Citrus - Phyllocnistis citrella; Groundnut and soybean - Aproaerema modicella; noch weiter recherchieren!
Leafmining caterpillars (Leucoptera meyricki and Leucoptera caffeina)
The adults of leafminers are very small (3-4 mm long) white moths. They lay very small eggs (just visible to the naked eye) on the upper leaf surface scattered in small groups (L. meyricki) or touching each other in a neat row along a main vein (L. caffeina). Upon hatching, the caterpillars bore into the leaf and mine just below the upper leaf surface. The mines of each L. meyricki caterpillar are initially separated but after few days they join to form one large mine. The young caterpillars of L. caffeine produce one communal mine. These mines appear as irregular brown blotches on upper side of leaves, which when opened reveals many whitish caterpillars.
Caterpillars are flattened, white and very small (4-8 mm when fully grown). Mature caterpillars come out of the mine and pupate in a H- shaped cocoon (6 mm long) on dead leaves on the ground or on the underside of leaves on the tree.
The mining activity causes a reduction of the active leaf surface, reducing assimilation. Attacked leaves are usually shed prematurely. Leafminers can live on shrubs belonging to the same family as coffee (Rubiaceae family).
- The caterpillars and pupae are attacked by a large number of parasitic wasps, which occur naturally in the field, and eggs are sucked dry by a predacious mites.
- Economic threshold level: If they tree is shaken vigorously and more than 35 moths are seen, the yield of coffee can be affected. The indiscriminate applications of insecticide usually kill the natural enemies faster than it kills the moths, resulting in more serious attacks.
- When intercropping Artemisia with coffee in East Africa, the incidence of coffee leafminers is drastically reduced (Per Diemer, FAO consultant).