425 



insects, ants and ground beetles are effective enemies. The following 

 Chalcids are the most important parasites : — Eurytoma ti/lodermatis, 

 Micwdonlomerus anthonomi, Hubroojtus piercsi, Calola^cus hunteri, 

 and C. incertus. Numbers of eggs and larvae are killed by the rapid 

 proliferation of the tissues in which the eggs are laid. The only effective 

 methods of control are cultural ones ; the destruction of cotton stalks 

 in the autumn, clean cultivation, crop rotation, early planting, fertilising 

 and working, are all important factors. The hand-picking of fallen 

 squares proves a satisfactory means of control in some localities ; the 

 squares sliould be burned or, preferably, placed in wire cages so that 

 the parasites may escape. Early varieties of cottan should be selected ; 

 tliose which do not form a " top crop " in late autumn, which tend 

 to retain infested scpiares, and which have hairy stems, are the best 

 kinds to plant. 



The disease of cotton, known as cotton wilt, which occurs throughout 

 South (jleorgia, can be controlled by rotation with peas, velvet beans, 

 or grain crops and by growing wilt-resistant varieties. 



Moore (J. G.). Strawberry Culture in Wisconsin. — Agric. Expt. Sla. 

 Univ. Wisconsin, Madison, Bull. 218, March 1915, 40 pp., 11 figs., 

 6 tables. 



The common pests of the strawberry are the leaf-spot disease, the 

 white grub [Lachnosferna], the strawberry leaf-roller [Ancj/lis <omp!ana], 

 the strawberry aphis [Aphis forhesii\, and the weevil [Ot/orrJu/nhus 

 ovalus]. The white grub attacks the plant near the crown, severing 

 the top from the roots. No very satisfactory remedy is known. Newly 

 ploughed land should be avoided ; shallow ploughing in autumn will 

 help to reduce the number of grubs. The leaf-roller causes injury by 

 rolling the leaves on which it feeds. The first brood appears at fruiting 

 time ; poison sprays may be used against the second brood. The 

 strawberry aphis is not easily controlled, since it works beneath the 

 ground. Precautions should be taken against infestation fiom outside 

 sources. If badly infested, it is best to start a new plantation. Burning 

 over the ground, late in autunm. is useful. The strawberry weevil 

 punctures the flower bud and lays an egg in the interior. There is 

 no satisfactory remedy. 



SwENK (M. H.). The Important Insect Enemies of Field Crops in 

 Nebraska and their Control. — Bull. State Entomologist, Lincoln, 

 Nebraska, no. 3, 15th September 1914, 24 pp., 12 figs. [Received 

 10th July 1915.] 



The effectiveness of crop rotation, as a preventive of insect increase, 

 is largely dependent upon the food habits of the pest concerned and 

 to some extent upon the ease of diffusion of the adults. The western 

 corn-root worm [Diabrotica longicornis] can be absolutely controlled 

 by crop rotation. The adults lay eggs at the base of tho maize in 

 late August and September, the larvae which hatch in the following 

 May and June attacking the roots. If another crop is planted on 

 this field, the larvae which hatch out the next year will find no suitable 

 food plant, and will be absolutely exterminated. Crop rotation affords 

 an important temporary check in the case of Aphis maidi-radici<. the 

 corn-root louse. Rotation often causes the destruction of the adults 



