Biology and host preference of Selitrichodes neseri: A potential
biological control agent of the Eucalyptus gall wasp, Leptocybe invasa.
Dittrich-Schroder G, Harney M, Neser S, Joffe T, Bush S, Hurley BP, Wingfield MJ, Slippers B. (2014)
(Hymenoptera: Eulophidae) is a parasitoid of the invasive gall-forming wasp Leptocybe invasa
(Hymenoptera: Eulophidae), which has caused serious damage to Eucalyptus
plantations in many parts of the world. S. neseri
is a recently discovered parasitoid considered to be a potentially important biological control agent of L. invasa.
The aim of this study was to provide the first basic data on the biology of S. neseri,
which is essential for its application in biological control. S. neseri
was shown to be a biparental ectoparasitoid. Observation from dissected
galls indicated that the parasitoid developed on late larvae, pupae and
callow adults, although development did occur in a range of gall ages.
Observed nominal parasitism in captivity ranged from 9.7% to 71.8%.
Adult S. neseri
specimens, fed with honey-water and galled Eucalyptus
leaves, survived an average of 26 days at 26 °C. The average
developmental time from oviposition to emergence was
19.3 days ± 0.2 days. There was no pre-oviposition period. A single
female produced a maximum of thirty-nine offspring, with a maximum of
ten per day. Dissection of the ovaries showed that twelve ovarioles were
present. The sex ratio of S. neseri
observed in this study was 1:3.43 males:females. Galls of native insects most closely related to L. invasa
and to galls of similar morphology to L. invasa
-induced galls, were not suitable for S. neseri
oviposition. S. neseri
showed considerable potential as a biological control agent of L. invasa
due to its relatively short developmental time, long adult life span
when supplemented with carbohydrates, ability to utilize a range of gall
ages and the fact that it has a high level of host specificity.
Download the full PDF publication: Dittrich-Schröder et al 2014