The western corn rootworm (Diabrotica virgifera virgifera): a new maize pest threatening Europe

The western corn rootworm Diabrotica virgifera virgifera is one of the most dangerous pests in maize in the USA. For many years, US growers have had to control this pest in maize fields by soil treatment or spraying. Ten years ago, this pest was also 'imported' into Europe. It was the job of the plant protection advisers and officials to inform endangered countries about the appearance of this pest, to develop control strategies for Europe and to establish research programmes to prevent further spread. This paper presents the history of this pest in Europe, its biology, the situation in 2001 and corn rootworm management scenarios for the future.     

Efficiency of pheromone traps for monitoring Diabrotica virgifera virgifera LeConte

Mark–release–recapture trials with male western corn rootworm Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) beetles were conducted to better understand capture data of pheromone traps produced in Europe during monitoring programmes. Median recapture rate in maize fields in Hungary, Italy and Switzerland was 10%. Two types of sex pheromone trap (sticky sheet and non‐sticky container traps), placed inside or outside maize fields, showed no differences in efficiency. Logit analyses of recapture data in maize showed that at distances of <1 m fewer than 20% of beetles ended up in the traps. A beetle in a 1 ha maize field would have about a 5% chance of being caught in a trap placed in the centre of the field.     

Validation of RNA interference in western corn rootworm Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) adults

BACKGROUND: RNA interference (RNAi) is commonly used in insect functional genomics studies and usually involves direct injection of double‐stranded RNA (dsRNA). Only a few studies have involved exposure to dsRNAs through feeding. For western corn rootworm (Diabrotica virgifera virgifera) larvae, ingestion of dsRNA designed from the housekeeping gene, vacuolar ATPase (vATPase) triggers RNAi causing growth inhibition and mortality; however, the effect of dsRNA feeding on adults has not been examined. In this research, WCR adults were fed with vATPase‐dsRNA‐treated artificial diet containing a cucurbitacin bait, which is a proven feeding stimulant for chrysomelid beetles of the subtribe Diabroticina to which rootworms belong. RESULTS: Real‐time PCR confirmed suppression of vATPase expression and western blot analysis indicated reduced signal of a protein that cross‐reacted with a vATPase polyclonal antiserum in WCR adults exposed to artificial diet treated with dsRNA and cucurbitacin bait. Continuous feeding on cucurbitacin and dsRNA‐treated artificial diet resulted in more than 95% adult mortality within 2 weeks while mortality in control treatments never exceeded 20%. CONCLUSIONS: This research clearly demonstrates the effect of RNAi on WCR adults that have been exposed to dsRNA by feeding and establishes a tool to screen dsRNAs of potential target genes in adults. This technique may serve as an alternative to target screening of larvae which are difficult to maintain on artificial diets. Copyright © 2011 Society of Chemical Industry     

Der Westliche Maiswurzelbohrer Diabrotica virgifera virgifera LeConte (Col.: Chrysomelidae) auf dem Weg nach Deutschland

Zusammenfassung Der Westliche Maiswurzelbohrer, Diabrotica virgifera virgifera (Dvv) LeConte (Coleoptera: Chrysomelidae), ist einer der wichtigsten Maisschädlinge in Nordamerika. Seit seiner Einschleppung nach Serbien und seinem Nachweis bei Belgrad im Jahr 1993 breitet er sich schnell über Südosteuropa und von dort zunehmend nach Zentraleuropa aus. Bis 2004 war Deutschland zwar noch frei von Dvv, ist aber außer an seiner Nordost- und Nordflanke von Ländern mit nachweislichen Dvv-Populationen umgeben. Es gibt außer stets möglichen Einschleppungen durch Flugzeuge drei Hauptrichtungen für das terrestrische Vordringen auf deutsches Staatsgebiet. Von diesen ist die südlich-nördliche Stoßrichtung von der Lombardei in Norditalien über den Tessin und die Nordschweiz bis nach Südbaden die wahrscheinlichste. Sie folgt einem sehr gut ausgebauten Straßen- und Schienennetz durch die Schweiz mit hochentwickelten Verteilungszentren für Güter und Dienstleistungen, womit die aktive Mitwirkung des Menschen als Verbreitungsvektor des Schädlings unterstrichen wird. Erzwungene Fruchtfolgevorschriften im Schweizer Kanton Tessin konnten die Ausbreitung nach Norden zwar bremsen, aber nicht verhindern. In Anbetracht seines jüngsten Vordringens bis an die deutschen Grenzen dürfte die Einschleppung von Dvv auf deutsches Staatsgebiet bevorstehen und als längerfristig unvermeidlich gelten.     

PM 7/2 (2) Tobacco ringspot virus

Specific scope

This Standard describes a diagnostic protocol for Tobacco ringspot virus 1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols.

Specific approval and amendment

First approved in 2000‐09. Revision approved in 2017‐03     

PM 7/39 (2) Aphelenchoides besseyi

Specific scope

This Standard describes a diagnostic protocol for Aphelenchoides besseyi. This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols. Terms used are those in the EPPO Pictorial Glossary of Morphological Terms in Nematology a .

Specific approval and amendment

Approved in 2003‐09. Revised in 2017‐04. This revision was prepared on the basis of the IPPC Diagnostic Protocol adopted in 2016 on Aphelenchoides besseyi, Aphelenchoides fragariae and Aphelenchoides ritzemabosi (Annex 17 to ISPM 27; IPPC, 2016 ). The EPPO Diagnostic Protocol only covers A. besseyi. It differs in terms of format but it is consistent with the content of the IPPC Standard for morphological identification for this species. With regard to molecular methods, one real‐time PCR test available in the region is included as well as DNA barcoding.     

PM 7/28 (2) Synchytrium endobioticum

Specific scope

This Standard describes a diagnostic protocol for Synchytrium endobioticum. 1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols.

Specific approval and amendment

Approved in 2003‐09. Revision approved in 2017‐06.     

PM 7/89 (2) Heterodera glycines

Specific scope

This Standard describes a diagnostic protocol for Heterodera glycines. 1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols. Terms used are those in the EPPO Pictorial Glossary of Morphological Terms in Nematology. 2

Specific approval and amendment

Approved in 2008–09. Revision approved in 2017–11.