Tag: insect pests

What is eating the Cannas?

On By durhammastergardenersIn Gardening information

By Jane Malec, EMGV

While volunteering at the Bahama Farmer’s market, an interesting discussion developed on the plight of the once beautiful stand of cannas near the roadside. The leaves looked curled and ratty…so sad.

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Cannas are one of the plants we depend on during the warm summer months. With its colorful leaves and huge iris like flowers, they’re a bright spot in the garden.  As tropical plant, they will stand up to the heat plus they are not at the top of the deer menu! Also, these rhizomes are generally easy to grow.
Although they are largely free of pests, there are two that you need to look out for.  Canna leaf rollers can be a real problem and is what we uncovered in the large bed at the farmer’s market.  Stalk borers can also cause big headaches.
The leaf rollers, also known as Brazilian skippers, chew straight rows of holes on canna leaves. Some rollers feed in groups under a netting of their own silk. The solitary types feed by rolling, folding or tying leaves together before they eat them. This last process is actually very interesting as it looks like the leaves have been sewn with a needle and thread. Leaf rollers are active at night while sleeping on the underside of the leaves during the day. The damage to young leaves usually prevents them from opening and they may die. Infested plants can’t bloom and are ugly.  Its easy to miss the first generation of these caterpillars if you aren’t monitoring the rolled leaves carefully. The second and third generations will be more obvious because by then the damage will be extensive.

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If you are able to detect these vile caterpillars early enough, you can cut the leaves and destroy them or wash them off.  Unfortunately, washing them maybe unproductive if there are many leaves as we found in Bahama. You can also use a systemic insecticide such as a 3-in-1 for roses. There are other options including insecticidal soap. Bacillius thuringienis is also effective if applied to the sticky underside of the leaves. Even a household detergent may work if applied to the leaf underside.

Stalk borers have a broad host range upwards of over 200 species of plants. This little villain can go after cannas, tomatoes, goldenrod and even some fruits. Sometimes even twigs of some trees are victims. The first sign that you have stalk borers in your canna will be wilting leaves but by this time, its often too late. You can try to kill the borer by cutting into the infected stem and digging it out.  Your best bet is to remove the infested plant and then kill the borer. This problem is often sporadic and thereby difficult to predict which plant will succumb.  Please check the second link at the bottom for greater detail on this pest.

Here comes some very important advice for both of these insect problems…discard all of the plant material after die back no matter when that is! DO NOT COMPOST! The leaf roller and stalk borer larva will overwinter in dead leaves. If you have a big stand of cannas and don’t clean up the debris throughly it will most likely present an even bigger problem next season.

There will also be the occasional slugs, snails, thrips and mites to deal with and should be treated as you do with another plants.

My cannas are in a pot and are three years old. So far I have not experienced either of these little menaces but I am inspecting the leaves very closely now.

http://www.aces.edu/pubs/docs/A/ANR-1315/ANR-1315.pdf

https://www.extension.umn.edu/garden/insects/find/stalk-borers/

 

 

Entire State Under Quarantine for Emerald Ash Borer

On By durhammastergardenersIn Gardening information

FOR IMMEDIATE RELEASE
THURSDAY, SEPT. 10, 2015

CONTACT: Phillip Wilson, plant pest administrator
NCDA&CS Plant Industry Division
919-707-3753

Entire state now under quarantine for emerald ash borer

RALEIGH – Agriculture Commissioner Steve Troxler signed an emergency order today expanding the quarantine for emerald ash borer to include the entire state, following the discovery of borers in several more counties across the state.

“We have surveyed the state to see if we could find evidence of this highly destructive pest in previously undetected counties,” said Agriculture Commissioner Steve Troxler. “Our staff have now turned up evidence of emerald ash borers in the central, eastern and western parts of the state, including areas near the borders with Virginia, Tennessee and South Carolina.”

The quarantine allows for the in-state movement of hardwood firewood and plants and plant parts of the ash tree, including living, dead, cut or fallen, green lumber, stumps, roots, branches and composted and uncomposted chips. However, movement of these items outside the state into non-quarantined areas would be prohibited. Firewood that has been treated, certified and labeled in accordance with federal regulations can be moved outside the quarantine area.

North Carolina becomes the 15th state in the country with a statewide quarantine. The beetle was first detected in the United States in Michigan in 2002. It is responsible for the death or decline of tens of millions of ash trees across the country.

“This is a devastating pest to ash trees, eventually killing the trees where the insects are found,” Troxler said. “We are not surprised to find more infestations in the state, particularly along the borders with Tennessee and Virginia, two states where borers have previously been found. Virginia also has a statewide quarantine in effect, and Tennessee has quarantines in nearly half of its 95 counties.”

The Plant Industry Division and the N.C. Forest Service are working in cooperation with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service. Contact the USDA State Plant Health Director for more information on federal quarantine regulations and firewood certification at 919-855-7600.

Symptoms of emerald ash borer in ash trees include a general decline in the appearance of the tree, such as thinning from the top down and loss of leaves. Clumps of shoots, also known as epicormic sprouts, emerging from the trunk of the tree and increased woodpecker activity are other symptoms. The emerald ash borer is not the only pest that can cause these.

Emerald ash borers overwinter as larvae. The adult beetle is one-fourth to a half-inch long and is slender and metallic green. When the adults emerge from a tree, they leave behind a D-shaped exit hole. The larvae can also create serpentine tunneling marks, known as feeding galleries, which are found under the bark of the infested trees.

Home and landowners are encouraged to report any symptomatic activity in ash trees to the NCDA&CS Plant Industry Division hotline at 1-800-206-9333 or by email at newpest@ncagr.gov, or by contacting their local N.C. Forest Service County Ranger. To find your county ranger, go to http://ncforestservice.gov/contacts/contacts_main.htm. Rangers can also suggest treatment options for homeowners.

The pest can affect any of the four types of ash trees grown in the state.