The journey of sustainable citrus farming in agriculture
Leaf miner control with the parasitic wasp Diglyphus isaea
Diglyphus isaea is a small parasitic wasp belonging to the family Eulophidae within the order Hymenoptera. It is widely recognized for its role as a biological control agent for leaf miner control. Its ability to effectively target and suppress these pests makes it an invaluable tool in sustainable agriculture and integrated pest management programs.
Diglyphus isaea is used for the control of the following pests:
The parasitic wasp Diglyphus isaea is available at Koppert as Miglyphus
Diglyphus isaea products
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Best conditions for Diglyphus isaea
Diglyphus isaea is most effective at temperatures between 15°C and 25°C (59 and 77°F).
How to use Diglyphus isaea
The parasitic wasp Diglyphus isaea is available in a bottle (Miglyphus).
- Release parasitic wasps between the leaves of the crop in the morning or in the evening
The dosage of the parasitic wasp Diglyphus isaea depends on climate, crop and leaf miner density and should always be adjusted to the particular situation. Start introduction as soon as the first mines are visible in the crop. Introduction rates typically range from 0.25-3 per m2/release. Releases should be repeated at least 3 times at weekly intervals or until control is achieved. At low temperatures (<20°C/68°F) it might be better to use Minusa. Consult a Koppert advisor or a recognized distributor of Koppert products for advice on the best strategy for your situation.
Behaviour of the parasitic wasp Diglyphus isaea
Diglyphus isaea is a parasitoid wasp renowned for its role in controlling leafminer pests, particularly the serpentine leafminer (Liriomyza trifolii). The female wasp deposits her eggs inside the larvae of the leafminer, where the emerging larvae feed on the host’s internal tissues. As they develop, the larvae consume the leafminer from within, leading to its death. This feeding behavior is highly effective in reducing leafminer populations, as each Diglyphus isaea larva can eliminate multiple leafminers during its development. The wasp’s feeding rate and efficacy can vary with the density of leafminer infestations, allowing it to adapt to changing pest pressures. Adult Diglyphus isaea does not feed on leafminers but sustains itself on nectar and honeydew.
Life cycle and appearance of Diglyphus isaea
Because Diglyphus isaea is an ectoparasite, all instars (egg, larva, pupa and adult) develop outside the host.
- Egg stage: A female wasp first paralyzes the leaf miner larva and then lays a single egg (occasionally more) next to it. In general, the wasp selects late second and third instar larvae to parasitize. An egg has an elongated shape, measuring 0.3 x 0.1 mm, and is transparent white in colour. It lies alongside the paralyzed leaf miner larva and is often difficult to spot.
- Larval stage: When the parasitic wasp larva hatches, it remains beside its host, punctures it and sucks it empty from the outside, as a result of which the leaf miner larva dies. A few days after being parasitized, the leaf miner larva turns flaccid and brown. Older larvae of D. isaea leave their dead host and crawl back into the mine to pupate. There are three larval instars: the first is colourless and transparent, the second is yellow and semi transparent with a brown fat body, and the third larval instar is blue-green. The full-grown larva usually pupates in the mine some distance from the dead host.
- Pupal stage:The pupa lies between the upper and lower epidermis of the leaf which are held apart by six pillars, made by the larva from its faeces. This is probably done to prevent the leaf collapsing should it dry out. At first, the pupa is green with red eyes subsequently turning black, and measuring about 1.5 mm.
- Adult stage: The appearance of the adult is already clearly visible. Pupae are often visible through the leaf. The parasitic wasp escapes from the mine by making a round hole through the upper epidermis. These round holes are the evidence that a parasitic wasp rather than a leaf miner has come from the mine. This is also seen in the pillars that remain visible as black spots in the leaf. The adult is metallic green to black in colour and unlike D. sibirica has short antennae. The female is generally rather larger than the male and can be recognized by a broad black stripe over the hind leg, whereas males have two small black bands
