Identification of leaf-mining insects via DNA recovered from empty mines

It is difficult to identify plant-eating insects once they have finished eating a particular plant. However, identifying these plant-eating insects is important especially if they are causing great harm to the plant. A particular group of plant-eating insect, leafminers, feed within the leaves of plants. These are notoriously difficult to identify because the larvae, which feed within the leaf, do not have many identifiable features and the adults, which generally do not feed on the plants, do not remain with the plants. When the larva finishes feeding, it leaves the plant and the ‘mine’ remains with some of the insect’s cells in the mine.

Matching the insect to the plant becomes a challenge. One way of identifying the insect that fed on a particular plant is to look at a portion of their DNA known as the barcode. In this study, we propose a refinement to a method where we are able to identify the insect from the left-over mine. We suggest cutting the mine out of the leaf with a sterile scalpel, crushing the mined leaf section and extracting the insect DNA from that. We succeeded to identify the leaf miner 20% of the time, which is an improvement of previous methods. But from 11% of the time, we were able to identify other insects that may be associated in some way with the plants, which leads us to believe that this method can used in monitoring insects in insect-plant interactions.

Read the full paper — Identification of leaf-mining insects via DNA recovered from empty mines by Julia J. Mlynarek, Jin-Hong Kim and Stephen B. Heard on the FACETS website.