76 INSECTS INJURIOUS TO VEGETABLES 



f erred by deduction) that one species, Lachnosterna arcuata,^ 

 requires only a little over two years for larval development, but 

 about three years are consumed from the time the egg is laid 

 until the appearance of the beetle above the ground, and this 

 is probably true of most of the species which occur in this 

 country. Thirteen days was ascertained as the egg period, 

 twenty-three for the pupa, and the total period from egg to 

 adult required two years and fifty-one days. 



The sexes pair soon after their first appearance and the 

 females enter the earth for oviposition. The eggs, which are 

 rather large and whitish or gray, are deposited singly in the 

 ground. The grubs, hatching among the roots of grass and 

 similar plants, feed at first upon the tender rootlets and after- 

 ward on the larger roots, and slowly increase in size until mature. 



The species which have been observed usually transform to 

 pupae from the middle of June to September of the second or 

 third year after hatching, and become fully-developed beetles in 

 August or September of the same year. They remain in the 

 earthen cells in which transformation has taken place, some- 

 times at a depth of from twelve to eighteen inches, where they 

 are protected from told and frost, and appear abroad the fol- 

 lowing spring to repeat the life cycle. Hibernation may occur 

 in two stages of the larva, and occasionally in a third, and as 

 beetles. 



The Arcuate May Beetle {Lachnosterna arcuata Sm.) is the 

 common May beetle of the Tvliddle Atlantic region. The North- 

 ern June Beetle (Lachnostera fiisca Frohl.) is abundant in the 

 Middle Atlantic region, and is quite as destructive and over 

 a wider extent of territory. It is the common species from 

 New England to Illinois, and occurs, but comparatively rarely, 

 farther west. A large proportion of the injury caused by white 

 grubs and June beetles in the region specified are due to this 

 insect. 



1 See article by the writer, Bui. No. 19, Div. Ent., U. S. Dept. Agr., pp. 74-80. 



