96 [^i"'i'' 



To these supposed parasites, of which the Nematode of Lyonet is 

 the onh^ one which seems to be certain, we may add the gregarine 

 Schneider i a mucronata Leger, which occurs in the mid-gut and anterior 

 caeca of Bibionid larvae. In this connection it is somewhat interesting 

 to note that the other species of the genus Sclineideria, S. cmidata Sieb,, 

 also occurs in the same region in Mycetophilid larvae {Sciara nitidicollis). 



In Bibionid larvae collected both in France and in Cambridge I 

 have also observed an epidemic bacterial disease. The affected larvae 

 appear motionless and stiff, and the slightest puncture of the diseased 

 larva's skin with a sharp needle leads to all the liquid in the larva 

 o-ushing out, the insect's body becoming flat and flabby. The liquid 

 extracted from these larvae when examined microscopically shows an 

 enormous number of bacteria. When the disease appears among the 

 larvae in a breeding-jar it spreads rapidl}', and 150 to 200 larvae 

 usually become affected in a few days. All these larvae die with their 

 alimentary canal full of food. I have not yet noticed this disease in 

 any other Dipterous larvae. Seatopsid larvae, however, are often infected 

 by a Microsporidium, probabl}^ a Glugea, which invades the epithelial 

 cells of the mid-gut and caeca. 



References. 



Anthon, S. I. (1908). Tlie hiiva of Ctenuphora anijustipennis Loew. Journ. 



of Murpliology, vol. xix, pp. 541 -oOO, tigs. l-o3. 

 Leger, L. (1892). liecherches sur les Gregarines. Theses. Poitiers. {See 



p. 153.) 

 Lyonet, P. de (1832). Piecherclies sur rAn.atoniie et les Metamorphoses de 



differentes especes d'lusectes. Oiivrage posthuiu. publi(5 par W. de 



Haan. Paris, J. Ballierej 580 pp., 54 planches. {See pp. 61-02 and 



552-553.) 

 Malloch, J. It. (1917). A preliminary classification of Diptera, exclusive of 



Pupipara, based upon larval and pupal characters, with keys to imagines 



in certain families. Part 1, Bull, of the Illinois, St. Labor, of Nat. Hist. 



vol. xii. [See p. 500.) 

 Meijerk, J. C. H. DE (1916). Beitrage zur Kenntnis der Dipteren-Larven 



und Puppen. Zool. Jabrb. Abt. Syst. Bd. 40. (See pp. 180-186.) 

 Morris, II. M. (1917). On the larval and pupal si&ges of Bibio Jo/ia/tms L. 



Ann. of Applied Biol. vol. iv. 

 Morris, II. M. (1918). The larval and pupal stages of Scatopse notata L. 



Ann. of Applied Biol. vol. v, pp. 102-111, pi. x. 

 Perris, E. (1847). Notes sur les iSJetamorjjhoses de la Trichocera anmdata 



Meig. et de la Scatopse punctata Meig. ; pour servir a I'histoire des 



Tipulaires. Ann. de la Soc. Entom. de France, 2"" Serie, t. 5, pp. 37-49, 



pl. 1. (&e pp. 43-48.) 



Fehniary 1919. 



