Archive for the 'Insects' Category

Beetle rearing

July 8, 2010

Tour de France time! Amazed it has come around again already… doesn’t seem like a year since all those late nights watching the cycling on SBS. Anyway, inspired by the beetle rearing antics of Beetles in the Bush, I thought I would put some larva bearing twigs (or should that be twigs bearing larvae – either way conjures weird images in my head) into an old aquarium and see what eventually would emerge. I actually found these larvae by complete chance, when my little boy broke a twig against the back of my leg (!!), and I noticed a neat shavings plug where the pith would normally be. Being the big kid I am, I had to investigate further rather than just popping the twig in the tank and waiting. After a little excavating, I uncovered a rather chubby creamy white grub which I believed to be a moth larva. I encouraged the little chap back into its hole, put the twig in the aquarium and left it be.

A few days later I went back to check for progress, and much to my dismay the grub had popped back out of the twig and was on the tank floor. I decided to leave it there, rather than poking it even more. Turned out to be a great move, as I was able to watch the daily change as it underwent pupation! Due to its position in the tank, I couldn’t take photos – but it was still fun to see the developmental changes happen.

Well… it wasn’t a moth! Here is the final fruits of my first rearing experiment (well – more of just a wait than an experiment). A small (~7mm) Cerambycid beetle! A handheld camera, no flash and huge aperture aren’t conducive to a good macro photo, but you get the idea. Not sure on the ID, and for the time being It will have to wait. I have ants to point and cyclists to watch!

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Green Tree Ants

June 5, 2010

What a crazy couple of weeks. Amazing amounts of work to catch up on, lots of reading and to cap it all a broken tooth (with a subsequent visit to the dentist). My trip seems like a distant memory!

Anyway.. I thought I would start off by putting up a few pics of my favourite ant. The green tree ant (also called a weaver ant) is very common in its favoured habitats, across the tropics of Australia. Why do I like them? Well, to my eyes they are quite graceful, with clean lines and a great colour. Usually they are yellow/orange with a greenish tinge forward of the petiole, and have a nice rich green gaster. They are also easy to find, and easy to photograph (i.e. large, slowish, and inquisitive aggresive). The scientific name, Oecophylla smaragdina, seems to have a different pronunciation for every entomologist I speak with. I use Ee-cof-illa sma-rah-dina. Any opinions?

Green tree ants have some really interesting behaviours too, which because of the aforementioned qualities, are easy to observe. They build their nests from living leaves, which they stitch together using silk produced by the larvae. It looks literally as they they are sewing; the worker holds a larva in her mandibles and moves it back and forth over a join, while other workers hold the leaves together using their freakily sticky feet and impressive weight-holding ability (see Archetype for some great info on sticky feet, here and here). A single colony can span multiple trees, with many of these nests in varying sizes. They are great communicators, and use vibrations in addition to chemicals. Tap on a nest a few times and not only do the occupants come running, but a few minutes later you will have ants from a fair distance around the tree racing towards you (wildly spraying acid!)

They are voracious predators, as can be seen in the photo below. Lacking a sting, they ‘spread eagle’ their victim, rendering it helpless against the rather brutal butchering which follows. This gruesome scene unfolded at our kitchen window each evening, where the ants feasted upon the various bugs attracted to the window. On more than one occasion they tried to pin down small geckos too!

Like many ants, they also tend hemiterids for the sweet solution they produce in return for protection from predators.Where available, they also visit extra-floral nectaries as in the photograph below. I was surprised at how much fluid these nectaries were producing, with a new droplet forming within seconds of being consumed. You can just see the nectar drop forming on the nectary (about 1/4 of its normal quantity), just below the elbow of the ant’s right antennae.

One last thing.. if you ever find a colony of these guys in a tree, check the ground where you’re going to stand first. I stood in a feeding column while watching a nest which was at head height. Didn’t realise until I started to get nasty nasty pin-prick pains up and down my lower legs! They have a mean pair of mandibles, and to cap it off, like to spray a bit of acid in the wound!

Holidays… don’t they go quick!

