Just Some Gnats Hanging on Silk in Singapore - Observation of the Week, 9-20-22

Our Observation of the Week is this trio of Predatory Fungus Gnats (in the genus Heteropterna), seen in Singapore by @airgel!

In early August, Sam (@airgel) and some nature guides went for a night walk on a dirt road named Track 15. “It's quite a popular spot for night walks here in Singapore,” says Sam.

I spotted these flies (presumably) sleeping, hanging from this strand of silk - like tiny line dancers! I called my friends over to take a look - but after just three shots they had disappeared. I feel kinda bad for waking them up, but if the picture can be used to educate and contribute to research, I suppose it's worth it. I was also fortunate enough to have the shots in focus - being able to make out wing venation is really important for identifying a whole host of insects.

When I uploaded the photo as an observation, I had no idea what type of fly I had seen. Next thing I knew, it was Observation of the Day and the identifications started coming in! I'm humbled and grateful for everyone's help with identifying these gnats.

As you’d suspect from their common name, predatory fungus gnats (Family Keroplatidae) can feed on both fungi and other animals during their larval stage. According to BugGuide

they spin hygroscopic webs to collect spores or small invertebrate prey. Predaceous species kill their prey with an acid fluid (mostly oxalic acid) secreted by labial glands and deposited in the droplets of their web; mycophagous larvae also have acid webs and occasionally feed on pupae of their own species or on dead insects. 

iNat user @treegrow suspects that the trio Sam photographed, which appear to be males, are hanging on spider silk and are likely looking for receptive females.

In addition to the gnats, Sam also saw his first Cyrtarachne bird dropping mimic spider and Bipalium hammerhead flatworms that night.

While Sam (above) has always been into nature (“there are pictures of me as a toddler staring at ants on the ground”), he credits his first macro lens as the impetus for his “deep dive” into the natural world. 

As I started looking for subjects to photograph, I learnt more and more and fell ever deeper in love with nature. My interests broadened when I got involved with a group of nature guides in my university - I started learning more and getting more into the conservation and outreach side of things. But my focus will always be my first love - inverts! I study aerospace engineering, but hope to contribute to research efforts some day - I still have a lot to learn!

He says that for about two years his photos mostly lived on his hard drive but a persistent friend finally persuaded him to start posting his photos to iNat this year.

It's been awesome! With iNaturalist, I've been able to learn so much more about the life I photograph. I especially love it when the experts come in and have discussions in the comments, on top of providing identifications. I think that's where the greatest potential for learning lies for me!

I think iNaturalist has also shaped the direction of my photography. On top of thinking about things like colour, composition and ethics, I've started thinking - how can I get the most scientifically useful and accurate shot? For instance, I've come to prefer shooting the dorsal view of jumping spiders instead of the classic anterior face-on view, because I find dorsal views more useful in identification. And the more identifiable something is, the more useful the observation.

I also think iNaturalist has broadened my focus. I've recently started to take more notice of plants, and although I have next to no relevant knowledge, the wonderful local identifiers have made it really easy to learn more.

(Photo of Sam by @phoebezhouhuixin.)


- You can follow Sam on Instagram here.

- Perhaps the most famous member of Family Keroplatidae is the New Zealand Glowworm. Check out PBS Deep Look’s video about them.

Posted on September 20, 2022 07:54 PM by tiwane tiwane

Comments

Great stuff Sam! Keep on keeping on!

Posted by susanhewitt over 1 year ago

What a great night hike, Sam!

Posted by carrieseltzer over 1 year ago

Wow, what a shot! Congrats!

Posted by ajott over 1 year ago

Love that photo! Especially the way the center gnat appears to be looking angrily at the photographer.

Posted by sullivanribbit over 1 year ago

Congratulations! What a cool shot and hike! I can definitely relate to your growing interest through the macro lens and then this site.

Posted by ashley_bradford over 1 year ago

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