Samu,
Your battle with these pests will never end unfortunatly. Once the leaf miner population is established they will return like clockwork every year. I too had limited success with leaf miner control initially until I understood how these pests operate. Anyway here is the mix ratio for Macho that Ive used. It is much more cost effective than Bayer and a far superior product for leaf miner control from what Ive experienced.
My Flowering is completed usually by Mid March. Some years though into April first. I adjust the below later to correspond with the end of flowering and bee foraging.
I use 1 tsp per 10 oz for soil drench inground plants. Pour around base of tree. Water lightly in. I apply March 15. By doing so the plants are already protected when the first leaf miners cycle begins April 1-15 here. The idea that leaf miners like the second flush while accurate is misleading as some of my Citrus break dormancy earlier and those later to wake up to first flushes being attacked by miners. Then like clockwork with bearing trees reapply every 35 days as the second and subsequent doses take 2-3 weeks to be drawn back up through the plant. I wont go indepth into Imidachlropid as it would take days and there is enough info out there already. But I will say this - the plants root system will only absorb so much of the compound wether .23 or 21.4% Imidachlropid- both which in ratio proportion to water are lethal to leaf miners. From my observations in my garden Macho leaches out of the soil slower due to the higher concentration allowing the plant to perhaps attain a longer period of root uptake. I say this because my Myers lemon tree flushes very fast and can actually outgrow the chemical coverage at the new flush leaf tips. Bayer did not work-Macho did. Then after reading the label for Macho you can decide how close to harvest you want to use the product. My advice is what I use to stop them.
Bayer for me works in my potted plants but not so much for inground trees.
I would suggest reading the label first.
use
http://hortipm.tamu.edu/ipmguide/ento/chapters/dilution.html to understand dillution ratios as boring as it is- it has helped me put my mind around the idea of mix ratios.
The following info is what I use for NON BEARING CITRUS-youngsters- those 1 or more years out from first fruit as in my opinion they are non bearing ornamentals . It is what Ive found to stop completely miners and is a spray pattern I use only after understanding compound half life, residual and toxicity.
First Macho 2.0 in April or so. Foliar spray Avid -Avid at 4ml per gallon to new flush growth. The miticide wipes out leaf miners at it pools inside the leave itself (translaminor) for 28 days. It also counters mite outbreaks I have noticed after Bayer or Macho. Ive used both in tandem and never had a citrus leafminer problem period.
Currently Im using Macho 2.0 with suffacant-spreader sticker- to new flush only on my larger trees in trandem with MACHO 2.0 soil drench.
