292 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



wherever bees are kept, and it js also more than probable that its fond- 

 ness ior insects of this sort leads it to kill "wasps" and "hornets," some 

 of which, as will be shown further on, are very efficient enemies of the 

 cotton- worm. The harm done in the latter way is undoubtedly more 

 than compensated for by the cotton-worms killed, but the former habit 

 is one which cannot be condoned, and which quite effectually spoils the 

 character of these otherwise beneficial insects. 



The next order, Coleoptera, contains very many predaceous insects, 

 and more species from this order have been found to prey upon the cot- 

 ton-worm than from any other. 



Tiger-beetles {Coleopt., fam. Cincindelidae). — The Carolina tiger- 

 beetle {Tetracha Carolina, Linn.) was mentioned by Mr. Glover in the De- 

 partment of AgTiculture Eeport 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 department during the jiast summer 

 from the Alabama cotton fields ; Dr. A. W. Hunt, of Denison^s Landing, 

 Perry County, Tennessee, mentions it in his list of insects jireying upon 

 the cotton-worm. Plate XI, fig. 4, represents very fairly the perfect 

 insect. It is usually about three-fourths of an inch (19™™) in length, is 

 of a brilliant metalMc color with purple and croi)pery reflections as 

 viewed in difierent lights. The eyes, legs, and mouth parts are of a dirty 

 white. The Carolina tiger-beetle can at once be distinguished from the 

 only other ISTorth American representative of the genus Tetraoha {T. Vir- 

 ginica) (see Plate XI, fig. 5) by the comma-shaped yellowish mark at 

 the end of each wing cover. 



Other tiger-beetles belonging to the typical genus Gincindelu are found 

 in the cotton fields perfoi-ming the same good ofl&ces. We figure several 

 common species in order to give a general idea of the group. At Plate 

 XL fig. 6, a larva and several species in the adult form are shown. 



G-ROUND-BEETLES(Ooi!eoj?t,fam. Garabidae). — Almost all of the beetles 

 belonging to this family are carnivorous, and the family as a whole does 

 much good by destroying injurious insects. These insects 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 nearly always predaceous. The generali- 

 zation is made by Packard that they are "generally oblong, broad, with 

 the terminal ring armed with two horny hooks or longer filaments, and 

 with a single false leg beneath." Of these beetles all which are to be 

 found In the cotton fields ^ill undoubtedly lose no chance to destroy the 

 cotton-worms. A correspondent from Texas speaks of "the large green 

 ground-beetle" as destroying the worms. These are, in all probability, 

 Calosoma scrutator, Fabr., shown at Plate XI, fig. 8. According to Har- 

 ris, this insect is known to ascend trees in search of canker-worms and 

 similar insects. Another beetle of similar habits is Calosoma calUdum, 

 shown at Plate XI, fig. 7. Mr. Glover, in the 1855 report, figiu-es a spe- 

 cies of Earpalus, probably JBT. caliginosus, Say (see Plate XII, figs. 1, 2), 

 and in the text refers to it as being abundant in the cotton fields and 

 .beneficial by destroying the diflereut enemies of the cotton plant. 



SoLDcaR-BEETLES (CoUopt., fam. Lampyridae, genus Ckauliognathiis, 

 Hentz). — The family Lampyridae is popularly known as the fire-fly family, 

 and the adult beetles are too weU known to need description. In the per- 

 fect state they are nearly all vegetable feeders, while the larvae are nearly 



