Pest News for Week of July 21st.

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Retailers to Labels Neonic-treated Plants

Scientific American is reporting (http://www.scientificamerican.com/article/home-depot-looks-to-limit-pesticides-to-help-honeybees/) from Reuters that Home Depot, BJ’s Wholesale, and other smaller retailers will soon require vendors to label plants that have been treated with neonicotinoid insecticides. Neonicotinoids are among the most commonly used insecticides on ornamental crops and all crops. This class of chemicals includes imidacloprid, dinotefuran, thiamethoxam, acetamiprid, clothianidin, and others. Controversy around neonics revolves around their potential to harm bees and other pollinators. Like most insecticides, neonic are acutely toxic to bees on contact. Since neo-nicotinoids move systemically within plant tissue, they can also contaminate flower pollen and nectar that bees consume. Though this can negatively affect individual bees, the effects on bee populations are not yet known (and very hard to measure). Information about this was recently reviewed in two extension publications and a scientific paper (http://rspb.royalsocietypublishing.org/content/281/1786/20140558.abstract). Of course, there is no news that these outlets will stop selling neonicotinoids to consumers. Nursery and greenhouse growers who produce crops for retail outlets should start figuring out alternative insecticides as this trend is likely to spread.

Potato Leafhoppers Cause Crinkled Leaves on Maples

This time of year the results of potato leafhopper feeding show up particularly in nurseries. Potato leafhoppers are a native insect, but mimic retired folks because they spend winters in Florida and the Gulf coast. From there adult potato leafhoppers, Empoasca fabae (Harris) (Hemiptera: Cicadellidae) migrate between late April and early June. Female potato leafhoppers oviposit along leaf veins and clustered at the base of leaves near the petiole. Development from egg to adult takes about three weeks depending on temperature resulting in five to six overlapping generations per year.

Adult E. fabae are 3 to 3.5 mm long, wedge-shaped, and pale green with a row of six, white spots on their backs, between the wings and head. Injury is caused by salivary phytotoxins injected into the plant phloem during feeding. Damaged leaves can have necrotic margins and severe cupping or stunting referred to as “hopperburn”. E. fabae feeding on buds and meristems causes loss of apical dominance and a witch’s “broom” can develop in which many stems grow from the apical tip of nursery trees and may require extra pruning to improve aesthetics and train a central leader.

Host plant resistance can play an important role in managing E. fabae and their damage. In general, red maple cultivars that break bud earliest in spring, including clones selected from northern provenances, will support the lowest numbers of E. fabae and sustain the least feeding injury by the conclusion of the growing season. Higher levels of foliar nutrient content, particularly nitrogen, will also predispose maples to injury due to increased oviposition, nymphal survival and development rate so do not go crazy with early fertilization. Mites, aphids, and other pests also appreciate high nitrogen provided by fertilizer.

Potato leafhopper arrival can be monitored using yellow sticky cards deployed above the canopy of young maple crop or in close proximity to outer canopy foliage. These traps should be deployed in early to mid-April across the mid-southern U.S. to detect early season arrival of migratory E. fabae adults which corresponds to approximately 591 degree-days. Pyrethroids can be applied bi-weekly starting at peak trap catch. However, many applications of pyrethroids may be needed to reduce E. fabae populations and damage. Pyrethroids can also cause outbreaks of other pests like mites by killing predators in the canopy. Alternatively, recent research indicates that systemic neonicotinoid insecticides applied as a drench can provide effective leafhopper control for two years. Systemic insecticide drenches need to be applied before leafhopper arrival and can help protect natural enemies within the nursery. Even though neonics can in some cases induce mite outbreaks I think it is still a less intensive approach in terms of both labor, active ingredient, and effects on non-target organisms.

Potato leafhopper. Photo: Steve L. Brown, University of Georgia, Bugwood.org.

From: Matt Bertone, Extension Entomologist

Hoppers, Hoppers Everywhere!

