228 ECONOMIC ENTOMOLOGY. 



their back, of jumping or throwing themselves into the air 

 by means of a sudden jerk of the thorax, in effecting which the 

 thoracic prolongations come into their places with a sharp sound 

 like the shutting of a spring. Hence their popular name of Click 

 Beetles or Skip Jacks. In the perfect state it is probable the 

 beetle does little or no harm to the crops, but in the larval stage 

 it is most formidable. The larva is something like the meal worm, 

 but more slender and elongate ; it is yellow and exceedingly tough, 

 like wire, whence its familiar name of Wire worm. They have, I 

 believe, no eyes, but possess a short, four-jointed antennae, and are 

 furnished with short, robust legs set close together. The apical 

 segment, possessing an anal prolongation, is especially hard and 

 frequently toothed ; they are found everywhere at the roots of 

 plants. 



The attacks of Wire worms are most serious to sainfoin and 

 clover crops, also to pasture lands, the finer grasses being invari- 

 ably chosen, and the frequent failure of the grass seeds results 

 probably more often from the work of the Wire worm than from 

 any other cause. It is throughout the United Kingdom a continual 

 source of harm and loss to every description of corn crops. The 

 Wire worms fix their heads into the soft part of the stems, and with 

 their hard, strong jaws gnaw away the tissues so as to entirely 

 arrest the circulation of the sap. The insect remains in the 

 larval state for several years (the limit generally accorded is five 

 years), but it is difficult to ascertain the exact period. It is this 

 long, larval stage that causes them to be specially dangerous to 

 those crops, such as sainfoin, that remain on the land two or three 

 years. When full grown the larva descends deep into the earth to 

 undergo its transformation. It remains for a fortnight in the pupa 

 condition, when the perfect insect emerges and comes to the surface 

 of the ground. Fortunately this pest may be got rid of. A field 

 that is infested with it should be thoroughly and deeply ploughed 

 and scarified, and all growth in the soil rigidly destroyed. It 

 should then lie fallow for a winter, and in the spring again carefully 

 gone over to stop all weed growth, then be sown with tares. After 

 this a crop of mustard should be put in, and the Wire worm will 

 be effectually starved out, for numerous experiments have proved 

 that it cannot eat either of these plants. 



