8 MASS. EXPERIMENT STATION BULLETIN 409 



were made. Throughout the studies onl}' 15 parasites were reared and in 1941 

 special collections of abnormal larvae which were suspected of being parasitized, 

 yielded only 8 parasites. The following parasites^ have been reared, all of them 

 from larvae: 



Family Genus - Species 



Braconidae Apanteles sp. (undescribed) 



Braconidae Microbracon sp. 



Ichneumonidae Campoplex sp. 



Eulophidae Horismeniis microgaster Ashm. 



Pteromalidae Hypopleromalus inimicus Mues. 



Of these species, the Chalcid, Hypopleromalus ivinncus Mues., has been record- 

 ed several times in Massachusetts as a secondary parasite on Apanteles melano- 

 scelus (Ratzeburg) (6), a parasite of the gypsy moth. However, the five speci- 

 mens reared from the grape plume moth at Waltham were definitely primary 

 parasites. 



Although insectivorous birds undoubtedly eat the larvae and pupae of the 

 grape plume moth, no definite observations of their feeding on this insect are 

 available. 



Hand-Picklng 



Crushing the caterpillars in their nests on the tips of the shoots or breaking 

 off and destroying the nests while the caterpillars are in them is the most com- 

 mon practice followed in combating this insect. However, personal experience 

 has shown that hand-picking as practiced by the average home gardener does not 

 prevent the development of normal infestations each year, and it is quite un- 

 satisfactory to the gardeners who take pride in the appearance of their vines. On 

 thick, unsystematically pruned vines it is difficult to find all of the nests and 

 frequently some of the caterpillars leave their shelter and crawl to protected 

 places before the nest is picked off. Although the moths are not strong fliers, 

 there is a definite migration from vine to vine which may reinfest vines in the 

 immediate vicinity each year. 



Pruning 



It is the opinion of the writer that regular, heavy, systematic pruning as 

 recommended by specialists in grape culture has been one of the most important 

 factors in preventing the establishment of the grape plume moth in commercial 

 vineyards. 



The eggs are laid at the nodes on one- or two-year-old canes (see p. 5) and 

 most of these nodes are removed by careful pruning according to the Kniffin 

 system or the high renewal system, the two most commonh' followed in the 

 Northeast (11), or by the spur or stool system, which is recommended for varieties 

 of Viriifera (4). Furthermore, the heaviest infestations ha^■e been obser\'ed on 

 unpruned vines or on vines which are unsystematically "cut back" and produce 

 a thick bushy growth. 



A small experiment on vines having an infestation of 7.6 and 7.7 eggs per 100 

 nodes showed that although the eggs are not uniformly located along the canes, 

 the percentage of eggs removed by pruning was nearly equal to the percentage 

 of nodes which was cut off. 



'Determined by C. F. W. Muesebeck and others of the staff of Bureau of Entomology and Plant 

 Quarantine, Division of Insect Identification. 



