[7] It has spread to three regions: Europe, America, and New Zealand,[2] where it prefers host plants belonging to Rosaceae, which includes apples, peaches, pears and cherries.

[8] In North America, insects that initially fed on wild relatives of these host plants, such as native roses, may have gradually adapted to cultivated apple trees.

[8] The historical association between D. mali and the wild species within the Rosaceae family likely facilitated its transition to cultivated apple trees as its primary host.

The establishment of D. mali in Nelson would present significant challenges for the industry, as this invasive pest induces the formation of galls on host leaves.

[10] Although current iNaturalist observations[2] may not fully support the presence of D. mali in New Zealand's apple orchards, the species' close affinity with these environments suggests the potential for its establishment.

[10] Apples (Malus domestica) have a rich botanical and cultural history, with archaeological evidence suggesting their cultivation dates back thousands of years.

[12] As one of the most widely cultivated fruit species, apples have undergone centuries of selective breeding, resulting in a diverse array of cultivars.

[10] The larval feeding gall inducing behaviour leads to the characteristic symptom of rolled or twisted leaves on apple trees.

[13] Feeding induces the formation of leaf galls on the outer edges of the leaves, providing a protective tent for larval development.

[13] The transition from eggs to the end of the white larval stage typically spans 6–27 days, with later generations of the apple leaf curling midge exhibiting more rapid development.

[18] In North America, insects originally feeding on wild relatives of these crops such as native roses, may have transitioned to cultivated apple trees over time.

[16] The galls disrupt the normal growth and development of affected foliage, potentially leading to diminished fruit yields and compromised tree health.

[16] The predatory mirid bug, Sejanus albisignata is also a player in the ecological balance of apple orchards and has been observed feeding on eggs of the D.

[18] By synthesising the sex pheromone, researchers can create specialised traps or attractants that target male D. mali individuals, allowing accurate monitoring of populations.

[20] Pheromone-based strategies holds promise for integrated pest management approaches, offering environmentally friendly alternatives to conventional insecticide treatments.

[21] While mature orchard yields may not be significantly affected, reduced fruit size and bud formation could occur, impacting newly planted trees and nursery stock.