RILEY — LARVAL HABITS OF BLISTER-BEETLES. 549 



Meloc. The triungulin after absorbing the contents of the bee 

 *SS» molts, and thereafter floats upon and devours the honey — the 

 pseudo-pupa, third larva and true pupa all forming in due time 

 within the second larval skin. The female does not feed, and on 

 account of her heavy abdomen travels but a short distance from 

 the bee-burrows where she developed. 



It is generally stated by writers on the Hive-bee that the Oil- 

 beetle {Afcloe) is one of its parasites. The posssibility that our 

 more common blister-beetles were similarly parasitic on bees, tak- 

 en in connection with the frequent complaints from apiarians of the 

 wholesale death of bees from causes little understood, led me, 

 some years since, to pay attention to the biological characteristics 

 of the blister-beetles, in the hope of ascertaining whether or not 

 they really bear any connection with bee mortality. From these 

 investigations I am satisfied that Meloe is only parasitic on the 

 perfect Hive-bee as it is on so many other winged insects that 

 frequent floweis ; and that it cannot well, in the nature of the case, 

 •breed in the cells of any social bee whose young are fed by nurses 

 in open cells. 



I have had no diflficulty in getting the eggs or the first larva of 

 several of our vesicants, and described some of them at the Hart- 

 ford (1874) meeting of the Am. Ass. Adv. Sc. ; but these young 

 larvae refused to climb on to plants furnished to them, or to fasten to 

 bees or other hairy insects. Nor would they nourish upon honey, 

 bee-bread, or bee larvae on which they were placed. They showed 

 a proclivity for burrowing in the ground, and acted 

 quite diflerently from those of Meloe or Sitaris^ 

 which not only readily attach to bees in confine- 

 ment, but which, in the case of Meloe, I have 

 known to so crowd upon mature hive bees as to 

 worry them to death and cause extended loss in the 

 V apiary. Explorations into the nests of Solitary bees 

 Epicauta viT. gave no clue, and, in fact, the immense numbers 

 normal form, in wliich the more common blister-beetles occur 

 rendered a parasitic life upon such bees highly improbable. In 



strongest microscope. Nor do any hairs or spines appear in any of the subsequent stages, 

 even on the true pupa. The pseudo-pupa lacks the prominent lateral ridge so striking in 

 the others. The stigmata are so faint in the triungulin that Mayet could not resolve them; 

 but with proper light .ind specimens rendered transparent 1 have discerned them in the 

 same positions as in Meloe.. The mandibles are toothed. 



