Japanese Beetles

[Frederick W. Schueler]

Everyone,

I've attached a photo of the first group of more than 2 Japanese Beetles
that we've seen in Bishops Mills.

I grew up in Connecticut where, in the 1950s, this species was the most
deplored alien species, but it was 1994 before we saw one in Ontario (in
Toronto), 2004 before we saw one in eastern Ontario (Cunningham Island,
on the Champlain Bridge), and it was 2021 before we saw any here. Now we
have 6 copulating pairs and 7 singles on a sprouting Plum bush, but none
on the other plum-sprout on the other side of the path (these Plum
bushes were cut back to remove black knot fungus).

We've also heard that there are a lot of Japanese Beetles around this
year, and wonder what others have seen?

fred.
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---------Frederick W. Schueler & Aleta Karstad ------------
Fragile Inheritance Natural History - https://fragileinheritance.ca/
6 St-Lawrence Street Bishops Mills, RR#2 Oxford Station, Ontario K0G 1T0
on the Smiths Falls Limestone Plain 44.87156° N 75.70095° W
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[e.g. g]

Today I saw my first sightings of the season in north Rideau Lakes Twp. A single Japanese beetle on the stairs in front of entry to RONA Smiths Falls, not particularly near any flowering plants.

Later this afternoon I found ~6 beetles, two of which were mating on the last blooms of my flowering rugosa rose in my own yard = South Burgess ward. ( I drowned them in soapy water.)
Elizabeth Gammell

> On Jul 14, 2025, at 7:13 PM, Frederick W. Schueler <bck...@istar.ca> wrote:
> Everyone,

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> <JapBeetles-14July2025.jpg>

[Candice Vetter]

They appeared in North Russell about 10 days ago and are eating raspberry bushes and some garden plants. At my neighbour's yard which is downhill from us there were dozens in her pool on Saturday. A lot of eew! and eek! while swimming.

---

Candice

 

[P Auritus]

I won't count how many we had in our garden, as, well, we practically need a Geiger counter to count them all.

Needless to say, the numbers we have in Niagara could solve the next food crisis.

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[Frederick W. Schueler]

On 7/14/2025 7:13 PM, Frederick W. Schueler wrote:
> We've heard that there are a lot of Japanese Beetles around this

> year, and wonder what others have seen?

* here's what I sent to the North Grenville Times:

Japanese Beetles

Fred Schueler – Fragile Inheritance Natural History

The Japanese Beetle (Popillia japonica) “is a species of Scarab Beetle.
Due to the presence of natural predators, it is not considered a pest in
its native Japan, but in North America and some regions of Europe, it is
a noted pest to roughly 300 species of plants. The first evidence of its
appearing within the United States was in 1916 in a nursery near
Riverton, New Jersey” (Wikipedia, edited).

I grew up in Connecticut where, in the 1950s, this species was the most
deplored alien species, but it was 1994 before we saw one in Ontario

(near Toronto), 2004 before we saw one in eastern Ontario (Cunningham
Island, on the Champlain Bridge), and the first in North Grenville in
2008. In 2016 we killed 30 of them in the daughter’s yard in Kemptville
and planted Marigolds to protect their Squash, but it was 2021 before we
saw two in Bishops Mills. This July we have found clusters of a couple
of dozen on a sprouting Plum bush, and there are general reports of
increased abundance. Beetle specialist Joyce Cook, a bit further from
settlement 4 km from Bishops Mills, had had only one specimen that she’d
trapped soon after they arrived in eastern Ontario, but she has seen a
few this year.

The larval beetles live on the roots of grasses, doing visible damage to
lawns when they are abundant, and groups of adults skeletonize the
leaves of plants by feeding on them – often with as many mating pairs as
single individuals in the group.

Control of Japanese Beetles begins with shaking adults off the plants
they are feeding on into soapy water. The larvae are susceptible what's
called Milky Spore Disease, caused by the bacterium Paenibacillus
popilliae, which is commercially available for application to lawns.

There are traps which use the beetles' pheromone scent to capture them,
but these are said to also attract beetles to the vicinity of the trap
without capturing them. Soil-dwelling Nemotode worms prey on the larvae,
and these are commercially available – the daughter used these on their
lawn in Kemptville, and has not been bothered by the beetles since.



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