Insect pests of farm, garden and orchard . illustrative of the important bearing of weatherconditions, it is found that in the case of the three important out-breaks of this insect, namely, for the years , 1901, and 1907,the temperature for the first five months of each of these years,including the latter part of the winter and spring, was above thenormal for the winter months and belowthe normal for the spring months; inother words, warm winters and cold, latesprings. The little parasitic wasp which is souseful in the control of this pest is nativeto this country, widely distributed, and
Insect pests of farm, garden and orchard . illustrative of the important bearing of weatherconditions, it is found that in the case of the three important out-breaks of this insect, namely, for the years , 1901, and 1907,the temperature for the first five months of each of these years,including the latter part of the winter and spring, was above thenormal for the winter months and belowthe normal for the spring months; inother words, warm winters and cold, latesprings. The little parasitic wasp which is souseful in the control of this pest is nativeto this country, widely distributed, andevery year does its work with the greenbug and with other aphides. It isalways present in grain fields, as shown byits appearance every year, to war on thesepests whenever the weather conditions Fig. 115.—Dead greenbugs, showing holefrom wliich the matu-red parasite of Lijaiph-lebus emerges. Thetop figure shows thelid still attached, butpushed back; the bot-tom figure shows theparasite , (AfterWebster, U. S. ).
Size: 2217px × 1128px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisheretcet, bookyear1912
