Good Bug, Bad Bug

Lawn and Garden Pests:

• 2-3mm long, soft, pear shaped insects often green but also brown black, grey or red.
• Found in clusters on the underside of leaves


• Aphids can cause curled and distorted leaves or buds by sucking the plant sap.
• Honeydew, a substance secreted by the aphids can cause sooty mold, a fungus to grow, turning the leaf black. This can be washed off.
• Transmits many virus’s

• Not every aphid attacks every plant though some will share a variety of hosts. Such as; Roses, apples, artichokes, cole crops, dahlias and other succulent plants.

• Aphids continuously give live birth to young nymphs, thus colonies grow quickly.
• Difficult to control with insecticides as one aphid can produce a new colony.
• Eggs laid on woody stems or in the crevices of bark can overwinter.

Prevention and control methods:
• Apply dormant oil in the fall to kill over wintering eggs.
• Avoid over fertilizing with nitrogen as the aphids are attracted to new succulent growth.
• Spray horticultural oil in the summer on trees and shrubs.
Companion Plants
• Carrots, dill or nastursums

Biological controls:
• Ladybugs, green lacewing or aphidoletes (aphid midges)

• Can be both, a pest of plants or a predator of pests. Species dependent.
• Tiny, winged, slender bodied insects ranging in colour from black, red, brown and yellow
• Commonly seen in flower heads and sometimes on the leaves.

• Stipling effect on the leaves appearing to have a sheen.
• Can distort flowers and developing fruit, such as peppers

• Found on a variety of flowering plants though the most destructive on cucumber and peppers

• Females will cut slits into stems and leaves to insert eggs.
• Many generations in a season
• Eggs can overwinter in crevices or bark.

Prevention and control:
• Yellow sticky traps placed around peppers and cucumbers to assist in identifying presence.

Biological controls:
• Minute Pirate bugs, cucumeris.

• Very tiny <.5mm, clear with 2 dark spots on abdomen. Two red eyes can be seen with the use of a microscope.
• Found in clusters on the underside of leaves
• Webbing usually present.

• Feeding will cause white stipleing on leaves. When infestation is severe leaf will turn bronze or yellow and become brittle.
• Webbing in plants also reduces photosynthesis.

• Will attack; houseplants, vegetables, fruit trees and ornamentals.

• Eggs and adults can overwinter in plant debris, crevices or in the greenhouse.
• Spidermites reproduce very quickly under hot and dry conditions

Prevention and control methods:
• Maintain high humidity in house or area of plants.
• Upon first detection wipe infested leaves with cloth to remove mites or spray plants with water regularly.

Biological controls:
• Persimilis, Feltiella

• Tiny 1mm long with delicate powdery white wings.
• Found in on the underside of leaves in the upper canopy of the plant

• Both adults and nymphs suck the plant juices
• They secrete honeydew which cause sooty mold to grow, this mold can be washed off.
• Infested plants will become discoloured and wilt
• Whiteflies can transmit many diseases.

• Many indoor plants, vegetables and fruit trees

• Eggs are laid on the underside of leaves.
• Whiteflies will be killed by a heavy frost. Though can over winter in partially warmed greenhouses.

Prevention and control methods:
• Use sticky cards to detect presence
• Inspect all plants prior to purchase.

Biological controls:
• Encarsia formosa

• Round or oval waxy like bumps without legs or wings found on leaves, petioles branches and stems of plants.
• Grey yellow brown black

• Scales suck plant juices, causing plants to weaken .
• Leaves may yellow and drop. Entire branches or plants may die.
• Some scale will secrete honeydew which can cause sooty mold, an unsightly black mold that grows on the surface of leaves. This can be washed off.

• Many indoor tropicals and landscape ornamentals.

• Scales will overwinter as eggs or nymphs on the bark of trees.
• Nymphs will walk over plants for several hours before they settle and become immobile. It is during the nymph stage when they are most susceptible to sprays.

Prevention and control measures:
• Inspect all plants prior to purchase.
• Remove an infected plant and place into quarantine immediately. One plant can infest all others.

Biological controls:
• Aphytis mytilaspidis, Metaphycus helvolus

• Oval with hard shells and prominent snouts.
• Black vine weevils can be brownish grey to black with small yellow patches on their backs 8mm long
• Strawberry weevils will be a shiny black, smaller than Vine weevils 6mm long.
• Unless in high numbers the damage rarely harms plants significantly.

• Larvae will feed on roots causing stunting in plant growth and allowing disease organisms to enter.
• Adults feed in the evening causing semicircular notches on the edges of the leaves

• Root weevils will attack berry plants as well as some ornamentals such as; Rhodo’s, azaleas, rose, viburnum and conifers.

