196 PROTECTION AGAINST INSECTS-. 



and oiil}' partiall}' covei-iiigtlie abdomen, sometimes imperfectly 

 developed. 



Larva ^Yitll horny head and 22 legs. 



The eggs are laid in moist soil, and the larvae pupate in oval, 

 hollo wed-out lumps of earth. 



The larvae and imagos devour insects. 



The common Paiiorpa communis, L., flies about around low 

 bushes and hedge-rows, and destroys the pupae of Li pans 

 salicis, L., etc. 



2. Sialidae. 



Imagos of moderate size, with broad head, long neck and 

 fairly broad abdomen ; with 3 ocelli, sometimes absent. 

 Mouth-parts free, fully developed. Antennae short, usually 

 setiform, and many-jointed. Wings many-celled, colourless, 

 with bristles on the veins, sloping like a roof when at rest. 



Larva \Yitli G short and stout legs, i^j/^a elongate, with the 

 limbs free. 



Example. — llhaphidia, L. The perfect insects fly in May 

 and June, and lay their eggs in or under the bark of Scots 

 pine or spruce. The snake-like brown larvae live through the 

 winter, and pupate in the spring, without any cocoon ; about 

 2 to 3 weeks later the imagos emerge, li. notata, Schum., is 

 very useful ; its larvae greedily destroy the eggs and larvae of 

 other insects which they find on and under the bark ; common 

 in coniferous woods. 



3. llcmerohiidae {Lacc-uiinicil jlics). 



Imagos long and delicate. Head small, with large hemi- 

 spherical eyes ; no ocelli. Mouth-parts free. Antennae long, 

 setiform, many-jointed. 



Wings similar in size, transparent and multicellular, sloping 

 like a roof when at rest. Legs slender. 



Larva elongate, and narrowed towards the ends, with tw^o 

 slender curved mandibles perforated for sucking, and G legs. 



The flight-period is in the early summer, and again in 

 autumn. The stalked w4iite or greenish eggs are laid in 

 groups on leaves. 



