Q: What is wrong with my citrus leaves and new stem growth?
A: The leaf problem is caused by a small leafmining moth, Phyllocnistis citrella Stainton, or the citrus leafminer (CLM). Citrus leafminer (CLM) was found in late May 1993 in several citrus nurseries in south Florida. Since that time, CLM has been found everywhere in Florida where citrus is grown, and has spread to other Gulf Coast areas. Adults of the CLM are minute moths (4 mm wingspread) with white and silvery iridescent scales on the forewings, with several black and tan markings, plus a black spot on each wingtip. Adults generally are so small in fact, that people barely notice them. They are active mostly during the day but have been known to continue their normal activities in the early evening hours. Adults live for only a few days but in Florida generations are produced about every three weeks. They are not easily controlled using chemicals as they burrow between leaf and stem tissue and are therefore protected. Infected leaves and small stems should be pruned, bagged and destroyed to help manage the insect populations. A predatory wasp, encyrtid parasitoid, Ageniaspis citricola, was introduced from Australia to Florida in 1994-95, and seems to have the key element in suppressing this leafminer to an acceptable level.