Recent data to the knowledge of the Japanese mulberry scale (Pseudaulacaspis pentagona targioni-tozetti 1886) (Homoptera: coccoidea)

In recent decades the Japanese mulberry scale (Pseudaulacaspis pentagona Targioni-Tozzetti) has considerably increased its area of distribution in Hungary. Its density extended primarily in the surrounding of Budapest, but its area increased in the middle of the country towards north-east as well as towards north-west. The number of males caught in pheromone traps significantly decreased in some places (e. g. Budapest), or decreased even to zero (Debrecen) by 1993. In other places, however (Kecskemet), there was an increase noted in the number of males between 1991 and 1993. The scale insect has appeared also in southern Slovakia; its progress seems to be promoted by mild winters. The spread of the Japanese scale could be especially followed by using pheromone traps as in case of low individual densities new foci of infestation are hardly detectable by plant surveys. Yellow sticky traps with vaseline were also useful in detecting the flight of males while for catching parasitoids Tanglefoot had to be used as sticky material. The attraction of pheromone traps was not satisfactory in case of scale parasitoids. In the flying period of males fluctuations of 1-2 months were observed. Between 1991 and 1993 the winter mortalities of females varied from 34,6 percent to 100 percent in different parts of Hungary, whereas cold minus 20 C mountly averages of minus 3-4 C degrees did not seem to prevent the spread of infestation. From among the natural enemies the specialised Encarsia berlesei was the most effective between 1991 and 1993, causing mortalities of 8,4-53,5 percent. Ectoparasitoids caused mortalities of 0-23,7 percent, while predators decimated the scales by 0-4,6 percent. It was concluded that the natural enemies are unable to stop the progress of Japanese scale in present years favourable for its reproduction and the use of chemical control methods is recommended