I continue to get reports of numerous hopper-like insects around North Carolina. These insects, planthoppers, froghoppers and leafhoppers (Auchenorrhyncha (http://bugguide.net/node/view/12745): Fulgoromorpha and Cicadomorpha), have been extremely abundant this year and can be found on many species of ornamental and food plants. The most common ones this year generally suck on the xylem, which is water-rich but low in nutrients. Thus, these insects produce a lot of honeydew (sugary water drops out of their anus) which can contribute to the growth of sooty mold (http://en.wikipedia.org/wiki/Sooty_mold). Otherwise, these insects generally do little harm to plants, although leafhoppers (especially sharpshooters in the subfamily Cicadellinae) can transmit the bacterial scorch/Pierce’s disease pathogen, Xylella fastidiosa (http://en.wikipedia.org/wiki/Xylella_fastidiosa). The following are some photos showing the most common types:

- Planthoppers (Fulgoroidea) -

Flatidae (http://bugguide.net/node/view/104)

Nymphal Metcalfa pruinosa, the citrus flatid (Flatidae), on a stem. Flatid planthoppers secrete a waxy field around them and rest in the middle, the barrier sometimes encompassing a great area but always housing one nymph in the center. Here the nymph was encouraged to move.

An adult Metcalfa pruinosa is grayish-blue with an orange eyes and black spots. In high numbers they can be a pest, but do not often attain such numbers.

This pale green flatid planthopper, Flatormenis proxima, is also common and its young are very similar to the one above.

Acanaloniidae

Nymphs of acanaloniid planthoppers (Acanalonia) are hump-backed and usually have a tuft of wax fibers coming from their tail end. They often hop when threatened, but otherwise walk along stems of plants.

Adult acanaloniid planthoppers are leaf-like and similar to flatids, but have wings that are completely reticulate, unlike flatids whose wings are bordered by rectangular cells (see above).

- Spittlebugs and froghoppers (Cercopoidea) -

Cercopidae s.l.  (http://bugguide.net/node/view/885448)

Nymphs of spittlebugs and froghoppers reside in a frothy mass of bubbles they create from gut secretions. Here they try to hide from predators while they suck on plant juices. This one is on a juniper.

Adult spittlebugs and froghoppers are usually shiny and readily hop when disturbed. Here is an adult clastopterid spittlebug. The two-lined spittlebug (http://bugguide.net/node/view/517) (Prosapia bicincta) is very common in North Carolina, where its young feed on grasses.

- Leafhoppers (Cicadellidae) -

Two sharpshooter nymphs (Proconiini, probably Oncometopia orbona) feeding on a new shoot of holly (Ilex). A drop of honeydew can be seen coming from the anus of the one on the right. Sharpshooters get their name from their constant ejecting of this liquid in long jets.

An adult broad-headed sharpshooter (Oncometopia orbona). These and their close relatives are among out largest leafhoppers.

The glassy-winged sharpshooter (Homalodisca vitripennis) is a famous pest, often implicated in trans-mission of Xylella fastidiosa. The white patches on the wings of this adult female are made up of microscopic waxy rods called brochosomes. They are kicked onto the eggs to apparently protect them from predators and parasites.

Cuerna costalis is another pretty sharpshooter commonly found here in North Carolina on many plants.

Unlike the previous large (~1 cm) sharpshooters, many are small and brightly colored such as this common Graphocephala versuta (~5 mm long).

And now you should be able to identify all the nymphs in this photo (on one shoot of holly)!

From: Mike Munster, Plant Disease and Insect Clinic, and Steve Frank, Extension Entomologist

Tomato Spotted Wilt Virus in Chrysanthemum

A greenhouse-grown chrysanthemum was received in the Plant Disease and Insect Clinic on July 10, 2014, and diagnosed with Tomato spotted wilt virus (TSWV) by Emma Lookabaugh. Symptoms consisted of dark leaf spots, lateral curling of the leaves at some of the spots, and at least one stem lesion. This is a common disease, but has not been diagnosed on chrysanthemum in North Carolina recently.

