Insect Flight Mill Research Returns Valuable Information for Pest Control
The larvae of codling moth and obliquebanded leafroller can cause enormous damage to fruit crops. While scientists have expended a tremendous effort to find ways to control the eggs and larvae of these pests, relatively little is known about the actual moths — those flying reproductive organs that disperse their fruit-munching caterpillar offspring far and wide. That’s not surprising, as it’s difficult to trail a moth and observe its behavior. But researchers at the WSU Tree Fruit Research and Extension Center in Wenatchee have resurrected an old technology, the flight mill, to put moths through their paces and see what moths in action are made of.
Insect flight mills were originally designed around 1895, and still operate under a simple principle: create a miniature mill with a horizontal rotation, attach an insect, and observe the insect in flight. While WSU entomologists didn’t invent the flight mill, they have significantly improved it by using polymer and metal components with magnetic repulsion to nearly eliminate friction. A sensor detects completed rotations, and a computer tallies rotations and calculates total flight distance.
Teah Smith adopted the flight mill as the centerpiece of her master’s research in entomology. Under the supervision of Vincent Jones, professor and insect ecologist at WSU Wenatchee, Smith constructed an array of 24 flight mills and, using moths raised in incubators, started to put the insects through their paces. Her procedure began with chilling a moth to make it torpid for easier handling. Then she used a brush to gently remove scales from the top of the moth. With a dab of glue, she attached the moth to the mill.
Moth… or Mothra?
The moths in Smith’s flight mills flew five kilometers on average. One marathoner, though, managed to travel 36 km, demonstrating that an orchard infested with moths can be a threat to fruit trees at a considerable distance. And while moths don’t typically come to mind as endurance athletes, they can typically fly 3.5 to 5.5 hours. The longest flight mill trial lasted 14 hours.
Smith and Jones expanded on this moth dispersal data by testing them for reproductive success and the effects of pesticides on flight distance. “We expected moths that flew the farthest would have the least reproductive success, as they had expended the most energy,” said Jones. Despite the logic, this turned out to be a faulty assumption. “Flight distance had no effect on the reproductive success of codling moth.”
Minimizing Moth Movement
To examine the effects of pesticides on flight distance, Smith exposed moths to 10 different chemicals at 10 percent or less of the field rate, then attached them to the flight mills. ìWe found that three insecticides, chlorantraniliprole, cyantraniliprole and lambda-cyhalothrin, reduced codling moth flight distance between 83 and 99 percent. [Note: Cyantraniliprole is not registered in Wahsington state at this time.] This discovery could help orchardists limit the movement of moths between blocks of trees. She also discovered that sublethal doses of pesticides interfered with reproductive success to a greater degree than was previously suspected.
When Smith tested the pesticides on a natural predator, the convergent ladybird beetle, she found that the sublethal doses of chlorantraniliprole and cyantraniliprole had no effect on their flight distance.
High-volume Data Contributes to Integrated Pest Management
Testing two dozen moths at a time in flight mills is far superior to expensive, logistically difficult field dispersal tests. With data from 3,000 moths, Smith’s lab work established a scientifically valid baseline for moth dispersal that can now then be applied to the field. Smith’s research contributes to the body of knowledge driving Integrated Pest Management, the combination of a range of practices that yield the most efficient pest control with the fewest economic and ecological impacts. Her initial findings are the launching point for additional research in Wenatchee on how pesticides affect the dispersal of both pestiferous moths and desirable pest predators.
For more information about research in the lab of Dr. Vincent Jones, see http://bit.ly/vincejones. For specific information on flight mills, see http://bit.ly/flightmill.
–Bob Hoffmann
Science on Your Plate
A bowl of raw white mushrooms is worse for you than a package of Hostess Twinkies. Your favorite brand of chocolate originated from the bean of a tropical fruit tree. You, guinea pigs, and fruit bats are among the unique creatures on the planet that don’t produce vitamin C naturally. Really?
Yes, really. Those are the kinds of noteworthy morsels that Washington State University professor Jeff Culbertson serves during his new UCORE (University Core Requirements) 201 class, “Science on Your Plate.”
Culbertson, a food scientist, began designing the course from scratch for undergraduates a decade ago and started teaching it at WSU this semester. Covering everything from food fads and myths to allergies and additives, he turns food science into English for students pursuing all kinds of degrees. “It’s the type of class that fits into their lives regardless of what their major is,” he said.
A Place at the Table
Anyone who has pulled a caved-in cheese cake from the oven or a rubbery omelet from the stove, wept while chopping onions, or sneezed after a whiff of freshly cracked pepper has encountered food science. “Everyone eats and almost everyone cooks. The beauty of food science is that it’s so applicable,” Culbertson said.
Not only that, but a surge in food movements, foodie blogs and food geek groups demonstrates the intense interest in food among laypeople, said Culbertson, who earned his Ph.D. in food science from WSU in 1984 and returned to teach here one and a half years ago after teaching at the University of Idaho, Central Michigan, and Ohio State.
