Pest News for Week of June 24th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Japanese Beetles Adults

I have a couple reports from around North Carolina and even reports that they are emerging in Maryland. So I guess they are trickling out, but populations seem to have gotten lower and lower in the past several years. For three years in a row we have had severe droughts during the time Japanese beetles are ovipositing. They need moist soil so their eggs do not dehydrate and so tiny young larvae can borrow into the soil. Droughts have restricted successful reproduction to only well irrigated areas. 

So keep an eye out and remember a few key things. Japanese beetle traps do not offer any protection to landscape plants and may actually attract more beetles on to your property so hang them in your neighbor’s yard. Likewise, treating a lawn for Japanese beetles grubs will not reduce defoliation of plants on that property since beetles fly in from great distances. Long-term protection for landscape and nursery plants can be achieved a neonicotinoid insecticide such as imidacloprid (e.g., Merit, Marathon II) or acetamiprid (Tri-Star). A new product with extremely low vertebrate toxicity, but good efficacy for a number of pests including Japanese beetles is Acelepryn (chlorantraniliprole). For more information on the biology and management of adult Japanese beetles in nurseries and landscapes consult the insect note http://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/note147/note147.html.

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

Japanese Beetles are Active Now!

Japanese Beetles Active

In scouting a streambank area this morning, I noticed that many of the wildflowers were covered with Japanese Beetles and some nearly defoliated.   While I would not say that we are having an early peak in the population of these pest, it is clear that they are very active and pest management efforts should be in place immediately for the adult control.
Turfgrass Managers on Sod Farms, Athletic Fields, Golf Courses, and Lawns should be on the alert and plan to apply a grub control  by the first of July.  These adult insects are currently laying eggs and those eggs will be hatching in 10-14 days.  The wet weather and lush grass will be create ideal conditions for the young grubs.  For more information on this pest please read the following publications:

Japanese Beetle Information

http://ipm.ncsu.edu/agchem/agchem.html



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

Pest News for Week of June 17th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Fungus Gnat Larvae

This week we had reports of fungus gnats forming long lines on sidewalks and driveways. This happens after a lot of rain or heavy irrigation. In the landscape larvae feed on plant roots and live in areas with a lot of thatch or organic matter. You can read more and see a picture of the larvae-snake in an insect note athttp://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/note29/note29.html.

Tea Scale Crawlers are Active

Tea scale, Fiorinia theae, is common on camellias. It is an armored scale that lives on the underside of leaves. You can find it on almost any camellia by looking for inner leaves that have yellow spots on top. When you turn it over you will see tan canoe-shaped scale covers and some white fluff from the males. These are tough to treat because the heaviest infestations are often deep within the foliage of large bushes. To find an insect note with more information and recommendations:http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note50/note50.html

Cottony Cushion Scale Activity

Cottony cushion scale, Icerya purchasi, is active much of the year. This week I found young crawlers that were being aggressively tended by fire ants on cherry laurel. The scale is most easily recognized by its oblong cottony ovisac that can reach 1 cm or longer. The rest of its lifecycle is less conspicuous though it is still one of the larger scales. Like other cottony scales, such as cottony maple scale and cottony camellia scale, cottony cushion scale is a soft scale. In the coming weeks the scale will be most easily managed as crawlers are active and exposed. Horticultural oil can be used to smother crawlers on small plants. A systemic drench can be used to treat larger plants and provide longer protection. The host list for this species is long and varied including: maple, boxwood, pecan, cedar, citrus, apple, Prunus spp., rose, and others. This week I found ovisacs on Euonymus, Nandina, and Fatsia. More information and chemical recommendations can be found in the cottony cushion scale insect note athttp://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note51/note51.html.

Spider Mite Damage

Although the cool season is over, damage from cool season mites is beginning to appear. I found this cherry laurel with extensive mite stippling. On the leaves there were no active mites, just lots of eggs. This is the last stand of southern red mite for the summer. They spend the hot months as eggs then come out again in fall. They feed in spring but often the damage does not become apparent until the plants face some stress in hot weather. So be sure to monitor these plants in fall. Horticultural oil may help smother the eggs, but be careful in hot weather.

In North Carolina, the most important cool season mites are the spruce spider mite (Oligonychus ununguis) and southern red mite (Oligonychus ilicis). These are among the earliest and most damaging pests in nurseries and landscapes. As their name implies, cool season mites are active in spring and fall when they suck fluid from cells on plant leaves and needles. In hot summer months these mites are dormant. However, it is summer when their damage becomes apparent as chlorophyll bearing cells die. Thus, by the time plants exhibit aesthetic damage the mites are gone and treatment is wasted.

