Fred the Thread

In 2003, Corinne Watts was standing in a Waikato domed peat bog (as wetland scientists sometime do) contemplating the stems of giant cane-rushes Sporadanthus ferrugineus.

She chanced upon lovely squiggly lines decorating the stems of Sporadanthus ferrugineu. and wondered who might be the artist responsible. Opening up stem after stem, she discovered amazingly thin, long thread-like larvae of a reddish orange colour, and the legend of Fred the Thread was born.

Fred has no legs, but he does have a hinged head-capsule (a ‘flip-top’ head) to allow him to eat his way along inside of the very thin stem. No entomologist (insect scientist) could work out what type of insect the Fred larvae belonged to; lepidopterists (moth and butterfly scientists) thought they were Coleoptera (beetles); coleopterists (beetle scientists) thought they were Diptera (flies); no dipterists (fly scientists) could be found to comment, even with the aid of Malaise traps.

Eventually Corinne and a lepidopterist colleague reared the beasties through to adulthood, and lo and behold, they were indeed moths (Lepidoptera)!  The moth was named Houdinia flexilissima from its very thin flexible larva, and its remarkable escape from the tight confines of the Sporadanthus stem.

 

Lepidopterist Robert Hoare wrote this poem in Fred’s honour.

Fred the Thread

I have a friend (his name is Fred)
He’s thinner than a cotton thread
His colour is an orange-red
He doesn’t feed on jam or bread
But Sporadanthus stems instead.
Such narrow tunnels must he tread
He needs a hinge inside his head
To give his jaws the room to shred
The food that is his home and bed
And stop himself from dropping dead.

Now when our friend is fully fed
And knows the time has come to shed
His final skin, a sense of dread
Begins to filter into Fred:
How fast, he thinks, the time has sped!
And what a sheltered life he’s led!
He hopes he’ll have some outdoor cred
And won’t be thought of as inbred.
He sloughs his skin from A to Zed
And there’s a pupa in his stead!

Three weeks have passed, and it’s incred
ible to see the adult Fred,
A mothy person born and bred
To look like that on which he’s fed.
He shows an admirable ded
ication to his art, his sed
entary posture leaving ed
ucated mothmen ruby-red,
The effort of locating Fred
Causing a rush of blood to head
Resulting in potential med
ical emergency and bed
With cooling drink and favourite Ted
Until delirium has fled.

To summarize, he’s Fred the Thread,
He’s red and has a hingèd head
His head is used to shred his bed,
His bed’s the food on which he’s fed,
His bed is red and I am led
To think the redness of the Fred
Reflects the bedness of the red
I mean the redness of the bed—
The bed he shreddeth with his head
Until the Fred is fully fed
And sheds the skin he has to shed
To flee the bed that must be fled
To lead the life that must be led
To woo the wife that must be wed
To father further Freds of Thread.
Then Fred can smile and drop down dead.

 I’ve said the things I wanted said.

 ROBERT HOARE: SIX-LEGGED THINGS AND SCALY WINGS

 

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Avondale Spider

The large harmless spider found around the Avondale area of Auckland is an Australian huntsman spider. This spider found its way to New Zealand in the early 1920s, with the first specimen found in 1924. It probably came in imported wood used for railway sleepers. It has not spread very far from Avondale, so it has received the popular name of Avondale Spider. In South Australia this species is quite common, and people encourage them to live in their houses to keep the pest insect population down.

Where found

They are nocturnal and like to hide during the day in dark, dry places. In their natural habitat, which is under loose-fitting bark of wattle trees, they live in large colonies. Around houses they hide in attics, under corrugated iron, behind pictures and bookcases, and in sheds and garages.

Food

These spiders are fascinating to watch. They sit motionless on walls and then rush after prey. They very quickly devour prey, sucking all the juices out and discarding the hard outer pieces. Their favourite foods seem to be moths, flies, cockroaches, and earwigs.

Size

The first reaction of most people on finding Avondale spiders is usually horror. The spiders move very fast when disturbed (as do people when frightened!). Mature spiders with legs outstretched can measure up to 200 mm across (8”).

Life history

The mature males are frequent visitors inside houses in the months January to March when they are looking for a female to mate with. Females are capable of laying up to 200 green eggs in an oval-shaped, white papery-looking egg sac about 25 mm long (1”) by 12 mm wide (1/2”). Females guard their egg sac, and after 4-6 weeks open this up to enable the spiderlings to hatch. They will look after the spiderlings for a few more months until they disperse. Spiderlings will feed communally if the prey is too big for them to manage on their own.

Film stars

In 1989/90, 374 Avondale spiders were sent to Hollywood to star in the Steven Spielberg movie Arachnophobia. Delena cancerides is harmless to humans, but it looks fearsome and therefore suited its movie role as a "killer spider".

