Bombus gerstaeckeri
Bombus gerstaeckeri is a medium size bumblebee (lenght in queens: 17-20 mm; lenght in workers 13-16 mm; lenght in males 16-18).
Predominantly pale brown coloring, black and white. Typically, females have a convex clypeus and very little dotted and ocelli situated almost in a straight line and below supraorbital line. Males, on the genitalia, present the basal formation of sawn gonostilos and concave distal edge.
IUCN has catalogued Bombus confusus as Vulnerable. According to criteria B1ab (IV, V) and C2a (I).
Conservation actions:
- Habitat conservation and native vegetation preservation. Special protection for Aconitum riparia, aconite which Bombus gerstaeckeri feeds. In adittion, Bombus gerstaeckeri pollinating these plants. Is recommended avoid felling, extinsive uses.
- Protection of distribution area.
- Identifying of current distribution areas of the species.
- Sampling and control of the Iberian population to better monitor their condition.
- Regulation of the use made of medium and high mountain, to reduce human impact.
-
Maintenance of protected areas Pyrenees
and Picos de Europa.
Major threats are fragmentation, isolation and loss of habitat. It should be added human pressure on high mountain.
Females of Bombus gerstaeckeri have rounded, pointed and prominent labrus tubercles. Clypeus slightly convex and dotted. Finely punctate front, except under the middle ocellus. Ocelli positioned almost straight. In the hind legs the basitarsus has long dark pubescence. Furthermore, the distal tibial posterior angle ends in a sharp projection.
Genitalia is similar than Bombus hortorum. The outer case of the sting projections are narrow. While internal projections are dilated until the middle.
Males have long antennae with the final part recurved. Ocelli situated on the postorbital line and separate around three diameters from the eyes. Long and dense beard. Slightly narrower middle basitarsus in distal region and posterior tibia is flattened. Genitalia is similar than Bombus hortorum.
Genitalia is distinguished from it by finely serrated escuamas in the basal part and because the distal edge is concave.
Bombus gerstaeckeri is a rare species of mountain. It is distributed in the Atlantic-Central European subregion, the Carpathians, the Balkans and the Alps. In
Spain is very localized in the Picos de Europa, Pyrenees and Sierra de Mampodre, between 1,100 and 2,200 m.
The extent of occurrence in Spain estimated between 20,000 to 30,000 km2.
Potential distribution map at the present time
Potential distribution map in 2050 with the same level of pollution emission and the climate changes consequence of these contamination levels
Map legend
Maps are made with GBIF data of this specie in Iberian Peninsula
Pollinator species of aconite, of which it feeds. They built an underground nest.
The queens emerge late in July. This is due to their close association with aconite (late flowering plants).
associated with Aconitum napellus, Aconitum lycoctonum and Aconitum vulparia
Flight period: July to October.
Generally cleared areas
mountain forests: Pyrenean temperate-oceanic supraforestales grasslands and orocantabrics grassland, shrublands coniferous alpine grasslands.
Occupation area reduced. Small, fragmented populations in decline.