124 PACKARD, HUMBLE BEES, ETC. 



generally prettily colored, and are met with upon plants and 

 Sowers. The species are parasites in the larva state upon 

 bees, as first discovered by Baumhauer. Latreille also 

 states that the Conops rufipes undergoes its transforma- 

 tions in the interior of the abdomen of living humble bees, 

 escaping at the margin of the segment, having reared four 

 specimens of the Conops in a box in which he had placed 

 some of the Bombi ; and Messrs. Lachat and Audouin 

 have published an interesting memoir upon an apod larva 

 found in the intestines of Bombus lapidarius which La- 

 treille attributed to this species of Conops. M. Robineau 

 Desvoidy has also observed a species of Conops pursuing a 

 Bornbus with great patience, and flying on it several 

 times (Comptes Rendus de V Acad. No. 23, 1836), as has 

 also M. Dufour, who, moreover, possesses a Bombus terres- 

 tris from the anal part of which a Conops rufipes is depen- 

 dent, the swollen extremity of the abdomen of the latter 

 being retained within the former. (Ann. Sc. Nat. Jan. 

 1837.) I have also frequently observed Myopa atra flying 

 about sand-banks in which were the burrows of various 

 bees.' 7 Vol. IT p. 560. 



I translate two passages from the memoir of Messrs. 

 Lachat and Audouin*, referred to above, which describe 

 the larvae and their habits. " A white, very soft and foot- 

 less larva (figs. 1, 2, 3, 4,) was found the 7th July 1818, 

 between the ovaries above the stomach, between it and 

 the sting and under the dorsal vessel of a Bombus lapida- 

 rius Fabr. which was deprived of its fat ; it had eleven 

 rings, a long neck, a mouth, two lips, two hooks and 

 several papillae dependant from the skin ; the rest of 

 its body was distended, a little furrowed above and be- 

 neath, by a longitudinal series of points grouped usually 

 three by three on the side of each ring, which likewise 

 appeared plainly constricted. The extremity opposed 

 to the mouth, corresponds to the rectum of the Bombus, 

 has an anus slit vertically, and two more elevated lateral 

 plates, placed near each other and very curious in their 

 organization and their importance. It bears much resem- 



*Memoire sur une larve apode trouvee dans le bourdon des pierres. Mem. 

 de la Soc. d'Hist. Nat. 1823. Tom. i. p. 326-339. avec fig. 



