February io, 192 i] 



NATURE 



772, 



Applied Entomology. 



BULLETIN 805 of tht United States Department 

 of Agriculture deals with "Iwo Lealhoppers 

 Injurious to Apple and Nursery Stock," and gives an 

 account of the apple leafhopper and the rose leaf- 

 hopper. Of the two species, the apple kathopper 

 causes the greater damage, and is most prevalent in 

 the eastern States, attacking a large variety of plants, 

 on which it chieOy injures tin: tender termmal leaves, 

 causing them to turn brown. The rose leafhopper 

 also attacks a large variety of plants, and is especially 

 prevalent in the north-western States, l-'ull accounts 

 of the life-histories and descriptions of the insects in 

 all stages are given, and sprays for controlling tfiem 

 recommended. 



Farmers' Bulletin 650 of the United States Depart- 

 ment of .Agriculture deals with the San Jose scale, 

 which attacks many species of trees, causing con- 

 siderable damage to, and sgmetimes killing, fruit 

 trees. During I he summer the scale reproduces ex- 

 ceedingly rapidly, the life-cycle taking thirty-three to 

 forty oays, and, although it has a large number of 

 parasites, they are insutlicient to act as an elTective 

 check. The scale is distributed on nursery stock, 

 etc., and the young are also probably spread by wind, 

 other insects, and birds. The scale can be kept in 

 check" by thorough annual spraying when the plants 

 are dormant, lime-sulphur wash being recommended 

 for this purpose. 



In Farmers' Bulletin 1061 an account is given of 

 the Harlequin cabbage bug, which occurs in all but 

 the northern States, and is a very bad pest of cab- 

 bages and allied plants. Removal of wild crucifers 

 and remains of crops, trap-crops, and hand-picking 

 are effective, and also contact insecticides, but co- 

 operation Ijetwcen neighbouring growers is necessary 

 to control this pest. 



P"arnK'rs' Bulletin 1086 gives an account of "How 

 Ins<'cts .Affect the Rice Crop in the United States." 

 The most import.int pest is the rice water-we<'vil, the 

 larva of which feeds amongst the roots of the rice 

 plant at the base of the stalk, causing considerable 

 damage to tlv crop. The stink bug attacks the soft 

 grains of the rice while they are forming. The fall 

 Army worm or Southern grass worm occasionally 

 becomes abundant and damages rice fields in the 

 spring, but is easily destroyed by flooding the fields. 

 The caterpillar of the rice-stalk borer feeds in the 

 stalk and causes the head to die. These pests are 

 controlksd by thorough cultivation, by suitable flood- 

 ing and draining of the fields, and by keeping the 

 fields and banks rle.ir of weeds. 



In Farmers' Bulletin lioi an nrrount is given of 

 "The Argentine .\nt as a Household Pest." This 

 ant occurs in scattered locilities throughout the South. 

 Owing to its encouraging aphids and scsflc insects, 

 it causes constdorable trouble to fruit-growers and 

 nfhers, while it causes much annoyance by swarming 



houses. The nnf has been distributed in foodstuffs, 

 I is also carried by floods. Formulae are given for 



•■-banding mixtures and for poisons for use in 

 ises and in the open. 



I'nnners' Bulletin 1104 deals with the hook IJce 

 Psocids which frequentlv occur in hou!>es and other 

 rniilHinsjs, and may occasionally increase in numbers 

 to such an extent that it is necessary to fake steps 

 Io destroy fhrm. for which piirpos ■ fumitralion with 

 sulphur or hydrocyanic acid is recommended. 



In the Jnurnnl nj Agricullureil Fesrarrh (vol. xviii.. 



No. 0. lozn) an account is given by I. M. Aldrich of 



"The European Frit Fly in North .America." Thi< 



pest occurs principally in the regions In which winter 



NO. 2676, VOL. 106] 



wheat is grown, from tfie Great Lakes to the Ohio 

 Kiver and westward to the Missouri, but it is generally 

 distributed over most of the country. A full descrip- 

 tion, with figures, is given of the lite-history, and also 

 a pjate of tfie adult and puparium. .As many as four 

 broods were obtained in tlw summer, the first, from 

 larvae which had lived through the winter, in .April. 

 Eggs and larvae are usually lound on the young and 

 tender shoots and also sometimes upon or within tlie 

 glumes, wheat, barley, and various grasses being 

 attacked. It is recommended that wlieat should be 

 sown late in the fall or early in the spring in order 

 to escape the attack of this insect. 



In the same journal (vol. xix.. No. i, 1920) an 

 account of "The Banana Root Borer," which is a 

 widely distributed pest of the banana, is given by 

 G. F. Moznette. The larvae of this weevil. Cosmo- 

 polites sordidtis, feed in the roots of the plant, and 

 the damage done to young plants causes them soon 

 to wither and die. Full descriptions of all stages 

 and of the life-history are given in the paper, which 

 is illustrated by four plates. Destruction of infested 

 plants and trapping of adults by means of strips of 

 banana-trunks placed on the ground are advised. 



The European corn-borer has recently been intro- 

 duced into the United States, being first discovered 

 there in 1917, and has already spread over consider- 

 able areas in the North-east, and it seems likely to 

 do more damage than any native species (State of 

 Illinois, Department of Registration and Education, 

 Division of Natural History Survey, Bulletin, vol. xiii., 

 art. 10, " The European Corn Borer and some Similar 

 Insects," by VV. P. Flint and J. R. Malloch). The 

 larva of this moth, Pyrausta nubilalis, Hubner, feeds 

 on all parts of the plant above the ground, many 

 species of plants being attacked, but corn appears to 

 be preferred. .An account is given of the life-history 

 of this insect, which may have two broods in the year, 

 the winter being spent as full-grown larva; which 

 hibernate in the stems of the foixl plant. This pest 

 is probably chiefly spread in the stems of its plant-host, 

 although, as the moth is a fairly strong flyer, it might 

 also be disseminated in the latter stage. .A number 

 of native borers clos<My resemble the European corn- 

 borer, and descriptions arc given to enable it to be 

 distinguished therefrom. 



Bulletin, vol. xiii.. No. 11, 1920, of the same series 

 is concerned with " .\ Study of the Malarial Mos- 

 quitoes of Southern Illinois, i. Operations of 1918 

 and 1919," by S. C. Chandler. .An account is given 

 of a survey of the mosquitoes of two districts of 

 Southern Illinois in which malaria occurred fre- 

 quently, in addition to less thorough work at other 

 points. The breeding areas were examined, and larvae 

 were most plentiful in fairly clean, still water in which 

 there was vegetation. Two of the species found are 

 capable of transmitting malaria. To get rid of the 

 mosquitoes drainage is the most effective measure. 

 Clearing the edges of the ponds, etc., of vegetation 

 is also suggested, as well as oiling the surface of the 

 water, and the use of larvicides. Houses should be 

 screened or fumigated. 



The Department of .Agriculture, Ce\Ion, Bulletin 

 No. 46, by N. K. Jardine. gives an account of "Field 

 Experiments with Anti-Tortrix Fluids." The experi- 

 ments showed B greater yield from the treated plots 

 than from the control, and the quality of the tea was 

 not lowered. In treating a substance intended for 

 human consumption, such as tea, the use of poisons 

 is not possible, and as contact poisons are useless 

 against the tea torfrix, owing to its rolling Itself up 



