338 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



By the use of these it is possible to direct the spray on the under 

 sides of the leaves, where the lice feed. 



The preventive measures against the turnip louse are rotation, 

 proper planting time, trap crops, clean culture, and the destruction 

 of the first colonies." 



Flea-beetles * 



A considerable number of small flea-beetles attack cabbage and 

 other cruciferous crops, and although as a rule only troublesome, 

 they appear periodically in enormous numbers and do serious 

 injury. They are mostly small species (there being seven species 

 of the genus Phyllotreta alone) not over an eighth of an inch long. 

 One of the most common throughout the country is the striped 

 turnip flea-beetle.f It is polished black with each wing-cover 

 marked with a broad, wavy band of pale yellow. The microscopic 

 white eggs are laid in a little excavation of the root near the crown 

 of the plant. The larvae mine into the roots and have been 

 reported to do considerable injury to them, but it seems probable 

 that most of them live upon the roots of cruciferous weeds. The 

 full grown larva (Fig. 285a), is about three-eighths inch long, 

 quite slender and tapering, yellowish white, with brown head and 

 anal plate, and with marks on the thorax and transverse rows of 

 minute hair-bearing tubercles as shown in the figure. The West- 

 ern cabbage flea-beetle J is the more common from the Dakotas 

 southward to Mexico and westward to southern California. It is a 

 uniform deep olive-green, with the surface irregularly punctate, 

 and 7-100 inch long. Another species almost indistinguishable from 

 the first species above, is the wavy-striped flea-beetle, whose larvae 

 mine in the leaves of wild pepper grass (Lepidium virginicwri), 

 and is most abundant in the Middle and Southern States. The 

 life history has been fully described by Dr. Riley (I.e.). 



Control. Where the plants are sprayed for the cabbage worms 

 with Paris green or arsenate of lead, there will probably be little 

 trouble with flea-beetles. Otherwise, spray with arsenate of lead, 

 3 to 5 pounds per barrel, or Paris green one-third to one-half 

 pound, adding the resin soap or " sticker," so as to give the 



* Family Chrysomelida. Refer to pages 266, 303, for other flea-beetles- 

 See C. V. Riley, Report U. S. Commissioner Agr., for 1884, pp. 301-308. 

 t Phyllotreta vittata Fab. 

 J Phyllotreta pusitta Horn. 

 Phyllotreta sinuata Steph. (zimmermani Crotch.) 



