Miner enquiry ends up in Australia

Mystery leaf miner

My last blog was all about getting down to the same level as the small, rather prostrate Fluellen plants and taking a good close look at this delightful annual species. I mentioned that while I was observing them I noted how Bumble bees were busy nectaring on the flowers, but I also spotted that something had been “mining” the leaves – so I took some photos to see if I could get the culprit identified.

I am lucky enough to know a wonderful entomologist who specialises in Leaf Miners, so I sent him the pictures to see if he could identify what insect had been busy munching these leaves. The larvae of leaf miners form a narrow, linear mine between the upper and lower leaf surface – literally consuming the inside of the leaf, rather like eating the contents of a sandwich without eating the bread!

You can find out more about this tiny world by going to: http://www.leafmines.co.uk/

Anyway, my little leaf pattern makers turned out to be made by the PEA LEAF MINER -Chromatomyia horticola. 

It is found across much of the world and is a species of fly that is a pest of high economic importance affecting the vegetable crops in some temperate and tropical regions. It belongs to the family Agromyzidae which is the most familiar group of leaf miners that effect horticultural crops, and contains species such as the Tomato leaf miner Liriomyza bryoniae and the Chrysanthemum leaf miner Phytomyza syngenesiae.

The large number of tunnels made by the larvae between the lower and upper epidermis interferes with photosynthesis and proper growth of the host plants, also making them look unattractive, so that the market value of salads or flowers can be severely affected. In fact, Australia categorises this same little fly larvae that was quietly munching away on my Fluellen plants, as a “high priority pest!”

Therefore, by lying prostrate on the ground in a Hampshire field so as to get close up and personal with a tiny flower, my observations and consequent enquiries, eventually take me to the other side of the world. Fascinating stuff!   

The culprit - a Pea leaf miner fly