Braconidae 493 



closet and bringing them out into light and warmth for only a short 

 time each day to allow them to feed and oviposit. 



Bibliography 



Vance, Arlo M. 1931. Apanteles thorn psoni, Lylc, a braconid parasite of the 

 European corn borer. U. S. Dept. Agric. Tech. Bull. No. 233. 



METHODS OF PRODUCING MACROCENTRUS 



ANCYLIVORUS IN LARGE NUMBERS FOR 



COLONIZATION IN PEACH ORCHARDS 



Philip Garman, Connecticut Agricultural Experiment Station 



PRODUCTION of Macrocentrus in large numbers for colonization 

 may be accomplished by laboratory breeding or field collection. 

 In regions where Macrocentrus is abundant on such hosts as the straw- 

 berry leaf roller (Ancylis comptana), collection from commercial plant- 

 ings is probably the simplest and most economical method. In regions 

 where field collection is difficult or commercial plantings widely sep- 

 arated, it may prove simpler and less expensive to rear Macrocentrus by 

 laboratory or other means than to collect from the field. In some 

 localities alternate hosts are scarce and the first generation of fruit 

 moth (Grapholitha moles ta) larvae is so small that recolonization from 

 these sources is impractical. 



(1) Field collection as practised in New Jersey by the U. S. Bureau 

 of Entomology and Plant Quarantine and others consists of assembling 

 crews of men who visit commercial plantings and remove folded leaves 

 with leaf roller larvae. The leaves are fastened together in bundles of 

 convenient size and placed with the stems in water. Before emergence 

 of the parasites they are put in a large, darkened, emergence cage with a 

 light screen at one end. In some cases the leaves have been shipped 

 to distant points and there placed in cages to obtain the parasites. It 

 appears more desirable, however, to ship the adult parasites after they 

 emerge, but in order to transport them without undue mortality it is 

 advisable to refrigerate by some means during shipment. In handling 

 field-collected leaves it is necessary to prevent them from becoming too 

 moist because of the danger of mold, and to provide occasional lots of 

 fresh leaves in which the smaller larvae may complete development. 

 After the parasites have spun their cocoons, the leaves should be spread 

 out in trays in the emergence room. 



(2) A second method designed for breeding Macrocentrus throughout 

 the winter consists of obtaining Oriental fruit moth eggs in large 

 numbers (see p. 345) and placing these on green apples sliced part 

 way through. The apples are then incubated at 8o° F. and five to six 

 days after the fruit moth larvae have hatched the slices are separated, 