I found all stages of southern red mites on cherry laurel, but they feed on many broadleaf evergreens such as azalea, camellia, holly, and rhododendron. With eggs juveniles and adults all present these mite populations are well underway and deserve attention from nursery and landscape personnel.

Scout plants that had mites or mite damage the previous year are likely to have them again because the mites have overwintered as eggs. You can identify plants that had mite last year by looking for fine stippling damage on the old leaves. Turn them over and look with a hand lens for silk webbing, shed skins, and mites. On broadleaf evergreens, look on the underside of leaves for the southern red mite. The most efficient method of scouting for cool season mites (and other mites) is to hold a piece of white paper or a paper plate below a branch and strike it with a pencil or stick to dislodge arthropods. Spider mites will appear as tiny moving specks about the size of the period at the end of this sentence.  

For more information and control options consult the North Carolina State University insect note at  http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/ort077e/ort077e.htm.

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

Pesticide Training - Red Imported Fire Ant Identification & Control

Pesticide Training - Red Imported Fire Ant Identification & Control

Fire Ants are on the move and coming into our nurseries, farms and landscape sites. Become better informed on controlling these pest at this workshop- coming up in July:

Fire Ant Program

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

Pest News for Week of June 10th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Hibiscus Sawfly Damage

In Georgia last week I found severe damage by hibiscus sawfly. Larvae and adults were present on the plants I surveyed. The adults are active throughout the summer. The larvae feed on hibiscus and related plants. The larvae skeletonize leaves when they are young, but quickly defoliate plants as they grow. Contact insecticides such as bifenthrin and Orthene will kill larvae. Other insecticides such as spinosad, acetamiprid, azadirachtin and others listed can be used (http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note07/note07.html). The larvae are not caterpillars so be sure to look for sawflies specifically on the label of the product you select. More information on this critter may be found at

http://www.ct.gov/caes/lib/caes/documents/publications/fact_sheets/entomology/hibiscussawfly.pdf.

New Pest: Daylily Leafminer Active Now

The daylily leafminer is a recent pest from Asia. It was first detected in 2006, but is now spread through much of the Southeast including North Carolina. I spotted some last week on a trip to Georgia. This fly lays its eggs in day lilies and the larvae produce relatively straight, vertical mines. Pruning infested leaves will help prevent the larvae from maturing and infesting new leaves. I do not know of any formal efficacy tests on this pest but other material targeting leafminers such as imidacloprid and pyriproxifen should help. A recent article about this pest is in American Nurseryman

(http://www.amerinursery.com/article-7705.aspx).

Cicadas in Nurseries and Landscapes

For folks in western parts of the state you may have periodical cicadas in your nursery or landscape. Of course this will depend on a number of things including the habitat surrounding your nursery. Areas with a lot of suburban development may have fewer than less disturbed areas.

Cicadas cause damage to trees when they lay eggs in branches. They use a knife-like ovipositor (egg inserter) to insert eggs into thin tree branches. This causes slits in the branch that could be 6 inches long or more. This long scar reduces plant aesthetic value, but also weakens branches. Scarred branches usually break and fall to the ground or break and remain hanging in the tree, but turn brown.

We have found that imidacloprid reduces oviposition in landscape trees (http://ecoipm.files.wordpress.com/2012/02/ahernfrankraupp2005jeconent.pdf). Females detect the insecticide with their ovipositor so treated trees have fewer scars and the scars are much shorter. Thus branches do not become as weak so there is less flagging. This is not to say you should treat every tree with imidacloprid. Most landscape trees over a few feet tall can withstand losing many branches with no negative effects on health. Even nursery stock could survive losing branches, but may need corrective pruning. Nursery stock can be pruned to remove scarred branches. 

Trees that are very valuable could be protected with mesh netting to keep cicadas off (http://ecoipm.files.wordpress.com/2013/06/cicada-tree-netting.pdf). This may apply to specimen trees in landscapes or to particularly expensive nursery trees. Japanese maples may be one species where shape is very important and it would be worth protection of some sort.

Cicada Management for Homeowners

With cicadas emerging, big box stores are overflowing with insecticides promising to kill periodical cicadas. This may be true. If you take a particular insecticide off the shelf and pour it on a cicada it will kill it. But these products will not ‘control’ cicadas. There are millions upon billions of them. 

