HOW TO KNOW THE IMMATURE INSECTS 



phosis, the intermediate stage between the larva and the adult. Anoth- 

 er term prepupa refers to the last larval instar of some insects which 

 retain the larval form and mobility but cease to feed. This condition 

 exists in many orders of insects, notably the Diptera, Hymenoptera and 

 Coleoptera. 



TYPES OF PUPAE. — The pupae of insects can be classified with 

 reference to the degrees of freedom of the 

 appendages. 



1. Obtect (Fig. 32). — If the appendages are closely 

 appressed to the body, it is said to be an obtect 

 pupa. This is a common type in the Lepidoptera, 

 in many of the Coleoptera, and in more primitive 

 Diptera. 



Pupae of this type are covered with a tight-fit- 

 ting, more ©r less transparent skin which holds all 



the parts except the end of the abdomen practically cl '^ 



immovable. Chrysalis is a term often appHed to the Fig. 32. pupae: a, 



pupae of the Lepidoptera, especially of the butter- ilS^ tos o'^'e e a'n*o 



fhes, and by some would be restricted to those bSS:o'^^/»ornworm' 



pupae bearing markings of silver or gold. q^emaVu\l*a**Ha 



worth. 



2. Exarate (Fig. 33). — 

 When the appendages 

 are not closely appres- 

 sed to the body but are 

 free, it is said to be an 

 exarate pupa. The Neu- 

 roptera, Tricho p t e r a, 

 most of the Coleoptera 

 and a few of the Lepi- 

 doptera (Tischeriidae) 

 have exarate pupae. 



Fig. 33. Pupae: a, Colorado potato bee 

 Leptinotarsa decemlineata (Soy); 

 Hesperophylax Ep. 



17 



