North American Fruit Explorers mailing list at ibiblio

[Don Yellman <don.yellman@webformation.com>]

1.  At the risk of stinkbug overload after previous coverage of this 
topic, there is one more feature of these insects that I think is worth 
mentioning.  Unlike any other insect I have seen, the stinkbug is 
capable of penetrating the plastic sandwich bags that many of us use for 
protecting apples.

2.  Apparently, the brown marmorated stinkbug has a feeding tube that is 
long and sharp enough to puncture plastic and continue on into the flesh 
of apples.  The result is to alter and discolor the cells of the apple 
down to a depth of one-half inch or more below the skin.  Damage is 
usually so extensive, that ripe apples are rendered practically useless 
for anything but cider.  Certainly they would not be marketable, 
although the home grower can cut off much of the apple and still wind up 
with something to eat.  The condition under the skin resembles what I 
have always (perhaps mistakenly) called corky spot.  I have always 
believed this was caused by calcium deficiency, but it may have been 
stinkbugs all along.

3.  Because the 2010 season was the first that I have noticed such an 
infestation of these insects (though they may have been present in 
smaller numbers before), and even though I knew they were present on the 
trees, I never saw one in an apple bag and was confident the bags would 
protect the apples just as they do from other insects.  The stinkbug 
seems to be  a warm-weather insect, and didn't really get going until 
August into September here.  Earlier apple varieties like Yellow 
Transparent escaped damage completely, but the midseason and later 
apples were devastated.  No problems were observed on peaches, plums or 
apricots, most of which are down before mid-August.  The best and most 
beautiful of the apples, such as Goldrush, Fuji, Pink Lady, Ashmead's, 
Albemarle  Pippin, Blushing Golden, etc. were practically ruined.  
Meanwhile, the stinkbugs were also attacking crops like tomatoes and 
peppers, leaving telltale areas of white cells beneath the skin.  It 
seems that as soon as sugar begins to show up in a fruit or vegetable, 
and the weather is warm, the stinkbug is waiting.

4.  I am preparing apple bags for this season now, but I am clearly 
going to have to take additional measures to keep this from happening 
again.  Permethrin seems to knock down the stinkbug pretty well, 
although it seems hard to kill with other insecticides.  I am prepared 
to spray the trees with bagged apples, but this strategy will work only 
if an insecticide has a residual effect on the stinkbug.  I seem to 
recall that Alan had observed little residual effect in his efforts to 
control this insect.  If he is right, as he frequently is, I really 
don't what I would do next.  Until USDA or someone comes up with a 
solution to this infestation, I will be experimenting and looking for an 
insecticide that would give me some extended protection without having 
to spray 2-3 times a week.

5.  We have watched stinkbugs emerge around the house, greenhouse, and 
even garage all winter long on sunny days, so they are certainly not 
gone.  I don't understand their life cycle or reproductive habits well 
enough to know the signs of trouble for next season.  Certainly, this 
stinkbug is different, and far more numerous and aggressive than others 
of this species that I have seen before.

6.  As a hobby grower, this is not an issue that affects my livelihood, 
but I surely sympathize with the commercial growers that still survive 
in the MD/VA area and along the east coast.  Not to mention Alan Haigh, 
whose business is fruit tree care.

Don Yellman, Great Falls, VA