Leaf Miners - The Bane of Most Citrus Trees


     Most of the questions I get regarding citrus leaf miners usually start off with one of two ways:
  • 1. The leaves on my citrus are shriveling up and have some squiggly lines embedded in them.
  • 2. The leaves on my citrus are curling up and have shiny little trails on them.

As a solution, a homemade regimen was concocted, and I can assure you the regimen below works. Once I saw the first infestation of leaf miners on one of my satsumas, I started the weekly control below on all my citrus trees (lemon, lime, and satsumas), and I haven't had a problem since.


Citrus Leaf Miner Regimen: Alternate Neem Oil and Spinosad

     Spray with one, wait a week to 10 days, and spray with the other. Here are some thoughts regarding the use of these two products and controlling leaf miners in general:na
  • One you start the alternation of neem and Spinosad, you must CONTINUE the process on a weekly or every-other-week basis.
  • You can stop applications once temperatures go below 85 degrees for an extended period. In Houston, this is typically from November through March.
  • Despite the warning on Spinosad labels, you CAN use it more than three times in a season, because you are alternating the controls - not just using Spinosad.
  • The alternating of controls keeps the insects from getting used to one insectide.
  • Neem oil and Spinosad are both organically-derived products and safe for fruit-bearing crops. There are no known "systemic" chemical controls for citrus trees.
  • The moths, which lay the leaf miners, love new growth. Thus, new growth needs the treatment.
  • While they can make a leaf turn "ugly," leaf miners are not life-threatening. These insects are relatively new to the Houston area — the problem originated in Florida in 1993 and came to Texas around 1995.
  • Highly infected/affected leaves can be pinched off.
  • Curled-up leaves are often an additional sign of leaf miners. Spread the leaf out to be certain and look for "snack trails."
  • You can find neem oil in most garden centers, but Spinosad is most often found in independent nurseries and garden centers rather than at "big-box" stores and mass merchandisers.
  • If you don't have an infestation, it has been noted that you can use these two as a preventive, on a 10-14 day basis.

Randy Lemmon is the host of the GardenLine radio program on Newsradio 740 KTRH. Randy has been doing GardenLine in one capacity or another since December of 1995, for all three of the now Clear Channel AM stations - KTRH, KPRC & KBME. When Randy took over GardenLine, he replaced long-time Houston radio veteran and GardenLine originator, Bill Zak. For those who remember that far back, GardenLine was a weekly radio staple on KTRH from 10 a.m. to Noon Mondays through Fridays - along with a Saturday show as well. Now GardenLine is heard exclusively on Newsradio 740 KTRH on weekend mornings.