LIFE HISTORY AND BIOLOGICAL NOTES ON 

 CHLAENIUS IMPUNCTIFRONS SAY. 

 (COLEOPTERA, CARABID^j.* 



p. W. Claassen. 



In the Proceedings of the Entomological Society of Wash- 

 ington I, 22, 1884, C. V. Riley says: "Perhaps one of the most 

 interesting discoveries of the year 1884 is the mode of oviposi- 

 tion in some of our Carabidas. From the terrestrial habits of 

 most of our species one would expect that the eggs are depos- 

 ited within the ground, and such may yet prove to be the case 

 with many; but I have proved by actual breeding from eggs 

 to the imago that it is not so with Chlcenius impunctifrons, and 

 have strong proof that Chlcenius cEstivus, Scarites siibterraneus 

 and the genera Diccelus and Galerita share with that species its 

 singular mode of oviposition. The remarkable and unexpected 

 fact, in insects so essentially terrestrial, is that the eggs are laid 

 singly on the leaves of trees and shrubs and encased in a cov- 

 ering of mud or clay. I had often observed these little convex 

 mud cells on the under side of leaves while collecting along the 

 Mississippi in Missouri in years gone by, and was puzzled to 

 make out their real nature. In May and June, 1883, while col- 

 lecting on the Virginia side of the Potomac, I found these clay 

 cells tolerably common and, fortunately, fresh, each containing 

 a large soft white egg. That year I obtained larvae, but only 

 during the past year were any of these reared to the imago." 



The above account is not accompanied by any figures or 

 descriptions, and as far as I am aware, the life history of 

 ChlcEnius impunctifrons has not been written hitherto. 



On May 23, 1918, while collecting in the cat-tail marshes 

 around Ithaca, New York, I observed a little ball of mud on the 

 upper surface of a leaf of Typha. The mud ball occurred near 

 the tip of the leaf, four to five feet above the surface of the 

 ground. I took the leaf with the mud ball into the laboratory 

 and upon breaking it open found a glistening white egg inside. 

 Plate VI, Fig. 5. The egg was put into a tin salve box for rearing. 

 The following day I found two more of the same kind of mud 



* Contribution from the Department of Entomology, Cornell University. 



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