102 
susceptible to organized attack. If they are ever thoroughly mastered 
by the farmers of America, it will apparently | e by concerted measures, 
possibly supplemented by legal requirement, for the destruction of June 
beetles before they have laid their eggs 
‘The food of the larva of Cyclocephala does not differ from that of 
the common species of Lachnosterna so far as our observations go, the 
Cyclocephala grub having been taken by us from grass and from corn. 
The food of the i imago of C. ummaculata is not known to me. Specimens 
of this insect enclosed June 23 in a breeding cage with branches of 
basswood, ash, birch, oak, elm, hard maple, and soft maple, began to die 
on the 25th, and had all died ‘by July 2 without eating anything. 
LIFE HISTORY AND HABITS. 
Lachnosterna. Imago (Plate XII., Fig. 1, 4, and 6).—The adult 
beetles of the genus Lachnosterna, hibernating in the earth in the cells 
where they originated, emerge in spring and early summer at periods 
varying according to the species of beetle, the general advancement of 
the season, and the character of the weather at the time. Warm and 
genial days in spring often bring them suddenly out in myriads where 
previously only scattered individuals have been seen, and their flight at 
night is of course more free when the weather is warm than when their 
energies are chilled by cold and storms. 
In Central Illinois L. fusca is een) the earhest to appear, com- 
mencing to emerge as early as April 12, and continuing alive to June 
4. Inversa and hirticula are likely to follow a few days thereafter*, 
and tristis, usually a woodland species, at about the same time (May 7 
with us to June 7). ZL. gibbosa is relatively late, our earliest specimens 
having been taken May 14, and our latest June 25: ; and L. rugosa later 
still—the latest, in fact, of all our very abundant species, ranging from 
May 18 in our collections to July 28, at which latter date specimens 
were taken flying at night in Northern Illinois. July 16, an imago of 
this species was ob served in Champaign county feeding on a leaf of 
corn in the field. 4. crenulata appears in Illinois in July and August, 
and, according to Dr. Riley, L. ephilida is also a late species, occurring 
in the same months. (Proce. Ent. Soe. Washington, Vol. II., p. 133.) . 
As a rule, the males are not only the first to appear but surpass 
the females in number, taking the season through. ‘They also come to 
lights much more freely than the females, as is Shown by a comparison 
of our collections made at lights with those made the same night from 
trees on which the beetles were feeding. The 7th of May, 1891, for 
example, a collection of LZ. inversa made with a lantern trap contained 
1,210 males and twenty-four females,—a ratio of fifty to one,—while 
we took from trees the same night one hundred and twenty-two males 
and seventy-three females—less than two to one. Taking all our collec- 
tions of this species for the summer of 1891, we find that in those from 
lights (1,418 specimens) the males are to the females as fifty-one to 
one, while in those from trees (271 specimens) the ratio was one and 
one half to one. This is, however, much greater than the usual differ- 
ence in other Lachnosternas, the species ev idently \ varying with reference 
* April 29 is our earliest date for each, and June 24 is our latest for hirticula 
and June 28 for inversa. 
