Mimeo E-60
July, 1964
Purdue University Cooperative Extension Service Department of Entomology
INSECT CONTROL IN CANNING PLANTS
Insect control is essential to Indiana canning plant operations. First, because law requires that food be processed and packaged under high standards of sanitation and cleanliness . And second, because insect control is part of "quality control," on which product sales depend. Therefore,
Indiana canners cannot afford to leave insect control to chance. Effective measures are the responsibility of top management and must be planned in advance.
The house fly is the major insect pest in most canning plants. However, equally serious to tomato canners is the Drosophila or fruit fly. Other insects that may require control are cockroaches and night flying insects attracted to light.
HOUSE FLY CONTROL
These five measures should provide effective house fly control -- (1) sanitation in and around the plant; (2) residual sprays outside the plant; (3) larval treatments of lagoons and waste pits; (4) screening of the plant; and (5) daily space sprays, mists or fogs inside the plant.
Sanitation
House flies breed in decaying organic matter. Around the canning plant, the principal breeding sites are lagoons and waste Pits, piles of cull fruit, garbage and outdoor toilets. Do not allow waste materials to collect anyplace except in lagoons or waste pits. No insecticide will control flies if they are allowed to breed unrestricted. And do not let a breeding site exist just because it is small. Ten thousand flies can develop in one cubic foot of suitable organic material.
Residual Sprays Outside the Plant
Use residual sprays outside the canning Plant to reduce fly populations and to keep
them from getting into the processing room. Dimethoate (Cygon) or ronnel (Korlan) are currently recommended at the following rates:
Dimethoate 25% emulsifiable concentrate at 1 gallon in 25 gallons of water OR
Ronnel 24% emulsifiable concentrate at 1 gallon plus 5 pounds of sugar in 25 gallons of water.
Other residual insecticides may not be effective because flies have become resistant to them.
Apply either dimethoate or ronnel with a power sprayer. A field-type sprayer fitted with a hose and spray gun having a fan nozzle will do. Make first application before the plant opens for the season, and repeat as needed. Treat all fly resting places to the point of run-off. Likely areas are unloading docks, around doors, protected corners of the building, southern exposures, waste deposits, fence posts, outdoor toilets, etc.
Larval Treatment of Lagoons
Waste pits and lagoons can be treated with a larvicide or, better yet, covered with polyethylene plastic sheets to prevent fly development. Polyethylene sheets can either be fastened together from 24-foot wide strips or be made to specification by the manufacturer. The sheet is allowed to float on the surface of the lagoon and is held in place by covering the edges with dirt.
To control fly larvae in uncovered lagoons, use ronnel (Korlan) 24% emulsifiable concentrate at the rate of 1 gallon in 25 gallons of water, as for the residual spray above, but do not add sugar. Apply 25 gallons of the spray per 2,000 square feet. Diazinon or dichlorvos (DDVP) may also be used for larvae control. Follow directions.