Gross! What are these creatures on my Mugo pine?

[Lulu]

Now I know why my mugo pines "dropped" all their needles last summer! One morning I came outside and found them stripped bare. I thought it was the drought last year, as that was about the time it happened. Today I noticed less needles than yesterday, and a closer inspection revealed these greedy creatures (see attached photos). They're really creeping me out.

A quick description: about 1 inch long, grey with black stripe down the side, black head, not fuzzy. There seems to be about 1 caterpillar per needle! Gross!

Should I spray them with something? Will it matter? By the time I get down to the garden centre and back, they will probably have moved on to dessert! Somebody please help me!

[mr.shep]

Hi Lulu:

I am not in tune with bugs or plants, for that matter, in your
area but your invasive critter looks like it is a European pine
sawfly - Neodiprion sertifer (Geoffroy).

Hopefully someone will verify. Below are three URL's
that might be of some help if I have this insect pegged
right.

http://www.pfc.forestry.ca/entomolog...an_pine_e.html

http://ohioline.osu.edu/hyg-fact/2000/2555.html

http://www.urbanext.uiuc.edu/bugrevi...inesawfly.html

Good luck finding a control you can use for your area.

Jim

[Lulu]

Thanks for the info! According to those websites, mechanical removal of the larvae is the best method of control. I spent some time last evening picking the larvae off the branches and throwing them into a bucket of soapy water. This seemed to work very well, and wasn't too difficult. Gross & fascinating, but not difficult. When I knocked against a branch, the larvae would all snap into a "straight" position, probably to camouflage themselves against the needles. When a few dozen of them do this in unison, it makes a cool, wet snapping sound. "Eeeeeewwww!" was the word of the day.

Now the mugo pine looks like a bottle brush. Anyone have an opinion as to whether it will come back, or will it always look spindly?

Thanks for all your help,
Lulu in Langley, BC

[hungry hippo]

Hi Lulu,
That really is a horrible looking infestation you have there. I have had major trouble with sawfly caterpillars and tent caterpillars this year too. If there is a good side, it's that they are relatively easy to kill once you have them spotted. I have found that Dr. Bronners Peppermint soap (you can find it at most health stores) and Tabasco sauce (about a teaspoon of each per pint of water) in a spray bottle knocks them down and kills them. It is also fairly safe and animal friendly. Encouraging robins to nest in your yard is another great way to keep caterpillars down. Hope your mugo comes back.... at least it is early in the season.

We saw a group of these critters last night and called all the neighborhood kids over to watch their "group backbending" exercises. We all though it was cool. However, cool only goes so far, and I am off to mix soap and tabasco sauce to stop them before they decimate my pine!

Alice
Buffalo, NY

[blue]

Lulu,

I have just discovered my two mugo pine shrubbery bushes are
covered with them and they are eating the needles away as they
did with yours.

Were you successful in getting rid of them? If so, what did you
use? Have they gone to any other shrubs?

[Lulu]

Originally Posted by blue

Were you successful in getting rid of them? If so, what did you use? Have they gone to any other shrubs?

Hey blue,

Yes, I got rid of them easily by putting on rubber gloves and knocking or brushing them into a pail of soapy water, or you could try hungry hippo's trick of soap & tabasco if you don't want to touch them. Good luck!

Cheers,
Lulu in BC

[mr.shep]

Hi Lulu:

Let me first say that I am proud of you for handpicking
those “drasted” things off your tree. Most people's first
response here in the US would automatically be to want
to spray them with an insecticide.

I was taken aback some, yet not surprised that a BT spray
is not all that effective on these. Other than using a home
remedy like hungry hippo's, you did what you had to do.
I've used ground Cayenne pepper with a light dormant oil
before on Ornamental and Rose Aphids and that has worked
very well for me. An insecticidal soap can be used instead
of the light oil. I like the whole idea of using a Peppermint
soap, that made my day!

