80 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



hymenopterous parasites either in the field or from the thousands of 

 larvae reared in rearing frames. It became apparent that the con- 

 ditions were unfavorable for the purposes in mind of assembling 

 parasites for export, and it was decided to shift our headquarters to 

 a more promising locality. 



On June 5 a new base of operations was established at the town 

 of Bendery on the Dniester River. Quarters were selected in the 

 principal hotel, the Petersburgia, and in a remote corner of the exten- 

 sive grounds of the hostelry a temporary laboratory was constructed 

 in which several tiers of rearing frames were erected. The forest 

 conditions in this district were much more diversified than at Gau- 

 chesty. To the northeast of the town at a distance of 7 versts was 

 the forest of Gerbofsky, occupying a dry elevated area of about 

 5,000 acres and consisting almost exclusively of mature oak trees. 

 To the southward, on the banks of the river, was the forest of Kitz- 

 kany, coxnposed largely of black poplar, maple, and willow. In both 

 of these forests the caterpillars of the gipsy moth were found in 

 immense numbers, and evidence of attack by both hymenopterous 

 and dipterous parasites was readily obtained, although nowhere in 

 the abundance hoped for. For two weeks the two forests, as well as 

 the extensive orchards in the vicinity of Bendery and the neighboring 

 town of Tiraspol, were scoured for parasites. A number of Russian 

 boys were pressed into service and trained to assist in making collec- 

 tions, at which they became quite expert. Except for a few clusters 

 of cocoons derived from Apanteles fulvipes Hal., the only hymenop- 

 terous parasite to appear in considerable abundance was Apanteles 

 solitarius. Caterpillars of the gipsy moth attacked by this species 

 crawl down to the trunk or lower branches of the tree and collect in 

 colonies on the lower side of the branches, under bark, in cavities 

 and other sheltered places. Here the larva of the parasite emerges 

 and spins its cocoon beneath the body of its host. The task of col- 

 lecting these scattered cocoons was a tedious one, since it was neces- 

 sary to remove each one carefully from the bark without undue 

 pressure and also to disentangle it from the hairy body of its host. 



In the forest of Kitzkany, where the conditions were favorable for 

 bacterial infection owing to excessive dampness, the caterpillars of 

 the gipsy moth were swept away in vast numbers by a bacterial 

 disease before any extensive defoliation took place. The search for 

 hymenopterous parasites in this district' soon become a vain one, 

 since very few of the caterpillars appeared to have escaped the 

 infection. 



The forest of Gerbofsky, owing to its being elevated, open, and 

 well drained, was not favorable for bacterial infection and no trace 

 of disease was observed. This forest was therefore almost com- 

 pletely defoliated by the caterpillars, and multitudes of the insects, 

 failing to find any further nourishment upon the oaks, descended to 

 the ground, where they died in great numbers, apparently from 

 starvation. Hymenopterous parasites seemed to play a relatively 

 small part in the destruction of the caterpillars, since the attacks of 

 Apanteles solitarius were of the most scattering character. In the 

 shrubbery growths adjacent to the main forest, where new planta- 

 tions had been recently established by the forester in charge, a con- 

 siderable number of Calosoma were found at work destroying the 

 caterpillars, but their operations did not appear to extend into the 



