ORTHOPTERA 



The method of reproduction among the Aphides is very remark- 

 able. The first of the Aphides to appear in the spring of the year 

 are wingless females, which give birth to living young without 

 the intervention of the male ; and these offspring, which are also 

 wingless females, in turn produce living replicas of themselves. 

 This system of non-sexual reproduction is called partheno genetic 

 reproduction, and may be continued throughout eight or nine 

 generations. Sooner or later, however, true male insects, gener- 

 ally winged, make their appearance, and also fertile females, 

 which are generally possessed of wings. The result of sexual 

 intercourse between these is the reproduction of eggs in place of 

 living young. The eggs are generally deposited towards the end 

 of the summer, the young insects emerging either in the autumn 

 or following spring, as wingless females producing living young. 

 The females which produce living young are called viviparous 

 females, and those which produce eggs oviparous. The fecundity 

 of the viviparous females is enormous, each individual producing 

 hundreds of young. As the viviparous female rarely moves from 

 the position she first takes up, the foliage in her vicinity soon be- 

 comes densely crowded with her wingless offspring, which move 

 but slowly, and rarely travel very far from the place of their 

 birth. The result of thousands of these insects crowded closely 

 together, with their sharp, sucking beaks inserted in the foliage, 

 is to exhaust the plant utterly and absorb all its sap, so that the 

 roots and leaves cease to function, and it dies. But with a decrease 

 of the supply of liquid nourishment the viviparous females pro- 

 duce oviparous females, which in most cases are winged, and 

 therefore capable of quitting the over-populated situation in 

 which they are born, and, after intercourse with the males, of 

 starting their offspring on life's race in a more advantageous 

 environment. 



The Order Orthoptera includes the Earwigs, Cockroaches, 

 Mantis or Praying Insects, Leaf and Stick Insects, Locusts, Grass- 

 hoppers, and Crickets. All are characterised by having the front 

 wings of a leathery texture, and much narrower than the hind 

 wings, which are membranous, and often large and fan-shaped. 

 Their metamorphosis is incomplete, the young resembling the adult 

 in general features, directly they leave the egg ; while in the wing- 

 less forms hardly any difference is perceptible between the larva 



