385 



ScHOENE (W. J.). Twelfth Report of the State Entomologist and 

 Plant Pathologist i9iS-i9. —Qtrlij. Bull. Virginia State Crop Pest 

 Commiss., Blackshurg, i, no. 4, January 1920, 28 pp., 4 figs. 

 [Received 10th July 1920.] 



In this report are given the paragraphs of the Acts of 1918 authorising 

 quarantines against pests which might in the future be found to exist 

 within or outside Virginia, and providing for the inspection and certifi- 

 cation of florists' stock. The danger of introduction of the sweet 

 potato weevil {Ci/las formicarius, P.) is emphasised and the quarantine 

 measures adopted against it in 1919 are detailed, prohibiting movement 

 of its food-plants from infested States without an inspection certificate 

 from the State of origin. The work done and proposed in connection 

 with the Oriental moth, Cydia {Laspeyresia) molesta, is described 

 [R.A.E., A, viii, 354]. 



Serious insect damage during 1918 and 1919 was caused by a number 

 of insects, including the codUng moth [Cydia pomonella] ; the green clover 

 worm {Plathypena scabra, F.) ; broods ix and x of the seventeen-year 

 cicada [Tibicen septenideciiii], against wliich trees were protected in 

 some cases by wrapping in cloth ; and potato aphis {Mdcrosiphimi 

 solanifolii), which occurred in large numbers on potatoes and spinach. 

 Spraying, which is a general practice on potatoes, seems advisable on 

 spinach also. The spray must hit the insect and should be stronger 

 than for other Aphids. On the spinach that had been attacked an 

 unusual outbreak of blight occurred four weeks later. 



The spring army worm, Cirphis {Hcliophila) unipuncta, was abmidant 

 in 1919. It was controlled on your.g grass and millet by rolling the 

 crop with a heavy roller. It was also confined to certain fields by deep 

 furrows ; when these became filled with caterpillars they were destroyed 

 by dragging a heavy chain or small log through them. 



An unprecedented outbreak of the false cabbage aphis [Aphis pseudo- 

 brassicae] occurred in the autunm of 1919 in a long-continued drought, 

 A spray of one pint nicotine sulphate to 100 gals, water and live 

 bars of laundry soap was applied, a special adaptation of a two- wheel 

 spraying outfit being devised to spray six rows at once. Over 75 per 

 cent, of the insects were destroyed. The locust leaf-miner {CJialepus- 

 dorsalis), which has for several years damaged leaves of the black locust 

 tree, has been observed on apple, but is not believed to cause important 

 damage. 



In the investigation work of the department the control of the 

 woolly aphis, Eriosoma [Schizoneura) lanigemm, Haus., is still 

 being studied. Work on the life-history of the pink and green potato 

 aphis {Macrosiphum solanifolii) has proved that this insect is instru- 

 mental in transmitting several serious mosaic diseases of vegetable 

 crops. The spray formula recommended against it is : f pint of 

 nicotine sulphate (40 per cent.), 4 lb. fish-oil soap and 50 U.S. gals, 

 water. Experiments have also shown that the tarnished plant-bug,. 

 Lygus pratensis, carries the virus of spinach blight. 



Flea-beetles {Epitrix fuscida, Crotch, and other species) damage 

 egg-plants and render them liable to infection from several diseases. 

 The most satisfactory method of control is to spray the plants weekly 

 with 3 lb. of calcium arsenate (powder) and 50 gals 4-6-50 Bordeaux 

 mixture. They should also be dipped in a solution of 2-4-50 Bordeaux 

 mixture with the addition of the poison when they are planted out. 



