Man vs Beetle

On the Bug vs. People nuisance chart, things are looking pretty good here. Black flies departed on Father’s Day as usual, mosquitoes arrived shortly thereafter, and annoying mayflies followed mosquitoes.  Whew!

All those flying biting insect numbers are dwindling and being replaced by garden pests, but not many yet….except for a few of the most gargantuan slugs I’ve EVER seen! They look more like small snakes after our wet spring!

It’s the scarab beetles that I am keeping an eye on in the garden. I’ve only seen only one Japanese beetle that are emerging from the soil right about now, but I’ve seen a dozen or more of their cousins in the garden, the oriental beetles (Exomala orientalis) feeding mainly on the daisies and lady’s mantle. They are not voracious feeders but they do enough damage elsewhere.

Oriental Beetle 2019

It’s the lawn that takes a hit from these beetles. Just like the Japanese beetle, the larval stage feeds on the root zone of the turf grasses.  I’ve yet to know whether I have a real problem, but since I am committed to Integrated pest management (IPM)  instead of chemical management in combating pests, I’ve looked for alternatives that don’t affect good insects…. butterflies, bees, etc.

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Treatment is tricky because it varies depending on the species of grub. According to the Conn.gov website, bacterial spores can kill this variety of grub but our NE soil can be too cold to sustain the bacteria. Nematodes, microscopic worms that live in the soil, can infect and kill grubs but it’s tricky to keep them alive and tricky to apply the worms under the right conditions. Milky Spore targets only the Japanese beetle species of grub, according to UConn… in the state where the first siting of the beetle occurred in 1920.

The best option for treatment just may be sex pheromone traps that capture only the Oriental beetle male, unlike the Japanese beetle traps that unfortunately attract both male and female Japanese beetles. I found one lone online company selling the pheromone cards I would need…. traps sold separately.  I may not have a real problem but at least I have a place to order if it actually comes down to man vs. beetle.

Another Uninvited Visitor

I’ve discovered another insect in New Hampshire that I never met in Virginia. At first I thought it was an unusual Japanese beetle but, no, it’s a relative… same size but different markings. According to UNH Cooperative Extension, this is the invasive Asiatic garden beetle or Oriental beetle (Exomala orientalis) that was first discovered in the US in the early 1920’s. It is found in most of New England although it has moved as far as South Carolina and west to Indiana and probably still spreading. It feeds off the roots of grasses as a grub and the adult can attack garden plants.

Click to enlarge photos.

oriental beetleI think it’s actually kind of a cute looking little beetle… and “about the size and shape of a coffee bean,” says cooperative extension. Cute looking, but does damage as a grub to the lawn, then in June and July, it emerges from the soil to mate and eat. Adults generally eat little but stick around all summer nibbling in the garden.

oriental beetleAfter mating, the females burrow into the soil to lay eggs that hatch in about 2 weeks. UNH states that rarely are chemical controls needed for these grubs in New Hampshire. Japanese beetle grubs in this state are more destructive than the Asian beetle grubs, however the USGA says it’s the most important white grub species in turfgrass in New Jersey, southeastern New York, Connecticut, and Rhode Island and causes major damage in ornamental nursery stock.

oriental beetleI do not see damage on many leaves or blooms in our little gardens. I’ve read that favorite foods are leaves and the petals of daisies, hollyhock, roses, phlox, petunias, sugarcane, and blueberries, cranberries, raspberries, peaches and sweet potatoes. Whew! I don’t have any of those!

Often overlooked in the yard because they are not good flyers like Japanese beetles and are nocturnal, doing all flying and mating at night. An Integrated Pest Management system that traps and disrupts mating with an in-ground pheromone lure for the adult male beetle may be my solution if it gets worse. The lures are good for 6 weeks but must be emptied weekly.

I wonder what new insect I’ll meet next….