Live in Huron County, ON near Stratford/ Goderich. It has been a cool and rainy summer as in much of S. Ontario. I have Heliopsis, Variegated leaf heliopsis , and a dark stemmed Heliopsis. While mosy of my garden has not been bothered much with insects, all 3 types of Heliopsis are covered in what look like aphids only they are a dark brown almost black color. When I try to rub them off my fingers are covered in dark brownish red squished bugs, I go out almost every day and spray with a diluted soap solution and every morning morning they are covered again. I have also tried Rose dust. What are these tiny pests and how do I get rid of them? Thanks in advance.
There are over 300 species of aphids that live in the Ontario area. They come in a wide variety of colours ranging in black, brown, grey, green, white, red, and yellow. Young aphids or nymphs also look different than adult aphids. The youth being more transparent and the adult being darker in colour with more pronounced antennae and legs. Its possible that if it looks like an aphid and has one of these colours and aphid attributes it is an aphid. Aphids reproduce rapidly and can grow to have large populations and decimate large amounts of plant material in a short time.
To control aphids before they cause damage you can create a habitat friendly to predatory species that prey on aphids such as lacewings, predatory wasps, and ladybugs to eat them. To promote beneficial insect habitat it is recommended that you provide nectar producing plants in the garden, provide a drinking or watering hole, and provide a shady place for them to hide during heat spells. It isn’t recommended to to use insecticides indiscriminately as that can reduce predatory insect populations in the long run and cause the aphid populations to grow larger as a result. We need long term and non chemical solutions for these problems while promoting pollinators as well.
A steady hose spray will also remove aphids from branches and leaves as they fall off easily due to water pressure.
If you do resort to chemicals several insecticides that are low risk to people, pets, non-target insects, and the environment exist.