|A native Lycaena or copper butterfly|
at Whatipu. New Zealand moths and
butterflies are the focus of an
Auckland conference in March.
Weta are another story, or several stories, but those monsters of the night have thrust themselves upon me, thus finding their way here and here. So now that’s enough about insects, isn’t it?
Well, no. While they are unlikely to win affection as hens (for instance) do, they are somehow fascinating. There are so many of them — yet we know so little about them. For all the diligence of collectors, forever ready with their killing jars and mounting boards, we cannot pin insects down.
Discovering Life on Earth
Earth may be home to 15 million species of insects, or 30 million. Of these, 10,000 or so are named species in New Zealand, but those unnamed may number as many again. So multitudes are yet to be discovered and described, a process akin to charting the planet by hand, down to the last millimetre ...several times over.
Even when an insect or other invertebrate is known to someone, it is seldom as widely known as the many larger creatures that most of us recognise; the ones with backbones, ranging from apes to zebra. Each day, an insect is discovered afresh.
In ‘The Exotic North’, New Zealand writer Penelope Todd described and drew a ‘small transparent moth ... simple, monochrome — black lace and glad-wrap’ that she spotted at her current place of residence, Whangarei Heads. She’d not encountered a passionvine hopper before; they don’t go as far south as Otago. But she’s given northerners (especially gardeners, who may have been rather jaded about them) a new way of seeing them.
Here Be Dragonflies — among Other Things
Until this year I didn’t know we had katydids. Then I saw one and learned that they are common, native, and beautiful: a vivid, glowing green.
|Katydid, Clevedon (above); |
blue damselfly, Whatipu (below).
About five years ago I ‘discovered’ the native bees and hoverflies in my sister-in-law’s garden at Thames. It hadn’t occurred to me that New Zealand had insects of its very own, other than huhu bugs, puriri moths and weta.
Subsequently, Andrew Crowe’s book Which New Zealand Insect? revealed a whole new country to me. It includes introduced insects, admittedly, but also many that are native or even endemic (exclusive to these shores, not necessarily abundant).
A Sticky End?
Stick insects or phasmatids lack the ‘ick’ factor of many invertebrates; there’s something endearing about their stick-figuration. In an acclaimed campaign for a UK disability organisation, ‘Slim the Stick Insect’ (complete with walking stick) was among Aardman animated characters telling real people’s stories.
|Slim, one of the faces of a UK advertising campaign.|
They require ventilation and a regular, light, fine spray of water, particularly when young. [Professor John T] Salmon had considerable trouble photographing stick insects moulting, as they frequently weren’t able to shed their old skin. This was probably because he kept his insects in an air-conditioned apartment, in which the air was far too dry. I’ve found that with regular spraying, failure to emerge from the old skin is extremely rare. By the same token, though, keeping the insects too moist encourages fungus, which can kill them.
It is also important to replace the insects’ food regularly, before it begins to dry up.... Many New Zealand stick insects have restricted food requirements, feeding on just a few plant species.
No spray; hardly any air; probably the wrong food and all past its expiry date. Little wonder ‘Sticky’ failed to thrive. I don’t know his fate. It may have been as unhappy as that of Hidgil the hedgehog, another captive of my childhood, found dead one morning with his snout in a saucer of milk.
Landcare Research has six distinct stick-insect projects on the go. It’s unlikely I’ll ever be willing or able to go to such lengths in my own study, but in recent months a bright and shiny new toy has piqued my entomological curiosity again.
No Private Life
A camera that can take good close-ups makes all the difference, and even though it’s merely a ‘compact’, the Canon IXUS is quite capable. This device, and a fantastic new website where nature fans interact, have made looking at insects more fun. So last week I joined NatureWatch New Zealand where I recorded my first 10 observations ...and received species IDs from scientists.
|Mating stick insects, Whatipu.|
a common sight, the small male hitching a ride on his larger mate, the end of his abdomen twisted round and plugged into the underside of hers. Copulation typically lasts days, even weeks, though it may be briefly interrupted periodically while the female lays an egg. Both insects continue to feed while mating, but the male, unable to leave his perch, must be content with what he can reach from the female’s back.
Entomologist Stephen Thorpe identified the ones I posted on NatureWatch as Clitarchus hookeri, smooth stick insects. These, the most common species in New Zealand, were first collected by a member of Captain Cook’s expeditions. I’d asked about the little red protuberances on the female in my photo, one each end, and it is hard to convey my excitement when Stephen noted, “Looks like two interesting parasitic mites...”
A Unique Biological Jigsaw
NatureWatch, funded by a government biodiversity information programme, aims to document sightings of New Zealand flora and fauna. That doesn’t mean my backyard chooks, really, but Nature, red (and other colours) in tooth and claw.*
The idea is to piece together more of this country’s unique biological jigsaw. Anyone can contribute to and use the developing database, but its management by people with significant scientific knowledge makes it reliable.
|Tree weta, Avondale.|
So even when we’re not looking for them, creepers, crawlers, jumpers, flutterers and freshwater fliers keep appearing — telling us the world is theirs as much as it’s ours, but also how spectacular and mysterious that world is.
Stick insects are from the order Phasmatodea, which includes nearly 3000 species worldwide. ‘Phasma’ means ‘phantom’ and refers to the cryptic coloration (camo gear) that enables them to blend with their natural environment.
New Zealand’s 20-plus species are members of the Phasmatidae family; some other countries have ‘leaf insects’ belonging to the Phyllidae. All are solely vegetarian and tend to be nocturnal. When we find them during the day they’re at rest, often away from their food source. Clitarchus hookeri eat mainly manuka and kanuka.
Clitarchus species can be 8–10 cm long when fully grown. The females (and those of some other genera) can reproduce with males or without — parthenogenesis. Couples may be of different colours.
Dragonflies and damselflies are related (they belong to the order Odonata). Both need fresh water for their larval stages, and both have amazing vision: dragonfly eyes cover most of the face, says Crowe, and in the damselfly, about 80 per cent of brain power works to process visual information.
The two are in different families. Dragonflies fly fast and rest with their wings spread out. Damselflies tend to be smaller and fly slowly, fluttering like butterflies. At rest, they fold their wings back over their bodies.
|Dragonfly and damselfly habitat, Whatipu wetland.|
* ‘In Memoriam’, Alfred Lord Tennyson
‘Princes of Camouflage: The Skinny World of Stick Insects’, Brian Chudleigh, New Zealand Geographic, Issue 83, Jan–Feb 2007
The Stick Insects of New Zealand, John T Salmon, Reed, 1991
Stick Insects, Steve Trewick and Mary Morgan-Richards, Reed, 2005
Conference: How to Help NZ’s Butterflies and Moths — Practical Ideas for Practical People, 16 & 17 March www.monarch.org.nz/monarch/projects/conference-2013/