GENERAL ZOOLOGY 



Fig. 15.32. Lepidoptera. Stages in the 

 life cycle of a moth, Platysamia cecropia. 

 ■4, group of eggs deposited on a wild- 

 cherry leaf. 5, young first-instar larvae 

 feeding. C, young fourth-instar larva. 

 A mature (fifth-instar) larva beginning 

 the construction of a cocoon. E, very 

 early pupa within the cocoon, shedding 

 the skin of the last larval stage. (Photo- 

 graphs by Charles Walcott.) 



Taken as a group, beetles, like butterflies and moths, present a bewildering 

 array of species adapted for many diverse conditions. Predaceous beetles 

 inhabit ponds and streams in both larval and adult stages, and others, like the 

 tiger beetles (Fig. 15.30), prey as larvae or adults on any small terrestrial 

 animals they can capture. Many beetles bore into wood, particularly in their 

 larval stages. The Japanese beetle, Popillia japomca, spends its larval life in 

 the soil, feeding on grass roots and causing serious damage to turf grasses. 

 The adult feeds voraciously on a wide variety of plants, including roses and 

 fruit trees. 



Order Lepidoptera (scale wings) — butterflies and moths. In this order, 

 the mouth parts are either suctorial or non-functional in the adult stage but 

 mandibulate in the larvae, which are called caterpillars (Fig. 15.31). There 

 are two pairs of membranous wings in the adult, covered with minute, over- 

 lapping scales which are responsible for the color patterns. The life cycle is 

 always holometabolous. 



Among butterflies, the monarch or milkweed butterfly, Danaus memppe 

 { = Anosia plexippus), is one of our commonest species. It ranges all over 

 North and South America and occurs in other lands also, particularly western 

 Europe, Australia, and the Pacific islands. Eggs of this insect are laid singly 

 upon leaves of various milkweeds, and in a few days at summer temperatures 



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