96 



Observations on the various Insects 



WlREWORMS. 



As no crop is perhaps altogether free from these destructive 

 larvae, we need not be surprised at their inroads upon the potatoes ; 

 indeed wireworms seem to be especially fond of them, since there 

 is no better trap than slices of potato stuck in the ground and co- 

 vered with earth, to be examined daily. In this way every wire- 

 worm may be attracted from a flower-bed and destroyed. 



I do not apprehend that a potato -crop is ever entirely destroyed 

 by wireworms, although when young they bore up into the haulm, 

 as observed by Mr. Graham, and the sets also are stated to have 

 been greatly injured by them in May; but they undoubtedly 

 diminish the value of the tubers materially by perforating them, 

 and thus rendering them a suitable nest for other insects. To- 

 wards the end of last September the potato-crops in this parish 

 were greatly infested in some localities by wireworms, millipedes, 

 and centipedes. A gentleman near Tadcaster* has suggested 

 that potato- crops may even attract the wireworm. It appears from 

 our correspondent, that "in 1844, in order to clean and redeem 

 7 acres of exhausted land, it was planted with potatoes after oats : 

 the potatoes did not suffer from the wireworm, the crop was as 

 good as could be expected, considering that the great dryness of 

 the season had delayed the planting till June. In March, 1845, 

 6 acres were sowed with oats, 1 acre having been dibbled with 

 wheat in December. The crops were most healthy, but subse- 

 quently patches of decay attracted attention, and it was soon found 

 that the wireworm had been at work to so fearful an extent, that 

 in ten days the whole crop seemed victimised. Soot was then 

 applied to 4 acres (16 bushels per acre), and not being able 

 to obtain more, the remainder was sown broadcast with guano, at 

 the rate of 2 cwt. per acre, all applied in a pouring rain. This 

 arrested the evil, and many of the patches, apparently destroyed, 

 struck up a second growth from about half an inch below the sur- 

 face, where the wireworms had bored through the shoots, and the 

 oats eventually became the best crop in the parish." 



Mr. Duncombe also says — " On seeing the change for the worse 

 in the oats, when averaging about 6 inches growth, I applied my- 

 self to discover the cause : I carefully removed the soil from very 

 many plants and rows, for death seemed to go by rows for several 

 yards together. I collected a paper full of wireworms, and uni- 

 formly found not a rotten but a dry mouldy potato or potatoes: 

 some which were not so advanced were full of wireworms. Hence 

 I conclude that the potatoes left in 1844 either bred or attracted 

 from a distance these pests to my oats in 1845. If I had not 



* The Rey. E. Duncombe, of Newton Lyme. 