TSWV symptoms on Chrysanthemum.

Tomato spotted wilt occurs on hundreds of field and crops, including peanut, tobacco, tomato, pepper, and potato, as well as on a wide range of ornamentals. In the last 6 1/2 years, we have diagnosed it on the following ornamentals from commercial sources: African marigold, angel-wing begonia, calla lily, Cyclamen, Gaillardia, Gerbera, Senecio confusus, Lisianthus, Lobelia, Madagascar periwinkle, Sedum, and Stoke's aster. Its sister virus, INSV, is a frequent problem on many ornamentals.

A different sort of TSWV symptom on mum, from a different sample.

Both TSWV and INSV can cause a wide range of symptoms, including mottling, ringspots, stunting, and necrotic leaf and stem lesions. Both are members of the genus Tospovirus and are transmitted by minute insects called thrips*. One curious fact about this transmission is that the virus is acquired by the insect during its larval development, but then the insect itself becomes permanently infected. Of course the virus can be brought into a greenhouse with infected plants, and could be perpetuated through vegetative propagation.

Mottling and ringspot symptoms on TSWV-infected Senecio (left) and Stokesia (right).

These strategies against TSWV (and INSV) are recommended for greenhouse flower production:

* Avoid growing vegetable transplants and flowers in the same greenhouse, and avoid growing plants of different ages together.

* Screen greenhouse vents and air intakes (http://www.ces.ncsu.edu/depts/ent/notes/O&T/production/note104.html) to exclude thrips from entering the greenhouse.

*  Control weeds in and around the greenhouse. Many weeds are susceptible to tospoviruses and can serve as reservoirs of virus and thrips.

* Monitor greenhouses for thrips activity using blue or yellow sticky cards, with the top 2/3 of the card placed above the plant tops. Use two cards per 5000 sq. ft. of greenhouse area.

* Use insecticides to manage thrips populations when necessary. Remove flowers from plants before treatment since the interior of flowers rarely get adequate coverage. It is important to note that some thrips populations have developed insensitivity to commonly used insecticides. In addition, no insecticide can completely eliminate thrips. Utilize the most effective chemistries wisely by rotating insecticides by mode of action (IRAC class) with each application, or at least with every generation of thrips. Always follow label directions and check that products are labeled for the intended crop. Details on insecticides for thrips management can be found in the North Carolina State University Information Note on western flower thrips (http://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/ort072e/ort072e.htm) and the University of Florida's thrips management information (http://mrec.ifas.ufl.edu/lso/DOCUMENTS/ThripsManagementProgram-February%202011-FINAL.pdf).

If you suspect you have infected plants, we recommend having the diagnosis confirmed by a laboratory. Large growers with recurring problems may want to keep a supply of the simple lateral-flow ELISA tests on hand. Suppliers** include AC Diagnostics (http://www.acdiainc.com/) and Agdia (http://www.agdia.com/). There is no cure, so all infected plants must be removed and destroyed. The potting mix of these plants should also be discarded, as this is where the thrips vectors pupate. Eliminate old stock plants as these are often sources of thrips and viruses.

More information about TSWV in the following crops is also available:

* peanut (http://www.peanut.ncsu.edu/Diseases/Spotted_Wilt.aspx)

* tobacco (http://www.cals.ncsu.edu/plantpath/extension/fact_sheets/Tobacco_-_Tomato_Spotted_Wilt_Virus.htm)

* tomato (http://ncsupdicblog.blogspot.com/2011/06/attack-of-killer-tomato-spotted-wilt.html)

  *  Grammatical footnote: The word thrips is both singular and plural.

