Assorted Small Pests

Aphids (family Aphididae)

These small insects come in various colours; all attack leaves and stems of host plants, causing leaves to distort then fall, and covering them in sticky secretion called honeydew; the latter may in turn attract ants which will protect the aphid colonies in return for feeding on this honeydew. A problem with most fruits and vegetables.

Avoid a vegetable problem by starting plants indoors early, hardening off early, setting outside well before last frost, where possible. Pick off affected leaves, or spray with soap or oil solutions. 'Sticky' yellow traps helpful with flying aphids.

Aphid midge (Aphidoletes aphidimyza), ladybugs or convergent lady beetles (Hippodamia convergens), lacewings (Chrysoperla carnea, C. rufilabrus) are all available commercially. Braconid wasps (Aphidius matricariae) also used to control apple aphids. Pyrethrins and rote-none may be used as a last resort.

Apple Maggot

Small white maggots that tunnel through ripening apples, and cause them to drop prematurely. Destroy fallen, affected fruit. Traps based on pheromone lures are quite effective; typically these are painted red and apple-shaped. Home-made traps of the same size and colour may be covered in glue, for the same effect.

Azalea Lacebug (Stephanitis pyrioides)

Lacebugs leave brown splotches on the undersides of azalea leaves, and may leave small dots on the surface of leaves; leaves eventually die. Lacebugs don't like shade - moving to partial shade should help fight the problem. Use insecticidal soap or pyrethrin compound early in the season, several applications 4 days apart.

Cabbage Maggot (Delia radicum, Hylemya brassicae)

These small white maggots feed on stems and roots of brassicas, worst early in spring. May avoid most of the problems by setting these out around the last frost date, and by planting in areas where brassicas haven't grown in the last few years.

Parasitic nematodes are commercially available. Wood ashes or diatomaceous earth may deter these pests; metal or cardboard collars surrounding plant stems and roots may help. Make sure no wild mustards, or other brassica-family weeds, grow nearby. Destroy infected plants.

Caterpillar (order Lepidoptera)

Caterpillars belong to a large family that includes cabbage loopers, tent caterpillars, cabbage worms, corn earworms, tomato hornworms, and many other pests.

Hand-picking is the most effective treatment for small infestations. Bacillus thuringiensis var. kurstaki is quite effective. The Trichogramma wasp and tachinid flies are available commercially; other wasps also can be very effective. Using various sticky compounds i.e. Tanglefoot on bark of trees can prevent them from reaching the fruit. Lures are now available to attract spined soldier bugs, Podisus maculiventris, a natural predator of many caterpillar species, as well as the bug itself. Pyrethrins can be used as a last resort.

Colorado potato beetle (Leptinotarsa decemlineata)

Shiny, striped, and yellow to orange, these beetles defoliate potato plants. Planting 1 to 2 weeks later than usual may be helpful. Smaller problems easily handled with a vacuum cleaner, or pick and destroy adults and larvae by hand. Spined soldier bugs, Podisus maculiventris, are commercially available predators; lures to attract it also exist. Bacillus thuringiensis var. san diego effective, as are some tachinid flies. Spray with neem, pyrethrins, rotenone, if other measures fail.

Corn Borer (family Pyralidae)

Whitish caterpillars with black dots that tunnel their way through corn-stalks. Rotate crops, destroy cornstalks after harvest. Bacillus thuringiensis var. kurstaki, and tachinid flies are commercially available.

Corn Earworm (Helicoverpa zea)

Another caterpillar, this one destroying ears of corn. Plant or set out corn as early as possible - using an early variety. Pheromone-based traps may be useful. Bacillus thuringiensis var. kurstaki is effective, but can be hard to apply; Trichogramma wasps are also effective. A pathogenic virus marketed as Elcar is available in some countries. Spined soldier bugs may be effective, and can be purchased or lured into the garden.

Cutworm (family Noctuidae)

Larvae are fat, gray or brown in color, about 1 1/2" long, feed during the night and spend the day underground. They feed on tender shoots, cutting them off at or below ground level.

A friendly toad can help with the problem, as can certain nematodes including Steinemema carpocaspae, and tachinid flies; the latter may be available commercially. Protect young plants with cardboard or metal collars at their bases. hand-picking at night can reduce numbers. Finally, the kurstaki strain of Bacillus thuringiensis can be mixed with bran and molasses and spread over the soil to kill them.

Damping off  Various fungi

Caused by a number of soil-borne fungi found in moist soils, this common affliction causes seedling stems to pinch off at their bases, so that seedlings topple and die. Using sterilized soils for seedlings, and avoiding cool, moist conditions helps avoid this problem.

