First published in The Record, March 17, 2018
Surrounded by predators, a monument to patience
Rhinoncomimus latipes, known to its captors as Weevil Knievel, is not an easy bug to catch by surprise. It’s one sneaky weevil. Like the motorcycle daredevil of a similar nickname, Weevil Knievel likes to leap high into the air. Anytime the bug feels startled it jumps, performs a few backflips, and searches for a cozy plot of soil in which to burrow and hide. (A pile of leaves also will suffice.)
“Which can be very annoying when you’re trying to count them,” said Mark Mayer, chief of New Jersey’s Beneficial Insect Rearing Laboratory, where 11 state employees raise, count and release hundreds of thousands of bugs every year. “They do this little somersault, and they waddle. They’re really cute.”
The only way to approach Rhinoncomimus latipes, and all the other species of predator bugs raised by the lab, is with patience. The bug’s only food is a creeping green weed that some people call devil’s tail or Chinese tearthumb, because its branches bristle with spiky thorns.
Others call it Mile-a-Minute because its vine grows six inches a day. Mile-a-Minute was imported from China to a plant nursey in Pennsylvania in the 1930s. It escaped, and grew like crazy. By the 1980s it was killing forests and smothering vacation homes up and down the Atlantic seaboard.
“If you leave home for a week? Whoa,” Mayer said. “You’d have Mile-a-Minute all over.”
Enter a certain backflipping bug.
Weevil Knievel loves to eat Mile-a-Minute and, critically, nothing else. Nevertheless, growing sufficient numbers of the weevil to contain the weed takes time. First, the insect lab must grow enough Mile-a-Minute to fill five greenhouses. Next its technicians train the vine into tight little bushes, and cram the bushes and the bugs into plastic boxes originally sold as display cases for commemorative footballs.
To the three-toed Weevil Knievel, each football case functions as combination airport motel, maternity ward and baby food jar, helping to birth a dozen generations of predators every year.
“We have to figure out a way to tame the plant and tame the weevil so you can raise a lot of them in the lab,” Mayer said. “There’s a lot of creativity involved.”
The lab’s scientists started raising the weevils in 2004. They didn’t know whether the predators could contain Mile-A-Minute until 2011. If the weevils continue to reproduce in the wild, Mayer figures, the lab can stop rearing them by 2023.
In Mayer’s line of work, this qualifies as speedy.
“This is not a pesticide paradigm where you spray the bugs, you kill the bugs, and you’re done,” said Mayer, 63, who has worked at the lab since 1987. “There are no quick solutions. You have to be patient.”
A monument to patience
The beneficial bug laboratory occupies an 11,000 square-foot building on a hill in West Trenton, a mile north of the Delaware River and a mile south of the Trenton airport’s runway. The spot has little practical benefit, since the lab does not transport bugs by boat, and its insects are not valuable enough to merit a commercial flight.
The location does carry symbolic significance, though. By definition, invasive plants and bugs arrive from someplace else. They hitch rides on airplanes and cargo ships; the Purple Loosestrife bush that now strangles swamps in New Jersey arrived from Europe in the 1800s, possibly in the ballast water of a sailing ship.
“New Jersey is surrounded by ports: New York, Philly, Newark, Elizabeth, Camden, Wilmington, and all these major airports,” Mayer said. “So if something gets out, New Jersey’s a really likely landing spot for it. That’s one of the major reasons why this laboratory was built.”
Our only chance to kill these invaders outright is to blast them with pesticides and herbicides the moment they make landfall.
If an invasive species escapes its port of entry, however, it encounters a little state with plenty of tasty food, on a big continent devoid of predators. Current interlopers include the Hemlock woolly adelgid, an insect from Japan that prevents trees from sucking water up their spines, and the Mexican bean beetle, which prefers New Jersey snap beans but will eat any variety.
“Green, snap, lima, wax. It doesn’t care,” Mayer said. “In this really tiny state we have six distinct ecosystems. It can be a really nice home for a lot of pests.”
Most invasive plants and bugs thereby get a head start, sometimes by centuries. After one takes hold, it’s too late for eradication.
“A lot of people just want their pest gone,” Mayer said. “But once we get involved, it’s already here, and we’ve got to deal with it. And it’s going to take a while.”
Here’s what Mayer means by “a while.”
The spotted lanternfly has a bee-shaped body and four wings colored in a motley clash of brown, black and fire-engine red. Originally from Asia, it is chewing its way eastward through the forests and fruit trees of Pennsylvania.
“That one’s coming,” Mayer said. “It’s right across the Delaware River. It’s gonna get here.”
When it arrives, New Jersey will have no antidote. To find one, scientists in Korea and the United States are working to identify predators that kill only the lanternfly and nothing else.
“Host specificity is the number-one thing,” Mayer said. “If the only thing they eat is the host, then they’re a good candidate. If they eat any other things, then they’re not getting out of quarantine.”
If such a bug is found to exist, scientists must figure out how to grow it in the laboratory; release it into the wild; then wait a decade to see whether it works.
In one likely scenario, New Jersey will bring the as-yet-nonexistent but total-coming plague of the spotted lanternfly under control by 2030.
“There are no short answers,” said Doug Fisher, New Jersey’s agriculture secretary.
Growing so many species of predator and prey in the same building requires a combination of specialized equipment and improvisation. One wing of the lab resembles the guts of the International Space Station, with reticulated steel doors and metal hoses strung all around. Angela Lovero has used the corridor’s humidity, heat and simulated daylight controls to trick 35 generations of invasive stink bugs into avoiding diapause, which is like hibernation for bugs.
Keeping stink bugs awake is essential to making them reproduce. That will be critical if the lab wins federal approval to rear Samurai wasps, which kill stink bugs by colonizing their eggs.
“They basically gave me the best lab rooms in the building,” said Lovero, an entomologist, “and I’m keeping them.”
This summer, lab technicians will deliver hundreds of thousands of predators to the wild. The tiny bugs will be transported in repurposed plastic guacamole cups, paper soup bowls and laminated buckets from a certain chain of chicken restaurants.
During a recent visit to the lab, Dr. Alexandra Villiard was busy using rubber bands to attach wooden sticks to the sides of a fat glass jar. The vessel will be used as a birthing chamber for Pediobius foveolatus, a tiny wasp that preys on the Mexican bean beetle; the sticks will prevent the jar from rolling away.
“They’re very hard to get,” Mayer said of the jars. “When one of them breaks it’s like losing a child.”