100 FIRST ANNUAL REPORT OF 



upper surface of the insect is covered with it. In other insects, which 

 do not indulge in this singular practice, the vent is situated either at 

 the extreme tip of the abdomen or on its lower surface. 



There are several other larvae, feeding upon other plants, which 

 commonly wear cloaks of this strange material, among which may 

 he mentioned one which is very common upon the Sumach, and which 

 produces a jumping, oval Leaf-beetle (Blepkarida rhois, Foerster) 7 

 about a quarter of an inch long, and of a yellow color, speckled with 

 brick-red. The larvae of certain Tortoise-beetles ( Ccsssida), some of 

 which feed on the Morning Glory and the Sweet Potato vines, adopt 

 the same practice, but in their case there is a forked process at the 

 tail which curves over their backs and receives the requisite supply 

 of excrement. 



Many authors have supposed that the object of the larva, in all 

 these cases, is to protect its soft and tender body from the heat of the 

 sun. This can scarcely be the correct explanation, because then they 

 would throw away their parasols in cold cloudy weather, which they 

 do not do. In all probability, the real aim of Nature, in the case of 

 all these larva?, is to defend them from the attacks of birds and of can- 

 nibal and parasitic insects. 



There are two broods of this species every year. The first brood 

 of larvae may be found on the potato vine toward the latter end of 

 June, and the second in August. The first brood stays underground 

 about a fortnight before it emerges in the perfect beetle state ; and 

 the second brood stays there all winter, and only emerges at the be- 

 jFig. 45.] ginning of the following June. The perfect beetle ^s- **-l 

 (Fig. 43) is nf a pale yellow color, with three black 

 .stripes on its back, and bears a general resem- 

 blance to the common Gucumber-beet\e(Di abrotica 

 "lvittata, Fabr., Fig 44). From thi3 last species, how- 

 ever, it may be readily distinguished by the remarkable 

 pinching in of the sides of its thorax, so as to make quite a lady-like 

 waist there, or what naturalists call a " constriction." It is also on the 

 average a somewhat larger insect, and differs in other less obvious 

 respects. As in the case of the Colorado Potato-beetle, the female, 

 after coupling in the usual manner, lays her yellow eggs (Fig. 42 d) 

 on the under surface of the leaves of the potato plant. The larvae 

 hatching from these require about the same time to develop, and when 

 full grown descend in the same manner into the ground, where they 

 transform to pupae (Fig. 42 c) within a small oval chamber, from which 

 in time the perfect beetle comes forth. 



The Three-lined Leaf-beetle, in certain seasons, is a great pest in 

 the Eastern States ; but, it has never yet occurred in the Valley ot the 

 Mississippi in such numbers as to be materially injurious. 



