Insects play an important role in the ecosystem.
They are low on the food chain which means that they are plentiful and are food for others: frogs, birds, bats, and spiders. Insects that feed on nectar pollinate plants insuring that there are seeds for next year.
Harmful insects usually infest plants that are stressed and in poor condition.
This being said, one of the best ways to control insects is to place plants according to their requirements. Plants that become infested every year need to be moved to a different location.
Aphids are insects that are commonly found on the new growth of plants. They are easy to spot as they are a translucent green, white or solid black.
Individual insects are small, oblong, objects about the size of a large pin head. An aphid that lays eggs in the spring will have billions of decedents by fall. When the colony becomes too large for the food supply, the next generations of aphids are born with wings allowing them to leave the colony to find a new food source.
Plants that are hosting aphids will have marbled coloured leaves. A sticky residue which is excreted from the insects is often visible on lower leaves. Ants on a plant is also another telltale sign. Ants will herd aphids and gather the insect’s residue as food for their colony.
Aphids can often be dislodged from the plant with a garden hose with a pressurized end. Spraying with Neem oil or a soap solution will coat and suffocate the insects. The chemical Melathion can also be sprayed on the insects to kill them. Infested plants will have to be sprayed daily to catch the new insects as they hatch.
Lacewing larvae are a natural predator that feed on aphids. It is possible to purchase lacewings as eggs. Given the correct conditions they will quickly hatch into larva. As adults, lacewings will lay eggs and help pollinate the flowers.
Ant populations have seemed to increase in the last few years to the point that ant hills are common in gardens and lawns. Ant hills are full of tunnels or air holes, which can dry out plant roots and kill the plants. Shallow rooted plants that have a large amount of fibrous roots tend to co-exist on the top of an ant hill.
Annoying or disturbing an ant hill on a regular basis will encourage the ants to move but unfortunately it is not possible to choose their next location. Digging up the ant hills and mixing them together, pouring boiling water in the hill and flooding the hill with a garden hose will encourage the insects to go deeper or relocate.
Permanent solutions involve bait. The ants take the bait into the hill and feed it to the rest of the colony.
The bait can be commercial or a home recipe. For the method to be successful the bait usually has a low concentrate of poison and should be used for a period of at least two weeks. Ants will avoid high concentrations of poison after an initial encounter. Make sure that all poison is out of reach of children and other animals.
While it is up to individuals as how to deal with problem insects please keep in mind your neighbours that might also be affected by the insects and the solution.
Insects are not bound by a property line and a large infestation will spread. Where an insect might not be a problem for one gardener, it might be for the neighbour. Be considerate.
Linda Tomlinson is a horticulturalist and educator living in Rocky Mountain House. You can contact her at firstname.lastname@example.org