318 INSECTS INJURIOUS TO VEGETATION. 



intermixed with the hairs of its body ; under this it then makes 

 another and tougher pod of silk, thickened with fragments of bark 

 and wood, and, when its work is done, changes to a chrysahs, in 

 which state it remains till the following summer. 



The caterpillars of the Nonagrians (Nonagriad^ *) are 

 naked, long, slender and tapering at each end, smooth, and gen- 

 erally of a faint reddish or greenish tint, with an oval, dark color- 

 ed, horny spotf on the top of the first and last ring. Most of 

 them live within the stems of reeds, flags, and other water-plants ; 

 some in the stems, and even in the roots of plants remote from the 

 water. They devour the pith and the inside of the roots, and 

 transform in the same situations, having previously gnawed a hole 

 from the inside of their retreat, through the side of the stem or 

 root to the outside skin, which is left untouched, and which the 

 moth can easily break through afterwards. The chrysalids are 

 generally very long and cylindrical, and a^e blunt at the extremi- 

 ties. Most of the moths have very long bodies, a smooth thorax, 

 and are of a yellowish clay or drab color ; the fore-wings want 

 the usual spots, are faintly streaked and dotted with black, and 

 have a scalloped hind margin. Those that do not live in water 

 plants are distinguished by brighter colors of orange yellow and 

 brown, with the usual spots more or less distinct on the fore- 

 wings, the margin of which is wavy ; the collar is prominent, and 

 the'thorax crested. In all of them the antennse of the males are 

 •&*iightly thickened with short hairs beneath. 



.' These insects are fatal to the plants attacked, the greater part 

 of which, however, are without value to the farmer. Indian corn 

 ^must be excepted ; for it often suffers severely from the depreda- 

 tl.'jns of one of these Nonagrians, known to our farmers by the 

 name of the spindle-worm. The Rev. L. W. Leonard has favored 

 me with a specimen of this insect, its chrysalis, and its moth, 

 together with some remarks upon its habits ; and the latter have 

 also been described to me by an intelligent friend conversant with 

 agriculture. This insect receives its common name from its de- 



* From Nonagria, the meaning of which is uncertain. 



t These dark horny spots are found on the first ring of most of the caterpillars 

 that burrow in the stems of plants, or in the ground. 



