Posted by Dan on August 10, 2010, 12:33 am
Hi all,
Need some help with an issue with clethra alnifolia (aka sweet
pepperbush, aka summersweet). I keep the plants extremely
well-watered (they are next to a rain barrel) and they are in full
sun...thought I had found the perfect spot for them until this
happened.
Small 1/4" long black caterpillar wiping out the leaves of two new
shrubs I purchased 6 weeks ago. The caterpillars looks very similar
to the virburnum leaf beetle larvae that have decimated the highbush
cranberries around here (this is zone 5 microclimate in northwest NJ).
However, they are black instead of the whitish color of the VLB larva.
The c. alnifolia plants were fresh and vibrant when I got them from
Edge of the Woods Nursery in Allentown, PA. The caterpillars have
wiped out the new bright-green growth to the stems (similar to
virburnum leaf beetle damage) and are now attacking the older
dark-green growth. Fresh growth is sprouting, but the caterpillars
are quickly attacking and destroying it.
All I can find on google is, "this is a pest-free shrub". When I look
up "clethra alnifolia caterpillar" or "clethra alnifolia host plant"
all the sites say, "great nectar plant" but nothing about being a
host plant for caterpillars. So I really need help with a
caterpillar/pest that doesn't seem to exist!
Thanks very much,
Dan
Posted by Amos Nomore on August 10, 2010, 1:45 am
> Hi all,
>
> Need some help with an issue with clethra alnifolia (aka sweet
> pepperbush, aka summersweet). I keep the plants extremely
> well-watered (they are next to a rain barrel) and they are in full
> sun...thought I had found the perfect spot for them until this
> happened.
>
> Small 1/4" long black caterpillar wiping out the leaves of two new
> shrubs I purchased 6 weeks ago. The caterpillars looks very similar
> to the virburnum leaf beetle larvae that have decimated the highbush
> cranberries around here (this is zone 5 microclimate in northwest NJ).
> However, they are black instead of the whitish color of the VLB larva.
>
I wonder if they might be alder leaf beetle (Agelastica alni) larvae
http://tinyurl.com/28knbn3
Posted by Amos Nomore on August 10, 2010, 2:21 am
In article
>
> > Hi all,
> >
> > Need some help with an issue with clethra alnifolia (aka sweet
> > pepperbush, aka summersweet). I keep the plants extremely
> > well-watered (they are next to a rain barrel) and they are in full
> > sun...thought I had found the perfect spot for them until this
> > happened.
> >
> > Small 1/4" long black caterpillar wiping out the leaves of two new
> > shrubs I purchased 6 weeks ago. The caterpillars looks very similar
> > to the virburnum leaf beetle larvae that have decimated the highbush
> > cranberries around here (this is zone 5 microclimate in northwest NJ).
> > However, they are black instead of the whitish color of the VLB larva.
> >
> I wonder if they might be alder leaf beetle (Agelastica alni) larvae
>
> http://tinyurl.com/28knbn3
Hmm, wrong photo, similar species. Try this
http://tinyurl.com/33fw89k
Posted by Pat Kiewicz on August 10, 2010, 6:59 am
Dan said:
>Small 1/4" long black caterpillar wiping out the leaves of two new
>shrubs I purchased 6 weeks ago. The caterpillars looks very similar
>to the virburnum leaf beetle larvae that have decimated the highbush
>cranberries around here (this is zone 5 microclimate in northwest NJ).
>However, they are black instead of the whitish color of the VLB larva.
>The c. alnifolia plants were fresh and vibrant when I got them from
>Edge of the Woods Nursery in Allentown, PA. The caterpillars have
>wiped out the new bright-green growth to the stems (similar to
>virburnum leaf beetle damage) and are now attacking the older
>dark-green growth. Fresh growth is sprouting, but the caterpillars
>are quickly attacking and destroying it.
Could be sawfly larvae. Sawflies, scale and spidermites are the only
pests I recall being mentioned for Clethra.
A gallary of sawfly larvae photos:
http://www.pbase.com/tmurray74/sawfly_larvae
--
Pat in Plymouth MI
"Vegetables are like bombs packed tight with all kinds of important
nutrients..." --Largo Potter, Valkyria Chronicles
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>
> Need some help with an issue with clethra alnifolia (aka sweet
> pepperbush, aka summersweet). I keep the plants extremely
> well-watered (they are next to a rain barrel) and they are in full
> sun...thought I had found the perfect spot for them until this
> happened.
>
> Small 1/4" long black caterpillar wiping out the leaves of two new
> shrubs I purchased 6 weeks ago. The caterpillars looks very similar
> to the virburnum leaf beetle larvae that have decimated the highbush
> cranberries around here (this is zone 5 microclimate in northwest NJ).
> However, they are black instead of the whitish color of the VLB larva.
>