The Douglas-fir beetle is the most important bark beetle enemy of Douglas-fir throughout its range. This insect normally breeds in slash, stumps, windfall and diseased trees, but at times during hot dry summers and warm winters the beetle populations can rapidly increase to high densities and can attack and kill healthy trees.
Use BeetleBlock™ MCH for:
-Douglas-fir trees
-Spruce trees
To Protect Against:
-Douglas-fir beetle - Dendroctonus pseudotsugae
-Spruce beetle - Dendroctonus rufipennis
BeetleBlock™ MCH is the anti-aggregation (repellant) pheromone used by the Douglas-fir beetle. The BeetleBlock™ MCH signals other Douglas-fir beetles that they need to find another area to occupy because these trees are all full. The beetles will move through a treated area and continue to fly until they find a suitable tree or die in the process.
Life Cycle of Douglas Fir Beetle
Douglas-fir beetles typically take one year to complete their life cycle. Over wintering takes place beneath the bark of the tree in which they developed and occurs mainly as adults. Adults emerge from their host tree and infest susceptible trees typically during late April to mid-June when ambient air temperature exceeds approximately 18ºC or 64ºF. A small percentage may over winter as larvae. Beetles that have survived the winter as larvae complete their development in spring and early summer. Those emerge and attack host trees in midsummer. In addition, a few adults who made initial attacks in the spring may re-emerge to make a second attack in mid- to late summer. This "second flight" usually accounts for less than ten percent of the yearly total of attacked trees. Often, these later attacks fill in trees which were attacked during the initial spring flight.
Attacks are initiated by female beetles when they bore through the bark and release an aggregate pheromone to attract more female and male beetles. Once the female has attracted a male and mated, she constructs a vertical egg gallery beneath the tree's bark, paralleling the grain of the wood. Eggs hatch within a week or so and larvae begin feeding at right angles to the egg gallery, first within the inner bark (phloem). As they mature, toward mid-to-late August, they feed more deeply into the bark and grow to 6 mm long. There they construct pupal chambers, pupate, and complete their development by late summer or early autumn. Newly matured adults remain beneath the bark until the following spring when they emerge to make new attacks and renew the yearly cycle.
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How do I use BeetleBlock™ MCH on my trees?
BeetleBlock™ MCH comes in small bubble roughly the size of a silver dollar. The MCH diffuses through the plastic membrane and is released into the surrounding area. The release rate is effected by air temperature; the warmer the air, the higher the release rate. The wind speed and direction determines where the pheromone plume will go. It is also important to note that our BeetleBlock™ products are volatile chemicals and insects can only ‘sense’ these chemicals from a down wind position. Use the wind factor to your advantage, if possible.
MCH is most effective when it is applied before the Douglas-fir beetles begin to fly and attack trees in the spring. This is usually in late April or early May in the Pacific Northwest and the northern Rocky Mountains. However, it is still effective in reducing further attacks even if used later in the season.
Simply staple BeetleBlock™ to the north side of the tree, as high as you can reach. See Deployment for further information.
Useful tip: If you plan on using MCH from one year to the next, clip a corner so you can tell which ones are from last year
CLICK TO VIEW THE EPA LABEL FOR BEETLEBLOCK™ MCH
Healthy trees in BC, Canada
The culprit:
Douglas-fir beetle
The solution:
BeetleBlock™MCH
Synergy Semiochemicals Corp 604-454-1122 synergy@semiochemical.com
Written by Dick Halsey and Phil Mocettini, USDA Forest Service, the ‘Hundle Hammer’ can make application of BeetleBlock™ easier if you have a lot of devices to put up high. Click here to see how you can make one
