40 ROMANCE OF THE INSECT WORLD CHAP. 



upon it, and a small parasite would always lay pro- 

 lifically, whatever might be the size of the receiver 

 detected. 



Sometimes parasitic larvae are so excessively minute 

 as to find accommodation and nourishment in the 

 eggs of insects. Those of many Lepidoptera, of 

 a small beetle and of the dragon-fly are thus de- 

 stroyed. Pupae are also invaded, as well as imagos. 

 Of all the conditions, however, that of the grub or 

 larva is princially liable to these terrible attentions, 

 because it is often the one of longest duration, and 

 therefore best calculated to carry out the object of the 

 parasite ; whereas the adult, and chrysalis, and egg- 

 stages are in many instances brief, and more likely, 

 the first and last especially, to be cut short by acci- 

 dent. Strange to say, insects which have long adult 

 life are subject to parasites, whilst those to whom an 

 ephemeral career is meted out go free. Weevils are 

 long-lived, and though encased in what would seem 

 impenetrable armour, and able to withstand the 

 assaults of many a large and open foe, they are per- 

 vious to the lancet-like sting of the indefatigable and 

 more insidious assailants. 



These parasites have a mighty business in the world, 

 being the means employed by nature to keep within due 

 bounds the superabundant multiplication of the phy- 

 tophagous, or vegetable-feeding, insects, which would 

 often increase to an unwarrantable extent, and do in- 

 finite mischief were it not for these appointed checks. 

 They perform a marvellous work to our advantage, 

 which is the more evident when we consider them in 

 relation to insects injurious to the crops. They afford 



