June. The beetles are diurnal and appear in the afternoon, remain active until sunset, then burrow into the soil. Swarming of the males was observed in April and May, between 5:00 to 6: 30 p. m. The males fly in search of a mate and in short distances, up to two meters from the ground. Mating was observed in April, with the females feeding during the copulation ( Fig. 2I View Fig ). After the mating, some of the beetles burrow into the soil, others continue to feed or crawl on the ground for some more time. This pattern of seasonal and circadian activity in general corresponds to what was described by Popov (1968). According to Popov, however, both male and female fly which was not confirmed in our study and does not exactly correspond to Butozania characteristics. Although macropterous, the female of Butozania , as described by Miksic, 1955, has a significantly shortened metasternum. The reduction in the metathorax most certainly affects the ability to fly and thus the female of Butozania should be flightless. However, this unusual case of metathoracic reduction with retained macroptery needs further investigation.

In the 20th century the known range of B. bulgarica in Bulgaria covered three adjacent valleys – Radomir, Pernik and Sofia. In Radomir Valley the species has been reported from the villages Varba (type locality, currently a district of Radomir town), Drugan, Dolni Rakovets, Chervena Mogila, Dren and Izvor ( Kantardzhieva-Minkova, 1953; Popov, 1968). In Pernik Valley the species has been found only at Moshino and Byala Voda villages (both are currently districts of Pernik town) ( Popov, 1968). In Sofia Valley known localities are Sofia ( Kantardzhieva-Minkova, 1953) and the villages Kazichane and Lozen ( Popov, 1968). During this survey we have visited all these historical localities (in the cases of subsequent urbanisation the suitable neighbouring areas). We have found the species only in the vicinity of the villages Chervena Mogila and Drugan, as well as in several new neighbouring localities. We did not find the species in its type locality, regardless of the repeated attempts over the years of study. It seems that the agricultural practices, including pesticide use, and the increasing urbanisation have significantly constricted the range of B. bulgarica in Bulgaria, turning this poorly studied endemic beetle into an endangered species. At present, the field margins and the uncultivated land adjoining arable fields appear to be the last refugia of this interesting and little-known species.