Garden Tool Set

Spinach leaf miner - Pegomya hyoscyami

Symptoms: Damage to the spinach leaf as the larvae mine through the leaves creating a blister. The epidermis has been removed from one side of the leaf, in the top photo, to reveal the leaf miner.

Cause: Caused by a the spinach leaf miner. The fly emerges in spring, mates and lays eggs on the spinach leaves (as below). They eventually drop from the leaves into the soil to pupate - creating the next generation. There can be several generations each year.

Control: Stop the adults reaching the spinach by using covers. Keep the area weed-free. Rotate spinach, chard, and beet crops. Try using a Neem based spray which acts as a repellant and also slows the leafminers' ability to feed, interrupting the cycle. Advice on making neem spray can be found here - I don't know of its effectiveness.