We've had a stunningly beautiful day here in Dunedin. It's been feeling pretty autumnal around here lately, so there was no way I was going to spend any more time in front of a keyboard than was strictly necessary. As a result today's post is going to be short, but, I think, rather sweet. The insects in our garden seemed to be enjoying some summery weather too. Like this bumblebee I caught visiting a Tradescantia flower. In this shot you can see the ocelli - the set of "simple" eyes on the top of the head and gauge the intensity of light.

In this photo you can see the feature that brought these bees to New Zealand.

There are a few native bee species in New Zealand, but none of them have a tongue quite like Bombus hortorum, and that's why we have bumblebees. European settlers tried to introduce red clover as a pasture, but the native bees and the (already introduced) honey bee couldn't reach into the flowers well enough to pollinate them. This meant early farmers had to import fresh seed almost every season, and were desperate to work get clover to set seed. An English naturalist by the name of Charles Darwin had talked about the pollination of red clover in a little book called The Origin of Species:

From experiments which I have tried, I have found that the visits of bees, if not indispensable, are at least highly beneficial to the fertilisation of our clovers; but humble-bees alone visit the common red clover (Trifolium pratense), as other bees cannot reach the nectar *

Evidently, someone in Canterbury had read their Darwin, so the acclimatisation society asked their contacts in the UK for some queen bumblebees to establish local populations. In the end four species (B. hortorum, B. terrestris, B. subterraneus and B. ruderatis) took hold and now the lovely baritone buzz of bumblebees fliting from one flower to the next is a part of summer in New Zealand.

The acclimatisation societies which were set up in New Zealand were basically ecological vandals, introducing familiar European species with no thought to what they'd do the native inhabitants . These are the people that introduced trout to our streams (decimating native fish species) and stoats and weasels to our forests (driving native birds to extinction). So, it feels bit odd to say that, in the case of bumblebees, the acclimatisation societies actually did something very good. Bumblebees are attracted to big showy flowers of the sort our native flora is lacking in, so they don't displace any native species in forests and their introduction has come an no cost to our native ecosystems. Even better, the thriving populations of bumblebees in New Zealand have the potential to rescue the seriosuly unhealthy populations from which they were sourced . One of the introduced species, B. subterraneus, is now presumed to be extinct in Britain and all of the others are declining due to habitat loss and the overuse of pesticides. Last year, members of the British Bumblebee conservation trust came to the South Island to collect mated queens in the hope of establishing new populations of these bees back home. I gather that particular mission didn't work out, but, if the causes of the bumblebees' decline in Britain can be turned around our bees will be the prefect stock from which to re-establish these species.

*The section from which this quote is pulled is and interesting in that it's one of several proto-ecological ideas in The Origin. Here it is in full:

From experiments which I have tried, I have found that the visits of bees, if not indispensable, are at least highly beneficial to the fertilisation of our clovers; but humble-bees alone visit the common red clover (Trifolium pratense), as other bees cannot reach the nectar. Hence I have very little doubt, that if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great degree on the number of field-mice, which destroy their combs and nests; and Mr H. Newman, who has long attended to the habits of humble-bees, believes that ‘more than two thirds of them are thus destroyed all over England.’ Now the number of mice is largely dependent, as every one knows, on the number of cats; and Mr Newman says, ‘Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice.’ Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district!

Labels: bumblebee, environment and ecology, insects, photos, sci-blogs

I've been going at this Sunday Spinelessness thing for the best part of year now, in that time I've been able to cover a decent amount of the diversity among animals without spines. But up until today there was one clearing omission, so here is The Atavism's first bug:

In day to day speech we use the word 'bug' to describe any creeping, crawling or flying creature that happens to have its skeleton on the outside It would take a taxonomic pedant of the highest order to object to that usage, but 'bug' can also refer to a specific insect order. The Hemiptera are a group of insects with mouthparts specially adapted to sucking. Cicadas, plant hoppers, bed bugs, aphids, scale insects and water striders can all be called "true bugs" as can the star of today's post. It's a member of the shield bugs, or Pentomidae. Both those names refer to the shape of these bugs' bodies:

Like most insects, bugs have two sets of wings. In the shield bugs the base of the forewings is very leathery and sits over top of the much finer and membranous hindwings whcih are used for flying. This particular shield bug didn't seem to the least bit interested in using its wings, I picked it up from the garden path (where I very nearly stood on it) and was quite happy for me to pick it up and drop it off on some plants for a photo shoot.

Labels: bugs, insects, photos, sci-blogs, sunday spinelessness

I think I've finally got back into the rhythm of life in Dunedin after The Big Trip, so it must be time to get back to spending a little bit of my weekend documenting some of the goings on in the spineless world. Thankfully, having gone to visit the summer I've got quite a cache of bug photos to keep the series going

Let's start by interrupting this couple, who I found enjoying summer amongst the flowers on the University of British Columbia's very impressive campus:

At first glance I thought I'd stumbled across a pair of mating bumblebees. But it's really the wrong time of year, bumblebee mating is usually restricted to the end of summer. As the days get shorter and cooler the flowers that keep a bee hive become in short supply. Honeybees get through the winter by hunkering down, but bumblebees skip it altogether. The sisterhood that runs a bumblebee nest sends out queens and males (drones) towards the end of summer, once she's mated the queen hibernates and emerges in the spring ready to set up a new nest. So, not quite sure what I was looking at, I took a closer look.

