Plant Pests

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Leaf Gall On Maple

Yes, they are galls! They're a result of feeding by Eriophyid mites. These are spider mites that vary from the usual 8-legged mites because they have only 4 legs, or 2 pair. They are very tiny, slow moving, and have a distinctive "carrot" shape (which is also different from the typical spider mite pests. The U of Wisconsin webpage link we've included here states, "The mites feed and mate inside the gall and lay eggs there, and their offspring stay at home until they are ready to disperse as adults. From their natal gall, they move to other leaves to homestead." We've also included a link to Penn States' College of Ag, Entomology program for more info about the damage these mites do and how to manage them, if it becomes necessary; most times it's not, so pesticide treatments are not often recommended. In this persons opinion the galls can be quite beautiful!
http://www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/galls3.cfm
http://ento.psu.edu/extension/factsheets/leaf-galls-maple

By | 2017-09-11T15:49:23-07:00 February 23rd, 2016|Plant Pests|0 Comments
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Spider Mites

This looks like it could be spider mites, and it looks like there may be a bad infestation. We've included a link so you can see what these little sap sucking spider-like organisms look like, but at this stage of damage, you may want to remove the affected leaves and treat with an appropriate pesticidal product as recommended below, or in the web link provided. For future reference, if you catch the problem before it gets too bad, you can control them by spraying with neem oil or pesticidal soap, which can be purchased at most garden centers. Be careful to read the labels and apply any of these types of products properly. Be careful to spray the undersides of the leaves, the stems, and the tops of the leaves. Repeat the application as recommended on the product label to kill any new mites that hatch from eggs afer the first application.
http://www.ipm.ucdavis.edu/QT/spidermitescard.html

By | 2016-02-22T22:12:08-08:00 February 22nd, 2016|Plant Pests|0 Comments
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Avocado Problem

The holes in the leaves could be attributed to a couple of things: insects and / or snails & slugs. Try to hunt for the critters after dark when they come out to feed and hand pick them off and dispose of them. You can use an organic snail bait such as Sluggo to curtail the snail & slug activity. If there is an insect problem of some type, the best thing to do would be to take this photo and a sample of the injury to your local garden center and see if they can suggest appropriate measures.
the other issue that I see is the browning of the leaves. This time of year, leaf tip burn is fairly common, and if it is due to salt burn, make sure there is adequate drainage around the tree. Avocados need excellent drainage (hillside is a good choice) and are very susceptible to root rots as well as salt burn from the alkaline tap water. Here's some helpful info: http://www.ipm.ucdavis.edu/PMG/GARDEN/FRUIT/avocados.html.

By | 2016-02-22T21:43:28-08:00 February 22nd, 2016|Plant Pests|2 Comments
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Leaf Miner

This damage appears to be caused by a leaf miner. A small fly or moth lays its eggs beneath the surface of the leaf and when the eggs hatch, the larvae tunnel thru the leaf tissue, consuming the nutrients in the foliage. Once the damage has been done, nothing will reverse it. Chemical pesticides are not effective against this pest because most products won't penetrate thru the leaf surface although organic products containing Spinosad have often worked to prevent further infestation. If you do use Spinosad, spray in the early evening after the bees have returned to their hives. Once the spray is dry it is safe for beneficials. However, once the damage has been done to the leaf, it is not reversible. Usually the damage done by these insects is not going to kill the plant unless the damage is extensive. Suggest you confirm the problem with a horticulturist at your local garden center and control recommendations.

By | 2016-02-22T17:51:40-08:00 February 22nd, 2016|Plant Pests|0 Comments
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Chewing Insect

The problem may be chewing insects rather than sucking insects. Perhaps some type of beetle or caterpillar? But without seeing the actual pest, we can't say for sure. Look to see if you see any sign of insects- top and bottom of leaves, day and at night with a flashlight. If there are small black dots, these might be excretions for the insects. You can spray with an organic control effective against chewing insects such as Bt (caterpillars). insecticidal soap or Spinosad. Once the leaves and flowers are damaged, they will not recover but try to control future infestation. Bt is a contact insecticide and Spinosad has a 7-10 day residual. Spray Spinosad in the early evening after the bees have returned to their hives. Once the spray has dried on the plant it is safe for beneficials. Suggest you show your photo or perhaps capture a few in a bottle as well as snip off a damaged frond for a local garden center to confirm their identity.

