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FOR IMMEDIATE RELEASE May 13, 19^0 



INSECT SURVEY BULLETIN NO. k 



. . \ti\ ._.. 



This is the fourth in a series of weekly bulletins on the general insect 

 situation in Illinois (fruit insects excepted), prepared "by entomologists of the 

 Illinois Natural History Survey, University of Illinois College of Agriculture, and 

 cooperating agencies. It is designed to forewarn people in Illinois of impending 

 changes in insect activity and suggests abbreviated control measures. These reports 

 indicate only general trends. Each individual should check his own fields to deter- 

 mine local conditions. 



General conditions : Most insects have been inactive or nearly so during 

 the cold weather of the past week. The situation has not changed materially since 

 last week. However, some species continue to feed and reproduce during cold weather. 

 With these insects and with retarded plant growth, damage becomes more apparent. 



Clover leaf weevils and pea aphids : Feeding by green clover leaf weevil 

 larvae is probably more prominent than it was a week ago. However, the value of 

 controlling this insect alone is now questionable. With warmer weather and with 

 moisture, a fungus disease of the weevil will aid in control, and clover and alfalfa 

 will grow away from the damage. 



However, fields with mild to severe infestations of both pea aphids and 

 weevils may present a problem. Parasites, predators like lady beetles, and a fungus 

 disease of aphids do not increase during cold weather, but the aphids continue to 

 feed and reproduce. The conditions in a few fields of alfalfa and clovers this 

 spring may parallel the 1953 situation, when spring growth was also retarded by 

 cold weather. Then clover leaf weevil seriously defoliated plants, and heavy in- 

 festations of pea aphids developed, killing the already-weakened plants. Many 

 fields were affected over a wide area of the state. However, if a similar situa- 

 tion occurs this spring, it will involve only occasional fields. 



If control is necessary, apply 1/4 pound of lindane per acre, but not 

 within 28 days of harvest or pasture. One pound of malathion may be used to within 

 one week of harvest. Neither insecticide is completely effective at temperatures 

 lower than 60 degrees. 



Seed corn maggot and other soil insects : Cool, damp weather is favorable 

 for this insect. It attacks a variety of seeds and, on occasion in the past, has 

 seriously affected germination of soybeans, corn, and garden beans. These maggots 

 will be likely to damage the germination of already planted corn, and stands will 

 be decreased accordingly. It is now too late to do anything about this corn. An 

 application of 1 1/2 pounds of aldrin or heptachlor broadcast and disked in prior 

 to planting will be profitable on fields yet to be planted. This treatment will 

 also control wireworms and other early-season underground feeders over longer 

 periods when the weather and soil remain cool. Applying a soil insecticide will 

 also help to prevent damage by the black cutworm that may occur in late May or early 

 June. 



Caution : Before applying insecticides, read labels carefully and follow 

 all precautions. This not only will insure personal safety, but also will eliminate 

 insecticide residue hazards. 



NOT FOR PUBLICATION - Special note to farm advisers and assistant farm 

 advisers: 4-H members will soon begin making their summer project plans. Members 

 enrolled in the entomology project can obtain a free packet of 50 insect pins by 



