December, 1958 



Df.cker: Economic Entomology 



113 



DDT came into general use the per-acre 

 potato yields practically doubled. 



Numerous early reports indicate that 

 the pioneer cabbage grower had to con- 

 tend with about the same insects that 

 plague the cabbage grower of today, but 

 the pioneer had no arsenal of effective in- 

 secticides. Lime, lye, and ash mixtures 

 advocated by some growers were of little 

 use except in those cases where the plants 

 were so heavily coated with one of the 

 mixtures that physical contact between 

 the insect and the plant was practically 

 impossible. The scalding water drench 

 proposed by some persons was at times of 

 value, but was very apt to damage the 

 plants. The arsenicals were used spar- 

 ingly and on small plants only; they could 

 not be safely employed on more mature 

 cabbages. Thus, for many years the 

 sound, unblemished head of cabbage was 

 a rarity, and there was always danger of 

 consuming protein with the slaw. In fact, 

 it is very doubtful if any kraut made in 

 those days could have passed present day 

 Food and Drug Administration inspec- 

 tions for insect fragments. There are 

 those who contend that the prevalence of 

 scurvy in the armies of the North and the 

 South during the Civil War was in no 

 small measure due to the fact that farm- 

 ers could not produce adequate quantities 

 of cabbage and related cole crops. 



Although some nicotine and pyrethrin 

 products had been known for many years, 

 they did not come into practical use until 

 about 1910. Derris, cube, and other ro- 

 tenone preparations made their appear- 

 ance in the 1920's. When properly ap- 

 plied, these insecticides were quite effec- 

 tive, but they possessed very limited re- 

 sidual properties and were relatively ex- 

 pensive. Their acceptance by cabbage 

 growers was not enthusiastic, and ento- 

 mologists were under constant pressure 

 to improve formulations by the use of 

 synergists or stabilizing agents. Then 

 came DDT and the organic phosphate in- 

 secticides, and it looked for a time as if 

 the cabbage growers' insect problems were 

 effectively solved. But the insects once 

 again demonstrated their mutability, and 

 soon cabbage worms were resistant to 

 DDT. Today the entomologist is worse 

 off than he was in the early 1940's, be- 

 cause the cabbage growers, having once 



experienced the fine performance and 

 economy of DDT in the early 1950's, are 

 unwilling to settle for anything less effi- 

 cient. The currently recommended spray 

 schedule, which calls for using endrin un- 

 til cabbage heads begin to form and fin- 

 ishing with occasional applications of 

 phosdrin or parathion, is a highly effec- 

 tive treatment, but the growers remem- 

 ber equally satisfactory results with the 

 less complicated use of DDT. 



Sweet corn growers in Illinois, like 

 the cabbage growers, must cope with 

 an insect problem that requires both a 

 thorough knowledge of the seasonal ac- 

 tivities of the pest and a rather meticulous 

 control treatment. The corn earworm is 

 a native American pest that has long con- 

 tested man's right to the sweet corn pro- 

 duced in Illinois. Unlike the cabbage 

 worm, this insect has continued to defy 

 man's best efforts to control it. Several 

 reasonably effective control measures have 

 been developed, but none has been fully 

 accepted by Illinois sweet corn growers. 

 The corn earworm control measure cur- 

 rently recommended involves precise but 

 not unreasonable methods of application 

 and accurate timing of treatments. Some 

 Illinois sweet corn growers have been un- 

 able or unwilling to apply the requisite 

 control measures. When infestations of 

 the corn earworm are light, mediocre con- 

 trol practices prove adequate, but, when 

 infestations are heavy, more meticulous 

 practices are essential. In parts of Flor- 

 ida and Texas, where sweet corn growers 

 cannot afford to gamble on having light 

 infestations, many growers produce 97 to 

 99 per cent clean ears of corn by care- 

 fully following the control measures rec- 

 ommended by entomologists. 



Cereal and Forage Crop Pests 



Insect depredations were by no means 

 confined to the fruit and vegetable crops 

 produced by the early settlers in Illinois. 

 Wheat, corn, and even the native prairie 

 grasses were subject to attacks that at 

 times amounted to almost total crop de- 

 struction. In an article in the first issue 

 of The American Entomologist, a writer, 

 presumably Walsh, observed : 



Few persons are aware of the enormous 

 amount of wealth annually abstracted from the 

 pockets of the cultivators of the soil by those 



