Screening of eucalyptus genotypes against gall wasp, Leptocybe invasa Fisher and La Salle (Hymenoptera: Eulophidae).
An experiment was conducted in Dandeli, Karnataka, India, during 2008-09 to study gall development in Corymbia citriodora [Eucalyptus citriodora], E. eurograndis, E. tereticornis, E. pellita and E. urophylla induced by L. invasa under greenhouse and field conditions. In August, October and December 2008, galls were not observed on C. citriodora. On E. pellita and E. urophylla, only the first-stage galls marked by ooze due to oviposition damage and subsequent tissue disruption were observed. E. urograndis showed mixed reaction to wasp infestation. E. tereticornis exhibited all the gall stages in all months (from 13.34 in October 2008 to 14.13 in December 2008). The leaf phenol content was highest in E. urophylla (41.50 mg/g) and lowest in E. tereticornis (11.50 mg). In October/November 2008, and April 2009, C. citriodora did not exhibit gall formation. Only the first-stage galls were evident on E. pellita and E. urophylla (2.23-2.62 and 2.23-2.04, respectively). E. urograndis and E. tereticornis recorded 8.30-8.63 and 14.36-15.05 galls/10-cm shoot. Clones 271 and AP 411 had 47.50 and 40.00% incidence of early-stage galls, respectively; thus, these clones were considered tolerant.