7u 7 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA -CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT. WEED & PLANT DISEASE SURVEY BULLETIN 



TATE/COUNTY/LOCAL GROUPS/US. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 4, April 28, 1972 



This series of weekly bulletins provides a general look at the insect, weed,and plant 

 disease situation (fruit and commercial vegetables excepted) , along with suggested, 

 abbreviated control measures. Each individual should check his own fields to deter- 

 mine local conditions. the libra 



of 



INSECTS 



THf- 



J °H 26 19/2 



FORAGE INSECTS 



Alfalfa weevil larvae can now be found as far north as Route y. Adult weevils, eggs, 

 and larvae can be found in most fields; pupae are abundant in extreme southern Illi- 

 nois. In general, the larval populations are no greater than they were last week; 

 in many places, even lower. Wasp parasites are appearing in most areas. 



South of Route 13, damage has been severe in unsprayed fields. Generally, the egg 

 hatch is nearing completion and the larvae are maturing. Larval populations will now 

 decrease gradually. With cutting near, second applications of insecticides will usu- 

 ally not be necessary. Observe these fields closely, however; if necessary, apply an 

 insecticide so as not to lose the benefits gained by the first application. 



Between Routes 13 and 50, damage to alfalfa fields is quite apparent. Treatments have 

 been made, and a lot of spraying was done this past week. Heavily infested fields have 

 that silvery appearance. A second application will probably not be necessary for fields 

 that are harvested early; but if the harvest is to be a late one, a second application 

 may be needed. 



Between Routes 50 and 36, feeding damage has become apparent. Treatments on some 

 fields will be profitable. This is particularly true in the southern half of this 

 area. In the other half, early harvest may take care of the problem. If the harvest 

 will be late, apply insecticides to questionable fields soon. 



Between Routes 36 and 9, damage is not very noticeable unless careful observations are 

 made. A few fields, particularly in the western section, now have tip-feeding of as 

 much as 50 percent. In such fields, treatments are indicated for this week or next. 



The insecticide recommendations are: 



1. Commercial appl icators . Apply 1/2 pound per acre of methyl parathion or azinphos- 

 methyl (Guthion) for good results. Use azinphosmethyl only once per cutting, and 

 do not harvest for 16 days. Do not harvest for 15 days after a treatment with 

 methyl parathion. As a general precaution, wear protective clothing. 



2. Persons not equipped with protective clothing . Use: (1) Imidan at 1 pound per 

 acre; (2) a mixture of 3/4 pound of malathion and 3/4 pound of methoxychlor per 



