Our 1st Generation
The following is the beginning of a fascinating story, a story of saving the rarest insects in the world! The long lost Phasmid; will we succeed, read on to find out how the entomologists get on.
Biology (the study of life).
Dryococelus australis, the long lost Phasmid is a giant, flightless stick insect, unlike any other found within Australia. Its probable nearest living relative inhabits the jungles of New Guinea. From historical records it is known on Lord Howe Island (LHI) that the Phasmid was nocturnal, spending daylight hours in humid refuges such as logs or tree hollows. Little else is known about the biology of this particular species.
Generally, stick insects expel their eggs while feeding in shrubs or trees. The eggs fall to the ground and are incorporated into the leaf litter. Females usually produce about 6 eggs each night and several species can lay between 400 to over 1000 eggs in their lifetime. Eggs hatch after at least 6 months gestation, producing nymphs, which look like miniature versions of the adults. The nymph goes through 4 or 5 moults, called instars, before reaching sexual maturity after about 6 months.
As the insect proceeds through each moult it increases substantially in size. From museum specimens it is known that, unlike most other stick insects, the long lost Phasmid has sexes of similar size. In most other species, males are significantly smaller than females. If female Phasmids lay eggs that are not fertilised these eggs hatch into females, clones of the parent female. If the eggs are fertilised they result in equal numbers of males and females.
Survival of male nymphs is generally significantly less than that for females, and males tend to die soon after mating. This heavy mortality of males can lead to a disparate sex ratio in the adults of several times more females than males late in their life cycle. A population generated from a single unfertilised egg will result in an all-female population that is capable of persisting without males.
Thought observations of the captive breeding program we are hoping to shed more light on the issues discussed above while also looking at conservation and biodiversity of threatened species.