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Poor Knights Island has some special insects

The Poor Knights weevil adults are unusually long-lived (for a weevil anyway)

• The adult of the Poor Knights weevil, Hadramphus pittospori, has been recorded as living for 3 years: most adults of weevil species of the world do not live more than 1 year.
• The adult is 16-20 mm long.
• The 6 larval stages last about 1 year, and grow inside their host plant karo (Pittosporum crassifolium).
• The pupal stage lasts about 3 weeks, then the adult hatches.
• The long adult life of these weevils is unusual. It is perhaps one explanation why populations of large-sized weevils related to this species are so badly affected by introduced predators such as rodents.

The Poor Knights cave wëtä (Gymnoplectron giganteum) has the longest appendages (legs and antennae) of any New Zealand insect or spider.

• From the tip of the antenna to the end of the hind legs it can measure an enormous 450 mm, although the body is only 50 mm long.
• It hides in caves and rock piles during the day and comes out at night to feed on flowers and lichens.
• It is only found on the Poor Knights Islands (Tawhiti Rahi and Aorangi).

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Tree lobsters of Lord Howe Island

“Tree lobsters” are an enigmatic group of robust, ground-dwelling, stocky-looking stick insects found across New Guinea, New Caledonia and associated islands.  The most famous member is the Lord Howe Island tree lobster, which was believed to have become extinct after rats reached the island earlier this century. In 2001, the conservation world got very excited when a population of barely more than 20 individuals were found on Ball's Pyramid, a very small, 200 metre wide rock about 25 k from Lord Howe Island. They were one of the rarest insects in the world.

Thomas Buckley (Landcare Research) and colleagues have recently had a paper published in the prestigious British journal Proceedings of the Royal Society, and this paper shows that the story is a particularly intriguing and complicated.

Thomas and his colleagues constructed DNA-based phylogenies* not just for the Lord Howe tree lobsters, but also for all the major stick insect lineages across the Australasian region. Instead of being related to the New Guinea lineages as everyone expected, the molecular analyses indicated they had diverged from an unrelated Australian lineage of stick insects more than 22 million years ago!  Because Lord Howe Island emerged as the result of volcanic activity only 6.4-6.9 million years ago, these tree lobsters could not have originated there.  It appears that the Lord Howe Island tree lobster may have evolved on the now drowned islands, the oldest of which is 23 million years, to the north of Lord Howe and progressively dispersed down the island chain, leaving ancestral populations to come extinct as their islands eroded away.

While that may explain the time paradox, it does not explain why the Lord Howe species look more like the unrelated New Guinea lineages.

Thomas believes that is due to convergent evolution, where similar traits are acquired independently. Their data indicate tree lobster body form evolved independently on the three isolated landmasses of New Guinea, New Caledonia and Lord Howe Island. Their overall uniformity of body shape and behaviour is probably the product of similar selective pressure associated with ground-dwelling life.

*A phylogeny, sometimes called an ‘evolutionary tree’, shows how groups of organisms have evolved, progressively branching away from a common ancestor.  Hence a phylogeny describes the relationships between groups of organisms. DNA-based phylogenies are infinitely more sophisticated than anything Charles Darwin envisaged.

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WooHooo! BioBlitz is back!

(Well ... it will be back at the end of March 2012. This time it is in the Auckland Botanic Gardens, Manurewa)

WHAT?

BioBlitz is a two-day scientific race against time.

It’s fascinating, fun, family-friendly and its free!

The goal is to find and count as many species as possible in 24-hours searching time in a large urban park or reserve. We expect to find 1000-1500 species.  This requires many teams of scientific experts. (In fact you seldom find so many biologists in an urban park but we don’t count each other).  Each team specialises in one group of organisms or micro-organisms, and you’d be hard pushed to find something they don’t know about their group.

 

WHEN?

Friday 30^th March 9 am – 11 pm

Saturday 31^st March  7 am – 5 pm. 

WHERE?

“Base camp” will be in a large marquee in the North West area of the gardens.  Pedestrian and vehicle access is best from the Everglade Drive northern entrance to the Gardens, via Manakau / Redoubt Road motorway off-ramp.   

Base camp is the hub of activity where identifications are made, species tallied, and public get to look down microscopes, chat with scientists, and 'ooh' and 'aah' over the beautiful, the curious and the downright thrillingly ugly.  Field trips (guided walks) depart from here.

There will be the usual guided ‘walks & talks’ with experts, including the ever-popular night time events: moths with ‘Dr Robert’ (who uses a super bright special lamp to lure them in) and the nocturnal walk with ‘spider woman Grace’ (most spiders come out to hunt at night and their eyes shine in the torch light).

 WHO CAN COME?

Everyone!

BioBlitz is suitable for people of all ages. It is a family friendly event. There is no charge.

• If you intend going on a ‘walk & talk’ with a scientist, please wear sensible shoes and clothes. If you are coming on one of the ‘after dark’ excursions, please wear sensible warm clothes and bring a torch (families should bring several torches if possible).
• Specialist scientific equipment is loaned especially for the event. This equipment is very expensive and should be treated with care and respect at all times.
• Young children should be supervised by an adult.
• Dogs should be on leads and supervised by an adult.
• The Botanic Gardens & all that lives there must be treated with care and consideration.

