INSECTS. 179 



stripes on the dorsal side of the thorax and four trans- 

 verse bands on the abdomen of the same colour ; the 

 latter region is scarcely longer than the thorax. The 

 insect (Fig. 11 7) is on the wing in corn-fields about 

 the middle of May. It lays its eggs separately on the 

 upper leaves of various species of wheat, rye, and 

 barley, choosing the upper side of the blade, not far 

 from the sheath. Only those plants are selected for 

 the purpose in which the ears are still hidden deep 

 down between the leaf- 

 sheaths. Wheat plants are 

 picked out whenever pos- 

 sible. The maggot when 

 hatched works its way 

 between leaf-sheath and 

 haulm, digging into the 



latter. It is yellowish Fio. m The Ribbon-footed Com 



white, clear and trans- Fijiou^ops ta^mopus^. 



lucent, and about a quarter of an inch long. While 

 still young it penetrates the haulm, and then attacks 

 the developing ear or the upper part of the haulm 

 which immediately adjoins this, and travels gradu- 

 ally up to the first node of the haulm or nearly 

 so, always continuing to slowly suck. Thus a 

 furrow, from 2^ to 3 J inches long (Fig. 118, C and 

 D), is formed along the surface of the upper part 

 of the haulm, and often also along the lower part of 

 the ear. The part of the haulm attacked swells 

 transversely, and the part below often remains short, 

 so that the ear cannot emerge from the leaf-sheath ; 

 but, in any case, only small worthless grains are 

 developed. The furrow is always much deeper below 

 than above, and its margins thicken in consequence 

 of the swelling of the tissues of the haulm. At the 

 end of June or in July, the larva becomes a pupa 

 at the lower end of the furrow. The yellowish-brown 

 pupa (Fig. 118, B), one-fifth of an inch long, remains 

 as such in the furrow for three weeks ; the fly 



