Spotting a Jumping Spider...*and* its Owlfly Predator! - Observation of the Week, 12/31/19

Our Observation of the Week is this owlfly larva and its jumping spider prey, seen in Cambodia by @geechartier! 

“I have been interested in nature for as long as I can remember but it tended to take a back seat until I started visiting Cambodia in early 2007,” says Gerard Chartier, who eventually moved the country in 2009. Since his move to Cambodia, he’s been studying the region’s flora and fauna, starting with lepidoptera, then moving on to odonata, and “with the help of experts, who I now call friends, and online forums I started to make some progress.” Now, he tells me, “I decided some time ago that I would rather not focus on any particular types of fauna or flora but, instead, focus on cataloguing as much as I can of the species living in the fairly small area where I guide nature tours.”

It was while leading a nature tour that Gerard captured the photos seen in this post, first noticing only the spider. 

As usual, I took photos from different angles. As I came round to the lateral view, I noticed that the spider was hanging from something so I focused in on that and found the jaws of the owlfly larva. Then I took more photos of the larva, which was so well camouflaged in the nook of the branches of the plant. There is no way I would have seen the owlfly larva had the spider not been there. The customers I was guiding were amazed!

Ambush predators, the larvae of owlflies (members of the order Neuroptera, along with antlions, lacewings, and others.) lay in wait for prey to come near enough for the owlfly to snag it with its pretty fearsome mandibles. Once captured, Neuropteran larvae  “inject toxic secretions as regurgitants into prey in order to paralyze and to kill it.” (Dettner, 2015; thanks for finding this article for me, @eddiebug!). After metamorphosing, the adult owlfly looks similar to odonata and the adults of other neuroptera, with four wings and much reduced mouthparts. 

Jumping spiders, like the Telamonia dimidiata capture here, are found throughout much of the world, and use their large front-facing eyes to seek out prey, which they pounce on by using a pretty phenomenal jumping technique. This spider’s eyes, however, did not seem to take note of the owlfly.

Gerard (above, discussing a Nepenthes kampotiana pitcher plant) has made quite a few friends via various online grouypswas encouraged to post his photos to iNaturalist by @hkmoths, and he’s now uploaded over 1,400 moth observations to iNat, as well as observations of other flora and fauna.

I have my own website that shows the full set of things I have identified so far but I see there is a risk that the data I have been recording could be lost...and I see iNaturalist as the ideal, public repository for that data. I still have a huge backlog of observations to add to iNaturalist based on 50,000+ nature photos, but still adding new ones all the time.

- by Tony Iwane. Photo of Gerard copyright Jason MacDonald, used with permission.

- Gerard found a new species of bug outside his house several years ago, recently described and named Sogana chartieri! (See the observation here.)

- The late macro photographer Andreas Kay shot some beautiful footage of an owlfly larva encountering an ant.

Posted on 31 de dezembro de 2019, 09:39 PM by tiwane