164 



INJURIOUS INSECTS AND FUNGI. 



[Sept. 1896. 



examined in the middle of July were found to be completely 

 scooped out, and their contents eaten by the caterpillars of 

 Agrotis exclamationis, which appeared to be more "plentiful 

 than those of Agrotis segetum. 



Surface caterpillars cause serious injury to many crops of the 

 farm, market-garden, and garden, and particularly to mangels 

 and turnips. They, in common with caterpillars of different 

 species, are styled " surface caterpillars," because they hide just 

 beneath the surface of the soil, and attack plants of most kinds 

 just at, or just below, the surface, and always in the night-time. 

 They correspond with the " cutworms " in the United States, 

 so-called because they cut the stems of plants asunder. Some 

 of these American " cutworms " belong to this same family of 

 Agrotis. 



Young mangel plants, and mangel plants whose growth is 

 retarded by drought, are frequently cut through by these cater- 

 pillars just below the surface of the earth, and potatoes are also 

 attacked, particularly where earthing has not been well done. 

 Turnips and swedes are often spoilt by these caterpillars, which 

 completely clear out the insides of the bulbs, or so injure them 

 that they become rotten. 



Lettuces, carrots, and beet-root are also frequently attacked 

 by the caterpillars of the Garden Swift Moth, Hepialius 

 lupulinus, but those of the Agrotis are far more destructive 

 to them. Wheat and other corn plants seriously suffer from 

 Agrotis caterpillars, especially wheat in mild winters. This 

 injury is often attributed to wire worms. Grasses in pastures, 

 particularly those with thick bulbous stems, are often eaten by 

 these caterpillars, which do more injury to grass land than is 

 generally i magined . 



There is no doubt that mild winters, without any frost, tend 

 in some considerable degree to account for unusual numbers of 

 surface caterpillars, as they pass the winter in the ground in the 

 caterpillar state, and might be affected by frost, or at least 

 by frequently alternating frost and thaw. Mild dry springs are 

 favourable for pupation, egg-laying, and for the caterpillars while 

 small, and dry weather later on prevents the caterpillar disease, 

 which is always more prevalent in rainy seasons. 



Life History. 



The female moth of Agrotis segetum is rather larger than 

 the male, and has dark black-brown wings, while the wings of 

 the male are greyish brown. The antennae of the male are 

 much pectinated, while those of the female are simple. In size, 

 Agrotis segetum differs little from Agrotis exclamationis. 



In Agrotis exclamationis, the female is reddish-brown, with 

 the fore-wings darker than the hinder wings. The colour of 

 the male is paler brown, and its antennae are slightly pectinated, 

 the antennae of the female being plain. The wing expanse 



