Doggone Birds (Fruit Protection)

September 13, 2012

Many bird species provide biocontrol by eating a wide range of insect pests, and are worth encouraging for controlling flies, mosquitoes, locusts, caterpillars, ticks, rodents and other pests around homes, forests, farms and gardens. Other bird species are considered pestiferous when feeding on our food plants, and can be repelled in various ways, including by loud noises, eyespot balloons, reflecting tape, scarecrows and scare devices, sensor networks and dogs.

Among the beneficial birds when they are not causing damage to utility poles or annoying people with their racket are woodpeckers. Personally, I like hearing woodpeckers working urban and forest trees, and was heartened to learn from Michigan State University’s Andrew Tluczek’s presentation to the Entomological Society of America (ESA) annual meeting that: “Woodpecker predation has caused up to 90% mortality of emerald ash borer (Agrilus planipennis) larvae in some sites.”

A 2006 tick control article in BioScience magazine devoted considerable discussion to birds for tick biocontrol. In Africa, birds known as oxpeckers (Buphagus spp.) provide biocontrol of ticks on mammals by consuming hundreds of adult ticks or thousands of nymphal ticks per day. Free-ranging guinea fowl experimentally tested around New York (USA) lawns reduced adult blacklegged tick numbers; but unfortunately the smaller nymph stage blacklegged ticks transmitting Lyme disease apparently were missed and not stopped very well.

The list of bird benefits for biocontrol, like barn owls for rodent biocontrol in Israel, Palestine, Malaysia and elsewhere could go on and on.

“Bird damage situations throughout the world are similar, involving many of the same crops and genera of birds,” wrote John W. De Grazio a few decades ago in the <em>Proceedings of the 8th Vertebrate Pest Conference. Seed-eating red-winged blackbirds, ring-necked pheasants, sparrows, crows, doves, parrots, munias, queleas, weavers and waterfowl are sometimes pests of corn, rice, wheat, sorghum, sunflowers, almonds, pecans, peanuts, etc. Starlings, sparrows, finches, grackles, robins, parakeets, etc. consume grapes, blueberries, and other fruit in yards, vineyards and orchards.

Dogs are used in pest control for sniffing out termites and bed bugs, and the natural proclivity of some dog breeds to chase birds can be harnessed to keep birds from destroying fruit in orchards and vineyards. In researching a grant proposal to travel to and write about Japan, which I failed miserably to qualify for, my Internet research for the proposal took me to the Japanese Journal of Farm Work Research. Being one of a select 4% of the USA population to have worked in agriculture, the journal title intrigued me enough to browse through several years of tables of contents, where I came across an intriguing article title: “Protection of Citrus From Bird Damage by a Dog.”

Not reading Japanese, I had to rely on the visual diagrams and English summary by researchers Hiromichi Ichinokiyama and Masami Takeuchi at the Kinan Fruits Tree Laboratory and Mie Prefectural Science and Technology Promotion Center:

“Effectiveness of a dog (Canus lupus familiaris) for protecting citrus fruits from bird damage was investigated using a citrus orchard (5.8 a in area) in the harvest season. In Experiment 1, a Border collie shepherd (male) was tied to a wire extended along one side of the square orchard to allow him to run along the inner side of the orchard. This watchdog system was effective in reducing fruit damage by birds (mainly brown-eared bulbul) only in the citrus tree row nearest to the dog runway.”

However, the researchers had better success letting the dog run free in the orchard:

“In Experiment 2, the orchard was enclosed with a tall chain-link fence and the same dog was allowed to move freely in the orchard. In this case, he persevered in chasing birds until they flew away from the orchard. This watchdog system effectively reduced bird damage to citrus fruits all over the orchard, resulting in an increase in crop yield…Further study is needed on the optimum number of dogs released per unit orchard area and the effectiveness of the watchdog system in case when this bird control system is spread to all orchards in the citrus-growing area.”

Like Richard Feynman’s Nontoxic Ant Ferry, dogs chasing birds away from trees laden with fruit or nuts is more a proof-of-concept awaiting further development than a fully developed technology you can order on the Internet.

Thank you to the organizations and people who created and are advancing the Internet, as even finding this sort of information would have been nearly impossible a few decades ago. Amazing how this high-tech infrastructure can advance low-tech solutions like the old-fashioned four-legged, tail-wagging dog as a bird-chaser in service of better fruit harvests.