There is no such thing as an insecticide that only kills cicadas. They also kill butterflies, bees, and other non-target organisms. It is important that homeowners consider the risks of these insecticides (some) compared to the benefit (none). Cicadas do not last long and pose no risk to people. Insecticides do.

The other problem with trying to manage cicadas with insecticides is that they are generally ineffective. Especially products available to homeowners provide so little benefit that the monetary cost and risk is just not worth it. If you managed to spray a whole tree with Orthene or Sevin for instance cicadas would likely colonize it again within hours or days.

Cicadas cause damage to trees when they lay eggs in twigs. They use a knife-like ovipositor (egg inserter) to insert eggs into thin twigs. This causes slits in the branch that could be 6 inches long or more. This long scar reduces plant aesthetic value, but also weakens branches. Scarred branches usually break and fall to the ground or break and remain hanging in the tree but turn brown.

Trees that are very small or that you just planted this year are at risk if they get many cicada oviposition scars. Cicadas prefer skinny branches (< 0.5 inch) so if your tree trunk is this skinny it could get damaged and this could kill your tree. Other trees will shed a few twigs and go on about their lives. You can protect trees with mesh netting to prevent cicadas from damaging them.

If you are unhappy about having cicadas on your porch or sidewalk just sweep them off. If you apply insecticide to these trapped critters (they don’t want to be on your porch) you will end up with a dead smelly pile of cicadas that you have to sweep up anyway. In addition, as you walk across the porch and sidewalk you will get insecticide on your shoes that will be carried into your house where kids and pets play on the floor. When you take your shoes off you get insecticide on your hands. Next thing you know you are eating a sandwich.

Insecticides have a place. That is to reduce economic or aesthetic damage to plants that we eat or enjoy.  Insecticide applied for cicadas won’t achieve this. So save your money and wait it out or try to enjoy it.

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

Marketing Abroad

Considering Marketing abroad to folk in other countries?  Then you might find this program useful:

http://www.susta.org/services/outreach_events_Asheville13.html

The event is on July 16th here in Asheville NC.

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

Pest News for Week of June 3rd

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Hawthorn and Azalea Lacebugs

Azalea and hawthorn lacebugs started hatching last week. Now we see a mix of adults and nymphs. Hawthorn lacebugs feed on pyracantha, serviceberry, and cotoneaster. Azalea lacebugs feed primarily on azaleas. Both cause stippling damage visible on the top of leaves and leave fecal spots on the bottom of leaves. For more information on lacebug management, see Ornamental and Turf Insect Information ENT/ort-39 at http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/ort039e/ort039e.htm. Imidacloprid will kill both pests, but should not be used on plants that are flowering or that will flower soon due to negative effects on pollinators.   

(http://www.xerces.org/wp-content/uploads/2012/03/Are-Neonicotinoids-Killing-Bees_Xerces-Society1.pdf).

Woolly Apple Aphids

This week we noticed woolly apple aphid infestations on pyracantha bushes around campus. These aphids produce cottony fluff along the branches. When you brush away the fluff (really it is wax the aphids produce) you will see hundreds of pink or grey aphids crawling around. Woolly apple aphids have been out for a month or so, but are becoming very noticeable now. Infestations for multiple years produce large leafless patches on bushes. The aphids cause galls to form on branches and branches become black from sooty mold. Soap or oil should provide some control. Additional aphid management information: http://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/note38/note38.html

Flea Beetles

Redheaded flea beetles, Systena frontalis, have become a serious pest of nursery stock over the past several years. They are an especially damaging pest because they feed on roots and leaves. They overwinter as eggs in the soil. Larvae hatch in spring and begin feeding on roots. The larvae are elongate and creamy-white. Heavy infestations may reduce root mass or girdle plants. Adult redheaded flea beetles are small, shiny black, beetles with reddish to dark colored head and long antennae. They are about 1/16 of an inch long and, as the name suggests, jump when they are approached. There are at least two generations in Delaware and may be more in North Carolina.

We found adults and adult feeding damage this week. The favored hosts are Itea, hydrangea, forsythia, and knockout roses. Adult management has been frustrating for growers who find that even frequent insecticide applications do not reduce adult abundance and damage to acceptable levels. Part of this has to do with not controlling larvae since even if you kill all the adults present in a crop (which you won’t) more adults are emerging from the soil every day. Research thus far in Delaware and grower reports indicate that Talstar, Sarfari, and Flagship provide good efficacy as foliar applications, but do not have long residual activity.

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.

For more information contact the commercial horticulture agent at your local Cooperative Extension Center.