96 BULLETIN 903, U. S. DEPARTMENT OF AGRICULTURE. 



nal structure, including- relatively larger sensoria. To these small 

 larvse has been given the name neogallicolw-radicicolw (young gall 

 lice with root louse characteristics), while to the type which merely 

 moves from one leaf to another younger one has been given the 

 name neogallicolce-gallicolce (young gall lice with gall louse char- 

 acteristics). 



On the European vine {Vitis vinifera), according to Grassi, winter 

 eggs were rarely laid and galls rarely found, the majority of those 

 found being imperfect. It was apparent also that growth was much 

 slower than on American vine foliage. In Italy, from eggs pro- 

 duced hj nine gallicoles that had produced galls on a European 

 vine, a few of the progeny had radicicole characteristics. This, 

 however, was a rare occurrence, the great majority of young larvae 

 hatching in galls on European vines showing the gallicole charac- 

 teristics and thus not being destined for subterranean life. The 

 Italian investigators were able to cause radicicoles to settle and 

 produce generations of gallicoles on the leaves of a Clinton (Ameri- 

 can) vine. This succeeded after several fruitless efforts. In this 

 connection it may be said that, at Walnut Creek, on a small Golden 

 Champion (American) vine, radicicoles ascending the stalk and 

 ovipositing in crotches of the stem as high as 5 inches above the 

 surface of the soil were observed in the fall of 1914. A few of the 

 resulting larvae settled still higher up on petioles. Finally cold 

 weather in November ended this aerial infestation either by killing 

 the larvse or compelling them to descend below ground. 



On July 16, 1913, a shipment of eight leaves of an American vine 

 well infested with gallicoles was received from Vienna, Va. The 

 gallicoles were egg-laying females, probably of the second genera- 

 tion (progeny of stem mothers), newly hatched larvse, and large 

 numbers of eggs. Only one adult occurred in each gall. Four of 

 these leaves were placed contiguous to foliage of three resistant 

 vines. The varieties were Riparia X Rupestris 3309, Columbaud X 

 Riparia, and Solonis X Riparia. The first two named, small vines 

 in pots, each were inoculated with one infested leaf; the third vine, 

 larger and growing in the vineyard, was inoculated with two leaves. 

 In no case were galls developed on the foliage of the three vines 

 inoculated. It is to be recorded that these three vines were of a 

 different type from the infested vine, but the Riparia type is sus- 

 ceptible to gallicole infestation. 



On September G, 1913, a selection of foliage of a Riparia hybrid 

 infested with gallicoles was received from Washington, D. C. The 

 following vines growing in the vineyard were inoculated with the 

 infested foliage in close contiguity: Riparia X Rupestris 3309, Ru- 

 pestris St. George, Rupestris X Berlandieri 301 A, Berlandieri X 

 Riparia 34 E. M., Riparia X Cordifolia X Rupestris 111-8, Riparia 



