311 



weather. From an educational and financial standpoint this system 

 has a greater value both to the individual and, particularly, to the 

 country as a whole. Efficiency requires that the work be done with 

 an organised grouy) of growers rather than with individuals, and tO' 

 achieve this result it is necessary that sound expert advice be available 

 and that the necessary information be placed in the hands of the 

 growers at the exact time when it will be of most use to them. A full 

 account is given of the co-operation devised in New York State between 

 the College of Agriculture and the Country Farm Bureau Associations 

 whereby a special field assistant is stationed during the growing season 

 in the country and conducts the work, mostly on specimen demon- 

 stration plots, sending his information to the growers chiefl}^ by letter 

 or telephone and keeping in close touch with a speciahst of the United 

 States Weather Bureau, since weather is often a vital factor. In all 

 his work he is under the supervision of the Departments of Entomology 

 and Plant Pathology. 



Ball (E. D.) & Fenton (F. A.). What Per Cent, of Tipburn is caused 

 by the Potato Leafhopper ? — //. Econ. Entoni., Concord, N.H. 

 xiii, no. 2, April 1920, pp. 218-221. 



An account is given of experiments following on the discovery 

 that a considerable amount of tipburn is caused by the potato leaf- 

 hopper [Einpoasca mali] [R.A.E., A, vii, 278]. Tests were carried out 

 with potato plants enclosed in cages which showed that hopperburn 

 can be produced at will by the use of leaf-hoppers, and prevented 

 as effectively by their elimination. Both nymphs and adults give 

 rise to the scorching, but the males do little or no damage. If the 

 numbers are small, the damage done by the nymphs is more noticeable 

 as they remain on one leaf till it is used up. 



Tipburn has never been produced artificially in any other way 

 (the effects of damp and shade were tried in these experiments) and 

 all the evidence points to the fact that its appearance in the field 

 is strictly correlated with the attacks of the leaf-hojjper. If these 

 conclusions are warranted, then " hopperburn " as a name for the 

 leaf- hopper effect on potatoes covers practically all that has formerly 

 been designated as " tipburn " on this plant. Tipburn has however 

 been used for scorching effects of all kinds on various plants, and the 

 substitution of the name " hopperburn " for the specific damage to 

 the leaves caused by the potato leaf-hopper is justified in the interests 

 of accuracy. 



Britton (W. E.). a Connecticut Cornfield injured by Crambus 

 'praefeclellas, Zinck. — Jl. Econ. Entom., Concord, N.H., xiii, no. 2, 

 April 1920, pp. 222-223. 



A field of over an acre in Connecticut was cultivated with maize 

 for the fi.rst time in 1919, and the resulting crop Avas almost a total 

 failure owing to the stalk of nearly every plant being attacked by 

 the larva of a Pyralid moth. The injury took the form of a hole 

 eaten into the side of the stem at, or just above ground level. The 

 larva was greyish, covered by a case formed of soil particles webbed 

 together bv silk threads. 



