Italiano English
Download PDF

Cydalima perspectalis, a threat for buxus

C.p has been detected for the first time in Germany in 2007. After that date the pest kept spreading his population reaching theneighbors Francia, Switzerland, United Kingdom, a Netherlands within 12 months from it’s first appearance. In 2009 it has been detected in Austria and Holland. Italy found out his first pest infection in July 2011 in Lombardy, in the province of Como. Being considered an easily spreading pest, in 2007 it has been classified from the EPPO (European and Mediterranean plant protection Organization) in a alert list (Eppo alert list) where it has for more than three years. The past warning of 2007 has been considered enough for the year 2011 and it has been removed from the alert list unless differently asked by the country member of the EPPO.
Fortunately this pest is not in a quarantine list, but larvae that usually feed on leaves of Buxus are the cause of large aesthetic, physiologic and economic damages.

Biology and description. Adults is a butterfly with 4 cm of wingspan and white wings with nuances of gold and purple edges brown.
The biological cycle is not perfectly known yet: the first studies made in Germany and Italy seems to demonstrate that this insect made up four generations each year and is able to get overwinter as pupa on trees. The year after, within the month of March when temperature rise up at 20°C the cycle get completed, adults reach their life stadium and with their eggs give birth to the first generation.
 The butterfly(adult stage) live normally 8 days and can fly several kilometers far. Despite his excellent attitude in flying, the main cause of his diffusion in far places from his original one is recognizable to the transport of plants among countries infested of eggs, larvae and nymphs. The eggs, only few millimeters big, are laid in groups of 25-30, casted one above another, on the low side of the leaf. The eggs get pale yellow in the beginning, almost transparent, and become darker while get mellow. Green yellow larvae are characterized by black and white stripes alongside their body, moreover they are covered by sparse hair originated from black pustules located longitudinally on the body.
 When adults, their size is normally around four cm, at that stadium they’re the main responsible for aesthetic damages, feeding by leaves and buds. High levels of infection can determine the complete loss of leaves on plants full of silk threads. They normally need 25 days to reach their adult stage, after that they become chrysalis. Nymphs normally are 2 cm length, they are green with black stripes alongside their back at first, they change their color to a darker brown becoming adults. They are normally well hidden into the vegetation, where, thanks to silk threads, they keep hanged to the leaves for around 14 days, meanwhile they do have enough time to turn into adults. At the end of the third generation Ninphs does not become adults suddenly but keep dormant waiting for better and more suitable climate conditions in Spring.

Prevention and defense from diseases. Prevention against pests is actually limited to a pest free check when plants arrive from infected countries; It is necessary to verify that these bought plants has to be free from any sort of pest attacks, eggs, larvae or ninphs .When the insect already successfully colonized a new area, spreading quickly, the only possible way to counteract is by using specific insecticides. Pest management of these phytophagous insects can be of three types: Biological, chemical and with use of biotechnologies.
Some products with a natural origin commonly used are mainly composed by piretro or with the use of Bacillus thuringensis var. kurstaki. Chemical control and biotechnological control, having a strong impact on the environment, need to be done following strict instructions for the use of authorized pesticides in order to reduce risks for our health and the health of the plants itself. Considering the numerous generations that this pest does within a year and the different growing stages, an efficient strategy could be the use of a mixture of bio technologic products( growing controller,inhibitor) and a chemical product.
The best time to assure a higher probability to win against this pest is to make treatments and prevent potential damages on the vegetation is the disclosure of eggs and of course the first stages of life of larvae.

Cydalima perspectalis (C.p) is the last pest arrived in Europe and It’s quickly spreading his population. It has a very fast growing rate having an average of 4 generations per year.