Scouting for Insect Pests, June Edition

Squash Bugs

squashbugweb

Photo: growingsmallfarms.ces.ncsu.edu

Squash bugs, which have overwintered as adults, are actively laying eggs now. Egg clusters can be found on the undersides of leaves. Remove and crush the eggs to reduce the population of squash bugs.

squash_bug_eggs
photo: Whitney Cranshaw, Colorado State University, http://www.insectimages.org

Nymphs and adult squash bugs suck sap from plants and can quickly destroy squash vines. Adults and nymphs frequently hide under damaged leaves and at the base of plants. Keeping debris and mulch away from the base of plants reduces cover for the bugs and may also reduce damage. In fact, Clemson University suggests the following method of trapping adults and nymphs: “The secretive nature of squash bugs can be used to your advantage in controlling these pests. Place a small, square piece of old shingle or heavy cardboard under each squash plant. As bugs congregate under it for protection, simply lift the trap and smash them with your hoe (or shoe).”

http://www.clemson.edu/extension/hgic/pests/plant_pests/veg_fruit/hgic2207.html
http://www.ext.colostate.edu/pubs/insect/05609.html

Mealybugs

mealybug

Photo: ucanr.edu

These pests can be a problem on ornamental plants in the landscape as well as on houseplants. Female mealybugs are oval shaped, soft-bodied, wingless, and covered with a fluffy wax. Males are gnat-like and have wings and a waxy tail. Eggs are contained in a fluffy, waxy mass. Mealybugs feed on sap from plants. They excrete waste called honeydew, which promotes the growth of sooty mold. Small infestations can be controlled by wiping away the insects with a cotton swab dipped in isopropyl (or rubbing) alcohol or nail polish remover or with insecticidal soap.

http://www.ces.ncsu.edu/depts/ent/notes/Ornamentals_and_Turf/flowers/note19/note19.html

Spotted Wing Drosophila

 

on-raspberry-1024x730

Photo: Jesse Hardin, North Carolina State University

The Spotted Wing Drosophila damages fruit crops by cutting a slit into healthy fruit and laying eggs inside. Spotted Wing Drosophila prefers softer fleshed fruits like berries, cherries, and grapes. These insects are less than 4mm in length, and their larvae can be found inside fruit, causing softness and holes.

How can I manage SWD (Spotted Wing Drosophila) in my garden?
While SWD infested fruit may be unpalatable, larvae are not harmful if consumed. Ripening and ripe fruit are susceptible to SWD attack, but flies do not appear to be attracted to unripe fruit. Good cultural management can reduce SWD damage. Good cultural control includes:
1.Excellent sanitation: fruit should be harvested frequently and completely. Any unmarketable fruit should be removed from the field and either frozen, “baked” in clear plastic bags placed in the sun, or hauled off site to kill or remove any larvae present. When you done harvesting for the season, strip any unwanted fruit from plants and destroy it.
2.Canopy and water management: Prune plants to maintain an open canopy. Do not overwater plants. Leaking drip irrigation should be repaired, and overhead irrigation should be minimized.
3.Exclusion: Fruit can be covered with fine mesh bags or paint strainers prior to ripening to exclude flies. Bags should be tightly sealed. Placing a foam plug between branches and the sealed based of bags is useful to prevent plant damage and maintain a tight seal.
4.Regular fruit sampling: Fruit should be observed regularly for infestation before and during harvest.

While cultural control may be sufficient to reduce SWD infestation below damaging levels, insecticides are currently the most effective tool to reduce or possibly prevent SWD infestation. Insecticides can only be applied to plants for which they are labeled. The label is the law! County extension agents and university
specialists can assist with selecting effective, appropriate insecticides. There are some organically acceptable insecticides available for SWD, but they are less persistent than conventional materials and may need to be applied more frequently. (per http://www.ces.ncsu.edu/wp-content/uploads/2013/04/Homeowner-Factsheet-2013.pdf)

http://swd.ces.ncsu.edu/swd-biology/

This video shows how to make a Spotted Wing Drosophila trap to assess the presence of these pests in your garden.

