216 ELEMENTARY STUDIES IN INSECT LIFE 



is the very opposite, the retention of such coloration 

 being to render as conspicuous as possible the form 

 wearing them. Some of the most striking illustrations 

 of warning colors are to be found among insects. The 

 young collector will soon be able to divide insects into 

 two general classes, those difficult to distinguish from 

 their surroundings, and those quite conspicuous. The 

 protection does not lie in the colors in these cases, but in 

 some unpleasant attribute connected with insects wear- 

 ing such colors. Many hymenoptera, for instance, pos- 

 sess stings. Stinging insects, we find, are rendered con- 

 spicuous by warning colors such as the contrasted dark 

 and yellow bands of the common wasp, the hornet, and 

 of many bumblebees. The red and black ladybirds 

 are quite conspicuous. These have been shown to be 

 extremely nauseous to insectivorous animals. Some 

 white moths and some moths made conspicuous by their 

 white and black colors have been refused in disgust by 

 insect-eating animals. Many caterpillars with the abil- 

 ity to emit noxious juices are rendered conspicuous 

 either bv striking colors or exposed positions upon their 

 food plants. 



Parasitism. Hunger and the quest for shelter have 

 doubtless led to the habit of existing as unbidden guests 

 in or on plants, other insects, or higher animals. The 

 one, a parasite, lives in or on the other, a host, securing 

 the necessities of life from the host. The host gives up 

 a part or all of its vital force to the parasite. Very 

 few species of insects are exempt from the entertain- 

 ment of parasites. Parasites themselves are parasitized. 

 Among insects are to be found all variations of para- 



