CHAPTER X 

 RASPBERRY, BLACKBERRY AND DEWBERRY INSECTS 



These fruits are closely related botanically and are in general 

 subject to the attack of the same insects ; their enemies are 

 here treated together for the sake of convenience\ As a rule 

 the raspberry and blackberry are not so liable to serious attack 

 as other fruits, and spraying is only occasionally necessary. 



The Red-spider 



TetranychuH hirnaculatus Harvey 



The red-spider is a minute mite (Pig. 27)^), about -V inch in 

 length, varying in color from pale gret^nish-yellow to dark crim- 

 son-red and usually marked with two dark spots at the side of 

 the body. It has long been known as a greenhouse pest, where 

 it attacks a great variety of plants ; it sometimes injures peach, 

 raspberry, currant and rose in the open. It thrives in a warm, 

 dry atmosphere and is most abundant out of doors in seasons 

 of drought. 



Red-spiders are usually found on the under side of the leaves, 

 where they live under the protection of a very delicate silken 

 web ; in feeding they break the epidermis of the leaf and suck 

 out the sap, causing the foliage to turn yellowish in spots. 

 The female deposits her minute, elongate, transparent eggs 

 on the surface of the leaf. The young mites resemble the adults, 

 but are lighter in color and have only six legs instead of eight. 

 There are several generations a season in the open, while in 

 greenhouses breeding is continuous the year round. The adults 



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