This tiny sawfly (Blennocampa pusilla), measuring only about four millimeters in size, lays its eggs on the edges of leaves, which then curl up protectively around the larvae, turn yellow and fall off. Affected leaves should be collected and disposed of with household waste, as the larvae continue to develop on the compost.
The larvae of the rose leaf scroll wasp love to eat the roses
Life cycle of the rose scroll wasp
Females of the rose scroll wasp lay their eggs on the edge of the rose leaf, with no more than two to three eggs being laid per leaf as a rule. The adult animal then pierces the central rib of the leaf, causing it to curl up. The larvae hatch between April and June and eat the rose petals, causing them to die and eventually fall off. In the fall, the larvae burrow into the soil around the rose to pupate over the cold season. Next spring, new rose leaf scroll wasps appear, which in turn lay eggs on the rose - the cycle starts all over again. Affected roses usually do not die, but they are a very unsightly sight.
treatment and prevention
It is important to start treatment as early as possible to contain the spread. As soon as the leaves sprout in April, start checking the rose petals regularly for signs of rolling.
remove leaves
Affected leaves should be removed immediately.
- Cut these off directly on the rose bush.
- Don't leave a single curled leaf on the rose!
- It is better to remove one leaf more than too few.
- Use clean and sharp scissors.
- This should be disinfected after use.
- Dispose of the clippings with the household waste, never on the compost.
- The pest also continues to develop on the compost.
Encourage natural enemies
Fortunately, the rose scroll wasp has many natural enemies that like to settle in and fight the pest (as well as other rose pests) if the garden is managed in an animal-friendly manner. Birds in particular (especially the blue tit), but also hedgehogs, shrews and insects such as parasitic wasps,(22.99€) ground beetles and spiders like to eat the pest and thus help to contain an infestation in a completely natural way. The prerequisite, however, is to design the garden in a natural way.
- Set up insect hotels near the roses.
- Small stone walls with holes in them also attract various beneficial insects.
- Hedgehogs and mice feel particularly comfortable in piles of leaves and brushwood.
- Feed the birds in winter, but stop feeding them when the leaves begin to sprout.
Only use pesticides if the infestation is very severe
A close-to-nature management also includes avoiding the use of pesticides as far as possible - these not only affect the pests, but also the desired livestock. This measure should only be considered in the case of a very severe and otherwise uncontrollable infestation by the rose leaf scroll wasp. Ask your specialist dealer for suitable and approved agents, which can then be sprayed not only on the plant itself, but also on the soil in late winter. The treatment is repeated in spring, spraying the underside of the leaves before they curl up.
tips
Holes in the rose petals, on the other hand, are an indication of an infestation with the larvae of the rose sawfly.