** Mention of trade names and companies does not imply endorsement by North Carolina State University or the Plant Disease and Insect Clinic.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest News for week of June 9th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Gloomy Scale Crawlers are Active

Gloomy scale, Melanaspis tenebricosa, is an armored scale that is found on maples and other tree species. It becomes very abundant on landscape maples and can cause branch dieback and tree death in some cases. It is not unusual to find trees with nearly 100% of their trunk covered in scale. Street trees are particularly prone to gloomy scale. I have never found one that didn’t have it! Crawlers of this scale are active now and can be seen on bark and under scale covers. Control of this scale is complicated be-cause crawlers emerge over 6 to 8 weeks so it is impossible to treat all the crawlers at once with horticultural oil or other contact insecticide. This is as opposed to scale such as euonymus scale in which all crawlers are produced within a narrow window of two weeks or so. However, horticultural oil can still be applied to kill gloomy scale. We have tested several products against gloomy scale with mixed results. None provides consistent high levels of control. Products including Safari, TriStar, and Distance can provide some suppression. It is important to note that imidacloprid (e.g., Merit) is not effective on armored scale. More information on armored scale control can be found here (http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note157/note157.html). Our home page (http://ecoipm.com/) has more information on our gloomy scale research program and a recent blog post. To see an overview of gloomy scale on urban trees watch our short video (https://www.youtube.com/watch?v=1Fg-ZPkJwRA&feature=youtu.be).

Gloomy scale on a maple branch. Photo: Steve Frank.

Crapemyrtle Aphids

Crapemyrtle aphids are one of the most common pests of crape myrtle, but rarely require treatment. Small populations are present in Raleigh and have been building over the past couple weeks. Feedings by these aphids result in leaf yellowing and distortion, leaf drop, and honeydew deposits which of course lead to sooty mold. Crapemyrtle aphids are generally kept in check by natural enemies. When scouting for them I often find almost as many lacewing eggs, lady bug larvae, and other predators as aphids. Interestingly, there are no known parasitoids of this exotic aphid. A variety of chemicals are available should these aphids reach unacceptable levels in nurseries or landscapes. Some of the same chemicals recommended for aphids such as imidacloprid can be applied as a drench to protect against Japanese beetles later in the year. For more information on this pest including control options, visit http://ecoipm.com/ and Ornamentals and Turf Insect Note ENT/ort-31 at http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note31/note31.html.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest Alert for Week of May 19th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Keep Alert for a New Crape Myrtle Pest

One of the newest pests to plague urban trees is the crape myrtle bark scale, Eriococcus lagerstroemia. It is not yet in North Carolina, but it is probably coming soon. The first detection of crape myrtle bark scale in the U.S. was just outside Dallas, Texas, in 2004. Since then, it has spread throughout much of Texas. It has also spread to Arkansas, Louisiana, Oklahoma and Tennessee. Last week it was also found in Georgia.  

Crape myrtle bark scale is similar to azalea bark scale and oak eriococcid scale that is common on willow oaks in Raleigh. Female scales produce fluffy white filaments that cover their bodies. In spring, they produce eggs beneath their body then die. Tiny crawlers hatch from the eggs and spread around the plant. Scale crawlers can also be spread by the wind. The crawlers settle in their new spot and begin producing white filaments as they grow. They have at least 2 overlapping generations in Arkansas and probably more in warmer areas.

At low density, crape myrtle bark scale feeds in rough areas around branch collars, but as the population increases, all the bark may be covered. These scales are most often noticed because trees become covered in black sooty mold. At first, many people assume this is from crape myrtle aphids so the scales may go undetected. If you notice unusually heavy honeydew and sooty mold on crape myrtles, take a closer look at the bark.

Since this is such a new pest in the U.S., we do not have a good idea how to manage it. Drench applications of neonicotinoids have provided some control in Texas. However, since crape myrtles flower continually and attract a slew of pollinators, this may not be the best option. Insect growth regulators such as pyriproxyfen and buprofezin are effective for many other scales and may be a good option. Horticultural oil, especially the heavier dormant rate, can reduce scale abundance also. 

White crape myrtle bark scales on a crape myrtle trunk blackened with sooty mold. Photo: S. D. Frank.

Lecanium Scale Crawlers!

