insect

Bees, harvestmen, wētā and more take the stage at the Entomology Conference

Recently the War Memorial Centre hosted the annual New Zealand Entomological Society conference, and researchers from all over the country congregated to share their discoveries and find out what was happening in the world of bugs.

2. Australian resin bee

An Australian resin bee Megachile ustulata. Photo: MPI, PHEL, Milen Marinov

One of the talks was very relevant to Whanganui residents. In January, a Springvale couple discovered an odd-looking bee when it stung one of them. Realising it was unusual they forwarded the corpse to the Ministry for Primary Industries. James Haw of MPI explained it was identified as a species of Australian resin bee, Megachile ustulata, never before recorded in New Zealand. MPI searched the neighbourhood for more bees but came up empty-handed. In Australia Megachile ustulata is a solitary insect that makes its home in cracks and burrows. It especially likes the hollow ends of bamboo garden stakes. It is not clear if this was a one-off incursion, or if these bees have taken up residence in Whanganui. If you’re a keen amateur naturalist, keep your eyes open for resin bees when spring arrives. Feel free to bring possible specimens to the Museum (in sealed containers, please).

4. Tree weta Brodifacoum

Tree weta feeding on Brodifacoum

One of the more intriguing talks was by Adele Parli, a Masters student at the University of Otago, working on Wellington tree wētā (Hemideina crassidens). The Wellington species is the more aggressive of the two tree wētā we get in the Whanganui area. Adele was quantifying their aggressiveness with a measure known as the “poke test”; how many times do you need to poke the wētā before it flips its lid and begins to thrash and bite? The answer for the Wellington tree wētā was generally “once”. Adele was poking wētā to test whether their behaviour changes after feeding on the poison brodifacoum. Brodificoum is commonly used for rat and mouse control in the bush and around buildings, and is the rat poison anyone can buy at the supermarket without a permit. (It’s much less humane than 1080 and takes longer to break down in the environment, but you don’t see people protesting brodifacoum outside supermarkets.) Wētā love to eat brodifacoum bait pellets, and it doesn’t kill them, but Adele suspects it may be changing their behaviour, such as how often they emerge to feed, how far they travel, and how aggressive they are.

3. Daddy long legs

A common household daddy-long-legs Pholcus phalangoides. Photo: Olaf Leillinger CC-BY-SA

As well as talks on insects, there were presentations on spiders, which are more or less an honorary insect at these events. Anne Wignall at Massey University Albany had been studying a common house spider, the daddy-long-legs Pholcus phalangoides. These are territorial, staking out one corner of a ceiling and repelling intruders. Anne was curious about whether these spiders could recognize each other; something called the “dear enemy” effect in vertebrates, where animals are more aggressive to complete strangers than rivals they’ve already encountered. Sure enough, when spiders were allowed to become familiar with each other, their territorial battles, while no less frequent, became less violent. It’s remarkable to think that a creature with such a tiny brain can remember its opponents and assess the risk of fighting.

The conference finished with Bugs in the Pub in Frank eatery. Three entomologists gave short talks on beetles, insect weaponry, and whether we should eat more bugs, and invited questions from the audience. Afterwards, beers in hand, pubgoers chatted with the scientists and looked at a selection of live insects they’d brought along – a fitting end to a grand three-day conversation on the wonders of the insect world.

 

Dr Mike Dickison is Curator of Natural History at the Whanganui Regional Museum.

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Insects of Java

5. Antheraea larissa

There are many species of silk moths in Asia: this one, Antheraea larissa, doesn’t even have an English name. Its caterpillars only live on the endangered forest tree Shorea glauca.

I recently spent nearly three weeks in Indonesia, mostly looking for tropical insects. In New Zealand we’re proud of our beautiful forests and amazing birds, but even a short time in Java drove home to me just how impoverished our flora and fauna are in comparison to the tropics.

Indonesia is the world’s fourth most populous country. Two hundred and sixty million people live there, 141 million in Java alone, an island smaller than the South Island. Even in a densely populated and developed landscape, there were still national parks and botanic gardens housing enormous biodiversity.

4. Milionia fulgida

Not all moths come out at night. Some, like this beautiful iridescent Milionia fulgida, pollinate flowers during the day.

We stayed in the Botanic Gardens of the town of Cibodas in the mountains south of Jakarta. The Gardens had guest houses for tourists and they left the outside lights on all night, for security reasons. Every morning all we needed to do was to stroll around the building to see extraordinary numbers of colourful moths and beetles that had been attracted to the lights overnight.

Each day we photographed about 15 species we hadn’t seen before; each morning would bring a new harvest, showing almost no overlap with the diversity of the night before. After a week of spotting a dozen new species every day without even trying, we realised we were barely scratching the surface of the biological richness of the tropics.

1. Grey Pansy

The grey pansy (Junonia atlites) is found throughout Southeast Asia; it was common in the Bogor Botanical Gardens.

New Zealand has a well-supported conservation movement, and DOC does its best to preserve our forests and endangered wildlife. We learn the names of our native birds, and every bookshop has shelves of coffee table books about kiwi and kākāpō as well as field guides to birds, insects and trees.

In Indonesia conservation operates on a shoestring. The national parks are full of litter. Poaching of endangered bird species is rampant. The bookshops have no field guides, just racks of publications about agriculture and fish farming. Huge swaths of untouched rain forest are being cut down for palm oil plantations – the same forests our shining cuckoos migrate to each winter.

3. Atlas beetle

Named after Atlas, who supported the world on his back, males of the giant Chalcosoma atlas beetle fight with each other over potential mates, using their enormous horns.

Most visitors to Indonesia holiday in Bali, but a better choice might be supporting ecotourism in Sumatra or Sulawesi where your money goes directly to preserving rain forest. New Zealand has thousands of threatened insect species that most people neither know nor care about, but our species are in safer hands than Indonesia’s. It sounds like heresy, but donating money to conservation projects in the tropics may do far more good for the world’s biodiversity than spending it here.

 

2. Hawk moth

Sphinx moths or hawk moths can hover like hummingbirds, and have long coiled tongues for drinking from tubular flowers. There are hundreds of species in Asia, and just one in New Zealand.

Dr Mike Dickison is Curator of Natural History at the Whanganui Regional Museum