Hmmm, thats odd. Those big eyes ...

... those little, hairy antennae ...

These are flies! I think, in fact, that they are hover-flies. The bee-like appearance is no coincidence, these flies are an example of something biologists call Batesian mimicry. Despite a widely held belief to the contrary, bumblebees pack a pretty mean sting and at least some would-be predators stay away from them as a result. By appearing enough like a bumblebee to fool birds these flies get the benefit of bumblebee's sting without having to pay the cost of making the venom. Hover-flies in particular make good mimics, there are species that specialise in aping wasps and honeybees and indeed there are other bumblebee mimics.

I'm afraid I can't say very much more about these particular flies, after all the Pacific North West's fauna is entirely new to me. Perhaps the dipterous and the British Columbian wings of the of the bug-blogosphere can at least give them a name. As always, the images link to higher resolution versions.

Labels: Canada, diptera, environment and ecology, hover-fly, insects, photos, sci-blogs, Vancouver

I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae ...

- Charles Darwin writing to Asa Gray

Here's one the Ichneumonidae, the family of wasps that Darwin couldn't fit into a world with a loving god.

What could Darwin find so abhorrent about such a fine looking creature? It was their unique approach to parenting the put Darwin off. Ichneumon are diligent parents, to make sure their offspring have all the food they could ever need the wasps lay their eggs in the bodies of other insects. The larva develops within the host insect, carefully keeping the doomed creature alive as it eats its way through first its fat stores then its non-essential organs. Finally, with the larvae almost fully grown it turns its attention to the host's essential organs before it eats its way through the skin. The ichneumon life-cycle was the inspiration for the chest bursting aliens in the Alien movies.

The quote that started this post is often presented as an observation unique to Darwin, or even as a sort of epiphany that did for Darwin's faith. In fact, Darwin was repeating what had become an old saw by the time he wrote it. The ichneumon lifecycle was widely discussed by Victorian naturalists and theologians. At that time there was a great deal of interest in an idea called natural theology, which amounted to learning about god by studying his creation. But some pats of nature don't seem to reveal a beneficent god. The natural theologians managed to convince themselves that the lion hadn't yet laid down with the lamb because predators saved their prey a worse fate, but the idea of ichhneumon larvae rasping away at their hosts from the inside out proved a greater challenge.

Stephen Jay Gould wrote an essay on the problem of the ichneumon which lists some of the ways natural theologians tried to deal with it. William Kirby, the great entomologists who also happened to be a reactor, emphasized the great dedication of the wasp to her offspring and praised the larvae's sustainable approach to eating their hosts while saving mroe live tissue for later. For modern readers it seems very odd to be describing wasps as virtuous. By and large we've come to realise that nature doesn't provide moral lessons, but we haven't quite given up the naturalistic fallacy that drove the natural theologians. How many times have you hear peddlers of snake oil claim their product was safe "because it's natural"? Or people object to genetic engineering or vaccines because they are unnatural?

We even still look on nature as a source for morality, proponents on either side of the debate for gay rights swap statistics on how common homosexuality is among other animals - as if the sex lives of bonobos or prairie voles had anything to do with human rights. If there is a lesson to learn from the gruesome life-cycle of the Ichneumonidae it's that nature just is, and we need to turn elsewhere for moral lessons.

Hold on, these posts are meant to be about celebrating weird bugs. Let's end with the great David Attinbrorough on the Ichneumonidae.

Labels: environment and ecology, Helpis minitabunda, ichneumonidae, insects, photos, sci-blogs, wasp

It's been a bit of a wintry Sunday here in Dunedin so I'll dedicate today's round of Sunday Spinelessness to a group of insects we should see a lot more of as summer takes hold, the Damselflies (Odonata:Zygoptera).

Labels: damselflies, insects, might interest someone, Odonata, sci-blogs, sunday spinelessness, Zygoptera

My sciblogs scibling Fabiana dedicates one post a week to celebrating important new findings, furthering the cause of Open Access science and other such important stuff. Me? I like weird invertebrates. So, starting today you can tune in here on Sunday morning and see some photos from the other 95% of the animal kingdom.

I found the subject of the first edition of Sunday Spinelessness in our living room, hanging out on a bunch of flowers I'd brought inside. It's a brown lacewing, probably the introduced species Micromus tasmaniae. Lacewings are part of one of the slightly less familiar insect Orders - the Neuroptera which are named after their net-like wings. I could have used these photos to illustrate my piece on Danial Williamson's crazy ideas because the Neuroptera are one of the groups that undergoes complete metamorphosis. As a larva our lacewing probably dined out on the the aphids that seem to love the our tulip flowers (if I ever take a decent photo of the aphids you'll see it here). Unusually, the adult lacewing above is probably making its living in much the same way - the prevention of intergenerational competition is often cited as one of the advantages of complex lifecycles but a lot of lacewings species are carnivorous as larvae and adults.

Other Neuropterans include the freaky looking mantidflies the fearful antlions (which, along with New Zealand's glow worms are among the very few animals with a common name that refers to the larval form) and more than a few beautiful species like this one photographed by Isidro Martiniez:

Labels: insects, might interest someone, neuroptera, photos, sci-blogs, sunday spinelessness