232 OHIO EXPERIMENT STATION: BULLETIN 332 



Description. — The adult of this species is a hard-shelled, flat 

 beetle slightly less than a quarter of an inch long and about half 

 as broad. Beneath, the insect is shiny black and above, the 

 antennae, head and legs are likewise black as is also an area down 

 the midle of the wing covers. The thorax and a part of the wing 

 covers are orange red. The black area on the wing covers is tri- 

 angular in shape, the coloration starting at the base of the meSian 

 line and gradually widening posteriorly. It varies considerably in 

 width with different individuals, sometimes being very narrow, 

 while in others it is so wide as to embrace nearly all the tip of the 

 wing covers. 



The wing covers each bear four strong ridges and the areas 

 between the ridges, as well as the thorax, are densely punctured. 

 A glance at Plate XXXII, Fig. 1, will convey a general impression 

 of the appearance of the adult beetle. 



The thin, flat, oval eggs are deposited on the underside of the 

 leaf and piled one upon another, somewhat shingle-wise and covered 

 with brownish fecal matter which hardens soon after it is deposited. 

 Rarely are more than five deposited together. 



The larval stage is passed within the shelter of mines which the 

 insect constructs within the leaf tissue. (See Plate XXXII, Fig. 4.) 

 The larva is about one-fourth of an inch in length, somewhat flat- 

 tened and tapers but little. When full grown it is yellowish white, 

 with the true legs, head, thoracic shield and anal shield, coal black. 

 The segmentation of the body is plainly marked, and distinct lateral 

 tubercles are borne by each abdominal segment. (See Plate XXXII, 

 Fig. 2.) 



The pupa also is found within the leaf mine and in many 

 respects resembles the larva. The body, however, is more pointed 

 and slightly shorter. The folded wing covers and legs are plainly 

 visible on the underside. (See Plate XXXII, Fig. 3.) 



Life history and habits. — The adult beetles hibernate over win- 

 ter in sheltered situations, such as crevices in the bark of trees and 

 under the litter of the forest floor. Coincident with the develop- 

 ment of the foliage of the black locust in the spring, and sometimes 

 slightly in advance of that time, the beetles emerge and begin feed- 

 ing, this occurring usually after mid-April. After a short time 

 the eggs are deposited in the manner previously described. They 

 hatch soon, the larva breaking through the underside of the shell 

 and eating its way into the leaf tissue and forming a mine. All the 

 larvae of the egg mass occupy a single mine for a time, but in a little 

 while new mines are constructed and the insects live singly. Several 



