Agronomic practices as potential sustainable options for the management of Pentastiridius leporinus (Hemiptera: Cixiidae) in sugar beet crops
Cixiid planthoppers (Hemiptera: Fulgoromorpha: Cixiidae) have been shown to vector phloem-limited prokaryotes associated to prominent plant diseases world-wide. However, little information is available on the management of such insects that spend a significant part of their life cycle underground as nymphal stages. Preliminary assays were carried out to analyse the potential of some agronomic practices to reduce the underground populations of Pentastiridius leporinus, a cixiid vector of plant pathogenic bacteria to sugar beets that completes its life cycle in the cropping rotation sugar beet-winter wheat. A first field assay was carried out to test the effect of spring barley as an alternative crop to winter wheat, a second one analysed the effect of reduced tillage as alternative to ploughing. Planthopper abundance, as evaluated by using horizontal sticky sheets to intercept flying adults that emerged from the soil beneath traps, showed a reduction of 80% and 28% of planthoppers when barley was grown instead of wheat and when reduced tillage was applied instead of ploughing, respectively. Barley roots had 81% fewer nymphs than did wheat roots. Indirectly this study demonstrates how conventional cultural practices for sugar beet production can promote the establishment of P. leporinus populations in sugar beet crops in eastern of France.