Oak and European fruit lecanium scale are one of the largest soft scales in our area. Scale ovisacs are brown and rounded reaching 6 mm in diameter. This is the most noticeable stage and is present right now. As members of the soft scale family Coccidae, lecanium scales produce honeydew that can cause sooty mold on oaks or plants below. Oak lecanium scale primarily infests oaks trees. However, European fruit lecanium can infest many tree species including oaks. They are impossible to tell apart without a microscope and even then it is hard. Large populations can reduce growth and vitality especially in newly planted trees.

Eggs are present now under adult scale covers and crawlers are beginning to hatch. The crawler stage should be targeted for best efficacy. On trees small enough to treat foliage, horticultural oil can be used. On larger trees, a systemic such as dinotefuran can be applied as a drench or trunk injection. This scale is not easily eradicated and optimal control measures are still unclear. It is attacked by many parasitoids and predators that can reduce scale abundance if protected from insecticides. A short video (https://www.youtube.com/watch?v=tD6I7P6BdKU) by graduate student Emily Meineke describes the scale biology. She is conducting research (http://ecoipm.com/research/urban-ecology/) to understand why lecanium scale outbreaks on urban trees.

Lecanium scale ovisac on willow oak. Photo: S. D. Frank.

From: Adam G. Dale, Graduate Student and Steve Frank, Department of Entomology

Bagworms Active in Raleigh

Bagworms have been hatching for the last week or so. You can find the tiny caterpillars with tiny upright bags anywhere there are bags left from last year. The bagworm, Thyridopteryx ephemeraeformis, is a very common ornamental pest throughout the eastern United States. These pests overwinter as eggs within the mother’s bag. Larvae emerge from the bag during the months of May and June. Once they have emerged, they crawl or drift via a silk strand to nearby foliage where they begin to establish feed. Bagworms are relatively sedentary during their lifetime, most often remaining on the same tree until they pupate. Adult females are wingless and never leave the tree, while male bagworms pupate and develop into a small brown moth. 

Bagworms feed on plant foliage and can cause a significant amount of damage in a relatively short period of time. Some common trees that they infest include: maple, sycamore, oak, poplar and apple while they mostly prefer conifers. The early instar caterpillars produce a silk bag on their posterior end that gradually collects plant tissue debris from them feeding. This creates a leafy bag that camouflages them as plant tissue. Since they don’t move much during their lifetime, they are commonly found in dense populations within the same tree. These dense populations have the potential to kill conifers within one to two seasons due to defoliation and are found more often on ornamental trees rather than in forests. Since they are so discrete and easily mistaken for plant tissue, pest management for these insects can be difficult and/or time consuming. One of the most effective, yet time consuming methods of treatment, are handpicking or cutting the female pupae bags from of the branches. Since this may sometimes be impractical or impossible, there are other methods of treatment to be considered. There are chemical control options available that should be applied during the early instar stages of the caterpillars, typically during June and early July. As with many other pest insects, bagworms are susceptible to predation from parasitoids and birds which can also assist in their control. Now that there has been evidence of these early instar bagworms, it may be time to take action against them.

Bagworms. Photo: Adam G. Dale.

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Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by North Carolina State University, North Carolina A&T State University or North Carolina Cooperative Extension nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact an agent of North Carolina Cooperative Extension.

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Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

Lecanium_ecoipm.m4v

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest News Update July 8, 2011

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Dogwood Twig Borer Oviposition

The last couple of weeks I have noticed flagging branch tips on the red twig dogwoods (Cornus sericea 'Baileyi') in front of my house. The damage was characterized by a cleanly girdled branch with a 1 cm oviposition scar just below. Gradually the tip goes from yellow to brown then falls off. Investigation and help from our excellent diagnostician revealed a large egg within each scar containing a round-headed borer larva. This was the dogwood twig borer. Adults have been active lately laying eggs in twigs. The larvae will overwinter within twigs then continue boring down the twig pith in spring killing the affected branch. This is not likely to be a big nursery pest but should be on the radar. It is much better to identify the flagging branches now and prune out the eggs than wait until spring when a whole branch or small tree will be affected.

