1901 



ENTOMOLOGICAL SOCIETY. 



77 



It is interesting to study the pupal forms of insects, with reference to their adaptations to 

 their surroundings. When pupse are incased within cocoons (Figs. 37, 38, 39) or earthen cells 

 (Fig. 36) they are smooth and rounded, but when chrjsalids are formed, such as is the case with 

 butterflies, and when there is considerable exposure to wind and weather, they are rough and 

 angular (Fig. 40 b). The chrysalids of the Nymphalidie, to which the Milk- Weed Butterfly 

 belongs (Fig. 41 j, are all suspended by means of a button of silk to the under surface of some 

 object, and they swing freely. It is plain that the " horny tubercles and roughened, calloused 

 ridges" of such chrysalids protect the swaying bodies. The chrysalids of the Papilionidse (Fig. 42),. 



Fifr. 40. a, Larva ; b, chrysalis of Limenitis disippus 



butterfly, showing angulations and mode of suspension. „. .„ „, ,- , t. •!• lm t, , 



° Fig. 43. Chrysalis of Papiho philenor. a. Back 



view, showing angulations ; b, side view, 

 showing mode of suspension. 



to which our Swallow-tails and Cabbage -butterfly belong, are held ii> place both by a button of 

 silk and by a girdle of the same material, which passes around the middle of the chrysalis. 



Among the common insects which hibernate as pupae are : 



The Sphinges (Sphingidoe). 



Cabbage-butterflies {Pieris i-apa). 



Cecropia (Samia cecropia). 



Polyphemus (Telea polyphemus). 



Corn-Worm {Heliothis armiger). 



Army- Worm (Leucania uniptmcta) 



Datana Ministra. 



Spring Canker- Worm (Pidceacrita vernata). 



Pea and Bean Weevils (Bruchus pisi, B. obtectus) 



Squash-Borers {Melittia ceto). 



Potato Beetle {Doryphora decenilineata). 



Saw-flies {Tenthredinida). 



Phorbia. 



Oboea bimacvlata. 



Pear Midge (Diplosis pyrivora). 



Clover-seed Midge {Cecidomyia legnminicola). 



The Adults. Many insects in tbeir adult condition are strongly chitinized and otherwise 

 protected against wind, cold and rain. Such forms are w«ll able to hibernate, more especially 

 in the dormant condition. Among common forms are : 



Grape-vine Flea-beetle {Haltica chalybea) 



Plum Curculio {Conotrachelus nenuphar) 



Potato-stalk Borer (Trichoba/i-is 3 — notata) 



