A Flying Success

The insects, later identified as flying aquatic insects such as black flies, midges and caddisflies, were landing on the paper as it traveled through a winding machine, where large rolls of paper are cut into smaller rolls. Because the winders travel at very high speeds, the unsuspecting insects, upon landing on the rolls were immediately wound into the roll and onto the paper. After traveling through the winder, the paper is sent through an extruder that lays a thin polyethylene film over the paper, thus sealing the insects’ fate and locking them into the paper permanently.

Because the pests were sealed in between the paper and the polyethylene film, no insects would have actually ever come in contact with the food held in the boxes. That said, sending a client thousands of food cartons dotted with flying insect parts, was not exactly Potlatch’s idea of customer service excellence. “Obviously if they open up the carton and find that there is an insect in there, even though it’s under polyethylene, it’s not a real comforting thing to find,” Williams said.

Adding insult to injury was the company’s struggle in finding relief from the situation. “None of us were really educated on pest control,” Williams noted. “The more insects we saw, the more we just sprayed outside, and that really didn’t phase it very much,” she said. Though Potlatch had contracted with a local pest control company, results were few and far between, and the problem was slowing productivity. Spot detectors along the manufacturing line were identifying enough defects that certain machines were lying idle. The downtime was beginning to affect operations, and throughout 1993 the problem was still unresolved.

A COOPERATIVE SOLUTION. To analyze the contamination issues, a team of 12 Potlatch employees was formed. The group, deemed the Contamination Team, began looking for pest control companies to provide a solution.

“Our salespeople had a meeting with Potlatch’s environmental services team and they referred us to Potlatch’s contamination team,” said Jeff Weier, technical director of Sprague Pest Solutions, describing how his company first became aware of the plant’s predicament.

“We started meeting with their contamination team over a period of months to talk about the problem and what we could do for them. So it wasn’t just coming in and throwing a bid at them,” Weier said. Potlatch, impressed with the approach, hired the Tacoma, Wash.-based company, and by the spring of 1994, Weier was traveling out to the mill several times, conducting inspections and developing a plan.

The finished products area of the plant, where the insect problem existed, is a two-level structure covering 1,200 feet in length and more than 200 feet in width. “There were lots of little things that needed to be corrected, lots of little openings the insects could come in through, doors being left open and not screened, etc.,” Weier said. Furthermore, the insects were breeding in a river that ran within 100 yards of the plant.

THE NEXT STEP. After sizing up the situation at the plant, Weier wanted a system to pinpoint the areas of significant pest activity in the building. He remembered a presentation he heard by Richard Brenner about a new software system developed to make a pest contour map of the facility. Brenner heads up the USDA’s Agricultural Research Services’ Gainesville-based Imported Red Fire Ant and Household Insect Research Unit. He and a team of researchers had developed a system that, after entering data about the amount of trap catches at various locations in a structure, would then make a map of the structure highlighting those areas most in need of pest control measures.

“I had heard Rick Brenner speak before and I thought this situation would be a perfect application for the mapping programs. So I went down to Florida to work with him for a couple of days to learn how to use the software. I learned the process from him and applied it to the account. I couldn’t have done it without him,” Weier said.

Monitoring. The Sprague crew then placed 135 light traps around the building and monitored the trap catches weekly. “We collect the insects, weigh them, plot the information (using the mapping system from Brenner) and go from there,” Weier said. If the plan sounds high-tech, it is, but if it sounds costly, it isn’t. “It’s not really expensive — you just need a computer and the software system,” Weier said.

In addition to monitoring trap catches to identify areas of intense insect activity, the Sprague crew set up a system to monitor environmental conditions in and around the plant, including air temperature in various areas, and the temperature of the river.

“They’re aquatic insects, so they hatch based on river temperature,” Weier said. By monitoring the water temperature, Sprague professionals can tell when there’s a likelihood of hatching (i.e. when the water temperature is higher), and then alert the facility to be on guard. “We have a big sign we put out, like a forest fire danger sign, but it’s an insect danger sign,” Weier said. When the sign goes up, the plant’s employees can then monitor the sign on their way in and, if the insect activity is high, know to be extra careful, making sure doors are closed quickly, etc.

Control. After inspecting the account and monitoring to determine the areas of highest pest intensity, Weier set out to create an IPM control plan based primarily on structural modifications. Openings were sealed or screened, and new doors were installed to limit the pests’ entry into the building. Double or airlock doors were also installed on all the doors in the building, so that there is no area where the pests have direct access to the building from outside. In areas where large industrial-sized doors were used and opened often for operational needs, rapid roll-up doors were installed.

“We had one door there, which, when we first started, we sat there and watched it and timed it. It took about a minute and a half to roll up and another minute to roll down. We replaced it with a rapid roll-up door and it opens and closes in a matter of seconds. The less time the door’s open, the less chance there is for any insects to come through it.”

The structural modifications continued. Color filters were put on glass in doors and windows to keep insects from seeing the light coming from the plant. Previous outdoor lamps were switched to high-pressure sodium lamps, which are less attractive to the insects, and lights were moved off the building and on to poles.

All in all, virtually no pesticide was used to resolve the problem. “We probably use 50 gallons of diluted chemical a year at the most, and that’s not much,” Weier said. “We were looking at using some pesticide out in the holding ponds, but we discovered that was not the source of the problem. We do a very small application around the lights and areas of a wall that are illuminated by a light and thus attractive to the insects.”

While the structural modifications were fairly classic and straightforward, says Weier, the biggest challenge was keeping pests out while also keeping the plant operational and not restricting its systems and productivity. While rapid roll-up doors and other similar structural changes helped significantly, the greatest success came from working and communicating well with the client. Sprague staff meet with the plant’s contamination team monthly, discussing levels of product contamination, levels of insect activity and educating the account about pest prevention methods.

The teamwork paid off for both parties, making the pest control effort easier and educating Potlatch staff about the role they played in preventing the infestation. “It has been a real education process to make people aware of how serious an issue it is, because any pest control program is only as good as the employee that remembers to shut the door when he or she comes through the door,” Williams said. “We can put up all the fine mesh screen, and all the light traps in the world, but if we have people leaving doors open, it doesn’t do a lot of good,” Williams said.

THE RESULTS. The mapping software and the subsequent control plan combined with the client/PCO cooperation all had a significant impact on the pest problem at the account, and the problem has been under control for four years now. “The pest pressure at the account has always been bad. It was significantly affecting their ability to produce their product. But now there is a much better situation,” Weier said. Williams agrees.

“The problem is greatly diminished. It’s not perfect yet...but it is certainly very, very much improved,” she said. Indeed while the initial program has been a success it is in many ways just a beginning. Still today, a Sprague technician monitors the account weekly and Weier visits the account at least once a month, if not more.

Illustrative of this ongoing effort is the fact that currently Sprague professionals and the plant’s contamination team are meeting to discuss making some significant capital improvements to the building itself, making it harder for the pests to gain entry into the winding areas.

While the plan is ongoing, and plant and Sprague staff are continually searching for ways to improve, they both relish in the success of what they’ve accomplished together. It is a large scale, high-tech, commercial IPM plan that has truly worked. “The point is that by identifying the insects and the source, we realized treatments weren’t the answer to this particular problem, and that you can get cooperation from a major client if you work with them,” Weier said.

The author is associate editor of PCT.