FRIEND OR FOE

FRIEND or FOE SERIES

INSECTS ARE EVERYWHERE and they are the most diverse creatures in the world! It’s impossible to keep them out of our gardens, but that's not necessarily a bad thing because a wide variety of insect life promotes biodiversity!

The TSMG's are pleased to bring you the 'FRIEND OR FOE' series!  We will look at a common garden insect to determine whether it is a Friend or Foe (or both)!

Posters of the following 'Friend or Foe' are included as .pdf documents at the bottom of this page.

• Ambush (Assassin) Bug
• Apple Maggot AND Codling Moth
• Wasp or Bee
• Caterpillar or Sawfly
• Colorado Beetle
• Lacewing
• Lady Beetle
• Leaf Cutter Bee or Weevil
• Parasitoid Wasps
• Scymnus or Mealy Bug
• Surphid Fly (Hover Fly)
• Tachinid Fly
• Wireworm (Click Beetle)

 

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AMBUSH (Assassin) BUG

Friend and Foe!

Ambush bugs are perfectly camouflaged and can change colour to match their surroundings. They sit, motionless, in a flower, and wait for an insect to come near. They prey on aphids, flies, caterpillars, beetles, wasps and, unfortunately are very successful in catching bees. So, we sometimes see them as FOES.

However, in this picture an ambush bug is attacking a conopid fly. Conopid flies attack bumble bees or honey bees, pry open the space between the body segments and insert their eggs. The eggs hatch quickly. The larvae feed on the bee, hollowing out its insides. The bee continues to be active until the conopid fly forces it to dig its own grave! The fly spends a year as a pupa in the ground before crawling out of the bee abdomen as an adult fly. And so, ambush bugs are also FRIENDS!

Image: Elaine Sedgman

 

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APPLE MAGGOT and CODLING MOTH

Foes!

Whether it is a fly or a moth, the backyard gardener does NOT need to use pesticides – organic or not!

Seattle Tree Fruit Society has a great explanation on how to apply barriers for pests. And you can: 

•  Bag your apples when you thin them. 
•  Pick up and destroy apples that have dropped to the ground.
•  Or cover the tree with a Kootenay Cover. 

Images: Codling moth – David Short; Apple maggot – Joseph Berger, Bugwood.org

Sources:
https://www.seattletreefruitsociety.com/maggot-barriers

http://www.kootenaycovers.com/Kootenay_Covers_2010/Home.html

Other resources: 
https://s3.wp.wsu.edu/uploads/sites/2083/2015/03/Codling-moth-vs-Apple-Maggot-Homeowner.pdf

https://www2.gov.bc.ca/gov/content/industry/agriculture-seafood/animals-and-crops/plant-health/insects-and-plant-diseases/tree-fruits/apple-maggot

 

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WASP or BEE?

Friend and Foe!

You might see insects nesting in the ground. Is it a friend or a foe? 

BEE: FRIEND!
There are almost 500 bee species in BC and approximately 70 percent of them nest in the ground! 

A common genus is Halictus as in the video of nectaring males. Some bees nest in aggregations as in the video of the genus Melissodes.

WASP: FOE if you step on it, but also a FRIEND because wasps are voracious eaters of aphid and leaf roller larvae and are also pollinators! 

Image:    Male Halictus – Elaine Sedgman
               Wasp Nest – University of Minnesota Extension 

Videos:   Melisodes Nest – Estelle Bérubé
               Male Halictus – Elaine Sedgman          

Sources:  
Wilson & Carril, The Bees in Your Backyard, Princeton University Press, 2016 Hahn, J. Be on the Alert for Wasp Nests.   University of Minnesota Extension.
https://extension.umn.edu/yard-and-garden-news/late-summer-wasp-nests

 

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CATERPILLAR OR SAWFLY?

Friend!

This gorgeous caterpillar will grow into a beautiful butterfly, so we can happily give up a bit of dillweed. 

Foe! 

Sawflies are actually not flies but belong to the same order as wasps and bees. Currant worm or sawfly larvae are voracious feeders and can decimate your currant bushes within days. 

What to do? Check daily and pick them off, or knock them off with a hard spray of water. Or if see them in time, remove the leaves that have eggs on them. 

Sources:
James and Nunnalle, Life Histories of Cascadia Butterflies, OSU, 2011

Linda Gilkeson, Natural Insect, Weed & Disease Control, 2013
http://www.lindagilkeson.ca

Sawfly larva pic 
Wiki Commons Daniel Mietchen 
Sawfly pic 
Wiki commons Gail Hampshire

 

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COLORADO BEETLE

Foe!

