129 



the colour-marking's of which are all on a given scheme (Deu- 

 TEKOANOPHELEs). This group sliows two main divisions, charac- 

 terised by a notable difference in the intensity of their coloration 

 and the ' effectiveness ' of ornamentation, possibly arising from 

 two different lines of evolution. Their area of special prevalence 

 includes Africa, South Asia and Malaya. The most widely 

 distributed of the genera of this group is Cellia and this 

 fact harmonises with its phylog-enetic position. Pyretophorus, 

 in the restricted sense in which the author uses the term, is 

 dominant in N. Africa, S. Europe and N.W. India. It does 

 not occur in S. America or Australia, and it is scarcely repre- 

 sented in India and Malaya. Myzomyia and A'yssorhyitchtis are 

 African, Malayan and Indian, Nyssorhynchus distinctly dominat- 

 ing in the two latter areas. 



MiTZMAix (M. B.). The Bionomics of Stomoa-ys calciti-ans, 

 Linnaeus; a preliminary account. — Philippine Jl. of Science, 

 viii. B, no. 1, February 1913, pp. 29-48, 4 tables. 



The author had unusual opportunities for studying" the bionomics 

 of Stomoxys calcitrans in connection with a large number of 

 experiments on the transmission of surra, in which thousands of 

 flies of this species v.'ere captured or bred. [ See this Z^eiuejt', ser. B, 

 p. 113.] This paper is to be considered as supplementary to 

 Newstead's treatise (Ann. Trop. Med. & Parasit., 1907, pp. 82-96). 

 Under normal conditions the egg's of *S'. calcitrans are laid in 

 the faeces of its host and have been found in those of the horse, 

 carabao, bullock and other domesticated animals, as well as the 

 guinea-pig. The age at w^hicli S. calcitrans begins to lay eggs 

 has been determined in bred flies to be nine days. The maximum 

 number of eggs produced by a single female may be stated as at 

 least 032 and possibly 820. As many as 20 depositions may be 

 iaade in the life-time of a female. The incubation period for 

 these eggs is from 20 to 26 hours at a temperature of from 30° 

 to 31° C. The larval stage under optimum conditions is usually 

 from seven to eight days, and the young larva loses no time in 

 consuming whatever desirable food may be present, the mother 

 laying the eggs only where there is an abundant food supply. 

 When confined in a test-tube the maggots will invariably remove 

 the moisture from each other's bodies and later on eat parts of the 

 latter. Injured larvae become an easy prey to their fellows. 

 The imago emerges from the puparium after five days, but under 

 laboratory conditions this period may be extended to from 6 to 12' 

 days. In more than 40 instances recorded, first emergences were 

 marked by the appearance of males, the male fly usually preced- 

 ing the female by two days. The sexes are readily distinguished 

 upon emergence, the female being invariably the larger and the 

 lighter in colour. The fly of either sex takes its initial bite in 

 from 6 to 8 hours after emergence. Stow^oxys was fed experi- 

 mentally on 17 species of vertebrates, including mammals, reptiles 

 and birds. It is essentially a blood-feeder and has never been 

 observed to take plant juices, but it sips water when confined in 

 tubes. Under conditions obtaining in the Philippine Islands, the' 



