Aug. 22, 2002 – Is the East End of St. Thomas under beetle attack? Will it spread to include the entire island? Will we lose all our trees and century plants? Can we get anyone in the know to work on coming up with answers to these questions?
Months ago, one of my turpentine trees began looking ill, covered with blisters. Since my wife is professor emeritus at the University of the Virgin Islands, she contacted the UVI Cooperative Extension Service and requested a reading of the tree. The experts came and had a look. Their conclusion was: death by termites.
I am not an entomologist. I'm not even a very active "tree hugger." I do, however, enjoy my trees and do not want them destroyed by anything for any reason. I also believe termites eat dead wood, not live, and I am adamant that they do not leave tunnels I can poke my fingers into.
In time, the sickly looking tree with bumps became a very dead tree with hundreds of holes looking worse than Swiss cheese. To date, I have had four trees killed by something. One day, I found an ugly "termite" with long feelers that seemed to be a new kid on the block and to have sprung from another tree where the blisters were bursting, revealing more tunnels.
After taking a digital picture of the sucker, I put it on the Web with a little help from Island Resources Foundation principals Bruce Potter and Ed Towle, asking for identification. Within a couple of days, I had one opinion that my beetle was not a possibility for the tree troubles, and another which stated the beetle had a predilection for turpentine trees.
According to Prof. Michael Ivie: "These trees were killed by a native longhorn beetle called Lagocheirus araeniformis. It hits primarily turpentine trees but will hit others under either high populations or stressed trees. The host list for this beetle is quite long. It periodically kills even large trees by girdling the bark from underneath. Usually the first sign is a sudden collapse of the leafy parts of the tree, and then a sappy, smelly bark, and finally, the trap doors on a dead trunk and large limbs."
The larvae bore into the trunk of the tree, making an oval tunnel about one centimeter across. This is visible on the bare areas of the accompanying photograph. When nearly mature, they come out under the bark and feed in the cambium and create a very characteristic oval pupation gallery under the bark, visible in the photo as the circles of wood shavings.
Before pupating, they chew a groove almost through the bark, around the edges of the chamber from underneath, so that when it dries, it creates a trap-door that opens easily when the adult beetle emerges from the pupa. It lines the gallery with chewed wood strips. Anybody knowledgeable about West Indian entomology can spot this pest just from the pattern, as seen in the photo — on a turpentine tree, no less.
The feeding under the bark in large numbers girdles the tree. A few beetles will not hurt a mature tree, but a massive attack of this type will kill it very quickly.
So far, then, the consensus is: The beetle kills trees and the best thing to do is let nature take its course.
The Asian connection
As luck would have it, the May 27 issue of Time magazine carried an article on the Asian Long Horn Beetle, which looks like an extremely close cousin of my beetle. According to Time, the critter came to the United States from China in wood packing materials; has killed thousands of trees in New York, New Jersey and Michigan; has been spotted in warehouses throughout the United States; and threatens hardwood trees throughout the United States.
Well over a year ago, a resort several hundred yards upwind from my house opened trailer upon trailer of new furniture. If there were adult beetles in the trailers, they have had time to find their way to the area where I live, bore into my tree, go through a metamorphosis, hatch, and eat their way around and out of the tree — killing it.
Once I became aware and wary of beetles, I began wondering about my century plants, which were mysteriously dying from the center out. Close inspection of only slightly sick plants revealed one or more dark brown spots on the core branch of the plant. When I broke one off and began dissecting it with a machete, I found a small black beetle about the size of my little finger. It had burrowed into the center of the trunk, metamorphosed or whatever, then was burrowing out.
Within a week the center of the century plant's trunk had turned sickly yellowish and flopped over. Within a couple of weeks, the plant was all yellow. And within a couple more, the center of the plant had fallen out and what was still standing was dead, dead, dead.
In the more than 30 years I have lived in Estate Nazareth, this is the only time I have seen either of the beetles. It is the first time I have seen a tree with hundreds of tunnels you can put your finger in, and the first time I have witnessed a mass killing of century plants.
I would be interested to hear from anyone else who has seen either a tree filled with tunnels you can put your finger into or century plants dying from the center out.
I'm hoping nature will take its course and some reptile or other will feed on the beetles. Otherwise, we may need to take immediate action of some kind before our island is denuded. If enough of us are experiencing a problem, I am sure we can obtain assistance from federal agriculture specialists in Puerto Rico.
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