May 22, 2010

Back from a great holiday up in the Daintree. Saw lots of cool stuff, and had a great time catching up with my parents (who live overseas). I will get some pics up online this week, but I had better get stuck into the mountain of dirty laundry which is stinkin’ it up in the bags! Appears I also have a tonne of reading (blogs, emails, papers) to catch up on.

Found these little guys on the beach yesterday, tidying up the remains of a frog. Always tickles me to see an invertebrate coming out on top! I had no hand lens nor means of retaining a couple,  only my wife’s compact digital camera so am not too sure of the ID. Looks to be an Iridomyrmex sp….

Pitfall pleasures

April 17, 2010

Wow, things are busy at the moment. Lots of work on, including some research planning. Going to be having a look at Pheidole megacephala in far north queensland… I will go through a few of the specifics in a later entry. To cap it all off, my wife’s brother and his partner are visiting for a week (starting tomorrow), and my parents are visiting for 3 weeks just after that! Tying off loose ends with work, tidying, gardening and packing for 2 weeks R&R in the Daintree. It’s all happening!

One of the projects I’ve been helping with over the past few months involves pitfall traps, and lots of them! A friend is working on his phd looking at carabid ecophysiology, and modelling the future distributions of both the carabids and associated ant faunas with predicted climate change scenarios. I’ve been giving him a hand, sorting through the pitfall trap samples retrieved from various sites across the wet tropics. It’s not exactly glamourous work, but it’s more interesting than some might think. All kinds of weird and wonderful arthropods turn up, as well as the occasional microhylid (which I can’t help but feel a little sorry for – interesting that I don’t feel the same way about the arthropods).

One of the more interesting organisms were numerous Peripatus, or velvet worms. I’ve not read much about these, but did notice the unusual distribution of the two families of Onchophora on wikipedia. Wonder what caused it… I won’t post any photos of trapped velvet worms here. Lacking a hard cuticle, they usually don’t look too pleasant after a year of rather crude wet storage!

I haven’t yet had time to identify either of these beetles, but as I thought both were unusual (to me at least), here are a couple of photographs taken just prior to labeling. This first pic is of course, a tiger beetle, which was surprisingly abundant considering the dense rainforest location. I’m certainly no coleopterist, but I have always thought of tiger beetles as being inhabitants of fairly open, sandy habitats. All of those found are of the genus Distipsidera (largely tree trunk dwellers). I haven’t had a chance to go through the key and ID to species yet.

The second photo is of another beetle, this one a little larger, sporting rather cool translucent flanges on it’s elytra and thorax. I am unsure of the ID, but I believe it will belong to the Silphidae family.

I’m not sure how much I will be get to post in the coming weeks, but I will hopefully come back from the Daintree with some juicy photographs.

Ootheca Explosion – Part 2

April 10, 2010

Well, I have alot to learn about both filming and video production, but here’s my first attempt. Shamelessly inspired to give it a go by some excellent footage at Myrmecos blog.

I have a fair amount of work on at the moment, so haven’t had much time to play around. I guess this was more a test to see if my camera (Sony HDR-CX12) was capable of producing reasonable macro footage. It’s already looking better than my dabbles back in the days of VHS. I’ve discovered that even a light breeze is a nightmare, and that my next post-production venture will be to learn how to correct colour/brightness/contrast on a vid.

If anyone wants to see it in full 720p HD, you can do so here. Looks much better in HD in my opinion.

I’m really looking forward to giving this a proper go!

The Ootheca Explodes!

April 10, 2010

Around 10 days ago, I found a mantid ootheca on a grass stem in the back yard. I believe the owner is an Archimantis latistyla, because it was around the correct shape and size, and this species is a fairly common urban garden inhabitant up here. I brought it inside, and placed it in a small terrarium in the hope of seeing them hatch. Unfortunately… I think I missed the big event by mere minutes. However, it was still very exciting and we had alot of fun sending these guys on their merry way back where I found them. I took a little video, and will hopefully get time to process it and put it up here by the end of the weekend.

Here are a few pics for the time being. Baby mantids, while a little alien, are incredibly delicate and cute. This species appears to be a fairly competent jumper while a nymph, which I would think gives them a good escape mechanism before they develop wings.

