Box tree moth caterpillars remain undetected for a long time. On the one hand, they start their feeding hidden inside the crown. On the other hand, they do not stand out visually from the foliage. But their massive presence cannot remain hidden forever - a challenge begins.
How dangerous are boxwood moth caterpillars?
Caterpillars of the box tree borer arevery voraciousIn the event of a mass infestation, they defoliate the entire box tree and weaken it accordingly. Neighboring boxwoods are also at risk. If the caterpillars of the boxwood borer are not fought early and with persistence,the box can die
What do boxwood moth caterpillars look like?
Young larvae of the boxwood moth (Cydalima perspectalis) are about 8 mm long, yellowish-green in color and have a dark head capsule. The adult caterpillars have the following characteristics:
- Length:up to 5 cm
- Basic color:yellow-green to dark green
- Pattern: black and white vertical stripes and black dots
- Head capsule: brown-black
- Other: white bristles
Also pay attention to fine webs and droppings on the foliage of the boxwood.
When are the larvae active on the boxwood?
Depending on the weather, the first caterpillars of the European borer, which migrated from East Asia, can alreadyfrom Marchfeed on the boxwood. This is the last generation from the previous year that overwintered in the boxwood. In Germany, the box tree borer can produce two, three or even more generations per year, depending on the region's climate. That's whyfrom spring to autumn you can always expect caterpillars.
How can I effectively combat boxwood borer larvae?
If your boxwood is already covered with many thick caterpillars, control methods are required that quickly have an effect:
- Collect caterpillars by hand
- rinse out with high-pressure cleaner
- vacuum with vacuum cleaner
- inject diluted neem oil
- spray with soft soap solution
- Use preparation with Bacillus thuringiensis (e.g. Xentari)
How can I prevent larvae from infesting my boxwood?
Prevent the butterflies from laying their eggs on the box with algae lime or primary rock powder. With an early pruning in March you can remove a large proportion of the previous year's overwintering larvae. Check the boxwood regularly from spring to autumn to detect an infestation early. A pheromone trap that attracts male butterflies can help you with this. Finally, encourage natural enemies such as sparrows or great tits.
Tip
Be sure to apply all spray agents with high pressure
No matter whether you use neem oil, soap solution or another insecticide. You should always use a pressure spray bottle to penetrate the fine webs.
