DISEASES AND PESTS OF THE MAIZE CROP 437 

 402. Cutworms, Agrotis spp. — Cutworms are among the chap. 



most troublesome pests with which maize-growers have to deal. 

 They are largely responsible for the relatively poor yields ob- 

 tained, because they destroy so many young maize plants, thus 

 thinning the stand. They are particularly destructive to early 

 planted maize ; to delay planting in order to avoid them may 

 seriously shorten the season and increase the risk of loss from 

 frost before the crop is mature. The following notes have 

 been kindly furnished by Mr. C. W. Mally, Government Ento- 

 mologist, Cape Province, who informs the writer that much work 

 has yet to be done on the systematic entomology and life- 

 histories of these insects, of which there are probably six or seven 

 species in South Africa. 



Cutworms vary in colour; some are green to yellowish, 

 while many are of a dirty greyish or light-brown colour. They 

 are smooth (without hairs or spines) and greasy looking, often 

 similar in colour to the soil in which they spend the day. 

 Some feed day and night, but others rest during the day just 

 below the surface of the soil or under logs, stones, bags, bark, 

 or rubbish, and come .out to feed at night. They feed for 

 about two weeks before pupating, and remain in the ground 

 in the pupal state for ten to fifteen days in warm weather, 

 or longer in the cold season. The female moth which emerges 

 from the chrysalis (" pupa "), flies about at dusk and lays eggs 

 on any suitable weed or plant. The eggs hatch out in a few 

 days and the young caterpillars at once begin to feed on any 

 green thing accessible to them. A life-cycle may thus be 

 completed in about six weeks, or longer in a cold season. 

 There are at least two broods of cutworms in a season, but 

 how many more is not yet known. 



403. Remedies for Cutworms. — A large number of cutworm 

 eggs may be destroyed by keeping the land clean of weeds, 

 and by the winter burning of, or deep ploughing-under of, 

 such haulms of harvested crops as are not eaten off by stock. 

 Where the cutworms are bad, Mr. Mally has found the use of 

 poisoned bait to be effective. This is prepared by dipping 

 bundles of green-stuff into a strong mixture of Paris green 

 (1 oz. to a bucket of water) or sprinkling them with a mixture 

 made according to the following recipe : — 



x. 



