Citrus need to be checked and sprayed against woolly aphid, as this can cause tremendous damage in summer and indeed stunt or kill off any fruit production. Most citrus fruits swell and grow in late summer to autumn and then ripen in winter. For this reason, please avoid the use of long-term systemic insecticides in summer, as this will render the fruit inedible.
We recommend that either regular weekly applications of an organic mineral oil is sprayed, or that short term Systemic Dimethoate (Grovida Aphids) based insecticide is used, as this only is active between three and four weeks. This will decimate the woolly aphids plaguing trees and the fruit will be safe to harvest 4 weeks after this.