147 



was to be found in warm horse manure, in company with that of 

 Musca domestica, L. (the Common House-fly), and in 1889 and 1890 

 Dr. L. O. Howard reared Stomoxys calcitrans from horse manure at 

 Washington.* In 1906 Newstead, in England, succeeded in inducing 

 a " small percentage " of captive females of S. calcitrans to oviposit 

 on fresh droppings of the horse, sheep, and rabbit, and was thus 

 enabled to study the metamorphoses. f Under these circumstances 

 it was found by this author that " two important conditions were 

 necessary for the development of the larvae, viz., an almost complete 

 absence of light and an abundance of moisture." Subsequently 

 Newstead observed the species of ovipositing under natural con- 

 ditions, in a heap of cut and heated grass. The following brief 

 summary is based upon Mr. Newstead's paper, J and upon an 

 examination of material kindly presented to the Museum by him. 



The eggs, which are laid in batches usually containing about fifty 

 to seventy, are white, 1 mm. in length, elongate and somewhat 

 resembling a banana in shape, with one side nearly straight and the 

 other curved, and with a broad deep groove on the straight side. 

 At an average temperature of about 72 F. by day, and 65 F. by 

 night, they were found to hatch in from two to three days. 



The larva, which is a footless maggot of the usual Muscid type, 

 and closely similar in colour and general appearance to that of the 

 Common House-fly, is 11 mm. in length when adult, and " creamy- 

 white to pale ochreous, translucent, shining and almost glass-like " : 

 the black mouth-hooks are visible through the integument of the 

 narrower, cephalic extremity. The larva of Stomoxys calcitrans 

 is distinguishable from that of Musca domestica by the two plates 

 on the posterior surface of the last segment, which bear the 

 respiratory apertures (posterior stigmata), being much smaller, 

 nearly circular (instead of the inner side of each plate being straight), 

 and from four to six times as far apart, with the three apertures 

 in each plate only slightly curved instead of extremely sinuous. 



* Gf. Howard, loc. cit., pp. 678-579. 



f Cf. R. Newstead, " On the Life-history of Stomoxya calcitrans, Linn." : Journal 

 of Economic Biology, Vol. I., pp. 157-166, Plate XII. (Reprinted in Annals of Tropical 

 Medicine and Parasitology, Series T. M., Vol. L, No. 1, pp. 76-85, Plate V.). 



J Cf. R. Newstead, loc. cit. 



L2 



