|
Although this insect breeds on native Neptunia spp., a decision was made to release it in Australia on the following grounds.
 | Three species of Neptunia occur in different regions or habitats to
Mimosa
pigra; the fourth species does occur in M. pigra habitats but was more common elsewhere.
|
| The damage to M. pigra was much greater than to Neptunia
spp.
|
| Mortality was higher on Neptunia spp. and hence these plants would probably not support high populations. |
Since its release in 1989, larvae of N. gunniella have caused widespread damage to thin stems of
M. pigra and adults have distributed widely. A minor level of attack has occurred on
N. gracilis in the field.
Thailand did not approve release of this insect as laboratory trials in Thailand showed that
N. gunniella could reproduce on the introduced Neptunia natans
(L.f.) Druce (= N. oleracea Lour.), an important vegetable in Thailand. This species does not occur in Australia and therefore was not tested.
|
A Mimosa pigra
plant in flower (Photo courtesy
of Queensland
Government, Department of Natural
Resources and Mines).
|
