My lemon tree is also losing leaves rapidly and I have noticed small flying insects around it and some fine cobwebs on the plant. It is sitting in a conservatory so I will move it to somewhere less sunny and will check the soil temperature but I thought it a coincidence that someone else also had the flies around it and leaf drop (my leaves have taken on a slightly mottled, dusty, yellowy tone too). Any tips greatly appreciated as I have nurtured this tree all year!
The webbing and speckled foliage are indications of an infestation of spider mites. They can be treated with repeated applications of insecticidal soap as indicated on the product label. An alternative product to use is horticultural oil. The "small flying insects" may be fungus gnats if they're tiny and black. Their presence is an indicator of excessive moisture in the soil. Allow the soil to dry somewhat before watering.
Thank you. I thought it might be spider mite having read other posts and I suppose the cobwebs were a giveaway! They are so tiny though that they look like speckles of soil or dust. I will go straight out and buy some insecticidal soap and treat it until better. Thanks again.
I have the exact same problem, and I sprayed ours with some dish soap and water mix - seems to have worked.
