THE GEKUS CALOSOMA. 21 



CALOSOMA EXTERNUM (Say). 

 (Syn.: C '. longipenne Dej .) 



ORIGINAL DESCRIPTION. 



East, Middle, South and Central States. Winged, black, margined with purplish; 

 elytra with three series of obsolete punctures. Length one inch and three-twentieths. 



Body elongated, deep black; antennae brown at tip; thorax punctured, margined 

 with bluish-purple; lateral edge regularly curved to the base; dorsal and basal lines 

 distinct; basal angles obtusely rounded; elytra striate; striae well impressed, much 

 narrower than the interstitial lines, and with conspicuous, definite punctures; in- 

 terstitial lines convex, equal, the 4th, 8th, and 12th each with a series of obsolete 

 small punctures, which do not interrupt them; exterior margin bluish-purple. 



A large species, brought from Arkansas by Mr. Thomas Nuttall. It somewhat 

 resembles C. sylvosus, but is larger, the strife of the elytra are much more regular, 

 exhibiting nothing of the granulated appearance of those of that insect, and the curve 

 of the exterior edge of the thorax is regular, or without any tendency to excurvature 

 near the base. 



EARLY RECORDS OF THE SPECIES. 



This species was described by Thomas Say in 1823 from a specimen 

 collected in Arkansas. Later Dejean discovered that Carabus 

 externus Say and Calosoma longipenne Dej. were synonyms. Some 

 valuable notes on the habits of both adults and larvae have been 

 recorded by Dr. L. O Howard and Prof. Lawrence Bruner. 



DISTRIBUTION. 



This species occurs in Arkansas, Connecticut, Delaware, District 

 of Columbia, Georgia, Illinois, Iowa, Kansas, Kentucky, Maryland, 

 Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, 

 Oklahoma, Pennsylvania, South Carolina, Tennessee, and Texas. It 

 is more common in the southern range. 



COLLECTIONS AND SHIPMENTS. 



Messrs. E. A. Schwarz and H. S. Barber, of the Bureau of Ento- 

 mology, have collected at electric lights in Washington, D. C, and 

 forwarded living specimens for study at the laboratory. In 1909 

 a female was received May 18 and a male June 7. June 19, 1910, 

 one live female was received from Prof. C. E. Sanborn, Stillwater, 

 Okla. In 1911, 6 males and 8 females were received from Washington, 

 D. ■ C, and in 1912 one pair of beetles was forwarded from the same 

 locality. 



HABITS OF ADULTS. 



A small experiment conducted in June, 1911, to test the climbing 

 habits of the adults showed that they are fairly agile on the bark 

 of trees. They run swiftly on the ground and climb as actively as 

 C. frigidum. During the short time the beetles were under observa- 

 tion they did not attempt to climb without being forced, but seemed 

 thoroughly at ease when placed upon the trees. 



FOOD OF ADULTS. 



This species has been reported by Riley as feeding on the Rocky 

 Mountain locust (Melanoplus spretus Uhl.), by Howard as an enemy 

 of the army worm (Girphis unipuncta Haw.), and by Bruner as feed- 

 ing on LacJinosterna sp. 



