LIFE HISTORY OF THELIA BIMACULATA FAB. 
(MEMBRACID£). 
W. D. FUNKHOUSER. 
(Contribution from the Entomological Laboratory of Cornell University.) 
Thelia bimaculata Fab., is one of the most common and 
widely distributed of the species of Membracide in eastern 
United States and is abundant on locust (Robinia pseudacacia 
L.) in the vicinity of Ithaca, N. Y., where the following study 
has been made. The life history of this insect has not hitherto 
been described and the only reference in literature to the imma- 
ture form seems to be the short description and the excellent 
figure of the last nymphal stage by Matausch* in 1912. Although 
both adults and nymphs may be collected in large numbers 
throughout the summer, the efforts of several years of rather 
extensive field work on the local forms of the family failed to 
show any records of oviposition or traces of the eggs until it was 
noticed that early in the spring the nymphs appeared most 
abundant near the bases of the trees and seemed to be migrating 
upward on the trunk, which led to the natural conclusion that 
the eggs were laid near the ground. This surmise proved to be 
correct and upon removing the dead leaves and humus from 
around the bases of the trees, great numbers of nymphs with 
their attendants were exposed, and the bark, a few inches under 
the forest litter and just above the roots, was found to be punc- 
tured with egg-slits and full of eggs and emerging nymphs. 
This location for the egg-punctures is rather peculiar, since most 
of the species of Membracide common to this locality lay their 
eggs in the buds or in the younger twigs near the end of the 
branches.t After the eggs were discovered and the egg-laying 
habits observed, no difficulty was experienced in rearing the 
insects and in securing the rest of the life-history data. 
3 aes Ignaz Bull. American Museum Natural Hist. 1912. Vol. XXXI; 
26, 333. Pl. 29, Fig. 7. 
+ Cf. Hodgkiss, H. E. The pple and Pear Membracids. Geneva Agr. Exp. 
Sta. Tech. Bull. No. 17. 1910. 
Riley, C. V.. Proc: Ent. Soc. Wash. 1893. Vol. Ils 88-92" p: 
Marlatt, Co. Insect Lites 1894- Viole Vil: 8-14" p. 
Matausch, I. Observations on the Life History of Enchenopa binotata 
Say. Journ. N. Y. Ent. Soc. March, 1912. Vol. XX: No. 1. 58-67 p. 
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