REPORT OF THE ENTOMOLOGIST. 21 J 



spots upon the wing-covers much more conspicuous and larger. Its 

 larva (Fig. 22, b) is of a pale straw-color with the spines long and 

 tipped with black, and besides has a dusky line along each side of the 

 dorsum, as well as two dusky spots immediately behind the head and 

 below these two larger crescent marks of the same color. "The dung 

 is spread in a characteristic manner, extending laterally in long shreds 

 or ramifications (Fig. 22, a). The pupa (Fig. 22, c) is dark brown, 

 variegated with paler brown, as in the figure, while the spines around 

 the edges are transparent and white." 



REMEDIES. 



These tortoise beetles are not the easiest insect enemies to handle 

 that we have to deal with, for their mode of life, almost entirely upon 

 the lower surface of the leaves of the plants which they infest, ren- 

 ders the application of remedies quite difficult. Then, too, the nature 

 of the sweet potato vines, trailing close to the ground, adds to the 

 difficulty. The protected larvae also are comparatively free from in- 

 sect parasites and other enemies. An early and careful watch for the 

 beetles after transplanting will repay one for his time thus spent. 

 London purple and Paris green sprayed upon the vines will destroy 

 many, especially if put on with considerable force and at an angle, so 

 as to reach as nearly as possible the lower surface of the leaves. 



INSECTICIDES. 



I present herewith a short paper on the different insecticides that 

 have been found by a long series of experiments to be most effective 

 in the destruction of the various insects with which the horticulturist 

 and agriculturist must deal. 



After having carefully studied the life histories and habits of the 

 different insects that attack our trees, shrubs, herbs, etc., externally, 

 we find that they all belong to either the one or the other of two 

 classes as regards their mode of attack ; i. e., they either take their 

 food solidly or else in the fluid form. The former devour the foliage, 

 and the latter suck the sap from the leaves and bark of the smaller 

 limbs and twigs. Therefore, in the choice of our remedies, we must 

 takes these habits into consideration. Those that devour the foliage 

 can be killed by poisons taken into the digestive canal with the food, 

 while such as live upon the juices of the plant only must be reached 

 and destroyed otherwise. 



