70 



NEW YORK STATE MUSEUM 



j^/4i^-- 



Natural enemies. Webworms are subject to attack by a number 

 of natural enemies, which are undoubtedly of much service in 



keeping the pests within bounds. A 

 minute four winged fly, L a m p r o- 

 nota frigida Cress., was reared 

 from the caterpillars by Dr Lintner 

 in 1 88 1, and Dr Riley obtained an- 

 other form, Cryptus mundus 

 Prov. A small Tachanid, allied to 

 the one which is so efficient in check- 

 ing army worm outbreaks, was bred 

 from larvae by Dr Lintner, who ob- 

 served in the infested fields a well 

 known caterpillar hunter, the fiery 

 ground beetle, Calosoma cali- 

 Fig. 2 crrmbus aibeiius, larval duiu Fabr. This latter insect is 



tube or nest in grass, the lower portion ,inrlniiKtpr1lv a A^nlnahlp allv in rliprlr- 

 exposed by the removal of a little humus UnciOUDteCIiy a VaiUaDiC aUy lU CnCCK- 

 (Redrawn from author's illustration) j^^^, ^^^^^ WcbwOrmS. Wc WOUld 



expect in addition that many of the smaller ground-feeding birds 

 would destroy a large number of these grass pests. 



Remedies. Grass webworms, as has been pointed out above, 

 live by preference on members of the grass family and ordinarily 

 abound only in grass lands. Their invasion of corn fields, tobacco 

 fields and cranberry bogs must be considered more or less acci- 

 dental, particularly as their depredations in these latter are usually 

 much more marked on the borders of fields adjacent to grass than 

 elsewhere. This naturally suggests the advisability of keeping crops 

 likely to suffer injury from these pests as distant from grass lands 

 as practical. Corn and tobacco fields and possibly cranberry bogs 

 could be surrounded by several rows of potatoes, for example, in 

 localities where these pests are likely to cause trouble. 



Another condition leading to injury is when grass sod badly 

 infested with these webworms is plowed and then planted with 

 some crop upon which the caterpillars can feed. This is the usual 

 explanation where there is extensive and serious damage to either 

 corn or tobacco, and the obvious remedy is so to arrange opera- 

 tions when practical as to render such an outbreak impossible. 

 Plowing of the infested land in late summer or early fall, in August 

 or early in September, should result in most of the caterpillars 

 perishing before the following spring. This can not always be 

 done, and danger of injury by those species of webworms which 