If you follow me on Twitter, you know this already! Follow @OrnaPests on Twitter for timely updates on ornamental pest activity.


Western Flower Thrips in Greenhouses

Thrips are a constant problem for growers, not just a problem this week. Western flower thrips, Frankliniella occidentalis, is the most important and damaging thrips of greenhouses and has been called the most damaging greenhouse pest in the world. This is true of greenhouse-grown food and ornamental crops. Nearly all floriculture crops are susceptible to thrips damage.

Western flower thrips reproduce rapidly and are difficult to manage because they live in the cracks and crevices of flower heads and foliage. Thus, they are difficult to contact with insecticides. Western flower thrips also develop insecticide resistance rapidly so it is important to emphasize chemical rotation and to have a resistance management plan.

Sanitation is also very important in managing thrips. Because thrips can feed and reproduce on hundreds of plant species weeds in and around a greenhouse, they have a constant supply even if the crop is sprayed. Western flower thrips pupate in soil, so cleaning up spilled potting soil and other debris can deny them a vital part of their lifecycle.

More information and chemical recommendations can be found in Ornamentals and Turf Insect Information Note at Note 72.


For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest News for June 14th

The weekly edition of NC Pest News has been posted.

In addition this week we have gotten word that the insecticide Endosulfan (active ingredient in Thionex) has been terminated: "EPA has concluded that endosulfan poses unacceptable risks to agricultural workers and wildlife, and can persist in the environment. New data generated in response to the agency’s 2002 decision have shown that risks faced by workers are greater than previously known. EPA also finds that there are risks above the agency’s level of concern to aquatic and terrestrial wildlife, as well as to birds and mammals that consume aquatic prey which have ingested endosulfan. Farmworkers can be exposed to endosulfan through inhalation and contact with the skin."


For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

New Products for Ornamental Greenhouse, Nursery, and Landscape Pests

New Products for Ornamental Greenhouse, Nursery, and Landscape Pests

From: Steve Frank, Extension Entomologist, NCSU

A new product Kontos is available to manage most sucking pests in greenhouses. It is also labeled for use in nurseries. Kontos from OHP is effective against whiteflies, aphids, mealybugs, thrips, and other insects. Kontos has a unique mode of action (IRAC group 23) that makes it an important tool in resistance management programs. This could be particularly important as a product to rotate with Conserve (spinosad) to kill thrips. It is also soft on beneficial organisms. More information on Kontos can be found at:Kontos.

In ornamental landscapes we now have Acelepryn by Dupont. This unique chemical has a very low vertebrate toxicity. So low in fact that it does not require a signal word on the label. It is effective on many landscape pests and can be used as a foliar spray or drench to provide translaminar and systemic plant protection. Acelepryn also is soft on beneficial organisms compared to older products. More information about Acelepryn can be found at Acelepryn.




For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Western Flower Thrips

Western Flower Thrips in Greenhouses- from Dr. Stephen Franks, NCSU Dept of Entomology

Thrips are a constant problem for growers. Not just this particular week, but all the time. Western flower thrips, Frankliniella occidentalis, is the most important and damaging thrips of greenhouses and has been called the most damaging greenhouse pest in the world. This is true of greenhouse-grown food and ornamental crops. Nearly all floriculture crops are susceptible to thrips damage. Western flower thrips reproduce rapidly and are difficult to manage because they live in the cracks and crevices of flower heads and foliage. Thus they are difficult to contact with insecticides. Western flower thrips also develop insecticide resistance rapidly so it is important to emphasize chemical rotation and to have a resistance management plan. Sanitation is also very important in managing thrips. Because they can feed and reproduce on hundreds of plant species, weeds in and around a greenhouse will provide a constant supply of thrips even if the crop is sprayed. Western flower thrips pupate in soil, so clean up spilled potting soil and other debris to deny them this vital part of their lifecycle. More information and chemical recommendations can be found in the newly-revised Ornamentals and Turf Insect Note No. 72 at Western Flower Thrips

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Granulate Ambrosia Beetle Alert

This message from Dr.Steven Frank. Please note that Granulate Ambrosia Beetles have been found here in Henderson County. Be on the look-out for these insects and let us know if you suspect that you have them. Please note the preventative measures recommended in the article below!

