174 



EEPORT UPON COTTON INSECTS. 



The Carolina tiger-beetle (Tetraclia Carolina Linn.) was mentioned by 

 Mr. Glover in the Department of Agriculture Keport for 1855 (p. 109), 

 as among those insects "beneficial to the cotton plant" by destroying 

 its enemies.* He remarks that "this species" appears not to be so 

 partial to the light of the sun as some other species, but often conceals 

 itself under stones. It is also seen much more frequently in the cotton 

 fields during cloudy weather, toward evening, than in a fervid midday 

 sun. Many specimens of this beetle have been forwarded to the depart- 

 ment during the past summer from the Alabama cotton fields ; Dr. A. 

 W. Hunt, of Denison's Landing, 

 Perry County, Tennessee, mentions 

 it in his list of insects preying upon 

 the cotton-worm. Fig. 19 repre- 

 sents very fairly the perfect insect. 

 It is usually about three-fourths 

 of an inch (19 mm ) in length, is of a 

 brilliant metallic color with purple 

 and croppery reflections as viewed 

 FIG. 19. Tetracha in different lights. The eyes, legs, FIG. 20. Tetraclia Vir- 



and mouth parts are of a dirty white. 



The Carolina tiger-beetle can at once be distinguished from the only other 

 North American representative of the genus Tetracha (T. Virginica) (see 



Fig. 20) by the comma-shaped 

 yellowish mark at the end of 

 each wing cover. 



Other tiger beetles belonging 

 to the typical genus Cicindela 

 are found in the cotton fields 

 performing the same good of- 

 fices. We figure several com- 

 mon species in order to give a 

 general idea of the group. At 

 Fig. 21 a larva and several 

 species in the adult form are 

 shown. 



GROUND-BEETLES (Coleopt., 

 fam. Carabidae). Almost all 

 of the beetles belonging to this 

 family are carnivorous, and 

 the family as a whole does an 

 immense amount of good by destroying injurious insects. These in- 

 sects are to be found during the day under sticks and stones and 

 under the bark of trees, from which places they go out at night to 

 hunt for their prey. The larvae live in similar situations and are also 



FIG. 21. Several forms of tiger beetles. 



*Mr. Glover uses the generic name Megaccpltala in speaking of this insect, but this 

 genus contains only South American and African species. 