“There’s an increased awareness that food is about much more than eating,” he said. “My course addresses taste and beyond.”
Mushrooms and Horseradish and BPA, Oh My!
In a recent class, Culbertson delivered his lecture from behind a table covered with mostly edible props, ranging from bottled water and chocolate bars to organic-labeled tomatoes and raw white mushrooms.
“Do you think just because a food is so-called natural, it’s good for you?” he asked. “I don’t want to doom and gloom you, but consider the raw white mushroom.” Offered up raw and sliced at salad bars, this fungi contains the natural compound hydrazine, he said: “These may be naturally occurring but they’re carcinogenic in mice. It’s safer to eat mushrooms when they’re cooked because the heat destroys hydrazine.”
Next on Culbertson’s list was grated horseradish, delightful to many in a teaspoon amount added to mashed potatoes. However, this root vegetable can trigger profuse sweating, vomiting, and diarrhea when eaten in large quantities, he said. So there’s good reason it burns and bites going down. The same goes for chili powder and pepper.
“Many plants have chemical weapons to defend themselves,” said Culbertson. “Because plants can’t run away, they have developed a myriad of natural pesticides to protect them from browsing mammals. Remember, it’s the dose that makes the poison,” he said, waving a jar of processed horseradish in the air.
Culbertson also tackled touchy topics such as BPA lurking in plastic bottles, a vitamin C-producing defect in humans, deadly E. coli outbreaks, and addictive caffeine use. But just when the doom and gloom started to cast a shadow over the lecture hall, he switched gears to address the happy side of food science.
Wowed by Chocolate
Culbertson seemed pleased to report that good types of bacteria transform milk into creamy yogurt and then help your intestinal tract when ingested; intentional mold creates the distinctive color and flavor of blue cheese; and chocolate’s luscious flavor, its sensual mouthfeel, and a substance related to caffeine all contribute to the fireworks going off when you eat it.
Ah, chocolate. Culbertson’s students appeared fixated as he talked. Then again, maybe it was this author, a lifelong chocoholic, projecting.
Either way, Culbertson presented some interesting tidbits. For example, cocoa butter added to chocolate makes the confection melt at mouth temperature. “This creates a pleasurable sensory sensation,” he said, while passing Hershey and Dove bars around the class.
Additionally, a chemical compound called theobromine found in cacao beans is a gentle cousin of caffeine. Though it triggers a soft buzz in humans, it can be toxic to dogs and other animals, Culbertson said. To think that a foil-wrapped chocolate heart presented on Valentine’s Day began with a whitish bean encased in a tropical tree pod–-who knew? Students Kelsey Clifton and Samantha Young didn’t. “All I knew is that it tasted good, and that sometimes people crave it so much they’ll drive to the store to get it at night,” said Clifton. “Oh, and it’s got lots of calories.”
No surprise that chocolate is loaded with calories. After all, as Culbertson likes to say, it’s the dose that makes the poison.
–Linda Weiford
Value-Added Food Workshop Series
Farmers, chefs, current and future food processors, as well as passionate foodies may want to get in on a workshop series being offered by the Washington State Department of Agriculture (WSDA).
The workshop series is composed of intensive sessions for participants to learn ways to extend their market season through value-added products. Value-added products, with a longer shelf life than fresh-market agricultural crops, offer the opportunity for year-round sales that can be marketed directly and potentially generate higher profits. The series begins in Spokane on Oct. 23 at 9 a.m. – 3:30 p.m. and continues through Nov. 13. Additional sessions are being offered in Wenatchee (beginning Oct. 24), Mt. Vernon, Port Hadlock. Sessions for Clark and King county producers are also being planned.
The workshop series targets beneficiaries are small and mid-sized fruit and vegetable producers and small and mid-sized food processors (including chefs) who may become partners or provide co-packing for the farmer/entrepreneur. For those interested and willing to make the commitment, diverting part of a crop into direct sales or value-added processing will diversify their revenue, reduce market risk, and give them greater control over their markets, pricing, and bottom line.
One of the biggest challenges to farmers expanding into value-added processing is not enough information about available resources, the potential benefits and risks, and the steps required to get started. In response, WSDA structured the workshops groups of 12 – 18 people farmers and small processors will be joined together to share ideas, experiences, and knowledge to develop self-sustaining teams to mutually support each other’s efforts.
WSDA’s primary objective for the workshops is to help specialty crop producers and processors be more profitable and economically viable. Some of the topics addressed in the workshops include:
- Benefits to producers from directly marketing their products
- Opportunities to develop unique or added-value processed products
- Critical steps in developing a value added product
- Commercializing a product
- Marketing and market research
- Food safety
- Sources of knowledge and expertise
- Financing
- Co-packing options
For more information or questions, contact Fred Berman via fberman@agr.wa.gov or at 360-656-5063.