GRAPEVINE ROOT WORM 69 



on the native Virginia creeper, Ampelopsis quinque- 

 folia. 



NATURAL ENEMIES 



This serious grapevine pest is subject to attack by several 

 natural enemies. Two interesting species of egg parasites, bear- 

 ing the scientific names Fidiobia flavipes Ashm. and 

 Brachysticha fidiae Ashm. were bred from eggs of 

 this insect by Professor Webster in 1894 and in 1896 he ex- 

 pressed the belief that a marked decrease in numbers of the 

 Fidia was possibly due to the work of these parasites. Pro- 

 fessor Webster also observed a small brown ant, L a s i u s 

 brunneus var. a 1 i e n u s feeding on the eggs, and a small 

 mite, provisionally identified for Professor Webster by Dr 

 George Marx, asTyroglyphus phylloxera eP. and R., 

 extracting the contents of several eggs in succession, and also 

 a smaller mite resembling H o p 1 o p h o r a arctata Riley. 

 One of these small mites, probably a species of Tyroglyphus, 

 was observed in our breeding cages feeding on the pupae, one 

 being almost entirely destroyed. 



Several predaceous insects were found by us during field 

 work, specially when digging for larvae in the early spring. The 

 grubs of some carabid beetle were observed to be about two 

 thirds as numerous as those of Fidia during the last of April 

 and it is very probable that they prey on this species. We 

 were unable to bring any of the carabids to maturity. A small 

 beetle, Staphylinus vulpinus Nordm. was associated 

 with Fidia grubs and possibly preys on them. The larva of an 

 aphis lion, Chrysopa species, was observed by the writer investi- 

 gating under loose bark where eggs were present, and it is not 

 at all improbable that these insects destroy many. 



REMEDIAL MEASURES 



It was felt that there was a lack of of definite knowledge 

 regarding methods of controlling this insect when this study 

 was undertaken, and it was accordingly planned to make a 

 thorough test of those advised as well as to experiment along 



