leaf miners are the larvae of flies, moths or beetles the feed between the upper and lower epidermal section of leaves. these larvae mine through the leaf in sometimes sporadic patterns or larger area blotches. as they feed they will leave excretion in the leaf that you will be able to see as where they have mined will be clear or opaque.
female flies will puncture the leave with their ovipositors to lay eggs inside the leaf structure, the larvae will then start its life ones hatched and mine the leaf.
many ornamental trees/plants are attacked by leaf miners but azalea, bougainvillaea, ixora, hollies, chrysanthemum, lantana, oak, and boxwood are a favourite for them.
control and iradication
so how do we control and iradicate? there is several options available including chemical but generally it is a simple as removing infected leaves and destroying them, this will fix that look of leaf mines, although not a major pest it can make the tree/plant unattractive. keeping the plant/tree healthy and well fed will allow the tree to outgrow the miners.
chemical wise, contact sprays are generally useless as the problem is inside the leaf where the contact spray cannot get to, so a systemic is a better option, remember not to use systemics on chinese elms as it can be disastrous to the plants health and will most definately kill the tree.
a systemic spray is good for the control of these sort of pests as it is taking in through the roots and spreads out to the whole tree through bark and leaves. this will get to the source of the problem of leaf miners and then leaves can be pruned and destroyed.
as usual if you have anything you would like to add please feel free, we are trying to build a database so any personal experiences, knowledge or questions are most welcome.
jamie
written by me.
pictures sourced via various locations on the internet.
taking the top half of trees of since 2005! 
