Grapevine leaf roller
The springworm moth is an 11 to 15 mm pest butterfly with a wingspan of 20 to 25 mm. The wings are brownish-yellow with two to three brown-reddish transverse bands and a spot at the base of the wing.
The eggs are scale-like, greenish-yellow in color, and are laid in overlapping groups.
The caterpillars are 20-30mm long and gray-green in color with a dark brown head capsule.
The pupae are about 12mm long and brownish in color.
The spring worm moth produces one generation per year, does not require much warmth and is also found in northern wine-growing areas.
The young caterpillars of the spring worm moth overwinter under the bark of the vine or in crevices of the vine stems in a cocoon. From the beginning of April to the beginning of May, they leave their hibernation hiding places and attack the buds. After developing and feeding on leaves and shoots for about 40 to 55 days, the caterpillars pupate in convoluted leaf nests. After a pupal dormancy of two to three weeks, the moths hatch, and their flight period extends from early July to late August.
The springworm moth lays several clutches of about 40-60 eggs, on the upper surface of vine leaves.
After about two weeks, the young caterpillars hatch from the eggs (from mid/late July to early September) and seek out overwintering quarters.
The caterpillars bore into and hollow out the buds at the time of budbreak and cause feeding damage to leaves, shoots and shoots after budbreak. The leaves and other infested plant parts are spun together. When these leaf nests open, the caterpillars retreat in a jumping manner ("jumping worm") and quickly descend to the ground on a secretion thread. The eaten leaves and shoot tips may wither and die. and feeding damage can lead to defoliation.
The feeding damage and the formation of webs on the shoots could be confused with infestation by the much smaller caterpillars of the first generation of thegrape berry moth ("hayworm").
Prevention and control
- Various predatory insects (e.g. ladybugs, lacewings, earwigs) as well as parasitic ichneumon flies and parasitic caterpillar flies are considered natural counterparts (protect beneficial insects!).
- Checks for egg deposition of the spring worm moth in the summer can serve as decision-making aids for possible shoot treatments in the following spring.
- The damage threshold for chemical plant protection measures is five to ten caterpillars per vine in the three- to five-leaf stage.
- As plant protection measures, only budburst treatments at the time of bud swelling (BBCH stages 01 - 11) or spring treatments from the three-leaf stage (BBCH 13 to BBCH 19) are considered useful - see the list of plant protection products approved in Austria.
Last updated: 04.09.2023