Beetlemania

Chris Fifo

Sir Paul McCartney returned to Iowa in July for what I heard was an epic performance. Young or old, everybody can sing along to at least some Beatles songs. Even my 16-year-old son, who listens to mostly (c)rap music, knows the chorus of some of the classic Beatles tunes. Me … I’m more of a White Album type of person.

Beatlemania is alive and well in Iowa and the show was sold out. I would have loved to have gone to the show, but I just couldn’t justify the cost.

Not only did Beatlemania hit Iowa this summer, so did beetlemania: Japanese beetles. And this beetlemania can be very costly.

Pictured: Japanese beetles have been running amok in Iowa.

The Japanese beetle arrived in the U.S. in 1916, suspected in the soil with some iris bulbs from, you guessed it, Japan. All it took was a handful of larvae to make it into the ground in New Jersey to begin an invasion that’s been spreading for more than a century now.

I hear the infestations have since subsided in the east, presumably as the environment has reached equilibrium, but in Iowa they’re new(er) and running amok and unchecked by Mother Nature this year.

At home, I hadn’t really been scouting my gardens until I started seeing some damage. Multiple varieties—including colocasia, hibiscus and hollyhocks—were all showing the telltale signs of a beetle buffet; the leaves were being eaten between the veins, leaving a lacy skeleton of a leaf behind. Fortunately, I caught it early and sprayed, thus saving my landscaping, but others haven’t been as fortunate.

One of my neighbors has, or should I say had, a beautiful American Linden in their front yard. It started turning brown and dropping its leaves from the top down at the beginning of July. I pointed out the infestation, but I guess they weren’t concerned. Four weeks later the tree is half bare, with only a few green leaves left at the bottom.

I spoke with my brother who owns a vineyard and winery here in Iowa. He said the beetles aren’t bad at his place, but “some vineyards are devastated because they weren’t scouting.” One grower knew of someone who was “spraying every other day” and “dead beetles were 4 and 5 in. thick underneath his plants.”

At the greenhouse, we’ve been preparing for their arrival and have had our defenses in place for years. Our local inspector and entomologist had been monitoring the area with pheromone traps for the past 10 years. It wasn’t until about three years ago that he finally caught one, signaling their arrival.

Our defenses are substantial and all-inclusive. Involving both physical and chemical management, we’re confident they’ve held. If they were to fail, it could be quite costly.

Our first line of defense is understanding the beetle life cycle and knowing when the mobile, adult stage will emerge. After that, scouting and protecting our 4 acres under cover is paramount. We won’t allow the beetles inside.

Our propagation houses, which are fan cooled, have always been screened for thrips. However, thrips screens would cut the air flow excessively in our largest, open roof ranges. Instead we installed netting (essentially shade cloth) spanning the gutters beneath the vents, held in place by wiggle wire. Unfortunately, this did cut our air flow more than expected and we had to add exhaust fans to help.

With the indoors protected, we turned to outdoors. We’ve been working hard to extend our weed boundaries even further away from the greenhouse, keeping the cover and alternate food sources limited in the immediate vicinity. Being in the country surrounded by farm fields makes it more challenging than if we were in an urban location.

However, that’s not helping us sleep better at night.

For that good nights’ sleep, we’ve treated our perimeters for adult beetles. Since they only live for six weeks or so, only two or three treatments are needed. We’ve also treated for the larvae in the soil in an attempt to reduce next years’ populations.

With these defenses and offenses in place, we’re hoping to quell another epic performance by the beetles before Mother Nature takes over.

Yesterday, all our troubles seemed so far away. Now it looks as though they’re here to stay … GT

Chris Fifo is Technical Services Advisor for Swift Greenhouses, Inc. in Gilman, Iowa.