The stowaways

Press, 21 April 1984, Page 19

The stowaways

By

ANTHONY SAVILL

Included in the Canterbury Museum's collections is a certain amount of human skeletal remains dating back to collections made last century. Nowadays, no responsible scientist would dream of removing human remains, particularly those of another race of people, and sending them off as scientific curiosities to institutions such as museums and universities. Last century, however, such practices were considered perfectly legitimate, and much of the material collected remains in the Canterbury Museum today, just as it was presented over a century ago. Among these relics of mortality is a human skull from New Guinea. As was customary, the head was removed soon after death to be displayed in the village for ceremonial purposes. During this time it was most likely impaled on a stake, and on occasions even worn around the neck. It was during this period that it became the home for at least two species of insect, and the evidence of their occupation (see photographs) travelled with it on its journey to New Zealand a century ago. The small mud chambers located around the ear of the skull belong to a New Guinea species of Mason Wasp. Relatives of this insect are found in New Zealand where we commonly but incorrectly refer to them as “Mason bees.” Mason wasps are agile and aggressive little animals. They will sting if provoked, although their venom seldom causes much pain to humans. However, this is not the case when they sting their prey which are always spiders. The unfortunate victim instead of being killed is completely paralysed and dragged off to the hunter’s larder. In this way many spiders can be “stored alive and fresh” unable to move to be eaten at the hunter’s leisure. In summer, the presence of Mason wasp is revealed by the high-pitched buzzing sound you hear in the gaps in the weather boards of the house or in some old coat left hanging in the garage. It is here that the female Mason wasp builds a number of mud chambers — a painstaking job taking many weeks. Before sealing each chamber she places in it a single paralysed spider on which

she lays an egg. On hatching, the wasp larva slowly consumes the paralysed spider and several months later emerges from its mud cell as an adult wasp. The second occupant of the human skull is revealed by the presence of two purse-like egg cases about Icm long. They are those of that übiquitous scavenger of our planet — the cockroach. No doubt the insect found much to

feed on in the slowly drying and decomposing contents of the skull, and being nocturnal by habit, found its dark crevices an ideal hiding, place during the day. Footnote: Without doubt, today’s vigorous inspection by the port authorities would have detected the presence of these “immigrants” and prevented the entry of yet another foreign animal into New Zealand!