Prosopis - 



-mSECTS.- 



-An'drexa. 



193 



labour is then repeated until she has furnished six or 

 eight cells, when the whole is completed." There is 

 little doubt that the same bee constructs more than 

 one of these tubes, as there is never any trace of a 

 second tunnel running into the first, as in many other 

 solitary bees. 



These bees are liable to the attacks of two parasites, 

 one of which feeds on the larvre, -while the other eats 

 tlie pollen. The first is a fly [Milto'jramma inmdata) ; 

 this fly may frequently be seen entering the cells of 

 the bees, and indeed it has been often bred from the 

 cocoons of the Colletcs. The second enemy is a little bee 

 {Epeolus vnrierjatus). The greatest enemy of these 

 bees, however, is the earwig, which commits wholesale 

 slaughter on them, devouring pupa?, larva;, and pollen, 

 and in some localities they abound to such an extent 

 that three-fourths of the bees perish from their attacks. 

 The type of the genus Colletcs is the C. succindd, a 

 si)ecies which seems to be very partial to the flowers 

 of the heath. 



Genus Prosopis. — At one time the bees of the 

 genus Prosopis were thought to be parasites, because 

 they wanted the usual apparatus for collecting pollen. 

 Mr. Thwaites, in 1841 found two of the species breed- 

 ing in bramble- sticks, and since that time others have 

 repeatedly bred the species from a similar nidus. Mr. 

 Sidney Saunders has observed in Albania a species 

 which constructs its cells in bramble-sticks, and lines 

 them after the manner of Colletcs with a thin trans- 

 parent membrane, able to hold a semi-liquid honey, 

 which they store up for their young. This species was 

 much suljject to be infested by a species of Stylojis. 

 The species of this genus found in the British islands 

 are nine in number, and are very partial to the flowers 

 of the wild mignonette {Reseda luteola). In this genus 

 the body is smooth and naked, and there are only two 

 complete submarginal cells : the ocelli are arranged in 

 a triangle. The last two genera belong to Westwood's 

 sub-family, called from the bluntness of the tongue 

 Ohtusilingues. To his sub-family with a pointed tongue, 

 and called in consequence Acutilingues, belong the other 

 British genera of the family Andreniclce; of these we 

 may specify some of the genera. 



Gemus Sphecodes. — The bees of the genus Sp/iccof/cs 

 lu\ve no pollenigerous organs; they have four submar- 

 ginal cells to the fore wings, and the antenna; are nodose 

 in the males. It is doubtful if this genus is parasitic, 

 notwithstanding the structure of the feet of the female. 



Genus IIalictus. — Twenty-six species of the genus 

 Hcdictus have been described as indigenous to these 

 islands ; one of these is the smallest bee found in this 

 country, the male being only two lines in length. This 

 species is aptly called Hcdictus minidissiriius. The 

 species are widely distributed, being found in every 

 quarter of the globe. The females of Halictus, and of 

 the last recorded genus, make their appearance in April, 

 and are to be found from that time until late in the 

 autumn, and no males of these genera appear until 

 long after the females. The following observations 

 have been made on a colony of Hcdictus Morio, one 

 of the most common species, frequently found in path- 

 ways in the suburbs of London. The females appear 

 early in April, and continue in numbers up to the end 

 Vol. II. 



of June. During the month of July scarcely an indivi- 

 dual is to be found. About the middle of August the 

 males begin to come forth ; the females succeed the 

 males in their appearance about ton or twelve days. 

 The following appears to be the history of Halictus : the 

 males and females appear in autumn ; the impregnated 

 females pass the winter in the perfect state, appearing 

 during the following season to perform their economy, 

 the males not appearing before the autumn, so that in 

 their economy they resemble humble bees and wasps 

 rather than solitary bees. 



In the genus Hcdictus the fore-wings have three sub- 

 marginal cells ; the abdomen of the females has a ter- 

 minal slit. The central division of the labium is longer 

 than the external, and in the males the antennse are 

 sometimes as long as the bod}'. 



Genus Andrena. — The genus Andrena contains the 

 largest number of species of all the British genera. The 

 venerable Kirby first greatly enlarged the genus Apis, 

 and divided it into sections, each of which was named 

 with a generic title by Fabricius or Laireille. They 

 took generally Kirby's characters, and merely gave 

 names.* Sixty-eight species of Andrena have been 

 described. The bees of this genus may be truly said to 

 be the harbingers of spring, as males may be found on 

 catkins and early spring flowers on the first fine April 

 days — two species (A. bicolor and A. Gv-ynana) as 

 early as March. The Andrencr, are all burrowers in 

 the ground, some species preferring baid<s of light earth, 

 while others prefer hard-trodden pathways. The bur- 

 rows vary in length ; they are seldom less than six 

 inches, whilst others excavate tunnels in the gi'ound 

 from nine to ten inches in length. At the bottom 

 of each burrow they form a small oval chamber, in 

 which the female lays up a small pellet of pollen mixed 

 with honey. These pellets are generally about the 

 size of a pea, varying in size in the different species. 

 The bee sometimes constructs branch tunnels, with a 

 simflar chamber at the end. When the egg is depo- 

 sited, the female bee closes the mouth of the tunnel. 



The species oi Andrena are subject to the attacks 

 of various parasites. The bees of the genus Nomada 

 are parasites, and appear to be on a perfectly friendly 

 footing with the industrious bees, being permitted, with- 

 out 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 on wdiich 

 they are parasitic. Some instances may undoubtedly 

 be advanced, as Apathvs and Bomlms, and also in the 

 different species of Volucclla which infest the nests of 

 humble bees; but amongst the solitaiy bees there ara 

 no such resemblances to aid in any necessary decep- 

 tion. It may be remarked that the two cases are not 

 analogous, and I am not prepared to say that in the 

 case of the Bomhi and their enemies it may not be 

 necessary ; but as regards solitary bees it certainly is 

 not — colonies of Andrenidic and their parasites mingle 



* I might have quoted from Kirby, but jirefer going to Jlr. 

 Smith's volumes, with the great additional information on tha 

 bees that has been collected since tlio publication of Kirby's 

 volume. 



2B 



