THE HIDDEN TYPE OF WING -GROWTH 107 



parents. Another group of beetles among which the onisci- 

 form larva is found is that of the glow-worms (Lampyris). 

 And here we find between larva and parent a likeness most 

 striking and yet abnormal, for the female beetle (the true 

 " glow-worm " of the British countryside) never acquires wings, 

 but becomes mature in a form closely resembling the larva. 



From this we may pass on to describe beetle-larvae which 

 illustrate an increasing degree of divergence from the parent- 

 form. Grubs of certain click-beetles (Elateridae) are on 

 account of their root-feeding habits well-known to all farmers 



st- 



FIG. 59- JAWS OF SXLPHA LARVA 



a, a, left and right mandibles (c, condyle ; add, abd, adductor and 

 abductor tendons), x 25. 6, maxilla (st, stipes ; I, lacinia ; g, galea ; 

 p, palp) ; c, labium (sm, sub-mentum ; m, mentum ; /, lobe ; p, palp). 

 X 32. After Schiodte, Naturhist. Tiddskr. I. 



as " wire worms " 



A wireworm 1 (Fig. 60) has a narrow, elon- 

 gate body with very firm hard cuticle, the dorsal aspect convex 

 and the ventral somewhat flattened ; each segment presents a 

 longitudinal ridge and furrow on either side where the tergal 

 and sternal regions join. The head is broad and flattened with 

 very short stumpy feelers, but the mandibles (Fig. 6 d) are 

 strong and well formed, each with apical and internal teeth and 

 a delicate lacinia, while the maxilla (e) has, in addition to cardo, 

 stipes, three-segmented palp, and two-segmented galea like those 



1 K. L. Henriksen : "Oversight over de danske Elateride Larver". 

 Entom. Medd., IV. 1911. G. H. Ford: "The Larval and Pupal stages of 

 Agriotes obscurus ". Ann. Appl. Biol., III. 1917. 



