Caterpillars for boxwoodmay appear from spring. They strongly bite the leaves, sometimes causing the bush to be completely stripped. It happens that entire rows of boxwood bushes die. See where the caterpillars for boxwood come from andhow to save boxwoodfrom the attack of this pest. We advise on how to fight voracious caterpillars and how to performspraying against boxwood caterpillars
The caterpillar visible on the boxwood is the larva of the boxwood moth
Fig. depositphotos.com
Where do the box tree caterpillars come from?
The voracious caterpillars that appear on boxwoodsince spring are most often the larvae of the Asiatic moth (Cydalima perspectalis), more commonly known in Poland as the box moth. The pest came to Europe from East Asia, possibly with imported plants, and mainly attacks evergreen boxwood and other boxwood species.
The caterpillars are green with darker stripes running along their body. The caterpillar can be up to 4 cm long.Young caterpillars gnaw the edges of boxwood leaves, while the older ones eat the whole leaves . The presence of caterpillars is accompanied by a string of silk threads.
A caterpillar of a boxwood moth gnawing on boxwood leaves
Fig. depositphotos.com
Caterpillars of the boxwood moth feed mainly inside the boxwood , in its central part, making them difficult to spot at first.Once the symptoms are visible from the outside, it is often too late to save the bush.
Caterpillars hatch from eggs laid by butterflieswhose wings can be white with a brown border or light brown , with a purple sheen and a white, crescent-shaped spot. These butterflies are adult boxwood moths.
This butterfly is an adult form of the box moth
Fig. depositphotos.com
This boxwood pest has only been observed in Poland for a few years, and it probably came to us along with the warming climate. During this brief presence,the caterpillars of the boxwood moth had already taken their toll onboxwood owners and caused large-scale damage. The caterpillars damaging the box trees became particularly loud in 2017, when there were numerous reports of entire rows of box trees destroyed in the vicinity of Krakow.
Boxwood bushes damaged by caterpillars
Fig. depositphotos.com
How to combat boxwood caterpillars?
The boxwood moth in Europe has no natural enemies in nature , therefore it spreads very quickly. Attempts to bring the Asian hornet from Asia, which eat the larvae of the box tree moth, have failed, because the hornet turned out to be a threat to native bees.So we have no other solution but to fight the boxwood moth on our own , using methods available to gardeners.
To save boxwood from caterpillar invasion , first of all, it is worth observing to spot the pest in time and perform the necessary spraying. Boxwood moth moths can fly from April to September and we need to be vigilant all the time.
In order to signal the presence of the pest , pheromone traps are used to catch adult butterflies. However, the traps catch only males and mainly help to observe the presence of the box tree moth (they are not a sufficient way to combat it).
However, I recommend installing pheromone traps, because we often notice caterpillars on bushes too late. Well,the caterpillars of the box tree moth initially feed inside the crown of the bush , and when the leaves from the middle shoots are gone, they move to the outer ones. It is often only at this point that we notice the presence of the pest and it is too late to save the bush. The pheromone trap will allow us to notice the presence of adult moths before eggs are laid on the bushes and voracious caterpillars hatch.
In order to prevent the complete destruction of the boxwood, you need to spray the caterpillars
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After spotting the caterpillars on the boxwoodyou can spread the foil under the bush and shake the twigs vigorously to shake off the caterpillars. The pests must be destroyed immediately (e.g. trampled or burned). Caterpillars that cannot be shaken off the bushes must be selected by hand. This will limit the pest but never eliminate it (it is difficult to get rid of all caterpillars this way, and others may still hatch from the eggs they lay).
Therefore, in order for the fight against boxwood moth to be effective, it is also necessary to perform spraying. The biological preparation Lepinox Plus 30g is the best for this purpose. It contains the bacterium Bacillus thuringiensis, which infects the caterpillars of the box tree moth, killing them within 3 days of spraying, and stops feeding on the first day.
Lepinox Plus is a safe to use preparation for combating boxwood caterpillars , allowed for use in organic farming. We can buy it in small packages, containing 3 sachets of 10g.10 g sachet should be dissolved in 5 liters of water. It is therefore a quantity that matches the most common garden sprayer capacity. When spraying, make sure to spray not only the outer shoots of the bush, but also the middle ones, by inserting the tip of the lance with the nozzle inside the boxwood crown. Due to the high efficiency and high safety of use,ecological Lepinoc Plus is the best preparation for combating the caterpillars of the box tree mothin home gardens and allotments.
However, according to its label, Lepinox Plus can be used no more than 3 times during the growing season, andthe feeding period of the caterpillars for boxwood is very long(from April to October, and therefore, up to 7 months), we can additionally support ourselves with other preparations for the protection of boxwood, which are registered against other pests that suck and eat leaves, but will also be effective in combating the caterpillars of the box tree moth.
As the caterpillars feed inside the shrub's crown , the usual surface and contact agents usually turn out to be ineffective (spraying does not reach the caterpillars). That is whyspraying against boxwood caterpillars must be performed with systemically or systemically acting agentsThis solution is suggested, among others, by dr hab. Paweł K. Bereś from the Institute of Plant Protection - National Research Institute in Rzeszów in the article How to save box trees? (Działkowiec, 1/2020), which lists, among others preparation Polysect Boxwood 005 SL. The same active substance and mode of action is also found in Mospilan Bukszpan 20 SP.
An agent combating caterpillars for boxwood
Fig. Substral
After spraying,Polysect Boxwood 005 SL is absorbed by the leaves and circulates throughout the plantwith its juices. Even if the spraying is not done very accurately or does not reach the inside of the bush directly, the preparation will be spread over the entire plantdestroying pests feeding on the boxwood leaves
Since the caterpillars attack on boxwood can be very sudden, and after noticing foraging symptoms, it may be too late to save the bush, it is recommendedto spray caterpillars on boxwood as early as April, when the moths of the boxwood moth begin to fly and lay eggs. Especially, if the conducted inspections of shrubs or catches for pheromone traps showed that the pest actually appeared.
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