63 

 WHITE G^UBS AND MAY BEETLES. 



Several species of white grubs and wireworms, the young of May 

 or June beetles and of "snap bugs" or "skipjacks," respectively, 

 attack the roots of beets, but none of them appear especially to favor 

 this form of food and we have yet to learn of very serious damage by 

 any of them. Both of these forms of insects follow the planting of 

 beets in grass lands, and if some other plant be used as a first crop 

 before the i)lanting of beets in virgin prairie or in sod land the 

 chances of infestation will be reduced to a minimum. 



It is recorded that about 15 per cent of a field of beets was once 

 destroyed in Nebraska b}^ white grubs, and the roots of beets in cen- 

 tral Illinois have also been injured, causing the plants to wilt. Only 

 two forms of white grubs have been identified with attack on beets, 

 but there are undoubtedly many more which affect this crop. 



Fig. b^.—Lachnosterna arcuata: a, beetle; b, pupa; c, egg; d, newly hatched larva; e, mature larva; 

 /, anal segment 6T~same from below— a, b, e, enlarged one-fourth; c </,/, more enlarged (author's 

 illustration, Division of Entomology). 



One of the commonest forms of May beetles is illustrated, with its 

 white grub, in figure 59, which also shows the egg and pupa. A more 

 complete account of this species is furnished in Bulletin. 19, new 

 series, of the Division of Entomology (pp. Tl— 80). 



THE RUGOSE MAY BEETLE. 



{Lachnosterna rugosa Mels.) 



This species was found by Forbes and Hart in the year 1900 injuring 

 the roots of beets in central Illinoi.s and causing the plants to wilt. 

 The beetle is of about the same size and color as the arcuate May beetle 

 previously mentioned. It is a little paler, however, and the elj^tra 

 are more distinctly lined with ridges, while the thorax is more strongly 

 and much more closely covered with punctures. Its distribution 

 extends from Massachusetts to Louisiana and Texas, and westward to 

 Colorado and Montana. 



