148 



Under favourable conditions, in August in England, the larval stage 

 has been found to last from a fortnight to three weeks. 



The fuya or puparium'^ is barrel-shaped, as in the case of Muscidae 

 generally, about 5.8 mm. in length, and in colour " bright terra- 

 cotta red, changing to dark chestnut-brown a few days before the 

 emergence of the fly." In Newstead's hands the duration of this 

 stage was from nine to thirteen days. 



Stomoxys calcitrans as a Disease-Carrier. 



I. Diseases other than trypanosomiases. 



(1) Anthrax.— In 1878, it was stated by Megnin that Stomoxys 

 calcitrans and a species of Pangonia (Family Tabanidse) had been 

 proved (by a veterinary surgeon named Germain, belonging to 

 the French Army) to have been the " principal agents " in the 

 dissemination of an extensive epidemic of malignant pustule in the 

 Isle of Pines, New Caledonia. f The outcome of the summary by 

 Nuttall on the subject of " Anthrax and Flies,"$ however, would 

 seem to be that, in default of direct experimental proof, neither 

 Stomoxys calcitrans nor other biting flies can be considered as 

 anything more than fortuitous transmitters of anthrax. 



(2) Filariasis. — Investigations carried out at Ostia, in Italy, 

 by Dr. Giovanni Noe,§ tend to show that Stomoxys calcitrans is the 

 intermediate host and transmitter of Filaria labiato-papillosa, 

 Alessandrini,|| of the ox. Noe's studies were not carried to a 



* What is seen is really the puparium, or pupa-case, consisting, as in all Muscidae 

 (and indeed in all Cyclorrhaplia, — the great primary division of the Diptera to which 

 the Family Muscidse belongs) , of the hardened and contracted last larval skin ; the 

 actual pujDa lies within this. 



f Cf. Megnin, Bulletin des Si'ances de la Socii'te Entomologiqne de France, annee 1878, 

 pp. CXLIV.— CXLV. (1878). 



J Cf. G. H. F. Nuttall, " On the Role of Insects, Arachnids, and Myriapods as 

 Carriers in the Spread of Bacterial and Parasitic Diseases of Man and Animals. 

 A Critical and Historical Study": Johns Hopkins Hospital Reports, Vol. VIII., 

 pp. 2-12 (Baltimore, 1899). 



§ Gf. Giovanni Noe, " Studi sul ciclo evolutivo della Filaria labiato-papillosa, 

 Alessandrini " ; Atti della Reale Accademia Dei Lincei, Anno CCC. Serie Quinta. 

 Rendiconti, classe di sc. fis., mat. e nat. Vol. XII., 2 Semestre, Fasc. 9, pp. 387-393 

 (1903). 



II Apud Noe (loc. cit., p. 392), F. labiato-papillosa, Alessandrini, is apparently a 

 synonym of F. stomoxeos, v. Linstow, which was described from embryoes found in 

 the proboscis of a Stomoxys calcitrans in Prussia. 



