Aphids

Posts Tagged ‘aphids’

Using Phenology To Predict Pest Emergence

Terrie Greco, B.A.; HLT Dip.

Phenology? What on earth does that mean? Well, and very simply put, it is the science of making associations with certain stages of plant development with the timing of pest emergence. Climatic variables such as temperature, moisture and day length all play a part in when a plant will break bud and bloom – we can co-relate the hatching of insect eggs, for example – with the bud break or blooming of an ‘indicator’ plant. Good indicator plants are ones in which they are common to a large geographical area (a province or state), are easy to grow and have a short but well defined period of bloom. Gardeners can use indicator plants to predict pest emergence and plan effective treatment at the correct stage. A monthly calendar is not an accurate predictor for plant bloom times. For example, unseasonably warm or cool temperatures in the spring can advance or delay plant flowering. As it says on the USA National Phenology Network (USA-NPN) website: ‘Phenology, put another way, is simply nature’s calendar’. Well said! Here is the link for this website where you can find all sorts of fascinating information and opportunities to become an observer in your area.

http://www.usanpn.org/about

Interestingly enough, the plant indicator in bloom may not even be a host for the pest we are watching for– but it has the same climatic requirements to emerge from a life cycle stage as the plant does to bloom.

Example – in Ontario and Quebec – when Saucer Magnolias (Magnolia soulangiana) are in the pink bud stage …. Cooley and Eastern Spruce Gall Adelgids should be treated with natural insecticides. Note that these aphid like-insects do not harm Magnolia, only certain Spruce species and Douglas Fir.

Example – in Ontario and Quebec – when Serviceberry (Amelanchier spp.) is in bloom – Gypsy Moth eggs will begin to hatch

Get the picture? Regardless of where you live in North America, you can find a phenology calendar or publication from your local horticultural or agricultural extension office that can help you accurately predict pest emergence. It’s really the coolest thing to know.

Here are a couple of pictures and links to explain further.

Image 1 – Magnolia soulangiana – Saucer Magnolia in bloom

Image 1 – Magnolia soulangiana – When the Saucer Magnolia is in bloom, gardeners should be checking conifers for Cooley and Eastern Spruce Gall Adelgids.

Magnolia image provided by www.permed.com/…/Magnolia_soulangiana_tree.jpg

For more information and images the Cooley and Eastern Spruce Gall Adelgids, check out the following two links:

http://www.for.gov.bc.ca/hfp/publications/00198/Cooley_spruce_gall_adelgid.htm

http://www.forestry.ubc.ca/fetch21/FRST308/lab4/adelges_abietis/spruce.html

Image 2 - Amelanchier canadensis, Serviceberry in spring bloom

Image 2 – Amelanchier canadensis When the Serviceberry is in spring bloom, gardeners should be watching for the emergence of Gypsy Moth Caterpillars on various tree species. Serviceberry image from the University of Delaware Cooperative Extension, Kent Co.

For information on the Gypsy Moth, check out the following link:

http://cfs.nrcan.gc.ca/factsheets/gypsy-moth

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Don’t ‘Cry Uncle’ if you have Ants!

Terrie Greco, B.A.; HLT Dip.

Many species of ants contribute to the ecology of the landscape, though there are times when we wish we could banish them from the home and garden. But you have to admire the work ethic of these ‘system engineers’.

The most common ants found on properties are small pavement and odorous ants. They are fairly easy to control using residual Pyrethrin sprays or Borax based baits. As a socially organized colony, the workers are really the only ones that enter the home foraging for food. The Queen hides deep in the nest – doing what Queen’s do best -wearing nice hats and waving to the masses. Seriously now…

Ants enter through cracks and crevices and are looking for a food source. Common sense dictates that if you see ants around baseboards (they usually create a path in straight lines) or on counters – you need to repair any openings around foundations and doorways. Protect food in airtight containers, wipe counters and baseboards with common vinegar (to disrupt pheromone trails) and practice good housekeeping – these simple habits will repel and minimize ants in the home.

In the garden, ants have a mutualistic relationship with aphids. Aphids produce a sticky sweet substance called honeydew which is a great food source for ant colonies. Ants protect, defend and transport wingless aphids in return for the privilege of ‘herding’ and ‘milking’ aphids for the rich honeydew.

Controlling ant’s outdoors requires patience and observation – make note of the ant pathways back to the nest and use diatomaceous earth or borax baits along the trails.

Take a look at the photos and links to learn more about the many species of ants, their odd behaviours, their relationships with other insects and natural control. They are a fascinating and complex creature. By the way, thank you to Alex Wild, a biologist at the University of Illinois for letting me reproduce these pictures here on the Biofloris blog. To see many other insect photos, check out his website at: http://www.alexanderwild.com/

Tetramorium caespitum - The Pavement Ant is a common household pest in many parts of North America. Photo courtesy of Alex Wild, http://www.alexanderwild.com/

Tapinoma sessile – The Odorous House Ant has a distinct smell when crushed – some say like rotten coconut! Photo courtesy of Alex Wild, http://www.alexanderwild.com/

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