INVERTEBRATE ENEMIES OF ALETIA. 89 



little good is to be expected in this direction. A number were obtained 

 from Kew York and let loose in 1870 at JMacon Station, Ala., but did not 

 colonize, while in Texas they seem unable to endure the intense sum- 

 mer heat, for, while they are found below latitude 30^ in winter, they 

 migrate north during the hotter months, or just when they would be 

 most useful in the cotton field. It must also be borne in mind that this 

 bird, except during the breeding season, is more graminivorous than 

 insectivorous. The almost universal opinion of naturalists is that the 

 introduction of this sparrow was a great mistake, and that its spread 

 should be prevented by every possible means.^^ 



The little tree frogs (genus Hyla) are very often met with on the cot- 

 ton plants in certain parts of the cotton belt, and they doubtless take 

 their share of the worms. The Green Lizard (Anolis principalis) is also 

 frequently to be found upon the plants, while the Ground Lizard {OUgo- 

 soma laterale) occurs in the fields and eats caterpillars with avidity. 



INVERTEBRATES. 



These consist principally of Hexapods or true insects. The spiders 

 {Arachnida), however, furnish a number of species which prey upon 

 the worms. The following species have been collected upon the cotton 

 plant : Oxyopes mridans Hentz, ^^ Theridula splimrula Em., Euryopisfu- 

 nebris Em., Attus fasciatus Hentz, Epeira stellata Hentz, Linyphia com- 

 munis Hentz, Tetragnatha extensa Walk., Xysticus quadrilineatus Key- 

 serling, Mesumena georgiana Keys., and Argiope fasciata (Hz.). 



The first-mentioned species is widely distributed and nests on cotton, 

 although usually it is not very abundant. The notion prevailing in 

 some parts of the country that this spider is confined to the cotton 

 plant is incorrect, as the species is also found abundantly upon weeds, 

 especially in moist places. Mr. Hubbard has found it common upon 

 cotton in Florida, and has seen it eating bees, leaf-hoppers, and other 

 insects, but it never seemed to take the slightest notice of Cotton Worms, 

 and remained for hours upon the same leaf with a worm without show- 

 ing the least inclination to molest it. Mr. Schwarz, however, has seen 

 it feeding upon the worms both in Texas and in Alabama. 



PEEDACEOTJS INSECTS. 



Of true insects which, from their well-known carnivorous propensi- 

 ties, might with safety be placed among the natural enemies of the 

 Cotton Worm, there are a very great many, especially among the Cole- 

 optera and Heteroptera; but we shall refer only to those which have been 

 actually observed to feed upon them ; and then note some of the species 

 commonly found in the cotton field, and which presumably have the 

 same habit. 



Hymenoptera : Wasps, Ants, etc. — In this Order none are of greater 

 importance than the ants. A careful observer, while going through any 

 cotton field the latter part of summer, has no difficulty in observing the 