• Weevils will overwinter as larvae in the roots of plants feeding until mid May when they will pupate into adults.
• Some adults will overwinter in leaf litter and bushy areas.
• Adults will begin to lay eggs in July in the roots and crowns of host plants
• There is only one generation a year.

Prevention and Control methods:
• Remove over wintering sites for adults such as leaf litter or trash close to strawberries.
• Plant resistant cultivars
• In the evening knock feeding weevils onto white sheet spread around the base of the plant. Drop weevils into soapy water

Biological controls:
• Beneficial nematodes

• Leatherjackets are brown, shiny, worm like with a hard skin. The juveniles of the European Crane fly.
• The adults are large mosquito like creatures with long legs.
• Found in the spring and fall around windows and lights.

• The larvae will feed on grass roots and decaying vegetation, causing brown dead or sparse patches in your lawn in May and June.
• Healthy lawns rarely show damage unless present in high numbers.
• Larvae are normally kept in check by natural enemies unless excessive chemicals have reduced predator numbers.

• Turf

• 1-2 generations per year.
• Adults of some species do not feed.
• Long slender eggs laid in grass and soil.
• Overwintering adults will emerge in the Spring

Prevention and control methods:
• Maintain a healthy lawn.
• Check for leatherjackets in the lawn by pouring a soap drench on the lawn and counting the number of leatherjackets that emerge within 10 minutes. 10 or so larvae per sq ft is high.
• Mechanical aeration will aid in keeping a healthy lawn and can kill larvae in the process.

Biological controls:

• Beneficial nematodes

• Segmented grey, oval with 7 pairs of legs. About 13 mm –19mm
• Pillbugs will roll up into a small ball when touched
• Found in damp environments.
• The only crustaceans adapted to spending their entire lives out of water.

• Do not cause serious damage considered more as an unsightly annoyance.
• They are beneficial decomposers of organic matter.

• Found in gardens, under rocks, moist basements

Prevention and control methods:
• If found inside the house, locate the source of habitat. Moist dark areas and dry area completely.
• Place a small amount of corn meal in a covered container with a small entry hole at the bottom to allow sowbugs in. place in areas of high populations. Sowbugs will feed on cornmeal and swell to death.

Biological controls:
• None at this time.

• Garden slugs – 3-25mm, Banana slugs – 10-15cm
• The Banana slugs can be black, brown, or tan with black spots and sometimes possess vertical ridges along their back. The garden slugs appear much smoother in colours of green, grey and tan.
• They need moisture to maintain the slime which aids in travel.
• Both are very slimy and leave slime trails in their wake.


• Feed mainly at night but can be seen on overcast days.
• Cause large irregular holes on leaves, flowers, bulbs, stems and can completely devour young seedlings.
• A slimy trail is evidence of their presence.

• Seedlings, tender plants

• Produce slime to aid in transportation and as a method protect eggs.
• Eggs are laid in the soil in the slimy mass.
• Overwintering stage is dependent upon species.

Home remedies:

• Use native predators by seeking them out and transferring them to areas of high slug population.
• Attract these natural predators by providing them with the right environment. Sod, bark mulch and clover between the walkways and along beds will provide excellent habitat.
• Ash and egg shells around plants has had some positive results but watch your pH.
• Cover seedlings with plastic milk jugs or a light cloth until plants are well established.
• For trees or plants that are consistently getting attacked, a copper band placed around the base of the trunk or copper mesh around edges of raised beds and cold frames.

Biological controls:
• None at this time

European Cabbage Worm
• velvety leaf green caterpillar with a slender orange stripe down the back.
• It may range up to 1 1/4 inches long.
• The adult white butterfly has a wingspan of 1 ¼ inches. The males possessing 1 black spot on the tip of each forewing while the females have two. The underside of the wings may appear to have a yellowish hue.
• The pupa are encased in a pale green cocoon with two protrusions present in the middle.

• Large irregular holes on leaf
• 1st –3rd caterpillars tend to feed on the outer leaves while the 4th and 5th move inwards.
• Caterpillars will feed right into head of cabbage for concealment but leave a trail of green excrement.

• All members of the cabbage family, nasturums, allysum and strawberry
• Females lay yellow, oblong, and deeply ridged length-wise eggs singly on the leaves of host plants.
• Eggs will hatch within 3-7 days
• Larvae will take 10-14 days to reach their full length of 1 inch

Home Remedies:
• Garlic spray (Note that in high doses garlic will kill beneficials as well.)
• Sticky traps
• Hand picking

Bug Fact!
Predatory insects need more than meat alone to live. Pollen and nectar are a necessary part of their diet. As a matter of fact, choosing plants for their pollen and nectar content is an excellent way to draw beneficial insects into your garden. Check out our Companion Plants section to learn more