272 



SCHOOL ENTOMOLOGY 



the foliage is curled by the aphides or it will not reach them. 

 Kerosene emulsion containing from 5 to 8 per cent of kero- 

 sene is the oldest spray, but should be used with caution on 

 melons and peas. Whale oil soap ; one pound to six gallons 

 of water, is entirely safe and equally effective. " Black-leaf " 

 extract of tobacco containing 2-fo per cent of nicotine is 

 effective when applied one part to 65 or 70 of water. Prof. 

 Franklin Sherman, Jr., states that any good laundry soap 

 used at the rate of one pound dissolved in three gallons of 

 water is effective against the cabbage aphis. Where water 

 under pressure is available in a small garden, many species 

 may be held in check by washing with a strong stream from a 

 garden hose. Cabbage plants infested in the seed bed 

 should be dipped in a soap solution when planted. 



147. Flea-beetles.* Almost all of the common garden 

 crops are attacked by small beetles, which from their power 

 of making long, quick jumps, are 

 known as flea-beetles. 



The Potato Flea-beetle f (45) at- 

 tacks potato and tomato plants 

 when they are but a few inches high 

 and often so riddles the foliage as to 

 cause the plants to wilt and some- 

 times to necessitate replanting toma- 

 toes. It is only one-sixteenth inch 

 long and is jet black, except the 

 yellowish antennae and legs. The 

 beetles hibernate under rubbish, 

 leaves, etc., and in the spring come 



forth and lay their eggs on the roots of common weeds of 



the nightshade family, such as the horse-nettle, or " Jimpson " 



weed, etc. The larvae mine in the roots of these plants 



* Family Chrysomelidce, see page 121. f Epitrix cucumeris Harris. 



FIG. 194. Potato flea- 

 beetle, greatly enlarged 

 (After Chittenden, 

 U. S. Dept. Agr.) 



