365 Urban Species. #212: Japanese Beetle

[urbpan]

Photos by cottonmanifesto. Location: Spectacle Island, Boston.

Urban species #212: Japanese beetle Popillia japonica

I n 1916, America's most densely populated state (New Jersey) became the first place in North America where a certain exotic Asian scarab beetle was found. This beautiful but destructive animal is now well-known to gardeners in the eastern states, and is becoming familiar in more places every year. Increasing amounts of regulation and use of biological controls (a bacterium and parasitic wasps) are the official weapons in use against the Japanese beetle. Others may use a more hands-on approach, as my parents did in years past, hand-picking beetles by the hundreds, off of the raspberry and rose bushes, and dropping them into jugs of soapy water. Still they seem to have a robust population in areas where they occur, including urban centers that have the plants the adults feed on (over 400 species documented) and grassy soil for their grubs to overwinter in. And they continue to spread, being found in San Diego for the first time in 2000, and at an airport in Montana in 2002.

Japanese beetles are often encountered in what appears to be mating groups. Females produce sex pheromones that attract many males, who compete for the opportunity to mate in large clusters. According to one researcher, relatively little mating actually occurs in these groups. Males will guard their chosen female from other males until she is ready to lay her eggs. At least while clustered, they can be easily picked off of plants.

Skunks are known to make holes in lawns digging for Japanese beetle larvae, and moles and raccoons may eat some grubs as well. Other known predators of Japanese beetle larvae include ants and ground beetles. Few creatures seem to prey on the adults, though this observer has noticed at least one turkey seems to have a taste for them.

Comments

[sin-agua.livejournal.com]

BOW CHICKA BOW WOW! Dat's some good beetle love, baby. Oh YEAH.

[featheredfrog.livejournal.com]

the instinct to cluster makes pheremone traps very successful.

[droserary.livejournal.com]

Indeed. I believe you can also obtain the pheromone by itself, separate from a trap. For a fun evening, capture a single male beetle, "lasso" the beetle by tying thread around it without impairing its flying ability, cover it in pheromone and let it fly like a beetle kite. Tons of other males will come and try to mate with it. And if I'm correct, the males usually die after mating. A fun and effective way to get rid of the beetles!

This will also work for the Oriental beetle, the Japanese beetle's ugly cousin.

[droserary.livejournal.com]

Interestingly, growing up in New Jersey, we would get thousands of these beetles in our pool every year. Every once in a while there would be a very large one, in the 3-5cm long range. Same color pattern, but just enormous compared to the other little Japanese beetles. I always wondered if it was a different morph of the species or a completely different species.

Any of the entomologists that read your journal know for sure if there's a gigantic subspecies?

[badnoodles.livejournal.com]

There are some ground beetles with a very similar color pattern that get up into that size range - or alternatively, some members of the genus Polyphylla get quite large indeed.

[droserary.livejournal.com]

You're amazing! Thanks for the lead :-) I suppose a picture would have helped, but it was so many years ago and I was a content 10-year-old drowing the beetles in chlorinated pool water (for some reason, I thought they were aquatic... a daft child I was).

Thanks again!

[anarqueso.livejournal.com]

Hi, I've been wanting to introduce myself! vinnie_tesla suggested I check out your LJ. I'm always interested in the mating habits of bugs, and other aspects of biology also catch my attention. However, I'm lazy and unscientific, so I gravitate toward people who actually know what they're talking about.

My personal talents tend more toward cheesemongering, massaging, and funniness.

[urbpan.livejournal.com]

I observed your cheesemongering elsewhere, and I approve. I hope you enjoy what you see around here!

[deathling.livejournal.com]

It's a humpfest!

[badnoodles.livejournal.com]

Anecdotally, cats and dogs will also play with and occasionally eat these little bastards.

[zipotle.livejournal.com]

I have fond memories of these beetles. They're pretty.

Actually I think I remember my grandmother paying me to pick them off her roses.I got a quarter for oh, I don't remember how many.

[stephanietberry.livejournal.com]

I pick them off my garden plants--they seem to love my plum tree especially--then I squish their heads and feed them to my chickens. (If I don't squish them some of them fly off before the chickens can get them). Call me the Exterminator.

[(Anonymous)]

they seem to not want to fly around sunset. Feed them to chickens then and they wont fly away

[squeakdance.livejournal.com]

*Randomly pokes nose in*

[mongrel.livejournal.com]

HAPPY BIRTHDAY!!!!!!!!

[rottnpagan.livejournal.com]

HAPPY BIRTHDAY!

[shockoflove.livejournal.com]

Those are frightening beetles xD

[evilkyttn.livejournal.com]

Ack!! So that's what I've been finding on my roses. Thank you for sharing... :-)

[matthewdh.livejournal.com]

Got bit by one of these buggers, hurt like hell, left a blister. Yet another piece of urban nature I haven't seen since moving out of Roxbury.