MAIZE. 441 



Wireworms. 



These are hard-bodied, smooth, yellowish-white grubs, common in the 

 soil, and varying in sizes up to 1£ inches in length. These active, wiry, 

 quick-moving grubs or wireworms are the larvae of the common brownish 

 beetles known as "click" or "skip-jack" beetles (Elateridce). They 

 feed on roots of maize, wheat, and other grains, and also on the freshly- 

 planted maize grains. The grubs remain at work feeding and growing in 

 the soil for from three to five years, when, like the white grubs, they con- 

 struct a small cell to pupate in, and then appear as the common brown 

 beetles mentioned. 



As they resemble " white grubs " in food and habits, similar methods 

 are recommended. Ploughing and harrowing in the autumn destroys 

 numbers of the cells and pupa;. Rotation of crops is also recommended. 



Laboratory experiments have shown that wireworms are destroyed by 

 feeding on bran poisoned with Paris green, mixed as recommended for 

 cutworms.' It therefore seems possible that over limited patches where 

 wireworms are at work, if a sprinkling of bran so poisoned were turned 

 into the soil just prior to sowing or during that operation, it might prove 

 of value. The absence of vegetation for two or three weeks before the seed 

 is sown or before it germinates would probably force the wireworms to try 

 the poisoned bait, and thus save the seed. 



White Grubs. 



These are the thick, white, curved grubs so common in the soil, and often 

 turned up by the plough. They are the larval or grub state of the common 

 " King " or " Christmas " beetles, and their allies, the " chafers," and vary 

 much in size, according to the age or the species, but are all very similar in 

 appearance. These grubs remain feeding in the soil on grass and crop 

 roots for two years or more before becoming full-grown, when they con- 

 struct a soft rounded earthen cocoon, pupate therein, and thus pass their 

 last winter in the soil, to appear the following summer as adult beetles, 

 which feed on foliage. 



Where these grubs appear in maize or wheat crops, rotation is recom- 

 mended, such as clover following wheat or maize, or potatoes in newly 

 turned-up grass land found to be infested. The change crop in each case 

 is not so seriously infested, and return can afterwards be made to the 

 original crop. Deep ploughing in late autumn is recommended, as it destroys 

 numbers of those which have pupated, by breaking their earthen cells and 

 exposing the helpless pupa? to other insects, birds, and frost. Treatment 

 of the soil with lime, apterite, &c., has not been found to give satisfactory 

 results. 



Rutherglen Bug (Nysius vinitor). 



This pest is dealt with under the heading of potatoes (see page 491). 



Grasshoppers. 



There are three species of grasshoppers in New South Wales which appear 

 in such swarms as to be a plague where they occur. The}- are "The Larger 

 Plague Locust" (Chortoicetes termini/era), "The Smaller Plague Locust" 

 (G. pusilla), and the "Coastal Locust" (CE'Jaleus senegalensis). They 

 attack grass, crops, fruit-trees, vegetables, and garden plants. 



