107 



The main point in their construction is that they permit of free air 

 circulation, which is of the utmost importance for general breeding 

 purposes with parasites of the fruit-fly, where moist and often decaying 

 fruit must be placed with them, resulting in the emanation of gases 

 from the fruit and in condensation of moisture on the sides of the cage. 

 Individual lots of parasites have been kept in such cages for nearly 

 two months without need of cleaning or other attention except the 

 renewal of food. 



A second type of cage that has been found useful is a straight glass 

 tube 6 to 9 in. long and 1 to 1| in. in diameter, open at both ends and 

 fitted with copper screen caps just large enough to fit tightly over the 

 ends. This arrangement also permits free air circulation and abundant 

 lighting. These improved cages are most useful in a study of the active 

 life functions of parasites ; when it is desired simply to preserve or 

 prolong the life of parasites, the closed test-tube or larger closed 

 sterilising tube is possibly better, as the parasites are best preserved 

 and their energies least expended when given but little food and kept 

 constantly in partial darkness. 



Kelly (E. 0. G.). The Biology of Coelinidea meroimjzae, Forbes. — 

 Jl. Econ. Entom., Concord, N.H., x, no. 6, December 1917, 

 pp. 527-531. 



Coelinidea meromyzae was first reared by Forbes in 1883 from 

 Meromyza americami in Illinois. At that time it was concluded that 

 the eggs of the parasite were deposited within the bodies of the host 

 larvae in autumn. In 1908, while observing the habits of M. americana, 

 the author of the present paper discovered a small Hymenopteron 

 o\'ipositing in the eggs of that species and this was later identified as 

 C. tneromyzae. It was a matter of conjecture how such a large parasite 

 could mature in so small an egg, it being fully four times as large. 

 In the following spring, Diplazon laetatorius, F., was observed 

 ovipositing in a similar manner in the eggs of a S}T:phid that 

 had been placed among a number of Aphids on chrysanthemum. These 

 Syrphid eggs soon produced S}T-'phid larvae, which were supplied with 

 Aphids for food ; they matured and pupated, but instead of a Sjrrphid 

 adult there issued an adult of Diplazon laetatorius. The author then felt 

 convinced that a similar process occurred in the case of C. tnero- 

 myzae. This parasite was not observed again until 1914, but in that 

 year many wheat plants infested with M. americana were placed in 

 breeding cages in the laboratory ; from these adults of M. americana 

 issued late in the winter, and shortly afterwards adults of C. mero- 

 myzae began to emerge from the same material. Parasites were 

 introduced among eggs of M. ainerican/x in the laboratory, and the 

 process of oviposition and development was witnessed. It requires only 

 a few days for the parasitised eggs of M. americana to hatch. The 

 larvae mature and reach the pupal stage in about 10 weeks, the adults 

 of both host and parasite maturing in about 12 weeks. Further 

 observation in field and laboratory indicate that adults of host and 

 parasite mature about the same time. The larvae of M. americana 

 were dissected and the larvae of C. -meromyzae were found in them in 

 the fatty tissues, apparently without disturbing the alimentary tract 



(C452) b2 



