63 
WHITE GRUBS 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 planting 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 by 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. 59.—Lachnosterna arcuata: a, beetle; b, pupa; c, egg; d, newly hatched larva; e, mature larva; 
/, anal segment of same from below— a, b, e, enlarged one-fourth; c, d,f, more enlarged (author's 
illustration, Division of Entomology). 
One of the commonest forms of Ma}^ 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. 71—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 Illinois 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 elytra 
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. 