I cannot say for certain if the needles will re-grow from
their bundles. I've seen it where due to pest damage that
they have grown back in and in some Pines they will not.
Mughos are tough plants for Pines so in my mind there is
a good chance that the needles will grow back in. I would
not be hopeful if the variety was a 'Sherwood Dwarf' or
even 'Mops' though. We will just have to see. Let us know
if you can what happens.

Best regards,

Jim

[alanhunt]

I also had a ton of these nasty critters on my mugo pines and austrian pines this spring. Some insecticidal soap cleared them up for the worst infestations, and hand removal worked fine for the trees where there were only a few. They did manage to eat an awful lot of needles before I found them, though. I guess the bushes will look funny this year :-(

I have read the discussions on the sawfly larva along with the inovative methods of getting rid of them however, we have a number of acres of trees many of them upto 60 feet high. Last year we had noticeable damage done and we have them back again this year.

Any suggestions on how to deal with these large trees, as BT does not appear to be a solution?

[mr.shep]

Hi Henry:

My best suggestion is to contact your Department of Forestry,
Cooperative Extension if there is one in your state or your State
Department of Agriculture should you reside in the US.

While I garnered the URLs I listed above I read that a good part
of the problem that areas are having with this insect is largely due
in part to not enough chemical sprays being used possibly on other
insects that can ward off this insect, to keep it from coming in and
establishing itself. Even when we turn to using no chemical usage
whatsoever there is a price to pay and that price is that an insect
that would normally stay away from our trees may at some point
in time become a major infestation that may require some sort of
chemical control to knock it down. I am not going to state which
is right and which is oversight as each area has to do what they feel
is best for them and later learn to live with their decisions.

I do not know where you are located and what trees this insect is
currently feeding on but there are some Over The Counter controls
as listed below that may be of help to you and then again they may
only knock down a small percentage of these sawfly larvae. Personally,
if the problem were mine with a serious infestation I would use a low
grade OTC organophosphate to help such as Orthene or Diazinon. I
cannot recommend using Sevin in a forest situation at any time due to
the hazards mainly to birds. None of these chemicals should be used
near a possible water source for humans or for animals either. Spraying
60' tall trees will require some aerial support such as a crop duster or a
helicopter. A boom type spray rig is not going to work all that well for
you. In either case you will have to be overly conscious of chemical
drift.

It may be better just to spray around the perimeter of where the trees are,
let the insect have its fun for a while this year but next year your chemical
barrier will act as a suppressant or a deterrent for next years attack. I
would go a spray used around the perimeter and then do it again about a
month earlier next year prior to the insects usual time of attack. I use
Creosote in my water seal just for that same purpose, not to kill termites
but to keep them long and far enough away from me that they will not
ever present a problem. The same is true for the wood scorpion not ever
showing up inside my cabin as long as I use the Creosote mixed in with
my water sealant for the wood deck and decking. It keeps ants away from
the perimeter of the cabin also.

http://woodypestguide.cas.psu.edu/Control/Pine.html

Good luck.

Jim

[warrwiz]

I see this is an older post but maybe someone is still looking. I think I have the same type of thing here in Massachusetts, USA. The one's here are yellow with black dots all over them. I'm going to try the suggestion earlier in this thread. Thanks.

My drawf mugo pine has needles that are turning black! This is the second or third year I've seen this. I also notice I get hundreds of wasps feeding on my pine (gathering sap?) or flying around it. Could they be causing the needles to tun black? Help!

[Ron B]

Look for sucking pests, the black is probably sooty mold fungus growing in their sugary excretions. I have seen white scale insects on the needles of mugo pines down here.

[chrism07924]

Wow, there they are. I've been trying to ID the critters that similarly devastated my pine bushes, and here I find them. Unfortunately, by the time I caught them, they had completed worked there way through one entire bush and had started on another, with me leaving for a week long business trip the day after. Now, they're all magically gone and so are my bushes. Disgusting little guys these things were.