THE SAND WIREWORM 



By J. N- Tenhet, assistant entomologist, Division of Truck Crop and Garden 

 Insect Investigations, Bureau of Entomology and Plant Quarantine 



The sand wireworm (Horistonotus uhlerii Horn) is a serious pest 

 of corn, cotton, cowpeas, and other crops in certain areas of the coastal 

 plain of South Carolina, and also, at times, in parts of Illinois, Missouri 

 Arkansas, Louisiana, Texas, Mississippi, Florida, Georgia, and North 

 Carolina. It is found in porous, light, sandy soils, which are usually 

 deficient in humus. 



How the Wireworm Lives 



In the life of a wireworm (fig. 1) there are four stages — egg, larva 

 (wireworm), pupa, and adult. The adult is a small, slender,' dark- 

 brown click beetle about one- 

 fourth to three-eighths inch in 

 length. After mating, the fe- 

 male burrows into the soil and 

 deposits her eggs, which hatch 

 into the tiny wireworms about 

 12 days later. The egg-laying 

 period in South Carolina is 

 during June and July. 



The newly hatched wire- 

 worms soon find their way 

 through the soil to the roots 

 and underground stems of cer- 

 tain plants, where they feed 

 and develop throughout the 

 summer. The larvae are ap- 

 proximately half grown by Oc- 

 tober. With the approach of 

 winter the larvae go deeper into 

 the soil and remain there until 

 spring. Some have been found 

 during the winter at a depth of 

 30 inches. During March and 

 April the wireworms move up- 

 ward and again start feeding on 

 the subterranean parts of cer- 

 tain plants. Feeding contin- 

 ues, usually until June, when 

 the larva becomes fully mature. 

 At this time it is dirty white, 

 slender, and threadlike, with a 

 characteristic knotted appear- 

 ance, and % to 1% inches loug. 

 Altogether the larval stage re- 

 quires about 350 days. 



The fully mature wireworm 



during which it ne lt her feeds nor mo^T^l ^ll s t%. 

 proxrmately 12 days, after which the adult, or click beetle, Ippears 



Issued December 1941 



wire- 



Figure 1.— Life stages of the sand 



TT : f'on¥ ;B ' larva;C 'P u P a ^ D > adult ; 



A about 20 times natural size, D about 8 

 times, B and C about 4 times. 



