BIO CONTROL

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ELIAS BORN GABRIELLE BODE

PALISADE INSECTARY USES INSECTS AS PEST CONTROL

in an agricultural world filled with pesticide and chemical usage, the Palisade Insectary, located in Palisade, Colorado, stands strong as an alternative that’s been in business for 75 years and counting.

The insectary conducts biological pest control — a substitute to pesticides that involves using insects to combat pests and invasive species. Since 1945, the insectary has sought to provide farmers and residents with a more natural way to fight weeds and other pests.

“Peach growers [of the past] were faced with a problem,” Director of the Colorado Department of Agriculture’s Palisade Insectary Dan Bean said. “They didn’t have the chemicals that are present today. This was before the development of most of our modern-day insecticides.”

The problem in question was Grapholita molesta, otherwise known as the oriental fruit moth. Originally native to China, this particular moth was a huge pest to peach farmers in the Grand Valley after its introduction to the United States.

With pesticides proving to be a tricky endeavor, given their early development and possible health and environmental hazards, it was time for innovative measures to combat this new pest. That’s the first job the insectary was created in 1945 for.

“The goal was to raise a small parasitic wasp, which is actually, in entomological terms, a parasitoid,” Bean said. The key difference here is a parasitoid will kill its host and spends its whole life inside of a singular host, while a parasite may latch onto several different ones.

This wasp is known as Macrocentrus ancylivorus, or as the insectary dubs it, “the Mac.” The insectary is responsible for cultivating over 2 million of them per year. The Mac begins its life by being deposited as an egg inside of its host larvae. Hatching soon after being laid, the Mac completes its development by the time the moth larvae are ready to spin a cocoon.

The Mac has been successful in the Grand Valley, and the insectary has cultivated these wasps, along with a host of other projects, ever since.

The process to raise the Macs involves a few steps for the insectary, including supplying an alternate food source in the form of a potato-boring caterpillar.

OPPOSITE:

Grapholita molesta Oriental Fruit Moth

BELOW:

Macrocentrus ancylivorus AKA 'the Mac'

“[Macs] can't survive without a host, and the caterpillars that we raised here are relatives of the oriental fruit moth,” Bean said. “So, we're basically giving them an alternate food supply and allowing them to parasitize the potato larva. We don't want to raise oriental fruit moths right in the middle of Palisade peach groves. We don't want any [moths] to get out on the peaches.”

So, what are some of the other projects that the insectary tackles?

Their most popular order, with over 500 requests per year, is to help control field bindweed, Convolvulus arvensis, with the bindweed gall mite, Aceria malherbae, which eats the weed. Field bind- weed, otherwise known as morning glory, is another invasive species to the United States. The mites are nearly microscopic and collected out in the field.

“They come in a paper bag, kind of like a lunch bag, and it's got some field bindweed with its leaves all curled up with mites residing in those curled up leaves,” Bean said.

One of their other popular requests is the containment of Russian knapweed, Haponticum repens, which was accidentally introduced to the U.S. in the 1800s. Two different biocontrols are used for this knapweed, namely the gall midge, Jaapiella ivannikovi, and the gall wasp, Aulacidea acroptilonica.

“Every year it varies, because people go out and see what weeds they have, and depending on temperature conditions, rainfall and how good it was last year, we get variable numbers of requests,” Bean said.

The insectary handles a variety of other insects, and they distribute around 10 total species, with more that they collect out in the field, depending on what is needed for the year.

“We have to figure out for each insect how we're going to raise it, and we have to make sure that we have a steady supply of plant material to keep them happy. Most of them don't do well on anything but live material,” Bean said. To keep this steady supply of plant material, the insectary has two dedicated greenhouses.

Other insects the insectary cultivates include the root mining weevil Hylobius transversovittatus, the tamarisk beetle Diorhabda carinulata and

THE INSECTARY CONDUCTS BIOLOGICAL PEST CONTROL — A SUBSTITUTE TO PESTICIDES THAT INVOLVES USING INSECTS TO COMBAT PESTS AND INVASIVE SPECIES.

stem-boring weevil Mecinus janthinus. They feed on a variety of invasive weeds and plants in the West.

The Palisade Insectary has few facilities quite like it in the United States.

“We serve Colorado," Bean said. "But in order to do our job right, we actually have a lot of cooperative agreements and do projects with every state in the West. Every state west of the Mississippi, we've had some sort of project with. They send us biocontrol agents and let us know how they're doing in their state, and we do the same, so that we’re not trying to reinvent the wheel.”

The insectary has also worked with Colorado Mesa University both in the past and the present. They’ve previously worked with Professor of Environmental Science Dr. Deborah Kennard and Professor of Biological Sciences Margot Becktell to analyze data and conduct research.

Given the continual challenges posed by invasive species and pests alike, biological control offers an alternative to chemical and pesticide usage, and the insectary looks to stand strong in the future right here on the Western Slope. ▪

BELOW:

Aulacidea acroptilonica Russian Knapweed Gall Wasp