Earwig (order Dermaptera)

Active insects, up to 1" long and brown in colour, and equipped with pincers, earwigs can in small numbers be beneficial. In large numbers, however, they affect shrubs, flowering plants and some fruits, eating leaves and flowers. Insecticidal soaps will kill them. Trap using inverted flowerpots filled with straw, then burn straw or immerse in soap solution; earwigs also will hide in lengths of bamboo or under boards left in a shaded, moist location. Attracting toads to the garden may help

Flea beetle (family Chrysomelidae)

Small black beetles, these poke small round holes in leaves of many vegetables; the larvae eat plant roots. Planting or setting out late may avoid a problem. Older transplants are also much more resistant to damage. White sticky traps spaced 20' apart near ground level can be very effective. Nematodes, especially Steinemema carpocaspsae, are commercially available parasites. Can spray with rotenone, pyrethrins.

Gypsy moth (Lymantria dispar)

These larvae cause wide-spread defoliation of trees, especially oak, and other plants. Spray with bacillus thuringiensis var. kurstaki when leaves are starting to open, repeat in 7 days. Find and destroy egg masses and pupae, using vegetable oil sprays. Using various sticky compounds such as Tanglefoot on bark of trees can prevent them from reaching the fruit. Pheromone-based traps may be quite effective. Spined soldier bugs, Podisus maculiventris, are available commercially, as are lures for them

Japanese beetle (Popillia japonica)

These bright metallic green beetles, brown or red wing covers, attack leaves, flowers, and ripening fruit; larvae feed on roots. Hand-pick or vacuum in early morning; milky disease spores may be purchased, placed on soil. Pheromone-based traps may be quite successful, and nematodes, including Steinemema carpocaspae, can control infestations. Spray with rotenone as last resort

Mealybug  (family Pseudococcidae)

Sap-sucking, oval insects covered in mealy white wax, control these pests using insecticidal oil sprays. Very small infestations can be con-trolled by thoroughly painting each individual bug with alcohol, avoiding contact with the plant. The mealybug destroyer, Cryptolaemus montrouzieri, is available commercially, as is the convergent lady beetle, Hippodamia convergens.

Mexican bean beetle (Epilachna varivestris)

Yellow-brown, 16-spotted beetles that destroy bean plant leaves from below. Plant target crops early, hand-pick bugs, crush yellow clumps of eggs on the underside of bean leaves for control. Spined soldier bugs again can be bought or lured to control this pest, or use the parasitic wasp Pediobius foveolatus for control. Compost bean plants immediately after finished yielding, and in worst cases, spray rotenone, pyrethrins.

Onion maggot (Delia antiqua)

1/4 to 3/8" long, white maggots target Alliums and especially onions. Rotate onion crop every few years. May sacrifice a few old onions in early spring, by planting them early, then destroying them a few weeks after sprouting.

Rhubarb-curculio or snout-beetle

This 1/2" to 3/4" rust-coloured beetle, bores into the stalks and crowns of rhubarb plants.

During the Spring, the eggs are laid in host plants. When rhubarb is occasionally attacked, the rhubarb stalks will leak sap. Decay takes place because of the egg laying holes that are made and because of the curculio feeding.

Hand-pick, destroy badly affected plants, and destroy wild dock plants, an alternative host, if any are growing nearby. It makes sense to remove all surrounding plants around your rhubarb especially during the month of July as this is about the time the larvae will be present.

Scale (family Margarodidae)

Female scale insects look like scales on various plant parts. Prune away affected parts, or scrub them free of pests with soapy water; may use oil sprays. Chilocorus beetles and lady beetles, Hippodamia con-vergens are effective, commercially available predators. Spray with ro-tenone or pyrethrins, if other measures fail.

Slug, snail (families Helicidae, Limacidae)

Pests that often feed on entire plants, they can hide in mulch, though using crushed gravel or shredded bark can deter them with their sharp edges. Hand-pick, attract toads to the garden, or fill shallow containers with stale beer, dealcoholized beer, or yeast solutions: they'll fall in and drown. Renew the solution every few days for best effect; cover to prevent rain from getting in. Finally, copper strips form a very effective bar-rier they won't cross.

Spider mite, incl. red (family Tetranychidae)

Tiny eight-legged pests, these may be controlled using Safer's or Wil-son's insecticides, vegetable oil sprays, or insecticidal soaps. Phytoseiulus persimilis, a predatory mite, and the minute pirate bug, Orius tristicolor, are available commercially.

Stink bugs (family Pentatomidae)

These predate on the fruits and leaves of many plants, and are easily hand-picked and destroyed. Dill and fennel may attract Telenomus wasps and other insects that predate on stink bugs. Note however that some members of this family, including the spined soldier bug, are extremely helpful as beneficials, and should not be destroyed.