WHO IS ORGANISING BIOBLITZ?

Landcare Research is a Crown Research Institute (CRI).  We’ve been involved in organising BioBlitz events in New Zealand since 2004, and we partner with Auckland Museum, universities, other CRIs, local government, the Department of Conservation, and people from interest groups so that we get as many biologists participating as possible.

The principal organizers of BioBlitz 2012 are Landcare Research, the Auckland Botanic Gardens and the Manakau Beautification Charitable Trust.  The Auckland Museum and DOC are represented on the organizing committee.  Forest and Bird Society, Ornithological Society, the Botanical Society, University of Auckland, Unitech, Oratia Native Plant Nursery, and WaiCare are also participating. 

BioBlitz events are conducted in many countries. We’d love to hear from others involved in BioBlitz events in other countries!

 

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Three Kings Islands — 56 km but an eon from New Zealand

The Three Kings Islands is a small archipelago only 56 km off the northern tip of New Zealand. They are the sole emergent part of the Three Kings Ridge, the remnants of an island arc that formed during the break-up of East Gondwana. Some rocks have been dated to 19-22 million years ago but   some people believe that the islands originated much earlier than that. It is uncertain how long the Three Kings Ridge has been isolated from the mainland but certainly for many millions of years! The very northern tip of New Zealand was probably an island as well at some stage in the ancient past, and is geologically more similar to the Three Kings than to the rest of New Zealand.

The Three Kings Islands host a large number of endemic species. For example, the beetle fauna is estimated to be 35% endemic and the terrestrial snail fauna is highly endemic. There are several endemic plant species including 12 trees and shrubs. What is intriguing is that the closest relatives of some of these Three Kings species are found not on mainland New Zealand but in New Caledonia, Australia, or elsewhere in the Pacific – extraordinary for a small group of islands within eyeshot of the coast of mainland New Zealand!

Thomas Buckley and Rich Leschen (Landcare Research, Auckland) have used comparative phylogenetic analysis to infer the age and biogeographic origins of insect fauna of the Three Kings Islands. They densely sampled six insect lineages (five beetle groups and one stick insect group) throughout New Zealand and sequenced mitochondrial DNA¹ to assess phylogenetic relationships² and determine the relative ages on the Three Kings Islands and mainland New Zealand lineages.

The analyses indicate that the Three Kings fauna have been long isolated from mainland New Zealand. Thomas and Rich recovered two biogeographic patterns:

• The first pattern was seen in three taxa, which had sister group relationships between the Three Kings and the adjacent Te Paki/North Cape area at the very northern tip of New Zealand.
• The second pattern, inferred in the other three taxa, had sister groups that were widespread throughout most or all of New Zealand.

These results are consistent with continual emergent land on the Three Kings Ridge since at least the Miocene and a lack of land connections between the Three Kings Islands and mainland New Zealand during Pleistocene sea-level lowering. Despite their narrow separation, westerly ocean currents may be limiting dispersal between the Three Kings Islands and mainland New Zealand.

The results further exemplify the biogeographic  significance of the Three Kings biota. The high levels of genetic differentiation of insect populations on the Three Kings relative to the ‘sister’ populations from the mainland, coupled with a more ancient endemic element, exemplifies the importance of these islands for New Zealand biodiversity. 

The research also highlights the importance of strengthening conservation measures to ensure the survival, integrity and recovery of the biota.  The islands were occupied by early Māori.  By the time Europeans arrived in mid seventeenth century, Manawatawhi was largely denuded of trees. But, following the eradication of goats in the1940’s, forest has begun to regenerate. Any active restoration and augmentation using species sourced from mainland New Zealand would requires detailed knowledge of both the biogeographic history of the islands and the phylogenetic distinctiveness of species populations to determine appropriate areas for sourcing related populations for translocation.

^{Buckley, T.R. and R.A.B. Leschen. 2012. Comparative phylogenetic analysis reveals old and recent lineages on the Three Kings Islands, New Zealand. Biological Journal of the Linnaean Society, in review}

Footnote 1: Mitochondria are tiny organelles or structures inside a cell that help convert food energy into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus of a cell, the mitochondria also have a small amount of their own DNA.Because mitochondrial DNA is passed through the maternal line, it enables researchers to trace an organisms direct lineage back in time.

Footnote 2:  A phylogeny depicts a pattern of descent. Traditional classification schemes were often based upon similar morphological characteristics that may or may not reflect descent, whereas phylogenies are based upon derived characters that are shared by all of the descendants from a common ancestor.  Recent efforts to unravel the phylogenetic ‘tree of life’ utilize morphological, anatomical and molecular characters even entire genomes. Because of their predictive power, phylogenies are becoming more widely used in plant classification, biodiversity assessment and ecological studies of character evolution.