FOR IMMEDIATE RELEASE June 9, 1961 



INSECT SURVEY BULLETIN NO. 8 



This weekly bulletin on the general insect situation in Illinois (fruit 

 insects excepted) is prepared "by entomologists of the Illinois Natural History Sur- 

 vey, University of Illinois College Agriculture and cooperating agencies. It is 

 designed to forewarn people in Illinois of impending changes in insect activity and 

 to suggest abbreviated control measures. These reports indicate only general trends. 

 Each individual should check his own fields to determine local conditions. 



Armyworms are approaching the damaging stage. They can be found in low 

 to moderate numbers over a large area of the state, with the highest concentrations 

 in western and southwestern Illinois. Some fields of grains in southern Illinois 

 have already been treated. 



For the next two weeks, examine luxuriant growths of small grains and 

 grasses. First examine down spots and then, if large numbers of worms are present, 

 examine the remainder of the field. If there are six or more worms per linear foot 

 of drill row or 10 to 12 per square foot in grasses, treatment is advisable. 



Toxaphene, 1 l/2 pounds, or dieldrin, X/h pound per acre, is recommended 

 for small grains. Allow '7 days between treatment with dieldrin and harvest, and 

 7 days for toxaphene on wheat, but Ik days on barley. For beef pastures, use toxa- 

 phene; allow k2 days between last grazing on treated pastures and slaughter, par- 

 ticularly if toxaphene is being used on the animals to control flies. For dairy 

 pastures, use 2 pounds of methoxychlor or 1 pound of malathion per acre, but do not 

 graze for one week after treatment. 



Black cutworms are appearing in corn, fields in spotted areas in central 

 and western Illinois and may appear in other areas soon. If the stands can still 

 be saved, apply 1/2 pound of dieldrin or 3 pounds of toxaphene, directed at the 

 base of the plant, and follow with immediate cultivation. The larger the worms, 

 the more difficult they are to kill, so early treatment pays off. If replanting 

 is necessary, broadcast at least 2 pounds of aldrin or heptachlor or 1 pound of 

 dieldrin per acre, and disk in before planting to safeguard against continued at- 

 tack. 



Flea beetles continue to feed on corn in the southern half of the state. 

 They strip the green from the leaf surface, leaving only the white tissue. When 

 the beetles are extremely abundant, the damage may be so severe that the leaf, and 

 in some cases the entire plant, dies. If these beetles are stripping the leaves to 

 the point of killing plants, then treatment is recommended. However, the greatest 

 part of the damage should be over within a week. 



If control is necessary, use l/k pound of dieldrin or 1 1/2 pounds of DDT 

 per acre as a band spray over the row. 



Chinch bug damage, appearing as dead spots, may occur in thin, open stands 

 of Email grains within the next few weeks in central and eastern Illinois. Examine 

 these spots for adults and nymphs. If bugs are extremely numerous throughout the 

 field, apply 1/2 pound of dieldrin, but not within 7 days of harvest. 



Corn borer emergence ranges from 10 to 20 percent as far north as Gales- 

 burg and up to 5 percent in northern Illinois. Corn growth and borer development 

 parallel those of the 1956 season. That year insecticide applications to field 

 corn began about June 25 in the central section of Illinois and continued to about 



