THE LEPIDOPTERA 



269 



the group there are great differences in the appearance of the moths 

 and in the habits of their larvae. Lochhead has divided the family into 

 nine sections, based mainly on differences of larval habits. 



Some members of the Noctuidse are known as the Catocalas or "Under- 

 wings." Some of these are quite large, spreading three inches or more, the fore 

 wings with quiet colors and marked so that they resemble the bark of trees (Fig. 

 276) . One has fore wings similar to the bark of the white birch : another resembles 

 the bark of the beech, and many kinds of trees are thus imitated in color and 

 markings. The hind wings are brightly, often brilliantly colored and it appears 

 to be the habit of the moths, which fly at night, to rest during the day on the tree 

 trunks whose bark their fore wings resemble, folding these over their gaudy hind 

 wings, in this way obtaining through concealment, protection from their enemies. 

 How far in the course of thousands of generations, the weeding out by these 

 enemies of those least closely resembling the bark, leaving behind to continue 



FIG. 276. Catocala Moth, natural size. (Original.) 



the race the closest imitators of the bark, has resulted in giving to the present 

 members of the group a closer resemblance than their ancestors, is a question for 

 speculation. The larvae of the Catocalas feed on foliage but are rarely if ever 

 injurious enough to be of importance. 



The largest Noctuid found in this country is known as the Black Witch 

 (Erebus odorata L.). It does not live in the United States, being an inhabitant 

 of the tropics, but its size and powerful wings which often spread six inches, 

 enable it to fly long distances and it is often captured in the late summer and 

 fall in the Northern United States. It has dark wings of various shades of 

 brown, and a small "eye" spot in each fore wing. 



The Cotton Worm (Alabama argillacea Hbn.). The Cotton Worm is not a 

 native of this country but of more tropical countries, from which it frequently 

 comes and attacks cotton in the Southern States. The moths (Fig. 277) are of a 

 nearly uniform reddish-brown or tawny color, and spread a little over an inch. 

 They lay their eggs singly on the cotton leaves and these eggs hatch in from 3 

 to more than 20 days, according to the temperature. The caterpillars are at 

 first yellowish-green with pale yellow heads. Later they vary much in color and 

 markings, some changing little, while others acquire a black stripe along the 

 middle of the back, with a fine central yellow line, and each segment has four 



