Q.What Is This Clear Gelatinous Substance On My Mandevillaplant
I noticed this on my plant. I have examined it with my small handheld microscope and see no pests. If you look closely at the pictures I have attached. The substance always seems to be in the Areas around what look link green perturbances that look like part of the plant. The plant seems healthy. The substance is not silky. It looks more like stringy glue from a glue gun. This plant is indoors.
Certified GKH Gardening Expert
Hello there!
This looks to be exuding sap! I believe that I might also see remnants of spider mites, or its frass. This would explain the sap, since it will indicate damage. I noticed a few curling leaves, as well.
Look for any webbing, though it isn't always present, and treat with something like Neem oil. Azadiractin is the main ingredient in Neem oil, so you may want to opt for a concentrate. Spider mites are notoriously difficult to get rid of, so vigilance and consistency will be key.
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/azadirachtin-vs-neem-oil.htm