140 NEW WORKS ON ENTOMOLOGY. 



of light earth, others hard trodden pathways, &c. ; their burrows 

 differ in depth, but are seldom less than about six, whilst others 

 excavate to nine or ten inches. At the bottom of each burrow is 

 formed a small oval cell, or chamber, in which the industrious 

 female lays up a small pellet of pollen mixed with honey ; these 

 little balls are usually about the size of a garden pea, varying some- 

 what in size in different species. Sometimes, apparently to econo- 

 mise time, the bee constructs branch tunnels, each having a similar 

 chamber at its extremity ; this peculiarity I have observed in 

 A. rubrlcata and A. fulvescens ; it is also probably not unusual 

 with many other species. When she has completed her task, she 

 closes the mouth of the tunnel. 



" These bees are subject to the attacks of parasites ; the first to be 

 remarked upon are those bees which compose the genus Nomada ; 

 they are more popularly known as wasp-bees, since they bear a 

 considerable resemblance to some of the small solitary species of 

 that family. These parasites appear to be upon a perfectly friendly 

 footing with the industrious bees, and are permitted without let or 

 hindrance to enter their burrows. It has been advanced as a proof 

 of the ingenuity and artifice necessary to be employed in effecting 

 the deposit of their eggs in the working bees' nests, that the parasites 

 should bear a close resemblance to the bees upon which they are para- 

 sitic. Some instances may undoubtedly be advanced, as Apathus 

 and Bombus, and also in the different species of Volucella which 

 infest the nests of humble bees, but amongst the solitary bees no 

 such resemblance is required to aid in any necessary deception. It 

 may be remarked that the two cases are not analogous ; this is true, 

 and I am not prepared to say that in the case of the Bombi and their 

 enemies, it may not be necessary, but as regards solitary bees it 

 certainly is not ; colonies of Andrenidcc and their parasites mingle 

 together in perfect harmony, issuing from and entering into the 

 burrows indiscriminately. I have on several occasions watched 

 with much enjoyment a large colony of Eucera longicornis, the 

 males occasionally darting forward with great velocity, then turn- 

 ing sharply round, and as it were swimming in circles close to the 

 ground, then darting off again and again in an unceasing round of 

 sportive enjoyment ; their industrious partners, whose whole exist- 

 ence appears to be bound up in one unceasing round of labour, 

 would occasionally return home laden with food for their young 

 progeny. Sometimes it would happen that a Nomada had pre- 

 viously entered her nest ; when such proved to be the case she 

 would issue from it, and flying off to a short distance wait patiently 

 until the parasite came forth, when she would re-enter and deposit 

 her burden. It will be observed in this instance that between 

 Eucera and Nomada no resemblance exists in general appearance, 

 one being several times larger than the other, and covered with pu- 



