280 



BRITISH IIYMENOPTERA. 



I have found tbem on various species of bees, usually on those which are 

 most pubescent, as Andrena fulva, thoracica, and nigro-cenea ; also commonly 

 on Melecta armata, Anthophora retusa and pilipes; this circumstance would 

 appear to confirm, or indicate a connexion between the insects, and from 

 analogy we might readily conclude that this Pediculus must be a parasite 

 on some species of bee; but we have nothing in support of this supposition, 

 and against it we have the following observations :— Mr. Newport has shown 

 that it cannot be the larva of Melon cicatricosus, and, as well as myself, has 

 proved that it cannot be that of M. viola ceus or of M. Proscarabeus ; and 

 since the only other species of Meloc, the M. variegatus, does not occur near 

 London, it appears certain that it cannot be the larva of any species of 

 that genus, unless it be discovered hereafter that the larva of Meloe not 

 only increases in size in its hexapod state, but that it also changes from 

 bright orange to black. 



Another circumstance which induces me to hesitate in adopting an opinion 

 of the Pediculus being a larva at all, is the fact, that on opening small 

 cells of Anthophora retusa, which I dug up on Hampstead Heath, I found 

 two living specimens of the hexapod in the same cell as the perfect bee ; it 

 is certainly possible that they might have subsisted on a portion of the food 

 laid up by Anthophora; but here was no change of condition, and how came 

 they into the cell? I am inclined to think that they, being insects in their 

 perfect condition, came there exactly in the same way as we find Forficulce, 

 having forced an entrance, which I did not observe, and that they were in 

 quest of food, seeking what they might devour. 



In the determination of the species of the genus Andrena much difficulty 

 will be met with, the similarity of the males of many species being so great, 

 that nothing short of a long and attentive study of them, combined with 

 out-of-door observations, will enable the student to discover those niceties of 

 distinction which are easily detected by the practised observer; these difficulties 

 are considerably enhanced by the changes in colour to which they are subject. 

 The species of the first division which are usually more or less red are very 

 inconstant; specimens of the same species from one locality being highly 

 coloured, whilst those from another have all a tendency to a sombre colour- 

 ing; those species which have fulvous, or yellow pubescence, are much changed 

 by exposure to light, so much so, that a bright fulvous insect becomes quite 

 grey, or cinereous; it must therefore be borne in mind, that the individuals 

 described are only such as are in fine condition. 



The genus Andrena contains several species which, in the neuration of 

 the wings, differ somewhat from that of the type; these will be found to 

 agree with the second type of neuration, in which the first recurrent nervure 

 is received by the second submarginal cell, towards the second transverse 

 cubital nervure; that is to say beyond the middle. The following species 

 belong to it: — A. pilipes, varians, helvola, fueata, Clarlcella, fulva, Lapponica, 

 Smithella, denticulata, and argentata. 



