Dageraadbij - Andrena nycthemera How to recognize Female : The dageraadbij is an early flying rather large, mining bee. The dirty brown hair on the back and black head are good field attributes for recognizing the females. The female has further 2 broad pronounced fovea (its grooves along the eye line) approximately twice as wide as the antennas. All tergites are long and dense hair. Tergite 4 has black hair, while tergite 5 and black hair band. The final french or fimbriae is dark. The females in the spring just been hatched, exhibit a characteristic color palette of black, white, gray and tan hairs on the head, thorax and abdomen. At that time the females are not to be confused with another species mining bee, even by the early flight period. The color of the antenna members seems to vary from black to reddish in part on the underside of the segments, which is also quite uncommon in sand bees. Hair of the legs greyish, all legs are completely black. Flocculus whitish. Scopa top black or black-brown, whitish below. Length 11 to 14 mm.
Male: As with most of the sand bees the size of the males is rather variable. They are much smaller than the females and unobtrusive gray hairs on the head, thorax and abdomen. Along the insidemargin of the eyes few black hairs, as well as the skull. The side of the chestpiece has pronounced black hair. Typically the long jaws without teeth on the jaw base. Hips and thighs long standing off white hairy. Legs black or dark brown. Tarsi brownish. Length: 10-13 mm
Recognition "in the field": The dageraadbij (Andrena nycthemera) is a very early flying rather large mining bee adequate temperatures at which animals have been found in February. The dirty brown hair on the back with the black heads are good field attributes for recognizing the females. This has further 2 broad pronounced "fovea" (its grooves along the eye line) approximately twice as wide as the antennas. The males are not easily distinguished from the (later flying) males gray mining bee (Andrena vaga). Flight
The species flies from March to May.
Ecology If the weather and micro-habitat are acceptable, they can sometimes be found as early as mid-February. The nest digging takes about 2-4 days. Average are 3 flights per day to run to collect pollen. They only seem to do this over a period of 4 to 7 days, rarely longer (up to 9 days). The males build a territory which they defend against rival males. Sometimes when looking for potential nesting sites, conflicts between females arise. Some females use only 1 nest, other up to 6. The dageraad mining bee has a specialized diet on Salix.
Possible cuckoo bees : Although we suspect that these mining bee also has a parasitic nomada, we could trace if this is the case via the literature which was available to us
Presence in the region :
This sandpile holds the only major nesting aggregation of the rare dageraadbij (Andrena nycthemera) in the region (Durmplassen, Merendree)
A female dageraadbij lies on the sheltered cove of sand mountain to enjoy the dreary cold spring weather to warm up. When it is heated again pulls them out to willows collecting pollen.
This extremely rare species was until recently only found in the surroundings of the Durmplassen (Merendree), where a strong population dwells around a heap. Every year this heap is been scooped so that this larger population (> 100 animals) may eventually disappear. In 2012 this species was lucky enough also found in the Natuurpunt nature reserve the Miserie bocht (Sint Joris) where they are having a much 'safer' home. On 20.06.2012 only 93 specimens were recorded in www.waarnemingen.be for the total of Belgium, spread over 9 different kilometer slots, stretching from Ghent to Beernem.
Foto : vrouwtje :mannetjeouwtje
Foto : mannetje :mannetjeouwtje
The dageraadbij (Andrena nycthemera) is an early flying willow (Salix ) specialist Foto : mannetje :mannetjeouwtje
Foto : mannetje :mannetjeouwtje Foto : vrouwtje :mannetjeouwtje
Given their early activity and sometimes cold weather, the males are often found on pale reflective surfaces to warm themselves in the few sunbeams and .. perhaps also to spot any ‘willing’ females ?