294 



AN ECONOMIC ENTOMOLOGY. 



bottom and folded over to form a cone, is a good substitute for 

 the raupenleim. 



Further on in the family we have a series of species which, 

 with similar habits in the adult, have quite different larval char- 

 acteristics. The moths themselves are different in appearance, 

 becoming white or yellowish, without obvious markings, except 

 irregular streakings on the veins and a series of more or less 

 marked black dots. These are usually members of the genus 

 Leucania, and the caterpillars have been called in general "army- 

 worms, ' ' though to only one of the species can this term be prop- 

 erly applied. The "army-worm," Leucania U7tipuncta, has the 

 fore-wings of a rather even, dull-reddish fawn, powdered with 

 fine black speckles, some of which form a transverse row of dots 



insect its specific name unipuncta. The moths fly at night, and 

 are attracted to both light and sugar, forming in some seasons 

 the most common of all the insects taken by the collector. The 

 eggs are laid on the leaves or stems of grasses, using that term 

 in its widest sense, and usually concealed. The moths favor 

 rank vegetation, and the caterpillars, when they hatch, attack 

 whatever is nearest at hand. When full-grown they are from 

 one and a half to two inclies in length, striped with yellowish on 

 a dark-gray ground. The head is yellow, with fine dark lines, 

 and the insect is easily recognized when it appears in numbers. 

 In ordinary seasons, though the larvae may be quite abundant, 

 they are little noticed and do no particular injury ; but sometimes, 

 by a combination of circumstances, the number of eggs deposited 

 early becomes very great and the resulting army of larvae so 



Moth of army-worm, Leucania unipuncta, at a,- tip of ab- 

 domen of female at b ; c, d, e, structural details. 



Fig. 332. 



on the veins beyond 

 the middle. There 

 is also a fine, ob- 

 1 i q u e, blackish 

 streak just below 

 the apex, and at the 

 end of the median 

 vein is a small white 

 dot, which gives 

 the wing a rather 

 characteristic ap- 

 pearance and the 



