Lightbrown apple moth - Life history

Most of the lightbrown apple moth population spends the winter as young (2nd to 4th stage) caterpillars on ground cover plants, on fallen leaves, in fruit buds, or occasionally under the bark. There is no true dormancy and the caterpillars feed on warm winter days. The caterpillars complete their development, spin a loose silken cocoon, and change to pupae in the spring and early summer before emerging as adult moths. In southern areas with two generations per year, emergence begins in early November and is spread over December and most of January. Males emerge a short time ahead of females. The second generation emerges from February to May. In northern areas, the emergence of the overwintered generation is completed by December, the second generation of adults occurs over January/early March, and overlapping with the third or partial third generation occurs in March to June. Females are normally mated only once and egg laying usually begins on the following day (range 1-7 days later) and reaches a peak after 2-3 days. They mature and lay a series of egg batches on the upper surface of leaves over a period of up to three weeks, although females may live for six weeks. The caterpillars hatch within 1-2 weeks and disperse to settle on the lower surfaces of leaves, often against the midrib and main veins. As the caterpillar grows, it moves to new sites, such as between two leaves, between leaf and fruit, or within a roll created by folding the edge of a leaf. Prior to pupation, the majority of larvae leave their feeding sites and prepare new rolls or spin up specially for pupation and emergence. A generation is completed in about 675 day degrees above 7.5^oC, which allows completion of 2-4 generations per year depending on latitude. The optimum temperature for development is about 20^oC and larval development is completed on apple leaves in 32 - 40 days at this temperature.

This life history is summarised in the life cycle charts.