Observations ox the Life History of Taphrocerus gracilis 13 



prothorax which assist it while feeding, and a pair of ambulatory ampullae, 

 or prolegs, developed on the abdomen which enable it to crawl about within 

 its mine in the leaf. 



The adult beetles are greatly influenced by temperature, and this behav- 

 ior complex seems to be very important. In high temperature and strong- 

 light, they are very active and take to their wings or cling to the leaves 

 when disturbed; but in low temperature, they are inactive, retract their 

 appendages, and drop into the crevices at the base of the leaves when 

 disturbed. This seems to be a protective measure, for the beetles would 

 in many cases fall into the water if they retracted their appendages and 

 dropped from the plant while actively feeding on warm days. The fact 

 that they are near the base of the leaves on cold days seems to be clue to 

 their negative response to light in low temperature, while their occurrence 

 on the foliage on warm days seems to be due to their positive response 

 to light in high temperature. 



PUBLICATIONS CITED 



Blatchley, W. S. Taphrocerus Sol. . In An illustrated descriptive 

 catalogue of the Coleoptera or beetles (exclusive of the Rhyn- 

 chophora) known to occur in Indiana, p. 805. 1910. 



Burke, H. E. Flat-headed borers affecting forest trees in the United 

 States. U. S. Agr. Dept. Bui. 437: 1-8. 1917. 



Collecting some little known Buprestidae (Coleopt.). Ent. 



Soc. Washington. Proc. 22 : 72-76. 1920. 



Craighead, F. C. Contributions toward a classification and biology of 

 the North American Cerambycidae. Larvae of the Prioninae. 

 U. S. Agr. Dept. Rept. 107: 1-24. 1915. 



Kntjll, Josef N. Notes on Buprestidae with descriptions of new species 

 (Coleop.). Ent. news 31 : 4-12. 1920. 



■ Annotated list of the Buprestidae of Pennsylvania (Coleop- 

 tera). Canad. ent, 14 (1922) : 79-86. 1923. 



Say, Thomas. T[rachys]. gracilis. In Descriptions of new American 

 species of the genera Buprestis, Trachys, and Elater. Lvceum 

 Nat, Hist. New- York. Ann. I 2 : 253. 1825. 



Memoir 62, Factors Influencing Catalase Activity in Apple-Leaf Tissue, the fifth preceding number in this 

 series of publications, was mailed on February 21, 1923. 



Memoir 63, The Relation of Soil Moisture and Nitrates to the Effects of Sod on Apple Trees, was mailed on 

 May 4, 1923. 



Memoir 64, Relation of the Composition of Rations on Some New York Dairy Farms to the Economics of 

 Milk Production, was mailed on June 30, 1923. 



Memoir 65, The Nature and Reaction of Water from Hydathodes, was mailed on March 15, 1923. 



