ENTOMOLOGY 29 



noticeable. Many experiments have been made in the treatment of 

 manure piles in order to kill the maggots of the house fly, and the 

 chloride-of-lime treatment has been found to be the cheapest and 

 most efficacious. 



It has been stated above that the closet for the reception of 

 manure should be made tight to prevent the entrance or exit of 

 flies. A window fitted with a wire screen is not desirable, since the 

 corroding chloride fumes will ruin a wire screen in a few days. 

 (Farmers' Bui. 135.) 



INSECTS INJURIOUS TO FRUIT. 



APPLE INSECTS. 



The Woolly Aphis. Throughout the summer on the lower por- 

 tion of the trunk and particularly on the water sprouts of the apple 

 may often be seen small bluish-white flocculent or cottony patches, 

 which indicate the presence of colonies of one of the worst enemies 

 of the apple, viz., the insect variously known in this country as the 

 apple-root plant-louse, woolly apple-louse, woolly aphis, etc., and 

 abroad very generally as the American blight. It exists in two forms, 

 the one just referred to, above ground on the trunk or water shoots, 

 and another inhabiting the roots and not open to observation. Closely 

 paralleling in these particulars the grape phylloxera, the damage 

 from the woolly aphis is also almost altogether due to the root form, 

 the aerial colonies causing scarcely any injury. On the roots its 

 attacks induce enlargements or galls or swellings very similar to 

 those produced by the phylloxera, and in the cracks of these galls 

 and swellings the root form occurs in clustered masses. The injury 

 to the trees is due both to the sucking up and exhaustion of the vital 

 plant juices and to the poisoning of the parts attacked, as indicated by 

 the consequent abnormal growths. The woolly-aphis of the apple is 

 found in nature in two so-called forms. One infests the limbs and 

 twigs, while the other lives under the ground upon the roots. The 

 presence of the aerial form of the woolly-aphis is readily detected by 

 the bluish-white cottony or downy looking substance that is excreted 

 by and covers the greater part of each wingless individual aphis; 

 and since these insects live in clusters or colonies, the patches of 

 white matter are very conspicuous, and can scarcely escape the no- 

 tice of even the most casual observer. (Mo. E. S. B. 35; Dept. of 

 Agr. Cir. No. 20, B. E.) 



The presence of the root inhabiting form is readily detected 

 by removing the earth from the roots near the trunk of the infested 

 tree. The appearance of a bluish-white cottony or mildew looking 

 substance, or of knotty and distorted roots will indicate its presence. 

 It is this root or subterranean form that causes so much damage to 

 the apple orchards in the southern half of Missouri, and to apple 

 nursery stock throughout the state. The infested' apple tree appears 

 sickly; it does not grow as it should; its leaves are less numerous 

 and they have more of a pale green or yellowish color than is nat- 

 ural; and finally the tree dies outright or is blown over with the, 

 first slight wind. 



