good repair. (4) Hang plastic resin strips (2" x 10") containing 20-percent 

 dichlorvos (DDVP)--one strip per 1,000 cubic feet of space, or about one per room. 

 These strips will kill mosquitoes and flies for 4 to 6 weeks. Hang the strips 

 out of the reach of children and away from fish bowls and food counters. Repeat 

 treatments with 0.1 -percent pyrethrum space spray- -applied from a pressurized 

 spray can- -can be used for quick knockdown in place of the dichlorvos resin strips. 

 (5) When entering mosquito -infested areas, use a repellent. One of the most 

 effective mosquito repellents is DEET (diethyltoluamide) . (6) For quick knock- 

 down at cookouts, outdoor parties, or picnics, use either 0.1-percent pyrethrum 

 or 0.5- to 1 -percent dichlorvos (DDVP) as an oil- or water-base space spray. 

 Spray the mist lightly beneath tables and chairs and into the air for a few feet 

 around the area. Repeat the treatment as needed. 



Ants, spiders, crickets, millipedes, sowbugs , roaches , and other crawling insects 

 continue to enter homes. If you sprayed the foundation wall of your home in May, 

 it may need another treatment now. Buy chlordane as a liquid concentrate and 

 dilute it with water to the proper strength (1 pint of 45-percent chlordane liquid 

 concentrate in 3 gallons of water gives a 2 -percent solution). Spray the founda- 

 tion from the sill to the soil until the spray runs off. Also, spray 2 to 3 

 inches of soil next to the foundation wall. Spray in cracks or expansion joints, 

 along porches and around steps, and along the edge of sidewalks and driveways. 

 In houses with crawl spaces, treat the inside of the foundation wall as well as 

 the outside, and spray support pillars. The average house requires about 3 gal- 

 lons of finished spray. Do not spray near wells or cisterns. Do not spray 

 shrubbery or flowers because the oil may burn the foliage. Repeat the treatment 

 again in late summer for protection in the fall. 



WEEDS 



Herbicide injury seems to be a little above normal this year. Injury to soybeans 

 from atrazine carryover is being observed in some fields. Symptoms vary from a 

 slight mottling of some leaves to necrotic brown sections in others. There are 

 some completely dead plants. The severity depends on the amount of atrazine left 

 in the soil. Injury is most evident on field ends where sprayers were filled, 

 where sprayers were left on when turning, or where there was overlapping. Where 

 correct rates were carefully applied, injury is usually not severe. And slight 

 injury to soybeans early in the season may not be reflected in final yields. In- 

 jury may look worse than it actually is. This indicates the need for future rate 

 adjustments and careful application. 



There are several factors that may have contributed to herbicide carryover in some 

 fields this year. Temperatures in 1967 were below normal. Some areas were 

 relatively dry last summer or early this spring. Both chemical and biological 

 degradation of herbicides proceed faster with warm moist conditions. 



In some fields atrazine postemergence was not applied until mid-June of 1967 and 

 soybeans were planted in early May of 1968. This gave a relatively short period 

 of time for herbicide decomposition as compared to preplant or preemergence applica- 

 tions in April or early May of 1967 with soybean plantings in June of 1968. Some 

 research suggests that when atrazine is incorporated into the soil immediately, 

 loss of the herbicide from the soil surface may be reduced and residue in the soil 

 may be increased. 



