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THE INSECT WORLD. 



spiders; and Mutilla (Fig. 372), whose females resemble ants, being 

 variegated with red and yellow, the males, being provided with wings 

 and smaller in size, and black". The Mutilla are parasitical on solitary 

 bees, their larvae devouring their larvae. 



Other Hymenoptera lay their eggs under the skin of certain 



Fig. 374. A species of Ophion. 



insects, especially when these are in the larva or caterpillar state, 

 thus rendering service to agriculture by destroying a great number of 

 noxious insects. In lieu of a sting they have an auger, intended to 

 pierce the skin of their victims. It is thus that the Ichneumons 

 introduce their eggs under the skin of caterpillars. The Pimplas 

 (Fig. 373), which belongs to this group, have a very long ovipositor, 

 which, with its two appendages, constitute three lancets, and enable 

 them to get at the larvae in their retreats. The Ophions (Fig. 374) 



