December, '17] KELLY: BIOLOGY of ccelinidea 527 



screened box cage, even when a moderate quantity of moist or decaying 

 fruit is placed with the parasites for a day or more. 



A second type of cage, illustrated in PI. 25, fig. 3, has been found use- 

 ful and is, in some ways, also superior to the glass tube open at one end 

 and plugged with cotton. This is a straight glass tube, 1 to 1^ inches 

 in diameter and 6 to 9 inches long. It is open at both ends. Copper 

 screened caps fit into the ends and are made just large enough to fit 

 into place tightly. This tube also permits free air circulation within. 

 It is of particular value as a container for individual parasites from 

 which oviposition, or other data, is being determined. In such cases 

 food and fruit, or other material, may be placed almost in contact with 

 the parasite without danger of gases of fermentation accumulating and 

 killing or injuring the individual from which valuable records may 

 already have been secured. 



Such cages as here described are of importance only in confining 

 parasites considerably larger than the mesh of the copper screening 

 used. The shape of the cage is not entirely essential, the free circula- 

 tion of the air and abundant lighting being the important points. 



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

 functions of parasites. When it is desired simply to prolong or pre- 

 serve the life of parasites, the closed test-tube or larger closed sterilizing 

 tube is possibly better. The parasites are then best preserved and the 

 energies least expended when given but httle food and kept constantly 

 in partial darkness. 



THE BIOLOGY OF CCELINIDEA MEROMYZ^ (FORBES) 



By E. O. G. Kelly, Entomological Assistant, Branch of Cereal and Forage Insect 



Investigations 



References to this parasite in literature are very few. It was dis- 

 covered by Dr. S. A. Forbes in 1883, having been reared by him from 

 the pupa of Meromyza americana at Cuba, 111., April 25, 1883. Dr. 

 Forbes described the parasite in his thirteenth report of the state 

 entomologist of Illinois, as Coelinius meromyzoe, stating that "the 

 abundance of these parasites in tliis field may be inferred from the fact 

 that out of fifty-five larvse obtained here, only twenty-one developed 

 the fly (Meromyza), and the thirty-four remaining all gave origin to 

 Ccehnius (Coehnidea) which continued to emerge from May 6 to May 

 19. Sweepings of these infested fields in April yielded none of this 

 species, and there can be no doubt that the eggs are deposited within 

 the bodies of the larvae in autumn. " 



Dr. Forbes' conclusion was quite the natural one. No one at that 