You might mistake Colorado beetle eggs for our friend the Lady beetle, but this beetle is definitely a foe! The Colorado beetle lays her eggs on plants of the night-shade family potatoes, tomatoes, eggplants, peppers, tomatillos. Her larvae are not interested in aphids but rather in gobbling up foliate! 

WHAT TO DO? Be vigilent! 

In May, look for eggs on the under-sides of leaves. Hand pick adult beetles, larvae and eggs and drop them into soapy water. Look for lady beetles – they also predate on potato beetle eggs and larvae. You might also cover the potato crop with a floating row cover as potatoes do not need to be pollinated. 

Images: Beetle with eggs – Ada’mozphoto (Wiki Commons); Lavae – Tavo Romann (Wiki Commons)

Sources
Gilkinson, L. Natural Insect, Weed & Disease Control, 2013. www.lindagilkes

Mulvihill, S. The Vegetable Garden Pest Handbook. www.susansinthegarden.com

 

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LACEWING

Friend!

Adult lacewings forage on pollen and nectar-rich flower: yarrow, coriander, daisies, Queen Anne’s Lace, and dill.  The larvae of lacewings are enthusiastic predators of aphids, thrips, and mites. 

They are attracted to lights so protect them by turning off your outdoor lights at night. 

Images: Lacewing, eggs, eating aphids – Elaine Sedgman; larvae – Katja Schultz

Sources:
Gilkinson, L. Natural Insect, Weed & Disease Control, 2013. 

Walliser, J. Good Bug, Bad Bug – Who's Who, What They Do, and How to Manage Them Organically (All You Need to Know about the Insects in Your Garden), 2011.

 

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LADY BEETLE

Friend!

Lady beetles are active hunters of prey and lay their eggs close to the food source. So as friendly gardeners let’s leave prey to attract them to our gardens! 

Lady beetle larvae are voracious aphid eaters! 

Leave some leaf litter or garden debris for adult beetles to overwinter. 

Flowers that also lure adults are dill, yarrow, and coriander. 

Lady beetle pupae picture.

Images: Elaine Sedgman

Sources:
Arthurs, S. & Aristizabal, L. “Convergent lady beetle.” University of Florida,
https://entnemdept.ufl.edu/creatures/BENEFICIAL/convergent_lady_beetle.html, 20 Dec 2021.

Helyer, N., Brown, K., & Cattlin, N. A Color Handbook of Biological Control in Plant Protection, CRC Press, 2003. 

Gilkinson, L. Natural Insect, Weed & Disease Control, 2013. www.lindagilkeson

 

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LEAF CUTTER BEE or WEEVIL?

Friend or Foe?

It’s good to know who is creating the leaf damage in your garden! 

FRIEND! Leaf cutter bees are solitary cavity nesting bees. They protect their eggs with a leaf or flower petal wrap. Those dime-sized cut-outs are a gift from your friendly pollinator! 

FOE! These snout-nosed female weevils chew notches into prized plants, but the damage is just cosmetic. It’s the damage that’s done underground by her larvae that is so destructive. They burrow into the roots and can kill the plant such as this Heuchera (coral bells). 

Images:   Weevil – David Short, Wiki Commons;

                Leaf cutter bee damaged foliage images by Elaine Sedgman

Sources: 
Gilkeson, L. Natural Insect, Weed & Disease Control, 2013. www.lindagilkeson.ca

https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/megachile_bees.shtml

 

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PARASITOID WASPS

Friend and Foe!

There are many species of parasitoid wasps, some of which are FRIENDS and some of which are FOES. Many are so tiny you may not even notice them!

ONE OF OUR FRIENDS – 

APHIDIUS WASP

A female wasp will lay her eggs in an aphid nymph. The wasp larva consumes the insides of the aphid as it matures, leaving a “mummy.”

Aphidius wasps can smell the footprint of lady beetles and will not lay their eggs on aphids (very wisely) if they are close by!  You can encourage these wasps to your garden with nectar and pollen rich plants such as sweet alyssum, thyme and yarrow.  And … by providing food for their larvae … leave those aphids alone! 

FOE – MONODONTOMERUS (a genus of the Chalcid wasp)

Lays its eggs in the larvae of mason bee nests, which is why it is very important to bring your mason bee boxes into your home at the beginning of June or bag them in a mesh bag. Do this very carefully as you do not want to knock the bee larvae off their pollen loaf! 

