374 INSECTS INJURIOUS TO VEGETATION. 



black tufts, and there are also two similar tufts on the middle 

 of the wing. The hind wings are dusky brown or light brown, 

 with a paler fringe, and are without bands or spots. The 

 wings expand about one inch and a quarter. 



The means for destroying the hop-vine caterpillars are 

 showering or syringing the plants with strong soapsuds, or 

 with a solution of oil-soap in water, in the proportion of two 

 pounds of the soap to fourteen or fifteen gallons, of water. 



The foregoing is the only kind of Delta-moth that appears 

 to be particularly injurious to any of our useful or cultivated 

 plants. 



5. Leaf-rollers. ( Tortrices.) 



There are many caterpillars that curl up the edges of the 

 leaves of plants into little cylindrical rolls, open at each end, 

 and fastened together with bands or threads of silk. These 

 rolls serve at once for the habitations and the food of the 

 insects; and to the latter Linnteus gave the name of Tor- 

 trices, derived from a Latin word signifying to curl or twist. 

 All the caterpillars now put in this tribe are not leaf-rollers. 

 Some of them live in leaf and flower buds, and fasten the 

 leaves together so that the bud cannot open, while they devour 

 the tender substance within. Some live in a kind of tent 

 formed of several leaves, drawn together and secured with 

 silken threads. Others are found in the tender shoots or under 

 the bark of plants. A few bore into young fruits, which they 

 cause to ripen and fall prematurely. A still smaller number 

 of kinds live on the leaves of plants, exposed to view, and 

 without any kind of covering over them. Most of these 

 insects, when disturbed, let themselves down by threads, like 

 the Geometers. Very few of them make cocoons; the greater 

 number transforming within the rolled leaves, or in the other 

 situations wherein they usually dwell. They are furnished 

 with sixteen legs, and their bodies are nearly or quite naked. 

 Many of their chrysalids have two rows of minute prickles 

 across each of the rings of the hind body, by the help of which 

 they push themselves half way out of their habitations, when 

 the included moths are about to come forth. 



