L. FURLAN, A. Di BERNARDO
Department of Agronomy, Entomology, University of Padova, Legnaro PD
M. VETTORAZZO
Veneto Region, Phytosanitary Service, Venice Office, Via Poerio 34, Mestre-Venezia.
M. BORIANI, E. GERVASINI
Lombardy Region, Phytosanitary Service, P.zza IV Novembre 5, 20124 Milano
G. MICHELATTI
Piemonte Region, Phytosanitary Service, Corso Grosseto 71/6 –10147 Torino
G. CAIELLI
Settore Agricoltura della Provincia di Novara, Via Dominioni, 28100 Novara
A. ORTEZ, C. FRAUSIN
Friuli Venezia Giulia Region, OMP, Via Beato Odorico, Pordenone
M. BARISELLI
Emilia Romagna Region, Phytosanitary Service, via di Corticella 133, 40129 Bologna

Over the past several years, extensive monitoring of Diabrotica virgifera virgifera (WCR) was carried out in different regions of Northern Italy (Friuli Venezia Giulia, Veneto, Emilia Romagna, Lombardy, Piemonte) following a common protocol. Maize fields were selected, in addition to the already defined focus areas, in sites where maize is often grown for multiple years and also at potential introduction areas (such as nearby airports, custom institutions, etc.). PAL sex pheromone traps were set up mainly, or exclusively, in maize after maize fields. In maize fields where high WCR captures had been recorded the root systems of at least 20 plants/field were evaluated following established protocols from the USA.

PRESENCE.
In Friuli Venezia Giulia and Emilia Romagna no specimens were caught over the last 3 years. In Veneto: in the focus or safe area defined after the first captures recorded in 1998, specimens were captured each year from 1999 to 2001 in monoculture maize fields. The current infested area is about 1500 ha. No specimens in the other sites (five to fifty km away from the focus area) were caught despite the fact that hundreds of PAL traps had been deployed in monoculture fields. Lombardy: three specimens were captured on a few traps placed out near Milan-Malpensa Airport (Varese) in 2000; many traps were placed out in 2001 and numerous specimens were captured in a area of over 100.000 ha including the provinces of Varese, Como, Lecco, Bergamo, Sondrio, Milano, Lodi and Cremona. Piemonte: in 2001 several specimens were captured in an area of about 17.800 (Novara province) which borders the focus area of Lombardy defined in 2000.

POPULATION LEVELS.
Adults: levels up to 30 – 40 WCR males/ PAL trap/day at the peak of the swarming period were recorded from monoculture maize fields in Lombardy and in Veneto while the peak population observed in Piemonte was about 15 males/trap/day. Only in fields planted to maize for at least two subsequent years did PAL traps capture conspicuous numbers of adults; more than 90% of the infested fields were monoculture maize fields, the others being first-year maize fields located near infested monoculture fields. Pherocone AM yellow sticky traps, which are often used in USA to determine the presence of economic WCR populations within a field, were placed in some fields where high captures had been recorded on Pal traps. These Pherocon traps, however, did not capture any specimens. No adult feeding damage on leaf tissues or ears was observed despite observations made on thousands of plants in the fields where the highest numbers of WCR males were recorded on the sex pheromone traps. Larvae: in none of the maize fields in Veneto and Lombardy did root systems show any visible WCR injury. Therefore NO economic populations are present so NO insecticide treatments for usual maize cultivation are needed in 2002.

STRATEGIES FOR THE FUTURE.
Veneto: the eradication/containment program should be continued following the strategies implemented in the previous years enlarging the area where the cultivation of maize after maize is prohibited (including fields five km from the area where specimens had already been captured). Lombardy, Piemonte: in order to stop or at least to slow down Diabrotica spreading a strip five km wide with NO maize after maize fields should be created along the border of the area where WCR specimens have been detected. This measure should be supported by an intensification of the information program on WCR biology and the importance of crop rotations that is targeted at farmers in the regions. Friuli Venezia Giulia, Emilia Romagna and other regions: monitoring should continue following the instructions utilized over the last several years.