By | 2016-02-22T15:13:26-08:00 February 22nd, 2016|Plant Pests|0 Comments
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Aphids On Leafy Vegetables

These look like aphids. They will typically feed on the newest plant growth. You can identify Aphids (with a magnifying lens) by the two "cornicles" (structures that look like tiny tailpipes) extending from the rear. If you see the cornicles, you will want to control these insects with a pesticidal soap, available at your local garden center or wash off with a strong stream of water. These insects reproduce rapidly (giving live birth, rather than laying eggs), so you can also narrow the possible insect species down if you see that some of them are smaller versions of the larger ones. Sometimes an adult will develop wings and they look a bit different than the rest, but they'll still have the "tailpipes". Also, the white bits are probably the cast-off exoskeletons of aphids, while the green or grayish moving creatures are the aphids themselves.Here is a link that you might find helpful: http://www.ipm.ucdavis.edu/QT/aphidscard.html

By | 2016-02-22T13:39:53-08:00 February 22nd, 2016|Plant Pests|0 Comments
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Psyllid

The raised spots are the work of psyllids, common name plant lice, small insects that depending on the species are host-specific, that is one species of a psyllid will colonize on one particular plant. They become abundant when temperatures warm and host plants develop fresh growth. The psyllid sucks the nutrients out of the foliage, stems, etc. and galls form on the leaves or buds. They also have ecreta, known as honeydew which can lead to the development of black sooty mold. Most experts agree that the psyllid damage is primarily aesthetic, but if population is extensive and the plant is yellowing there are several options: Use yellow sticky traps, spray with Neem or horticultural oil (will need to re-apply until the problem is controlled) or since the plant is an ornamental, a chemical insect control containing imidacloprid. Visit your local garden center for confirmation of the problem and appropriate remedy.

By | 2016-02-21T23:49:52-08:00 February 21st, 2016|Plant Pests|0 Comments
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Aphids On Leafy Vegetables

It is really hard to tell from this photo but these look like they could be aphids. They will typically feed on the newest plant growth. You can identify Aphids (with a magnifying lens) by the two "cornicles" (structures that look like tiny tailpipes) extending from the rear. If you see the cornicles, you will want to control these insects with a pesticidal soap, available at your local garden center or wash off with a strong stream of water. These insects reproduce rapidly (giving live birth, rather than laying eggs), so you can also narrow the possible insect species down if you see that some of them are smaller versions of the larger ones. Sometimes an adult will develop wings and they look a bit different than the rest, but they'll still have the "tailpipes". Also, the white bits are probably the cast-off exoskeletons of aphids, while the green or grayish moving creatures are the aphids themselves.Here is a link that you might find helpful:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html

By | 2016-02-21T12:44:57-08:00 February 21st, 2016|Plant Pests|0 Comments
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Chewing Insect

The problem with chewing insects such as grasshoppers, beetles, caterpillars (too numerous to name) etc. is they move about and often are difficult to spot among the green foliage. Chewing insects can be large enough to see with the naked eye, but they can be green, brown, black, etc. so look closely and pluck off any you see on this plant or its neighbors as long as the infestation is not too extensive. If it is extensive, maybe you can spray with an organic control for chewing insects recommended by your local garden center, such as Bt or Spinosad. Bt is a contact only control and Spinosad has a 7-10 day residual but spray Spinosad in the early evening after the bees have returned to their hives. Once dry it is safe for beneficials. However, the most benign control is pick and squish. Also look for slime trails to see if the damage is due to slugs/snails, but we think it is likely a chewing insect.

By | 2016-02-21T04:54:37-08:00 February 21st, 2016|Plant Pests|0 Comments
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Aphids

These appear to be common sap-sucking insect pests (found on many plants) called Aphids. They are pretty easy to control. The females reproduce live young (minatures of themselves) in multiple numbers, and without being fertilized by a male, so they can reproduce quickly in the right environment. As they suck out the sugary plant sap they also excrete it, which makes the leaves sticky. We recommend you control this population as soon as possible by either spraying off with a high pressure spray of water, picking off the most infested leaves, and when new populations are found clean/wipe them off by hand, and continuing to do so until they stop showing up. You can also use a product like pesticidal soaps or an horticultural oil. Be careful to follow the directions on all product labels. (The oil in particular can cause plant damage if applied incorrectly/under the wrong temp and moisture conditions). We've included a link with more info about Aphids and ways to control them.
http://www.ipm.ucdavis.edu/QT/aphidscard.html

By | 2016-02-21T03:48:22-08:00 February 21st, 2016|Plant Pests|0 Comments
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