WINTER MEETINa. 263 



Entomology, derived from two Greek words, wbich signify a discDurse on in- 

 sects. Economic entomology is a practical application of a knowledge of the 

 forms and habits of insects to the more thorough exterminatioa of injurious spe- 

 cies and the protection of those that are either directly or indirectly beneficial. 



55. What is an insect ? 



An insect is an animal with its skeleton on the outside divided into thirteen 

 more or less distinct rings or joints, heli togetber by elastic membrane, having in 

 its perfect state the body divided into three regions— head, thorax and abdomen — 

 and having always six jointed legs and usually two or four wings. 



56. Why do insects infest plants ? 



Because the fruit affords them a congenial place where they may live, develop 

 and propagate their species. 



57. What insects are directly beneficial to the horticulturist and florist? 



Bees, wasps and many sorts of flies Butterflies and moths are useful in con- 

 veying the pollen from the stamens of one flower to the piscils of another, thus 

 securing perfect fertilization and desirable cross-fertilization. 



58. What are some other beneficial insects ? 



Some of the ground beetles, which feed upon the larv?e of the curculio, and 

 upon other grubs, as well as cut-worms, after they have entered the ground to 

 change. Hundreds of species of large and small flies, also, are direct parasites, 

 breeding in the bodies of and killing cut-worm? and other caterpillars, borers, and 

 all varieties of fruit worms. Other useful insects are the Mantes or devil's horses, 

 the lace-wing and syrphus flies, and the lady-bird or lady-bug beetles, whose 

 larvse are the especial foes of plant-lice and devour countless numbers of them. 



69. What is the most remarkable peculiarity in the development of an insect ? 



Their transformation or metamorphosis. The life of every insect includes 

 four distinct stages — the embryo contained in the egg ; the larva, in the shape of a 

 caterpillar, grub, maggot or worm, or of wingless bugs, grasshoppsrs and certain 

 water insects. It is in the larva state that all true growth takes place. The next 

 stage is that of a pupa or chrysalis, which in the great majority of insects is a 

 period of quiescence, in which there is very little motion or appearance of life. 

 The last stage is that of the imago, or perfect insect, in which it acquires its true 

 antennae or horns, its six jointed legs and its two or four wings. In this stage only 

 can the sexes be distinguished. 



60. In their relation to min, how do we classify insects ? 

 Into useful or injurious species. 



61. Which are the most numerous? 

 Injurious insects. 



62. In which stage of their existence do insects, as a rule, do the most dam- 

 age to our crops ? 



In the larva or growing stage. 



63. What are some of the larvae most injurious to fruit and fruit-trees ? 

 Grubs in the trunk and branches, such as the round-headed and flat-headed 



borers; caterpillars on the leaves, such as the canker-worm, web- worm and tent 

 caterpillar; and so-called worms in the fruit, such as the larvae of the codling moth 

 and the plum curculio. The white grub also, which is the young of the May beetle, 

 is a very destructive larva which feeds upon the roots of stawberries and other 

 herbaceous plants. 



64. What insects are very destructive in their perfect as well as in their larva 

 state ? 



All grasshoppers and locusts, all true bugs and many beetles. 



