Sept. 1896.] 



INJURIOUS INSECTS AND FUNGI. 



165 



is about 1J inches, and the length of the body is about 

 three-quarters of an inch. 



The habits are the same in both species. Eggs like 

 poppy seeds are laid at the beginning of the summer, and 

 fastened near the ground to the leaves of cultivated plants, 

 plantains, goosefoot, chiekweed, and many cruciferous weeds. 

 Caterpillars come from these in from 10 to 12 days, and 

 begin to feed at once. When quite full-grown the caterpillars 

 are nearly 1\ inches long. One species can be distinguished 

 from the other only by careful inspection. Close observers 

 will note that the Agrotis exclamationis caterpillars (No. 2) 

 are darker than those of Agrotis segetum (No. 1), being 

 decidedly brownish, while the others are grey. The most 

 important distinction, as pointed out in Buckler's British Moths, 

 is that in Agrotis exclamationis the quite black spiracles are 

 always larger than the spots before and behind them, and that 

 upon each of, at least, the first live segments, there is a 

 pear-shaped blotch, rather darker than the body colour. 



These caterpillars feed from their first appearance in summer 

 to the spring of the next year, though probably a few of them, 

 as stated by Mr. Barrett in his Lepidoptera of the British 

 Isles, " appear to feed up rapidly by the middle of August, 

 ei producing moths the same autumn, and reinforcing the great 

 <c army of wintering larvae." During severe frosts they retire 

 to ceils in the earth. In the spring the caterpillars change into 

 reddish-brown pupae, in earthen chambers, in which state they 

 remain for about 28 days. 



Methods of Prevention and Remedies. 



To prevent a recurrence of the attack it is desirable to lime 

 infested fields with ordinary lime, or gas and lime, and to plough 

 deeply. Turnips and swedes that are infested should be fed 

 off early by sheep. Land after mangels, where there has been 

 infestation, should be limed, ploughed deeply, and not cropped 

 again till the spring, if possible, and ploughed again before 

 it is sown. It would be dangerous to sow wheat at once after a 

 badly infested crop of turnips, swedes, or mangels. 



Weeds must be kept down in fields and gardens, especially 

 cruciferous weeds, as charlock, which afford shelter for eggs, 

 and food for the young caterpillars. 



The frequent stirring, with horse and hand hoes, of land 

 having crops in drills, such as turnips, swedes, and mangels, 

 disturbs the caterpillars and kills some of them. Drawing 

 drags and harrows over young swedes, turnips, and mangels, 

 when possible, is also of considerable advantage. 



Fresh, pure, finely-powdered soot scattered on both sides of 

 infested plants and lightly chopped in has proved to be of 

 considerable benefit. It keeps the caterpillars off, at all events 

 for a time, and gives the plants a chance to grow away, at 



D 2 



