WIRE-WORM. 



WIRE-WORM. 



necessary, in consequence of the shortness and 

 weakness of their legs. The wire-worms have 

 a long, slender, and cylindrical body, covered 

 by a hard crust, which has obtained for them 

 the above name. They are composed of twelve 

 segments fitting closely to each other, and are 

 provided with six conical scaly feet, placed in 

 pairs on the three segments next the head. 

 The latter is furnished with short antenna?, 

 palpi, and two strong mandibles or jaws. 



Upwards of sixty different species of these 

 insects occur in Britain, and it is probable that 

 a considerable proportion of them feed upon 

 the most valuable cultivated plants. The same 

 species of larva does not appear to confine 

 itself to one kind of food, but attacks indiscri- 

 minately the roots of grain and other grasses, 

 as well as esculent roots, such as turnips, car- 

 rots, radishes, &c. Bui it is at the same time 

 deserving of notice, that as a strong similarity 

 prevails among larvae specifically distinct, it is 

 probable that different kinds may often have 

 been confounded, and a more correct know- 

 ledge may prove them to be more restricted in 

 their choice of food than is at present sup- 

 posed: this, at least, is rendered not unlikely 

 by what is observed in analogous cases. We 

 are as yet acquainted with the metamorphoses 

 and habits of a very small number of these 

 insects ; and it is, therefore, highly desirable 

 that whenever a destructive species of wire- 

 worm prevails, it should be traced to the per- 

 fect condition. This, however, is attended 

 with considerable difficulty, owing to the length 

 of time they continue in the larva state, ex- 

 tending, in many instances, to several years. 



This insect occurs in considerable plenty 

 throughout the country in grass fields and pas- 

 ture lands, and is usually found creeping 

 among the herbage, or lying at the sides of 

 stones ; it is scarcely ever observed on the 

 wing. The extent of the injury they sometimes 

 occasion may be estimated from the fact, that 

 a single worm has been observed to bite from 

 8 to 20 plants in a very short time; and they 

 are occasionally so abundant, that from 4 to 8 

 have been turned up by the spade in a space 

 of 4 square feet. The depredations of the 

 wire-worm in England being principally con- 

 fined to wheat sown upon clover leys, old pas- 

 lures recently broken up, pea and bean stub- 

 bles, &c., we may suppose the general average 

 of the injury to amount to about a twentieth 

 part of what is sown upon this description of 

 lands. This may be deemed a very fair and 

 moderate calculation. 



When the fields lie fallow, these insects conti- 

 nue to feed on the grass and other weeds, which 

 are frequently allowed to overrun the surface ; 

 whereas, if the soil were kept clean, they would 

 either die for want of food, or be compelled to 

 remove to some other place. As these larvae 

 invariably live beneath the surface of the soil, 

 every plan suggested for their destruction must 

 be founded on this consideration. 



Without adverting to this fact, many super- 

 ficial applications, such as strewing the sur- 

 face with quicklime, soot, &c., have been tried 

 without effect. The most obvious remedy is to 

 saturate the soil with some fluid which has 

 been previously ascertained to destroy the in- 

 1150 



sects without injuring the plants ; that is, if the 

 latter be of a kind which it is necessary to 

 preserve, as will usually be the case. In a fal- 

 low field, this precaution need not be observed, 

 as a double benefit would ensue from the de- 

 struction of both insects and weeds. More 

 carefully conducted experiments, and on a 

 more extensive scale than any that have yet 

 been undertaken, will be necessary to show 

 what kind of liquid is best adapted for this 

 purpose. Probably, different substances will 

 be found most useful in different situations, ac- 

 cording to the nature of the soil and the chemi- 

 cal ingredients which enter into its composi- 

 tion. The latter consideration should be par- 

 ticularly attended to in all experiments on the 

 subject, as most likely to suggest the most ap- 

 propriate remedy; and it might even happen 

 that the fluid employed to destroy the insects 

 might be so managed as to produce a most 

 beneficial change in the chemical qualities of 

 the soil. If a strong saline solution, for exam- 

 ple, should be found to kill the insects, as it is 

 very likely to do, there are few soils which 

 would not derive benefit from such an applica- 

 tion. Of course, many substances prove 

 speedily fatal to these insects, and among these 

 the choice would have to be determined by 

 cheapness and ease of application. Beirkan- 

 der, a Swedish observer, who has investigated! 

 their habits, found that they lived among 



Garlic - - 

 Spruce leaves - 

 Fir leaves 

 Lediim palustre 

 Myrica gale 

 In water - 



He suggests that such of these plants as 

 proved most speedily fatal should be mixed 

 with the manure. He also considers it of great 

 advantage to cause children to follow the 

 plough, and pick up all that happen to be- 

 turned up. He states that in this way he has 

 seen 351 wire-worms collected in a field not 

 exceeding 600 feet by 56. 



Sir Joseph Banks suggested a very simple 

 plan for alluring the wire-worms from the 

 plants, and collecting them that they might be 

 destroyed. This consisted merely in burying 

 slices of potato, stuck upon skewers, near the 

 seeds sown. As the larvae are very fond of this 

 root, they leave the young plants and fix upon 

 it These slices require to be examined every 

 day, and the wire-worms collected upon them 

 destroyed. Mr. Tall ant affirms that he has fre- 

 quently freed fields entirely from wire-worms 

 by sowing a crop of white mustard-seed. The 

 experiment he has tried so frequently, and in 

 circumstances so well calculated to demon- 

 strate its effects, that he is perfectly satisfied 

 that the remedy is efficient. "Encouraged," 

 he observes, " by the results of my former 

 trials, I sowed a whole field of 42 acres, which 

 had never repaid me for 19 years, in conse- 

 quence of nearly every crop being destroyed 

 by the wire-worm; and I am warranted in 

 stating that not a single wire-worm could be 

 found the following year; and the crop of 

 wheat throughout, which was reaped last har- 

 vest, was superior to any I had grown for 21 

 years. I am, therefore, under a strong persua- 