Finally, Japanese Beetles are active. Beetle traps are more effective at attracting Japanese Beetles than controlling them. If you do use traps, locate them far from plants you wish to protect. Per NCSU: Homeowners can take advantage of the beetles’ aggregation behavior by shaking plants to dislodge beetles each morning. Without beetles already on a plant, it is less likely that beetles will aggregate there later in the day. Picking beetles off by hand will also reduce the accumulation of beetles that results in severe damage. They can be easily knocked into a widemouth jar of soapy water.  In some settings, flowers or plants can be protected with cheesecloth or other fine mesh.

http://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/note44/note44.html

Classes and Lectures, week of June 9 – 15, 2014

Herb Gardening – Extension Gardener Series
Thursday, Jun 12, 2014 6:30 – 8:00pm Sarah P. Duke Gardens, 420 Anderson St.

Enjoy growing these handy and helpful plants. Taught by Master Gardener Marti Warburton. Class is free/registration is required. Sara Smith 919-668-1707 gardenseducation@duke.edu

 

CRAWLIN’ CUCURBITS – Gourds, Pumpkins & Squashes
June 14,  10-11 am, Durham County Cooperative Extension, 721 Foster St.

Early summer is the perfect time to plant cucurbits — the zucchini, squash, pumpkins, melons, cucumbers and gourds that we’ll harvest in late summer and early fall.

Join the Durham Co. Extension Master Gardeners for this FREE 1-hour talk for suggestions on best varieties, when to trellis or not, how to outsmart cucurbit pests and tips so you can cultivate an abundant crop.This FREE program is open to the public; all are welcome to attend. Please pre-register with Pana Jones at the Extension Office by calling 919-560-0525 or send an email to: prjones2@ncsu.edu.

Downy Mildew on Cucurbits

downy mildew

 

Downy mildew is a disease that affects members of the cucurbit family, which includes cucumbers, melons, squash, and watermelons. It is caused by the fungus Pseudoperonospora cubensis. Host specificity is found in P. cubensis, with at least 5 pathotypes (isolates of the fungus that will infect some cucurbits but not others) found in the United States.The fungus must live on a living host plant, so it overwinters in areas that do not have a hard frost. The spores are spread by wind and can travel quite far. The disease thrives in high humidity, and can be found in NC nearly every summer. Downy mildew affects leaves, causing lesions such as those in the photo above. In severe cases, leaves curl upward and die.

downy mildew 2

 

This can result in reduced yields and sunscalded or misshapen fruits.

To control this disease, plant resistant cultivars in sunny plots with good airflow. Avoid late day irrigation. Follow a spray program if desired. Early detection of the disease is important. Downy mildew outbreaks are tracked and a forecasting system has been developed to help growers time their fungicide applications. The home grower can access this information as well. http://cdm.ipmpipe.org/

For more information and additional photos:

http://www.cals.ncsu.edu/plantpath/extension/fact_sheets/Cucurbits_-_Downy_Mildew.htm

http://www.apsnet.org/edcenter/intropp/lessons/fungi/Oomycetes/Pages/Cucurbits.aspx

Squash bugs

Squash bugs have been spotted in gardens around Durham. This pest attacks all members of the cucurbit family (which includes squash, cucumbers, pumpkins, and melons). Scouting for and removing the eggs and insects is an environmentally friendly way of controlling the population and reducing the use of pesticides. Check your plants several times per week, looking at the undersides of leaves as well as the tops. Once you learn to recognize the pests, the job is fairly simple.

Squash bug eggs can be wiped or gently scraped from the leaf surfaces by hand. Destroy (squash) the eggs so they don’t hatch!

squash bug eggs

Squash bug nymphs: Just squash them. Wear gloves – they have a bad odor.

squash bug nymphs

Adults (yes, squash them too – with your gloves on)

Squash_Bug1627

Photos from Missouri Botanical Garden

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/plant-bugs/squash-bugs.aspx