Good morning – I’m hoping you can help me with identification and eradication of an insect which leaves a white web on my largest Serviceberry, as well as eating the leaves on all 3 of my bushes. On two occasions I have found a small cocoon within the web. The only “living” organism that I have seen is small, brown. about 1 mm long. I only saw one, on the underside of 1 leaf. (I put it somewhere safe to seek advice and now I can’t find it!!).
Thank you for contacting Toronto Master Gardeners. Based on your description, it sounds like it might be spider mites. Spider mites are tiny, eight-legged pests that can cause severe damage to plants and flowers. They can grow quickly so it’s wise to eliminate them as fast as you can. Infected plants droop, appear stressed, the leaves might have yellow, bronze or reddish flecks. The plants may have webs across them.
Some strategies to eliminate spider mites include to:
• Trim the affected areas. Bag and remove all infected leaves, stems and shoots.
• Hose down the tree with moderate pressure.
• Introduce predatory insects such as pirate bugs, lace wings or dark-hued lady beetles.
• Spray the shrub with insecticidal soap.
For more information about spider mites please refer to the following websites:
https://www.gardenguides.com/67542-kill-spider-mites-plants.html
https://www.planetnatural.com/pest-problem-solver/houseplant-pests/spider-mite-control/