Ant Plants

April 1, 2010

Mutualism in nature has always been something that interests me, and in my eyes one of the more amazing examples would have to be the relationship between certain ants and plants. These relationships can be relatively simple, where the plant produces supplemental food, or more complex with the plant providing a home for the ants.

Plants which produce supplementary food can do so via small food nodules, or by the production of sugary secretions at extrafloral nectaries (basically, a nectary outside of a flower). These attract ants, which benefit from the easily harvested nutrient, and in turn this benefits the plant because the ants defend the food supply.

The next step up is plants which actually create an area for the ants to inhabit (domatia). These can range from simple hollow thorns, such as in Acacia sphaerocephala, to the more complex tunnel networks found in the tuber of the Myrmecodia. Now here’s a superb example of a refined mutualistic relationship. This plant gains both a defense mechanism and a food source from its association with ants. Myrmecodia are epiphytes (they live on other plants), and are somewhat unusual in appearance, as the bulk of the organism is usually made up of the tuber (some call this the caudex, which is a modified stem). Within this tuber is a network of tunnels, some with smooth walls which the ants live in, and some covered in nodules in which the ants deposit their refuse. This refuse is then used as nutrient by the plant. A variety of ant species have been found living in these plants and in Australia they include Philidris cordatus (most common inhabitant), Pheidole megacephala and Crematogaster physothorax (Huxley, 1978). Even frogs have been found using them as a temporary home!

No prizes for photography... a young Myrmecodia beccarii found on the beach.

The fact that organisms from two completely separate kingdoms have managed to co-evolve and work so efficiently together is always pretty neat.

Huxley, Camilla R. 1978. The Ant-Plants Myrmecodia and Hydnophytum (Rubiaceae), and the Relationships between their Morphology, Ant Occupants, Physiology and Ecology. New Phytologist.

As a side note… how’s this for a title!

Amador-Vargas, S. 2008. Spartan defense in the Thermopylae pass: Strategic defense by aggregations of Pseudomyrmex spinicola (Hymenoptera, Formicidae) on the trunk of Acacia collinsii (Mimosaceae). Insectes Sociaux 55 (3):241-245.

Mosquito? Hmm…

March 29, 2010

Noticed this in the local toy shop earlier… my 2 year old didn’t seem as surprised about it as I was (you can see his finger at the bottom of the image)!

Ecdysis

March 27, 2010

We bought our little boy a small terrarium today, so I decided to pop out and have a poke around in the long grass that was once our lawn, to see if I could find a grass mantid or phasimid to live in it for a few days. Instead, I found this hedge grasshopper in the final stages of a nymphal moult. I ran in to get the camera but by the time I had put some fresh batteries in the flash, the little guy had already pushed around half way through his old cuticle.

The images you see here were taken over the course of about 5 minutes, so once the ball is rolling the process is actually quite quick. This was all very exciting for me, as I have only ever seen an insect molting in a lab.

Macro flash solution

March 26, 2010

I’ve been searching for a method of lighting my macro shots for a while now (without having to purchasing a dedicated macro flash unit). The most success I have had so far has been using my standard bounce flash unit, with an off camera cord and bracket. This works fairly well but the light can be fairly harsh even with a diffuser, and it is still very directional with only one flash head. I’ve tried a couple of cheap manual units (diffused and on brackets) and this works ok, but it is a pain because it is so cumbersome, both in terms of handling and in checking the exposure (which is manual without a TTL flash).

I’ve pretty much resigned myself to purchasing a dedicated twin head unit when I get a little more time to spend on my photography. Until then however… I have come across a simple, but surprisingly effective reflector which allows me to use my standard bounce flash head. It’s simply a piece of long white card, held onto the flash with a rubber band. The card is allowed to droop a little, forming a white arc above the subject and bouncing the light evenly. It even works when your subject is only a few centimeters from the lens! It is by no means perfect: the flash requires alot of light so has a longish recycle time, it is still fairly directional and you get a large highlight on shiny insects (such as the fly below). Even so – I’m quite excited by the results so far!

Credit goes to this guy, Bob Frank. Many thanks if you ever read this!

Here are a couple of pics I took in the yard this afternoon, using this technique.

Hedge Grasshopper nymph (Valanga spp.)

Lucilia spp. (possibly L. cuprina)