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Q: Safe to use old used oil to fight Wooly apple aphid? ( Answered 4 out of 5 stars,   0 Comments )
Subject: Safe to use old used oil to fight Wooly apple aphid?
Category: Family and Home > Gardening
Asked by: marinusdenbreejen-ga
List Price: $2.00
Posted: 22 Jul 2005 03:22 PDT
Expires: 21 Aug 2005 03:22 PDT
Question ID: 546528
is it safe and effective to appy old oil used to fight Woolly apple aphid? 

(Eriosoma lanigerum, see for a
description, and
for a photo)
Subject: Re: Safe to use old used oil to fight Wooly apple aphid?
Answered By: hummer-ga on 22 Jul 2005 06:40 PDT
Rated:4 out of 5 stars
Hi marinusdenbreejen,

I've looked at a wooly aphid using a loupe and believe it or not, they
are almost cute and cuddly!

Assuming you mean used motor oil, the answer is no, it would not be
safe to spray with used oil because it contains many contaminants
(heavy metals, metal shavings...) which are harmful to the
environment. A "dormant oil spray" would be a better choice but
parasitic wasps are considered to be the most effective control.

Used Oil Recycling Program
What Are the Hazards of Used Oil?
"Used oil can contain such contaminants as lead, magnesium, copper,
zinc, chromium, arsenic, chlorides, cadmium, and chlorinated
compounds. Oil poured down drains or onto the ground can work its way
into our ground and surface waters and cause serious pollution. One
gallon of used oil can foul a million gallons of drinking water.
Federal reports indicate that used motor oil accounts for more than 40
percent of the total oil pollution of our nation's harbors and

Why Recycle Used Oil?
"The mismanagement of used oil can contaminate air, water, and soil.
According to the Environmental Protection Agency (EPA), used oil from
a single oil change can pollute a million gallons of fresh water.
Contamination from used oil occurs primarily from improper storage in
containers and tanks, disposal in unlined landfills, burning of used
oil mixed with hazardous waste, improper storage practices at used oil
handling sites, and road oiling for dust suppression (EPA, 1991).
"The EPA estimates that less than half the oil from do-it-yourself oil
changes is collected ? the remainder is put in the garbage, poured on
the ground, down sewers, etc. Many components of oil are toxic to
living systems. Oil poured on the ground can find its way into our
water systems. Improperly disposed oil could contaminate drinking
water and poison or damage other living things. Even small amounts of
oil in water can be detected by odor and taste (1 part per million,
ppm), cause a visible slick (35 ppm), or disrupt bacterial action (50
ppm to 100 ppm) (Rose, 1989)."

EPA Managing Used Oil: Advice for Small Businesses

"The WAA is frequently parasitized by Aphelinus mali, a tiny wasp that
is also native to North America. Parasitized aphids appear as black
mummies in the colony. A. mali has been successfully introduced to
many apple-growing areas of the world, and is providing adequate
control of the WAA in several areas. It does not provide sufficient
control in commercial orchards in the northeastern United States
because of its sensitivity to many commonly used insecticides;
however, the wasp is thought to reduce WAA populations in abandoned
Because the woolly apple aphids are somewhat protected by their waxy
covering, regular spray programs may not provide adequate control.
High volume applications of recommended insecticides may be necessary
to penetrate the wax. Failure to control aerial infestations can
result in underground infestations on susceptible rootstocks. Chemical
control of root infestations is not possible; resistant rootstocks
provide the only defense against underground infestations. The
Malling-Merton (MM) rootstock series was developed to provide
resistance to WAA infestation. The table below lists the
susceptibility of various clonal rootstocks to the WAA."

Natural Control
"Small parasitic wasps attack aphids; they lay their eggs in aphids by
stinging with their ovipositor (egg-laying organ). The wasp egg
hatches within the aphid, and the young wasp larva consumes the aphid.
Parasitized aphids turn brown or black. In time, the wasp larvae
emerge as adults from the aphids, leaving behind empty aphid skins.
These skins, called "aphid mummies," can be found attached to leaves.
Aphelinus mali is a tiny wasp native to North America that frequently
parasitizes woolly apple aphid. This wasp is susceptible to
insecticides; it can reduce woolly apple aphid populations in
abandoned orchards where insecticides are not used, but usually cannot
survive in commercial orchards where insecticides are used,
particularly pyrethroids or carbamates. Other natural enemies of apple
aphids include predators such as hover fly larvae, lacewing larvae,
lady beetle larvae, and lady beetle adults. These predators feed on
many different aphid species in addition to other insect pests. A
cool, wet spring favors aphid development because these conditions are
unfavorable for the aphid's natural enemies.
Cultural Control
Resistant varieties must be used to prevent underground infestations.
The Malling-Merton (MM) rootstock series provide resistance to woolly
apple aphid attack. Some apple varieties such as Northern Spy are
resistant to this pest.
Removal of suckers at the base of trees will create conditions that
discourage development of woolly apple aphid populations in
early-spring. Summer pruning of water sprouts also contributes to
woolly apple aphid suppression.
Pruning cuts and water sprouts should be examined in late-spring and
every few weeks throughout the summer for the presence of new colonies
of woolly apple aphid. Specific action thresholds have not yet been
Chemical Control
An insecticide can be applied if woolly apple aphid is detected at
damaging levels on above-ground parts of trees. Insecticides are most
effective if applied when the aphid is in the active crawler stage and
is just moving up into the tree. This may occur in late-spring or not
until mid-summer. Thorough coverage of the canopy is needed for
insecticide to be effective. Because of the aphids' waxy covering,
high volume application is needed to get thorough spray coverage. A
second application may be needed two weeks after the first if aphids
continue to be detected.
Insecticides used to control woolly apple aphid in commercial orchards
are dimethoate (Cygon), endosulfan (Thiodan), chlorpyriphos (Lorsban),
or methyl parathion (Penncap-M). Home gardeners can use diazinon or
insecticidal soap.
Woolly apple aphid infestations on rootstocks cannot be controlled by

I hope this helps you with your vexing problem. If you have any
questions, please post a clarification request and wait for me to
respond before closing/rating my answer.

Thank you,

Google Search Terms Used: wooly apple aphids wasps dormant oil spray
used oil contaminants

Request for Answer Clarification by marinusdenbreejen-ga on 23 Jul 2005 13:22 PDT
Hi hummer-ga,

Thanks for the answer! Do you know if using used moter oils is also
bad for our health if it is not applied to the fruit, but only to the
places on the tree affected by wooly apple aphid?

Clarification of Answer by hummer-ga on 23 Jul 2005 14:33 PDT
Hi marinusdenbreejen,

If you apply used oil to your tree, it would not stick like a piece of
gum but rather it would ooze down and eventually find its way in the
ground. That is the trouble, there is no way to contain it. The tree
won't "drink up" the oil, but the contaminants will percolate down and
depending on what the oil contains, the tree and apples could be
effected. The little bit of oil you use this year may not seem like
much, but after several years I would imagine your tree would start to
show signs of stress. But it doesn't stop there and the contaminants
will find their way to water (and perhaps your drinking supply). The
best thing to do would be to contact your nearest Cooperative
Extension Service (it's a free service), they will help you control
the aphids. Here's a link to all of the States:

Cooperative Extension Services, By State

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