160 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



essential to success is very small. The most successful shipments 

 ever received were carefully packed in slightly dampened sphagnum 

 moss, so arranged that the individual pupae rarely touched each other. 

 One or two successful importations thus received in 1908 were used 

 as the basis for future instructions to collectors, and in every instance 

 in which the directions were carefully followed in 1909 the results 

 were equally good. In 1910 additional material apparently packed 

 with the same care was received from the same source and via the 

 same route. For no apparent reason whatever it was worthless 

 when received. 



In consequence of this another method which has occasionally been 

 followed, will be recommended for shipments in 1911. This has 

 been employed successfully upon various occasions, although without 

 anything like uniform success, and is in effect the same as that used 

 for the shipment of full-fed and pupating caterpillars and the same 

 precautions must be used. It will probably be better to place a 

 somewhat larger quantity of foliage in the box to prevent the pupa? 

 from being thrown about too much in transit. 



So very few shipments of gipsy-moth pupae have been received 

 at the laboratory as to have rendered unnecessary any special devices 

 for their handling after receipt. Each year a few of the lots of cater- 

 pillars have contained a few individuals which were collected as pre- 

 pupae or as pupae, and from such, an occasional parasite of one or 

 another of the species peculiar to the pupae has been reared. These 

 have been so few, however, as to be of entirely inconsequential value, 

 except from a technical standpoint. 



The actual shipments of pupae collected as such have been handled 

 exactly as though they consisted of active caterpillars which pupate 

 en route, with the one difference that the pupae received have usually 

 been inclosed in darkened cages with tubes attached, in order more 

 easily to remove the parasites as they issued. 



In 1908 pupae were received in satisfactory condition for the first 

 time since the preliminary shipments were made in 1905, and it was 

 not until then that the host relations of several of the parasites, 

 notably Chalcis spp. and Monodontomerus xreus, were finally deter- 

 mined. These lots were studied with the greatest care, each indi- 

 vidual pupa being opened on receipt and for the most part isolated 

 in a small vial, in order that it might be dissected after the contained 

 parasite had issued. 



BROWN-TAIL MOTH EGG MASSES. 



No difficulty has ever been experienced in the importation of the 

 egg-masses of the brown- tail moth (PL VII), except that when cold 

 storage is not used a portion of the parasites are apt to hatch, 

 and either escape or die en route. Wooden boxes of various sizes and 



