Evaluating damage status, morphological characteristics and behavior of Leptoscybe invasa Fisher & La Salle causing eucalyptus gall wasp in Vietnam

Abstract

Eucalyptus gall wasp was found on Eucalyptus urophylla × Eucalyptus
camaldunensis, E. urophylla and E. camaldunensis in plantations under two
years in 26 investigation locations. Damage level (P%) caused by this pest
was from 26.8% to 57.2% and damage indicator (Rtb
) from 0.3 to 2.2.
Eucalyptus gall wasp has identified Leptocybe invasa Fisher & La Salle
(Hymenoptera: Eulophiadae). Adult female averaged 1.36mm in length and
ranged from 1.10 to 1.55mm; head and body black with slight blue to green
metallic shine; antennae formula with one scape, one pedicel, four ring
segments (or four anelli), three funicle and three claval segements and thinly
trichoid antenna. Adult male: small size mean length 1.04mm, range from
0.90 to 1.2mm; head and body black with bluish to green metallic shine;
antennae formula with one scape, one pedicel, three anelli, four funicle and
three claval segements, antenna are slight brown and distinctly hairy antenna.
Eggs are oval body and a long narrow anterior stalk, grayish white. In
generally larvae undergo four ages, the larva grows, the first instar body
length is from 0.08 to 0.19mm, mean length is from 0.20 to 0.38mm in
second instar ages, the third instar larvae length ranges from 0.42 to 0.79mm, and length of at the fourth instar larvae is from 0.81 to 1.20mm. Pupae are milky, color of pupae changes over time transfers from enter milky cocoon to its final moulting stage, length from 0.80 to 1.21mm. Adult female laid eggs on young parts of the plant viz tender shoot, petiole and tender leaf midrib.