Dig carefully next to a few and look at the rooting area, maybe there is a problem with the soil conditions that has come on as the planting has aged. Also study the remaining foliage closely, in case they are being sapped by mites or scales.

A picture would be worth a hundred words in this case. Another possibility could be the results of sawfly larvae damage. These critter devour last years needles first, then older and new growth and a heavy infestation can leave a plant similar to that described by carldusky. This usually occurs in early to mid May in these parts. The critters disguise themselves very well to look like the pine needles and are easy to go unnoticed until one realizes the plant is starting to look different - then it's too late as they have done their damage. Google "pine sawfly larvae" and you can learn more, plus select the IMAGE search and you'll see some rather graphic images of them and their damage.

The sawfly that suck on the mugo are one of the grossest things on this planet. I walked up to the front door one day and a hundred little black snakelike things rear up at attention in unison. It made the mugo look like Medusa in a horror film.
I since steer clear of mugo which is sad, because they have been excellent otherwise.

I agree with you Jolly Roger, they are about as disgusting as a creature can get. The first time I saw them all act in unison, I looked on in horror and amazement. What's the best way to get rid of them? I don't have them in my garden, but if I did, I'd sure want to get rid of them quickly.

Lainey

Put on an old pair of gloves, and pull your hands along each branch. That'll squish'em just nicely.

Another option - put a brightly coloured bird feeder close to the infested branches. Then birds 'waiting in the queue' for the feeder will find them and eat the lot.

Resin

Since my original posting I determined that it was not an insect problem.I took it upon myself to fertilize the mughos periodically with Miracle Grow azalea,camilea,rhododendron plant food and they are making a comeback.I also started an Ortho garden disease control semi-monthly application in late July and plan on continuing thru September upon a recomendation from the Ortho people to prevent a recurrance next spring.

Help again !!! I just noticed that my mugo's are taking a beating again but this time I can see that they are being attacked by small worm like critters about an inch long with round black heads. They do blend right in with the needles so I suspect they are what others in the forum had told me before as "sawfly larvae". My hope is that someone can tell me what I should be doing to get rid of them "pronto like". Thanks in advance.

As above  put on an old pair of gloves, and pull your hands along each branch. That'll squish'em just nicely.

Resin

...or try Bt. It's a systemic poison affecting only caterpillars. In two or three days they'll be gone. Its safe enough you could still use Resin's bird feeder idea as well.

tj

"small worm like critters"- I get them on our Scotch Pine every year. Damn they are nasty! I used to squish em' but I can't reach them them all this time, the tree has just grown too big. I used a generic Ortho type spray. They are quite destructive! It worked too.

LOL @ Jolly Roger - you described it so well!

I had a very healthy 3yo mugo that just kicked the bucket this spring. No insect issues but I think our wet winter followed by freak subzero cold did it in. I imagine that the drainage wasn't as adequate as I thought it was. Poor little fella. :(

I'm quite sure I was wrong last September in thinking that I had solved the mystery of my mugo pines deteriation by fertilizing and using a disease control spray.What I learned this year was that I was looking in the wrong place for any insects.I was looking at the branches that had already been devoured by the sawfly larvae. This year, thanks to the forum help I got,I found them little suckers on the good, healthy needles devouring away. I went to Google as recommended and was able to find an insecticide at Wal-Mart called Bug Killer Concentrate Sevin by Eliminator (a Gro Tec company) and sprayed the pines,both those that had already been devoured (3 of 9),2 that were partially hit and the remaining 4 that were in good shape.I know now that you have to pay attention (inspect) the pines a lot sooner than late May when a lot of the damage is already done. I suggest start looking in early April so you can take corrective action sooner.
I'm not totally sure if spraying with the insecticide is the only corrective action to take but it is the only one that I know of that works because when I inspected the pines after a few days there was no sign of the critters on the pines but there sure were a lot of dead ones lying on the ground adjacent to the trees.
If anyone knows of another spray to use beforehand, like a powder,before the sawflies emerge, I would be forever grateful.

I just wanted to thank you for taking the time to pass along all this great information!

Sawfly larva are easily killed by making a solution of 16 oz of 70% rubbing alcohol, 16 oz of tap water and 1 tablespoon of Ivory or Dove dish soap and putting this mixture in a trigger spray bottle and spraying the beasts. This is a contact poison and you need to spray the larva to kill them. I use this mixture on my pines when they get sawfly larva and it works great.

Don't use Dawn or any other detergent as the "soap". Ivory or Dove dish washing liquids will kill without hurting your plants (you're just making an insecticidal soap with a punch [the alcohol]).
tl³

I also had this happen last year. They ate all but a few branches. I tried to clean up all the little droppings of needles and all the mulch around the base of the plant as I read that the larva breed there for the following year. I'm hoping it worked and I'll try the above spray this spring if there are any.

Last year I got an infestation of worms - not sure what type - but not black. They did a lot of damage in a short period of time. I sprayed with a vinegar/backing soda mix (not sure of the mixture - but common mix recommended for garden). Killed them in minutes.

They're baaaaack. I've been watching out for those little saw-fly larvae critters since mid-April and haven't seen any until today -- Mothers Day, May 11. There are not a lot of them yet and they are quite small also, only around a 1/4 inch long. So I did spray all 7 mugho pines that I have,(I removed 2 last fall that got too scraggly looking) and will be on the lookout to see if and when I'll need to spray again. I'm using the same insecticide I used last June (Bug Killer Concentrate Sevin by Eliminator). I feel that by being alert earlier in the spring than I was last year should prevent the damage I had then.

I have lost 1 Mungo Pine and I now see black worms in the remaining pines. How may i get rid of these worms and save my Mungo Pine bushes?

seriously ardath????

that question was answered at least a dozen time in ALL THE POSTS ABOVE ... did you read them????

ken