Tarnished plant bug (Lygus lineolaris)

Fast green to brown bugs with yellow, brown, black markings, that suck sap from leaves and stems. Difficult to control except with rotenone.

Thrips (common family Tripidae)

Tiny to very tiny winged insects, these leave whitish blotches on leaves, and deform leaves. Lacewings including Chrysoperla carnea, mites such as Hypoaspis or Geolaelaps, minute pirate bugs, Orius tristicolor, may be purchased; ladybugs also predate on thrips. Keeping the garden clean of weeds and organic debris may help keep these pests manageable..

Whitefly (family Aleyrodidae)

Tiny flies with large wings, white powder covering body and wings, these rarely affect plants seriously unless present in large numbers; if sooty mould fungus is also noted, they're probably too numerous.

Insecticidal soaps or oils and yellow sticky traps may be helpful. The parasitic wasp Encarsia formosa is commercially distributed as pupae which are placed in infested areas, three or more times, until four-fifth of whitefly pupae have turned black. These may be used in conjunction with soaps and yellow tape, as the wasp is little affected by either. Pyrethrins may be helpful.

Problem Mammals

Deer (genus Odocoileus)

Very difficult to get rid of once they have the habit of visiting; most of the more popular deterrents below aren't very effective. Fencing, or green-house gardening, are often the only permanent solutions.

Success has been had with commercial deer repellents, especially those containing Thiram. Other organic 'solutions' include spraying with a dilute egg mixture every few weeks, three eggs per gallon of water, hot pepper sprays, several tablespoons per gallon, and hanging soap or human hair from rope near the garden, changing the soap when it loses its potency. However, these latter home remedies are rarely useful if deer are hungry, or used to frequenting your garden.

For true protection, individual plants, or the whole garden, should be enclosed. A 6' fence should suffice if the deer cannot see over it, 8' if they can, or space two 4' fences, 4' apart. A single-strand electric fence strung 3' above ground can be very effective; baiting it with aluminum foil covered in peanut butter imparts a strong lesson.

A new commercial product consisting of strong, 7 1/2' high black polypropylene fencing, which is thin enough that it cannot be seen at a dis-tance, has also been quite effective. Initially one flags the fence for a month or more; deer quickly learn to stay away.

Groundhog, woodchuck (Marmota monax)

Very capable diggers, with burrows often 10-15' deep, these rodents can prove very difficult. Commercial repellents are available, or spray plants with hot pepper solution as deterrent. Strong wire mesh fences may keep them away: must be buried some 24", extend up about 3' and have a third, upper floppy section that extends horizontally, outwards; the fence should be well-supported.

Mouse (families Muridae, Cricetidae)

Protect individual plants from these rodent pests using collars of wire mesh, buried some 6" deep. Alternatively, trap and kill mice if the prob-lem is severe.

Mole (family Talpidae)

While moles are generally benign and can even be useful, their tunnels are often undesirable. Sticks of Juicy Fruit buried in their runways will be eaten, and kill them, or use mole traps for this purpose. They tend not to bury through gravel, and thick gravel-filled trenches may help keep them out. Note also that a mole problem may indicate an underlying grub problem.

Opossum (Didelphis virginiana)

Opossums can be very hard to dissuade once established; they're also fierce fighters when cornered, and can carry rabies. Electric fencing can keep them out; other forms of fencing are easily climbed. Call your your local Fish and Wildlife Department, Animal Control, or equivalent, and ask them to live trap the animal, releasing it elsewhere.

Pocket gopher (family Geomyidae)

Strong burrowers, though fairly small, these rodents do their damage from below; you'll rarely see one above ground. One-inch or tighter mesh fences only need to extend 12" above ground but must go down 24" or more underground, to keep them away. Daffodils and squill tend to deter these pests, but must be spaced closely around the garden. Gophers can be flooded from their tunnels, and killed.

Rabbit (family Leporidae)

The dog may or may not keep rabbits away; commercial repellents are available. Or use a tight-mesh chicken-wire fence, buried at least 8", at least 30" high; may wish to slope the upper few inches outward. Wrap trees in burlap in wintertime, high enough to compensate for snowfall.

Raccoon (Procyon lotor)

Raccoons love sweet corn especially, and also have a fondness for melons. Do not go after these animals directly: they may fight fiercely when cornered, and can carry rabies.

Fox urine, sold in sports stores, can deter raccoons from visiting, but washes off with rain. Battery or solar-powered electric fencing, two or three wires with the lowest 6" above ground, may be effective; use very thin supports for the wiring so that the posts themselves aren't used as ladders. Or cover corn plants with bird netting that drops to the ground on all sides, and pin the edges down firmly