Parasitized Cocoon

Images:    Braconid (Aphidiinae) Wasp — Alan D Mansion, Wiki Commons

                    All other images by Elaine Sedgman

Sources: 
Walliser, J., Good Bug, Bad Bug, 2011

@aBeeNamedBob

Pinkington, G. Monodontomerus Wasp's Life Cycle 

https://www.youtube.com/watch?v=_bwhBipHktI

 

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SCYMNUS or MEALY BUG?

Friend!

The genus SCYMNUS includes many species of small black, brown, mottled or spotted beetles. The larvae are usually covered with a white wax and are often mistaken for mealybugs. They feed on mealybugs, scale insects, aphids, red spiders, mites and insect eggs. Adults are about 1/12 inch (2 mm) long.

Foe!

MEALYBUG LARVAE are much smaller – 1/8 inch(2-3mm) and are found on houseplants or plants in greenhouses. They cannot survive outside in our climate. Always inspect new plants – if they have mealybugs throw them out as they can spread quickly to other plants! 

Image:  Scymnus images – Elaine Sedgman
              Mealy Bug image – Çarl Davies CSIRO, Wiki Commons

Sources: 
Gilkeson, L. Natural Insect, Weed & Disease Control, 2013. www.lindagilkeson.ca

Western State University.  http://treefruit.wsu.edu/crop-protection/opm/lady-beetles/

 

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SURPHID FLY (Hover Fly)

Friend!

Syrphid fly or hover fly larvae are voracious aphid eaters. You can identity the larvae by a faint line down its back. The fly itself feeds on nectar rich flowers such as dill, cilantro, sweet alyssum and yarrow. She lays her eggs among the aphid larvae. So don’t squish aphids- you might be swishing your friends! 

Sources:
Linda Gilkeson Natural Insect weed & Disease control, 2013 

A Pocket Guide to Common Natural Enemies of Nursery Crops and Garden Pests in the Pacific Northwest, Scherr, Rosetta, Nackley, revised 2021 

https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1613.pdf

 

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TACHINID FLY

Friend!

There are more that 1300 diverse species of parasitoid Tachinid flies in North America – most look like a bristly house fly.

Adults feed on nectar and pollen but it’s heads-up when they smell the volatile chemicals from pest-infested plants!

Egg laying is variable: they glue them on to the exterior of a caterpillar; inject them into the body of a caterpillar; or deposit them on a leaf beside the leaf chomping pest. The caterpillar will unwittingly eat the egg with the leaf. Once hatched, the larva consumes the host’s internal tissues. 

Hosts can be cabbage loopers, tent caterpillars, corn borers, or Colorado potato beetle larvae. Lure the adult fly into your garden with alyssum, coriander, or Ammi Majus.

Image:  Elaine Sedgman

Sources: 
Walliser, J., Attracting Beneficial Bugs to Your Garden, Timber Press, 2014.

Mahr, S. Tachinid Flies. University of Wisconsin-Madison. Division of Extension.   
https://hort.extension.wisc.edu/articles/tachinid-flies/

Tachinid Fly Lays Egg on Caterpillar. 2019. https://www.youtube.com/watch?v=iY73stFQEaE

 

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WIREWORM (Click Beetle)

Foe!

You might have played with this harmless beetle as a kid: turning it upside down so that it would flip itself back onto its feet with a click. 

But its offspring, wireworms, are nasty foes!

Overwintering beetles lay their eggs in late spring. Larvae (wireworms) can take up to 3-6 years to develop into adults; wreaking havoc all those years, boring holes into tubers such as potatoes or corms such as dahlias, but also large seeds such as corn, peas and beans, and even into crowns of lettuce.

What to do? 

Don’t grow fall rye as a cover as it attracts click beetles. Instead of cover crops use compost to increase organic matter. Keep empty garden beds weed free. Delay planting tubers until the soil is warm. Start dahlias in pots and transplant later. Make traps by skewering chunks of potatoes and carrots and burying them 6-8 cm deep. Pull them up every few days and drop the wireworms in soapy water or put them in your bird feeder.  

Images:   Wireworm: McKee Beshers; Click Beetle: Katja Schultz – Wiki Commons

Sources: 
Gilkeson, Linda. Natural Insect, Weed & Disease Control, 2013. www.lindagilkeson.ca

Mulvihill, S. The Vegetable Garden Pest Handbook, 2021. www.susansinthegarden.com