THE ACARINA OR MITES— BANKS. 



25 



Each female ma}^ laj- from live to ten eggs ii day for a period of eight 

 to twelve da3^s•, the .young hatch in from three to live days, and in 

 about live days more are adult. A succession of Ijroods is continued 



Fiii. 29.— Tetranychus leg. a, coxa; />, trochanter: f, femur; '/, patella; c, tibia; /, tarsus; 



<i, onychium; /(, claws. 



throughout the summer, but wet weather is apt to stop or greatly 

 retard their development. 



The mites ordinarily move slowly, but when disturbed can run quite 

 rapidly. For the greater part of the time they remain in one phice 



Fi(i. :?0. — Tetraxychus, genital organs. 



sucking the juices from the leaf. In the spring some species attack 

 the buds. Several of our species are very abundant and destructive. 

 The common greenhouse species, known as "the red-spider," and 

 which also occurs on many outdoor cultivated plants, is T. himaculatus 



Fig. ol. — Three styles of claws of 

 teteanychus. 



Fig. 32.— Tetranychus gi.overi, pal- 

 pus ANI> mandibular PLATE. 



Harvey; it is probably the T. cucaiiterls oi Boisduval. Specimens of 

 this species often vary greatly in coloration; the members of each 

 colony, however, usually being alike. T. mytilatijJuH^ Riley is abun- 

 dant on orange leaves in Florida. In this species the abdominal 

 bristles arise from warts or tubercles, and the tarsus has two simple 



