Naslov
The Spread and Population Density of the Western Corn Rootworm

Autori
Igrc Barčić, Jasminka ; Dobrinčić, Renata ; Maceljski, Milan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
IWGO Newsletter "Western Corn Rootworm 99" of the 4th FAO WCR/TCP Meeting of the EPPO ad hoc Panel and of the 6th International IWGO Workshop on Diabrotica virgifera virgifera LeConte / - Pariz, 1999

Skup
Western Corn Rootworm 99 : 4th FAO WCR/TCP Meeting of the EPPO ad hoc Panel and 6th International IWGO Workshop on Diabrotica virgifera virgifera LeConte

Mjesto i datum
Pariz, Francuska, 04.11.1999. - 05.11.1999

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
western corn rootworm; spread; population density; Croatia

Sažetak
Monitoring the Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) started in Croatia in 1995 and was continued the following years. In 1995 cucurbitacin traps, and in all following years hungarian pheromon traps and various yellow sticky traps were used. The traps were placed in average on 130-150 sites. In 1999 the traps were placed on 117 sites. On each site one pheromon and one yellow sticky trap were placed at least 100 m apart. They were replaced by fresh ones each 25 days, thus 4 pheromon and 4 yellow sticky traps were used on each site. 70% of sites were situated in previously infested areas and 30% in areas which were not infested in June 1999. The results of monitoring the WCR in the period 1995-1999 are summarised in the table. The spread of the WCR in the direction to west was in average 20-50 km per year. The spread was faster along both great rivers which are folowing from west to east: the river Drava along the Hungarian border and the river Sava along the border of Bosnia and Herzegovina. The mountain region (600-800 m) between these rivers was overrun by the WCR with some delay. It is interesting to point out that in some sites infested for the first time this year number of beetles reached: even 25 beetles. In spite of a very strong traffic from east to west no spread of the WCR by vehicules was registered. The spread of the WCR in Croatia is shown in the map. The farthest point of the WCR spread toward west along the river Sava is about 120 km from Slovenia and along the river Drava only 100 km from Austria. The population density of the WCR was in 1999 much higher than in the previous year. This statement is supported by data of the WCR catch of some monitors shown in the map. Alltogether, before disposing with all results, we evaluate that the increase factor in the earlier infested areas for 1999 is at least 4-5. The increase factor for the years 1997 and 1998 was about 2.8. In our insecticide trials conducted at a site on the border with Yugoslavia, the highest root damage registered by the Iowa University scale on some plants was 5.5. In this trial on some plants minor goose neck symptoms appeared. The yield losses due to root damages in this trials were 15-20%. No damages caused by the WCR were reported by the corn growers.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA