| Show FARM ARM TOPICS topics INSECTS CAUSE MAN CONSTANT WARFARE natures athrel s balance often upset by cultivated fields by DR LEE A STRONG civilized man with his cultivated fields and domesticated live stock often upsets natures balance and gives some insect species a profitable inning to offset this advantage man must strike an artificial balance this he may do by setting one insect to prey upon another by changes in farming practices by developing resistant plants and animals or by the use of insecticides a principal product of this chemical age insects in other lands may be checked by natural enemies birds and animals other insects or even disease if in this country they threaten agriculture the entomologist sometimes can check them by introducing their natural enemies when the citrus industry of california was threatened by the cottony cushion scale from australia a little lady beetle was imported from that country cottony cushion scale is no longer a pest in california citrus groves wheat growers circumvent the hessian fly by planting after the flies emerge and die however insecticides are the main main reliance of the entomologist the problem is not simple the insects of this country that are actually pests differ so in physical characteristics and live under such a variety of conditions that an insecticide sect icide that is death to one may not affect another scale insects cannot be poisoned by placing poison on their food their mouth parts are a bucki sucking n 9 tube which they thrust through t the he poison into the plant tissue beneath young mosquitoes breathe through a tube in the tail thrust above the surface of the water in which they live separating this tube from the air with an oil film is an approved control to better insect control the entomologist is now turning to organic insecticides these show great promise |
