475 



the cochineal insect into different parts of the world, and the many 

 varieties now known as " wild cochineal insects " are probably the 

 variations produced by climatic conditions. Diaspis echinocacti, Bch. 

 {calyproides, Costa) (grey round cactus scale), has a very wide range 

 and is common in Australia. Nysius vinitor (Rutherglen bug) is one 

 of the few native insects attacking prickly pear. During the time of 

 the great drought, when the mustard weed on which the bug breeds 

 had dried up, the insects migrated to the prickly pear and infested it 

 so heavily that it seemed as though the problem of the destruction of 

 this giant weed was going to be solved ; however, with the coming of 

 the rains, the insects returned to the native herbage and the cactus 

 recovered. Another insect found on prickly pear is Oxycarenus lectu- 

 laris (coon bug), which is abundant in New South Wales. It has been 

 suggested that the plant bugs, Chelinidea vittigera and Narnia pallidi- 

 cornis, might be imported from the United States to control the 

 cactus. Several insects recorded from the United States on cacti are 

 mentioned, and a suggestion is made of experimenting with a large 

 land snail which is said to show marked preference for cacti. 



Thrips attacking French Bean Flowers. — Agric. Gaz. N.S.W., Stjdney, 

 xxviii, no. 6, June 1917, p. 426. [Received 23rd August 1917.] 



In April 1917, the flowers of French beans were found at Wamberal, 

 where they are an important crop, to be badly infested with thrips, 

 which, coming from dandelions, swarmed on the bean flowers and fed 

 on the pollen, causing the flowers to fall without pods being formed. 

 In the next crop of beans spraying the flowers with tobacco and soap 

 solution was tried with success. Clean cultivation was advised and 

 particularly the turning under of all grass and weeds in which thrips 

 might shelter before the bean flowers opened. 



Clement (G. E.). Control of the Gipsy Moth by Forest Management. 

 Part I : The Gipsy Moth in Woods. — U.S. Dept. Agric, Washing- 

 ton, D.C., Bull. no. 484, 9th April 1917, pp. 1-16. [Received 

 7th August 1917.] 



The author divides trees into four classes according to Mosher's 

 classification [see this Review, Ser. A, iii, p. 668], having regard to their 

 susceptibility to gipsy moth attack, and gives the following 

 recommendations in forest management. Trees of low commercial 

 value should be cut when interfering with the gro'wth of more valuable 

 ones of more resistant species. All trees that have begun to die should 

 be cut, so as to prevent borer attacks. Valuable trees should not be 

 cut merely from fear of insect attack, nor should they be removed, 

 if not interfering with the growth of still more valuable species, unless 

 they can be replaced by something better. Hardwood growth should 

 be confined to the best soils ; conifers, particularly white pine, should 

 be encouraged on soils not adapted to hardwood. Woodlands should 

 be so completely stocked with trees that undergrowth providing food 

 for the gipsy moth will be too overshadowed to grow. Public forests 

 should be given every encouragement. 



