128 On the Life Historif of " Wireworms'' 



Evidence has also been obtained that the larvae of Athous haemor- 

 rhoidalis, Corymhites cupreus and others which are believed to be C. 

 pectinicornis, L., undergo two ecdyses in the course of the year, but this 

 cannot yet be certainly stated. 



Agriotes larvae will feed upon almost any crop and apparently upon 

 a good many weeds, apart from grasses, which were probably their 

 original food-plants. They are not however indifferent to the species of 

 plant which they attack and though mustard does not appear to be 

 absolutely immune, as was once supposed, it is probably only attacked 

 in the absence of some more palatable plant. Charlock on the other 

 hand appears to be favoured, larvae having been found boring into the 

 root in cornfields, where it might be supposed their choice would be 

 exercised otherwise. Beans usually do not suffer so much as other crops, 

 but wireworms will on occasion attack the seed beans in the ground. 

 Attacks in pots are difficult to induce, but in a test on a small scale, 

 one bean out of four sown was found somewhat eaten, there having been 

 ten wireworms in the pot. The other three beans were not affected and 

 all four plants subsequently developed equally well. 



Potatoes are often much damaged by Agriotes larvae and to some 

 extent also by Athous haemorrhoidalis, but much of the damage done to 

 potatoes and attributed to wireworms is in reality wrought by slugs and 

 millipedes. Athous haemorrhoidalis, and also Agriotes, have been re- 

 ported as pests of tomatoes grown in glass-houses (Carpenter (G)), the 

 latter of course being a well-known trouble to the grower. The larvae 

 enter the plants below the ground-level and, boring their way up the 

 stem, kill the plants, frequently at a time when it is too late in the 

 season to replace them. The fondness of Agriotes for the roots of Dock 

 (Rumex) has been noted by Curtis ((7) p. 159) and both it and Athous 

 haemorrhoidalis have been found in or about them. 



It is hardly necessary to mention the propensity of Agriotes for 

 attacking young growing corn, but we do not appear to sufter seriously 

 in this country from attacks on the sown seed, though experimentally 

 larvae have been found to hollow out corn seed in the laboratory. In 

 the United States and other parts of America the attacks of Agriotes and 

 other genera on seed is serious and they are also stated to be injurious 

 to maize seed in Russia (Vassiliev(2J)). Probably in this country the 

 seed of cereals is sown too late in the autumn and too early in the spring 

 to be much affected by wireworm attack before the plant develops. 



Apart from the capacity of the larvae for fasting, there is no doubt 

 that they can subsist in any ordinary soil for a very lengthy period with 



