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INSECTS INJURIOUS TO COTTON PLANTS -NO. 4. 



SOUTHERN GRASS-CATERPILLAR OR ARMY WORM. 



LapJirygina maclira. 



There is another caterpillar also found in the 

 cotton fields which has frequently been mistaken 

 for the real cotton caterpillar, {Anomis xylina.) and 

 which is commonly known by the trivial name 

 of the grass-worm or caterpillar, owing to the cir- 

 cumstance of its feeding upon grass and weeds, 

 although when pressed by hunger it will some- 

 times eat the leaf of the cotton plant. By some 

 planters this caterpillar is known as the army 

 Avorm, but must not be confounded with the more 

 northern army worm, [Leucania cxtrance,) which 

 sometimes appears in such immense numbers in 

 ^'''^,, the west, and also feeds upon grass, corn, and 



wheat. 

 These caterpillars were very uiwnerous in the vicinity of Columbus, in 

 Georgia, about the end of September and the beginning of October, 1854. 

 They devoured grass, young grain, and almost every green thing which came 

 in their path. Instances have been known in which, urged as they were by 

 necessity and starvation, they actually devoured stacks of fodder that were 

 stored away for winter consumption. Deep ditches cut in the earth to stop 

 them were immediately filled up by the multitudes which fell in and perished, 

 while eager millions still rushed over the trembling and half living bridge 

 formed by the bodies of their late companions, bent on their mission of destruc- 

 tion and devastation. 



The caterpillars do no essential injury to the cotton, especially when weeds 

 abound, as they content themselves with the grass growing between the rows, 

 and unless very numerous they cannot be classed among those doing much 

 harm to the general crop, and are mentioned here principally as having been so 

 frequently mistaken for the real cotton-caterpillar. When pressed by necessity, 

 however, as has already been stated, they will feed upon cotton leaves. 1 

 raised about thirty of them upon this food alone, merely as an experiment, and 

 they grew and perfected their transformation, although appearing to prefer a 

 grass diet if it could be obtained. When about to change they formed cocoons 

 of silk under stones, or in the ground near the surface, interwoven with parti- 

 cles of earth, and came out perfect moths from the 24th to the 30th of October ; 

 and as these specimens were kept in a room without artificial heat I conjectured 

 that those in the open fields would appear about the same time. 



At a plantation in the vicinity of Columbus, where the caterpillars were very 

 numerous, and had already devoured all the grass on one side of a field, which 

 was divided into two equal parts by a broad and sandy carriage road ])assing 

 through the centre of it, the grass on the other side having been untouched, it 

 was interesting to observe the operations of numerous colonies of ants that had 

 formed their holes or nests in the road, and were lying in wait for any unfor- 

 unate grass-worm, the natural desire of which for a fresh supply of food should 

 tempt it to cross this dangerous path. First, one ant more vigilant than the 

 rest would rush to the attack, then another, and another, until the poor caterpillar, 

 entirely covered by its pigmy foes, and completely exhausted in strength by its 

 unavailing efforts to escape, was finally obliged to succumb to superior numbers 

 and die as quietly as possible, wlien the carcass was immediately carried off by 



