THE SAXD WIREWORM 7 



Tomatoes, asparagus, early-planted melons and cucumbers, pea- 

 nuts, oats, rye, Austrian winter peas, velvetbeans, sweetpotatoes 

 planted after July 10, and dewberries are often attacked but are 

 seldom seriously injured. 



Cabbage and bur-clover are seldom injured. 



Corn, cotton, cowpeas, potatoes, late-planted melons and cucum 

 bers, early sweetpotatoes, and native lespedeza, however, are especially 

 liable to injury. 



Planning Favorable Crop Rotations 



Land planted in susceptible crops for 2 or more years may quickly 

 build up a large wireworm infestation. Hence it is important to 

 use a crop-planting plan that will avoid this danger and at the same 

 time build up soil fertility. Two plans are suggested. 



(1) When the land is heavily infested with wireworms, the following 

 2-year cropping plan should reduce losses from wireworms: 



First year: Starting in the fall, sow a cover crop of small grain such 

 as oats or rye. After harvesting the grain in the spring, let the land 

 lie idle until about July 10, when sweetpotatoes, a cover crop, or hay 

 can be planted. Late in the fall, plant a winter cover crop such as 

 Austrian winter peas or vetch. 



Second year: Early in the spring of the second year, turn under the 

 winter cover crop and plant the land to corn, cotton, or other crop 

 susceptible to wireworm injury. Immediately after harvest of the 

 susceptible crop, seed the land to oats or rye, beginning again the first 

 year of the 2-year planting plan. 



(2) When the wireworm infestation is known to be light, the following 

 3-year cropping plan may often be used to advantage: 



First and second years: Use the 2-year plan for the first 2 years. 

 After the susceptible crop is harvested in the fall of the second year, 

 plant a winter cover crop of Austrian winter peas or Vetch. 



Third year: Turn under the cover crop early in the spring and plant 

 the land to one of the crops less susceptible to wireworm injury, such 

 as velvetbeans, tomatoes, or early watermelons. As 'soon as this 

 crop is harvested, seed the land with a winter cover crop of oats or 

 rye, beginning again the first year of the 3-year cropping plan. 



Figure 6 is a diagram showing both the 2-year and the 3 -year crop- 

 ping plans that have been outlined above. 



Avoiding Unfavorable Planting Dates 



The eggs laid during June and July produce the injurious infesta- 

 tions of wireworms for the following spring. In South Carolina the 

 period of greatest damage to crops from the wireworms which over- 

 winter in the soil occurs from about April 15 to June 15. Therefore 

 crops susceptible to severe injury, such as corn, cotton, cowpeas, 

 potatoes, sweetpotatoes, or melons, should not be planted during this 

 period in lands known to be heavily infested with wireworms. 



Since about 75 percent of the eggs are laid by the females during the 

 period June 15-July 10, there is a likelihood of avoiding a heavy wire- 

 worm infestation the following spring in fields that are not in crops 

 attractive to the beetle during this important egg-laying period. A 

 further advantage of planting attractive crops after about July 10 is 

 that a crop planted after this date will not be subject to appreciable 

 damage from the small wireworms that hatch during the season. 



