Leaf Miner Predator (Diglyphus isaea) Vial of 250 Adults - Live Parasitic Wasps for Leaf Miner Control
Best for: growers spotting the first leaf-mining tunnels on their crop who want a targeted biological control rather than a broad-spectrum spray.
Our thoughts
This is a vial of live parasitic wasps, so it needs releasing properly and promptly, not left on a shelf. Diglyphus isaea has a genuinely clever way of dealing with leaf miners: it paralyses the larva inside the leaf, lays an egg next to it, and the wasp offspring feed on it as it develops. Release it as soon as you see mines starting to appear rather than waiting for a full-blown infestation.
This vial contains 250 live adult Diglyphus isaea, an ectoparasitic wasp used as a biological control for leaf miner larvae, including Liriomyza species and chrysanthemum leafminer. The adult female wasp locates a leaf miner larva feeding inside the leaf, paralyses it, and lays an egg alongside it; the wasp larva then feeds on the paralysed host as it develops. Adult females also directly kill and feed on some larvae that are too small to support a developing parasitoid, giving a second mode of control beyond parasitism alone.
Being a live product, it needs handling carefully from the moment it arrives. Biological control suppliers who work with this species (including Koppert and Bioline, who supply Diglyphus isaea commercially) advise using the wasps within around 18 hours of receipt and keeping them in darkness at roughly 10 to 15°C until release. Release as soon as the first mines are visible in the crop, ideally early morning or late afternoon, holding the vial horizontally and gently tapping it while walking through the affected plants so the wasps spread naturally rather than being dumped in one spot.
How it compares
Leaf miner control has a handful of routes, biological and chemical.
- Dacnusa sibirica is a companion parasitic wasp species often used alongside Diglyphus isaea, it prefers cooler conditions and is an endoparasitoid, so the two are frequently combined rather than used as alternatives to each other.
- Chemical leaf miner sprays can work but kill other beneficial insects in the room indiscriminately and leave residue on the crop.
- Yellow sticky traps catch adult leaf miner flies for monitoring purposes but don't control larvae already mining inside the leaf, so they're a detection tool rather than a treatment.
For a targeted hit on leaf miner larvae that doesn't disrupt a wider biological IPM programme, a parasitic wasp like Diglyphus isaea is the more precise option.
Usage guidance
Correct storage and release technique both matter with a live parasitic wasp product.
Storage on arrival
Keep the vial in darkness at around 10 to 15°C and use within roughly 18 hours of receipt rather than storing it for later.
When to release
Release as soon as the first leaf miner tunnels are visible in the crop rather than waiting for a heavier infestation to develop.
How to release
Release early morning or late afternoon. Hold the vial horizontally, carefully remove the lid among the plants, and regulate the release by gently tapping and tilting the vial as you walk through the crop.
Follow-up
Monitor for fresh mines over the following one to two weeks and repeat the release if the infestation isn't clearing.
Technical specifications
- Species: Diglyphus isaea
- Life stage supplied: Adults
- Quantity: 250 per vial
- Target pest: Leaf miner larvae (Liriomyza spp. and chrysanthemum leafminer)
- Mode of action: Ectoparasitism plus direct host-feeding on smaller larvae
- Storage: Dark, approx. 10-15°C, use within approx. 18 hours of receipt
- Product type: Live biological control agent
Who this is for
- Growers who've spotted the first leaf-mining tunnels and want to act before it spreads
- IPM programmes wanting a targeted leaf miner control that won't harm other beneficials
- Growers who can release the wasps within a day of delivery rather than storing them
- Anyone avoiding chemical sprays in a room already running biological pest control
Our take
Handled correctly, live and released promptly, Diglyphus isaea is a precise, effective way to deal with leaf miners without reaching for a spray that would undo the rest of your IPM programme. It's a specialist product, so read the storage and release guidance before it arrives.
Does exactly what it should when released promptly and correctly, a solid pick for growers already committed to a biological pest control approach.
