BY T. HARVEY JOHNSTON AND M. J. BANCROFT. Z i 



fly pupae or larvae, ultimately destroying them. The most 

 important as fly controllers seem to be Alysia manducator, 

 ApJmreta cephalotes Hal. (both belonging to the Braconidse) 

 and Melittobia acasta Walker (Chalcididse). 



Alysia manducator : Graham- Smith's observations 

 (1916, p. 524-531, figs. 12, 13 ; 1919, p. 376-381, fig. 20), 

 on this relatively large Braconid which is as long as a house 

 fly, show that it is fairly common in England, parasitising 

 a« many as 83 per cent, of fly pupse collected at certain 

 times, being present particularly in those obtained from 

 sheltered situations. " These facts reveal the extraordinary 

 destruction ^^TOught by these parasites and indicate that 

 larvae feeding in warm and sunny situations are more liable 

 to attack than those living in shady places " (Graham- 

 Smith, 1916, p. 530). The female which lives only a few 

 days in confinement, attacks and oviposits in larger living 

 larvae, not waiting for them to pupate. In one experiment 

 Graham-Smith (1919, p. 380) found that a female deposited 

 €sggs in at least 206 out of 544 lar\'ae provided ; that 80 

 other larvae died, possibly due to infection by the insertion 

 of the ovipositor ; and that no less than 343 eggs were 

 still contained in the wasp"s ovaries. " Under more 

 natural conditions it is likely that she would have infected 

 a. greater number, as the ovaries contained at least 549 

 eggs." This wasp over- winters as a pupa, emerging in the 

 spring. Its habits should make it a very desirable insect 

 for use against sheep maggot flies in Australia. 



Aphcereta cephalotes Hal. This is a much smaller 

 Braconid, being only half the length of the preceding wasp 

 (Graham-Smith 1916, p. 531, fig. 15 ; 1919, pp. 381-2, fig. 

 21). From each parasitised blowfly pupa a number (7 to 

 14) of these insects haVe been bred out. The species appears 

 to prefer sunny situations for oviposition, small larvae 

 being selected for the purpose. It passes thi'ough the 

 winter while within the fly puparium. From the inform- 

 ation available it does not. seem to be as valuable a fly- 

 controller as the preceding species. 



Melittobia acasta Walker. This is a tiny chalcid 

 whose habits are described in an interesting account by 

 Oraham-Smith (1916, p. 532-543, figs. 16 and 17 ; 1919, 



