538 ANNUAL, REPORT OF THE Off. Doc. 



earth is carefully removed from around the wilted plant the small 

 white "worm" may be found, and the rootlets and soft outer portion 

 of the roots will be found eaten away. (Fig. 31.) They pupate in 

 the grou'jd and hibernate as adults. 



The earliest remedy is mechanical protection (No. 1) by a net or 

 cloth with liner meeh than the common coarse mosquito netting. 



The adults can be killed by the arsenites (1 — 5), also by to- 

 bacco (11), lime (14), land plaster (13), and they can be prevented by 

 the various methods under "Farm Practice." The larvae can be 

 killed by using tobacco dust or pulverized stems in the soil around 

 the hill. We have had decided success by sticking a few holes four 

 or five inches deep in the ground around the hill and putting about 

 a teaspoonful of calcium carbide in each and filling again with 

 earth. Land plaster and turpentine are also preventives. A pinch 

 of nitrate of soda in each hill acts both as an insecticide and as a fer- 

 tilizer. 



Ground Beetles [Ilarpalus) and their larvae destroy many of the 

 larvae and pupae. 



(See general Remedies and Preventives given later.) 



ORDER COLEOPTERA: The Beetles. 



FAMILY CHRTSOMEIvID^: The Leaf Beetles. (Fig. 32.) 



The White-striped Flea-beetle {Systena llanda). The Elongate Flea- 

 beetle {Systena elongata), and The Cucumber Flea-beetle {Crepldo- 

 dera cucumeris. ) 



As all the Flea-beetles belong to the same sub-family and as their 

 habits, life histories, effects and remedies are similar we here treat 

 them together. They can be known by their very small size and the 

 enlarged segment (femur) of the hind leg, with the fact that they are 

 able to jump and suddenly disappear like fleas (hence the common 

 name), although their jump ends in a short flight. The White-striped 

 Flea-beetle [Systeyia hlanda) \& one of the commonest and most de- 

 structive. (Fig. 34.) 



They are the first insects of the spring to attack the plants, eating 

 fine round holes in them before the leaves have expanded and con- 

 sequently inflicting considerable injury. As the leaves grow the 

 holes enlarge and become conspicuous with brown edges. (Fig. 33.) 



The larvae of most species mine in leaves, feeding on the fleshy sub- 

 stance between the two outer coverings, but they do not effect much 