This is the second alert from the Granulate Ambrosia Beetle Monitoring and
Alert program.

Granulate ambrosia beetles were captured in Henderson Co. which is in the
Western part of the state zone 7a-6b. Ambrosia beetle damage was seen in
Johnston Co. also. These at least one detection has been made at each end
of the state. That in combination with current warm weather suggests
growers should begin protecting susceptible trees with preventative
applications of a pyrethroid insecticide.

Recommendations: A landscape borer spray containing a pyrethroid such as
permethrin or bifenthrin can be used and may have to be reapplied every
two to three weeks while beetles are active. A surfactant or sticker may
help the insecticide adhere to bark and provide longer protection.

Astro, Permethrin Pro (permethrins), and Onyx (bifenthrin) are registered
for use on tree trunks in the landscape.

For nursery sites Perm-Up (permethrin) is labeled for field grown nursery
stock. OnyxPro (bifenthrin) is labeled for application to tree trunks in
landscape and nursery sites.

Generic equivalents to the above products are also acceptable.

More details on Granulate Ambrosia Beetle can be found at
Granulate Ambrosia Beetle

If you have other questions DO NOT reply to this email. Contact me at
sdfrank@ncsu.edu

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest News

This information comes in weekly from the NCSU Plant Disease and Insect Clinic from mid April until October. The following is an alert from Steve Bambara:

European Red Mites


We haven't seen this mite often in the landscape the last few years, but it has shown up twice in the Plant Disease and Insect Clinic at North Carolina State University over the last two weeks. European red mites usually overwinter in the egg stage. The tiny orange-red colored eggs hatch at about the time when apple trees bloom. The European red mite is an introduced pest that in North Carolina primarily infests apple trees. Although it is reported to infest various shade trees and ornamental plants in the landscape, cherry laurels seem to be the major ornamental plants that European red mites infest. The European red mite causes typical pale stipples on the leaves of their host plants, but this spider mite spins very little webbing. This mite is slightly different from the southern red mite. With your hand lens you should be able to see that the hairs on the back of the mites each arise from a small, white bump whereas the hairs of southern red mites arise from red bumps. I believe any horticultural oil spray should give adequate control. Oils will not significantly harm beneficial predator mite populations are often preferable for this reason. For professionals, most of the favorite miticides will also work.


For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Slug-like Sawfly Larvae

Caliroa is a genus of sawfly slug caterpillars that usually feed as a skeletonizer on the lower surface of the leaf. The pear slug belongs to this group. There was a regional outbreak of these slug caterpillars on oak last year. The females have a saw-like ovipositor with which they pierce leaves to lay their eggs inside. Sawfly slug caterpillars are slimy and usually smallish caterpillars (about 0.5 inch in length). When there are large numbers, sawfly slug caterpillars may cause large portions of their host trees to “brown out.” Sawfly slug caterpillars overwinter in the soil in a small cavity that is lined with the secretions of the larva. The larvae pupate the following year and the new adults emerge to mate and lay eggs. The adult of this caterpillar is an insect that more closely resembles a fly than a wasp. If there are enough of these insects present to cause alarm, Sevin insecticide should give more than adequate control. If it is a small shrub, you could wipe them off.
From Dr. Stephen Bambara.

For more information call your local Cooperative Extension Agent.

