engleski

Occurence, Spreading and Population Density of Western Corn Rootworm (Diabrotica Virgifera Virgifera Leconte, Coleoptera : Chrysomelidae) in Ccroatia in Period 1996-2001.

Western corn rootworm (WCR) was found for the first time in Croatia in 1995. Since 1996 pheromone traps (PAL) and yellow sticky traps (Multigard or Pherocon AM) were used for monitoring of WCR. Each year WCR was monitored on 119-145 monitoring sites. Some sites were located in previously infested regions, some sites were located along the line of spread and some whithin uninfested areas. The population density was observed on 10 permanent monitoring sites. The established line of spread of WCR in Croatia was in 1995 Županja- Vukovar. In 1996, WCR moved 40-60 km to the west and the line of spreading was Moslavina Podravska- Beničanci-Đakovački Selci – ; ; Šušnjevci. In 1997, WCR moved 30-35km to the west and the line of spreading was Gornje Predrijevo-Kutjevo- Pleternica-Batrina. In 1998, movement of the WCR to the west was much less than in the previous two years. The only movement recorded was along Sava river in the southern part of the infested area. In 1999, WCR spread up to the line Gola-Daruvarski Brestovac-Novska, approximately 30-45 km to the west. In 2000, the WCR spread up to Mali Bukovac-Nova Rača- Klokočevac-Pakračka Poljana-Novska, 20-30 km to the west. On only one monitoring site located outside of the area infested in 2000, in 2001 one WCR male was caught. The infested area of Croatia is about 15 500 km2. Of that area there is about 800 000 ha of arable land on which 560 000 ha is sown to crops. Out of that area, 220 000 ha of corn is sown. The movement of WCR in Croatia correspond to the movement of WCR in other neighbouring countries. The population density was observed on 10 permanent monitoring sites. The population density of WCR in each year was higher than in previous year. The estimated population growth index for the years 1996-2001 was between 1, 7 and 3, 6 times with an average of about 3 times. In the regions where WCR was first time observed in 1995 (around Vukovar and Županja), the population level has been increasing and the catch in pheromone traps in 2001 was more than 60 beetles/trap/day. The emergence of beetles in Croatia starts between June 15 and July 4 with an average being June 30. The maximum appearance of beetles in the field is observed, depending on the year, in the 2nd and 3rd decade of July and in the 1st decade of August. The beetles are present in the field until the 2nd decade of October. The development of WCR in Croatia proved the state (Igrc Barčić and Maceljski, 1998) that WCR will have adequate conditions for acclimatization and development in Croatia.

Western Corn Rootworm; occurence; spreading; population density; Croatia

nije evidentirano