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The Asian Invasion -Insects in Global Trade

January 8, 2011

NATURAL WOOD PRODUCTS are better than synthetic petrochemical plastics is a common refrain, almost a rallying cry for many who consider themselves “green,” organic, sustainable or environmentally correct. Thus, the fashionable zeal in some sectors of society to ban plastic shopping bags and allow wood-pulp paper bags. But what if being “green” and using natural materials like wood instead of synthetic petrochemical plastics led to deforestation and pestilence? That’s pretty much the world trade situation these days.

At first glance wood pallets, crates, dunnage, and packaging materials seem to be the low-cost, sustainable “green” alternative vis-a-vis more expensive, synthetic petrochemical plastics. But wood packing materials used in global trade have spread a pestilence of native Asian wood-boring beetles to new homes worldwide. The North American invasion by Asian wood-boring species of bark beetles, ambrosia beetles, and long-horned beetles were among the hot topics at the Entomological Society of America (ESA) annual meeting of Dec. 2010 in San Diego, California.

Since hitchhiking to North America from Asia in solid wood packing materials and being detected near Detroit, Michigan in 2002, the wood-boring emerald ash borer has killed an estimated 30 million ash trees in the northern United States and southern Canada. The remaining North American ash trees are threatened. Though Sara Tanis, whose Michigan State University work is on You Tube, reported at the ESA annual meeting that blue ash (Fraxinus quadrangulata) “can withstand infestation and continue to survive.”

Emerald ash borer control is now multinational, involving the U.S. states of Michigan, Illinois, Indiana, Iowa, Kentucky, Maryland, Minnesota, Missouri, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin plus the Canadian provinces of Ontario and Quebec. The Asian wood-boring beetle invasion is so far along it might make little difference if world trade abandoned wood pallets, crates, dunnage, and packing materials.

“Control strategies are now shifting to how we can manage established populations in the longer term,” Shajahan Johny of the Canadian Forest Service Great Lakes Forestry Centre in Sault Ste. Marie, Ontario, Canada, told the ESA. “One possibility is biological control, which is recognized as the most suitable long-term pest management strategy for invasive species.” Johny is looking at fungi in the genera Isaria and Paecilomyces attacking emerald ash borer in Ontario.

In Michigan and Ontario, Canada, the early emerald ash borer hot spots, woodpeckers can peck out up to half the wood-borers; which is good for the birds, but not stopping beetle movement to new trees. “In their native habitats, Agrilus (sci name of genus of 3,000 wood-boring beetles) populations are generally suppressed by a diverse group of natural enemies and/or host tree resistance, and rarely become serious pests,” said Jian Duan, Lead Scientist of the emerald ash borer biological control team at the USDA-ARS Beneficial Insects Introduction Research Unit in Newark, Delaware. The USDA has searched Russia, Mongolia, China, and South Korea to find specialized parasitoids that can be introduced to North America to hunt wood-boring beetle eggs concealed under loose bark and larvae hidden inside trees. The idea being to restore a natural ecological balance.

Asia has not been immune to wood-boring beetle outbreaks. “The mass mortality of oak trees (Japanese oak wilt) has recently increased explosively in Japan,” Masahiko Tokoro of the Forestry and Forest Products Research Institute (FFPRI) in Ibaraki, Japan, told the ESA. The Japanese are using a Decoy Tree Method (patent pending). Trap trees are baited with an aggregation pheromone attracting the wood-boring oak ambrosia beetle (Platypus quercivorus). Ethanol (alcohol) is added to the mix, because it is emitted by unhealthy or stressed trees and attracts beetles.

“Oak trees survive when they have been inoculated with a fungicide against the pathogenic fungus (oak wilt) before being attacked,” said Tokoro. “The decoy trees are lethal to the beetles because the symbiotic fungi (i.e. the ambrosia) that the beetles feed on are killed by the fungicide.” Neighboring trees can be similarly protected.

Variations on this method called push-pull are being developed in the U.S. to protect nursery trees from exotic ambrosia beetles (Xylosandrus spp.), said Christopher Ranger of the USDA-ARS Application Technology Research Unit in Wooster, Ohio. Ethanol is injected into sweetbay magnolia trap trees to stimulate ambrosia beetle attack. Beetles are “pushed” out of trees being protected by application of a repellent compound such as verbenone (dispensers) or via commercial botanical repellents such as Armorex, Veggie Pharm, Cinnacure. Azatin or Eco-Trol.