54 8 



TRANS. ST. LOUIS ACAD. SCIENCE. 



HISTORY OF SITARIS. 



The history of Sitaris is also well known and agrees very 

 closely with that of Meloe. Its first larva was figured many 

 years ago by Westwood (Introduction, etc., Fig. 34, 5) from 

 specimens obtained from Audouin, who found the female Sitaris 

 in the cells of AntJiophora enclosed in its thin pseudo-pupal and 

 second larval skins, which Audouin erroneously took to be the 

 pellicle of the devoured bee-larva. But the complete life-history 

 of the genus was first given by Fabre in 1857 (-Attn. d. Sc. Nat., 

 Z00L, t. vii. p. 299 ; t. ix. p. 265), who studied the S. humeralis 

 Fabr., while that of S. colletis V.-M. has been more recently 

 given by M. Valery-Mayet, of Montpellier, France (Ann. Soc. 

 Ent. de Fr. 1875, p. 65), from whom I have specimens in 

 all stages. The former species infests the nests of Anthophora, 

 the latter those of Collctes. In the former the newly hatched 

 larvse hybernate in huddled masses in the galleries of the bee ; in 

 the latter they hybernate in the bee-cell, slowly feeding while the 

 temperature permits ; but such differences doubtless depend on 

 the relative earliness in the autumn that the eggs are laid. The 

 first larva or triungulin (Fig. 36, a) agrees very much in the head, 



tarsal and general 

 characters with that 

 of Meloe, but differs 

 in several important 

 particulars and espe- 

 cially in having a 

 pair of pre-anal spin- 

 nerets, from which 

 is secreted a serous 

 sticky fluid, which 

 -£ td^y 4 ~ aids the animal in 



Sitaris :-a first larva; g, anal spinnerets and clasps of hol( jj ng firmly to the 

 same; b, second larva; e, pseudo-pupa; /, third larva; c, o j 



pupa; d, imago ? (after V.-Mayet). bee that is • to Carry 



it into the nest. A pre-anal pair of claspers also assists in this 

 work.* The hypermetamorphoses are very similar to those of 



* The small size (about I mm. long) and the hairless and spineless nature of this larva 

 contrast strongly with the other triungulins considered in this paper. The tarsal claws are 

 somewhat narrower than in Meloe, and unicolorous. A few soft lateral hairs are repre- 

 sented on the abdominal joints in the figure, but they are scarcely perceptible under the 