Springtails

Springtails (collembola) are among the smallest insects in the home landscape. They are flea-like and barely visible. Springtails possess a forked structure folded under the body that when flicked, allows it to catapult around quite well. Springtails may differ in size, shape and color. They are slightly smaller than a flea and do not bite. Springtails prefer moist environments and feed on decaying plant material, fungi, etc. and are most often seen in mulch. Sometimes they may annoy people if they occur by the millions in a yard and show up on the foundation, the driveway or in the swimming pool. If they are very prolific, they may be found indoors on floors. If found in houseplant pots, change the bark mulch and reduce the watering frequency.
Control is not very effective. If desired, they can be hosed off of hard outdoor surfaces with or without a little soap added. Infestations are short lived and rarely justify the expense of control. Determined homeowners may use one of the available lawn products containing a pyrethroid insecticide such as permethrin, bifenthrin or cypermethrin. Ornamental and Turf Insect Note No. 123 contains more information on springtails.


For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Another Boring Insect?- Iris Borers

Iris borer damage begins in the foliage and may be evident now. Most of the time, the damage is to rhizomes discovered when people dig them to transplant during the summer. The moths emerge in late summer to mate and lay eggs on the oldest, roughest, dead and bleached iris leaves or on plants nearby. The eggs hatch the following spring. The tiny caterpillars first feed on the new foliage and sometimes cause the margins of the leaves to be ragged. The holes caused by the young caterpillars bleed causing deposits of sap on the leaves. The caterpillars then mine in the leaves for a time before working downward toward the rhizomes. The caterpillars are about half grown by the time they reach the rhizome. There they feed on the edge or on the underside of the rhizome, sometimes boring inside. Often a single caterpillar may completely the insides of a rhizome before moving to another. The mature caterpillars are pale yellow/pink to pink in color with brown heads.

To control the iris borer, it is important to remove all old iris leaves and other plant rubbish from the beds in early spring before new growth emerges. If the borers are discovered later in thehttp://www.blogger.com/img/gl.link.gif spring, it may be possible to crush the caterpillars with the thumb and finger inside the leaf. By holding the injured leaf so that the sun shines on the far side, the silhouette of the small caterpillar should be easily visible through the leaf. John Weidhaas at Virginia Tech University has determined that Sevin and malathion give good control of the iris borer when these pesticides are applied early while the caterpillars are feeding on the outside of the leaves. (It may be late for this, now.) For more information and treatment suggestions, see Ornamental and Turf Insect Note No. 46 at Iris Borer

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Pest to Monitor: Flower Thrips-

The eastern flower thrips, Frankliniella tritici, feeds mainly on flowers and fortunately is not known to vector any virus. Because of their tiny size, flower thrips are carried over large areas by wind systems. Flower thrips are found throughout North Carolina with peak migration early to mid June. They have been found on dozens of hosts. Control of flower thrips is difficult because of constant migration from weeds, grass, flowers and trees. They are also known to make a mild, but noticeable "nip" to the skin.

The first step in management is to eliminate as many weeds in the area as possible, or keep them mowed so they do not flower. To protect flowers, homeowners might use products such as neem or Mavrik. Pyrethrin insecticides might be used before blossoms open to protect pollinators. The commercial industry should rotate chemicals to reduce concern of resistance. They might use products such as Conserve, Pedestal, Azatin (or Ornazin) and BotaniGard. Monitoring for thrips with yellow sticky cards can also help detect populations as they are increasing, allowing controls to be started before substantial plant damage. Note from Dr. Stephen Bambara

For more information on flower thrips, see Ornamental and Turf Insect Note No. 21 at Thrips


For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Early Bagworm Treatment

If you had problems with bagworms last season, now is the time to inspect for the tiny bags and treat, if necessary. They should be large enough to see by now without having done damage. Practice your observational skills. Early treatment avoids defoliation and is more effective against early instar caterpillars. This is especially true if you use Bacillus thuringiensis (B.t.) products. If you only have a few bagworms, handpicking them always works well. For more information on bagworms, see Ornamental and Turf Insect Note No. 81 on the web at http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/ort081e/ort081e.htm.



For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.