XX. THE ACULEATE HYMENOPTERA OF MID-SOLWAY. 



There is no more conspicuous tribe of insects at all times, from the 

 opening of the leaves in spring until the chill airs of October have 

 turned the foliage to the brillance of autumn hues, than the Humble 

 Bees. With the flowering of the willow catkins in March, and often 

 much earlier, the large fine coloured females of Bombus terrestris 

 are out in force from their hibernating quarters. Their noisy hum, 

 as they buzz through amongst the willow branches to sip the 

 fragrant greenish-coloured nectar from the catkins, is the most 

 welcome music to the naturalist's ear. This species is usually • 

 considerably in advance of the others, but if the weather continues 

 mild, B. hortorum, so readily distinguished by the length of its 

 face, soon follows. And then one species after another puts in an 

 appearance as the spring advances, till when we have seen the beauti- 

 ful B. distinguendus drinking at the bottom of the rhododendron 

 chalices, we may conclude that all our old friends amongst the Humble 

 Bees are once more in full flight. As yet there is, however, of the 

 different sexual forms none, except the old females to be found. These, 

 fertilised in autumn, have been hibernating all through the cold season, 

 till a suitable temperature and other conditions call them forth in spring. 

 Then they flit about looking for a suitable site for a domicile, and pre- 

 pare for setting up house. Their nidus may be in an old mouse hole, 

 in a dyke, or in a bank or slope, or under a stump, or it may even be on 

 quite open level ground if a suitable aperture into and underneath the 

 surface soil can be discovered. That is in the case of the ground 

 builders. Other species build on the surface amongst the herbage, and 

 make a very neat and snug domed dwelling of felted grass and vegetable 

 fibres, very often adopting to this purpose the nest of the Short-tailed 

 Field Vole. Many times I have seen nests of B. muscorum built inside 

 those of birds. The nests of the common wren, yellow hammer, tit- 

 lark, robin and willow war bier, I have found filled up with a nest of 

 the last named species of Bombus, and more than once I have seen 

 where the mtruder had built her own nest over the eggs of the right- 

 ful owner. In such cases the birds had in all probability deserted 

 their nests before the bees took possession, for one can hardly think the 

 birds would give way to such a tiny burglar, and one, moreover, that 

 would furnish such a nice little eatable morsel. Nests being fairly into 

 shape, cell-building and egg laying proceed in due course, then the 

 young grubs hatch and go through their interesting series of transfor- 

 mations, and by the middle of May, the workers of an early species, 

 like B. pratorum, may be noted enjoying their first flight. Within a 

 fortnight or three weeks later, workers of all the species found here 

 may be observed, with perhaps the exception of B. distinguendus, 

 which is a somewhat late species. Males are not developed till far on in 

 the summer, indeed autumn has fairly arrived before there is any great 

 show of the male Humble Bees. This sex is in all the species, as it is in 

 so many other families of insects, very much smaller than the female sex, 

 and is even smaller, as a rule, than the workers or neuters (which are 



