250 ] The Wonderful Ways of Insects and Spiders 



appearance, nearly all the adults are easy to identify by the hard, 

 veinless forewings that meet in a straight line over the abdomen. 

 In flight these forewings serve much the same purpose as the 

 wings of an airplane, providing elevation, while the beetle is 

 actually propelled by the hind wings. The forewings also serve as 

 protective coverings for the hind wings, which are folded beneath 

 them. If you could see some of the tropical giants, you would be 

 quick to notice their huge mandibles, or upper jaws; but most of 

 the smaller species also have well-developed mouth parts, as all 

 beetles bite rather than suck. 



The Firefly Childhood Delight: The firefly is a member of the 

 beetle family. Children are always intrigued by the way the insect 

 "lights up" as it flits through the night, and they are forever 

 catching and imprisoning "lightning bugs" in the hope of dis- 

 covering their secret. In brief, this is the explanation: The firefly 

 produces a substance called luciferin, which glows when it comes 

 in contact with air. Underneath the light-producing area of the 

 body there is a reflecting surface which serves to strengthen the 

 glow. 



In some species the females and the larvae have no wings and 

 are therefore limited to ground travel. Both groups are also light- 

 producers our common glowworms. 



Eating Too Much or Too Little: Fireflies are valuable to man 

 because their larvae feed on slugs and snails, which sometimes 

 do damage to cultivated plants. Mysteriously enough, most of the 

 adults, as far as we can observe, do not eat at all! We still have a 

 great deal to learn about the habits of this fascinating beetle. 



The LadybugPest Exterminator: Another beetle dear to the 

 hearts of little children is the ladybug or ladybird beetle which 

 they admonish to fly away home to its burning house. These small, 

 hemispherically shaped insects are also dear to the hearts of fruit- 

 growersbut not for any sentimental reasons. The ladybug preys 

 on great numbers of such destructive fruit pests as aphids and soft 

 scale citrus mealy bugs. 



If you happen to be exploring the countryside in the fall you 

 may come on a great assemblage of lady beetles; they congregate 



