P p p parasites

 Canon R5, canon 100mm f2.8 L Macro IS USM Lens. 

1/120s f/16 ISO400. Manfrotto Tripod, ball head. Two off camera GodoxAD100pro flashes; homemade foam diffusers; remote cable release. Small hand torch.

This photo captures the exact moment when parasitoids are emerging from a host pupa, a dramatic and rarely seen interaction between a developing butterfly and its natural enemies.

I had previously found and photographed at night this astonishing gold pupa of the crow butterfly (genus Euploea) as this was an important addition to my book. It shows biological metalised camouflage with real metallic reflections and mirror-like surfaces which confuses predator and is a natural form of structural colour.

 I returned a few days later during late afternoon to try a different lighting set up - using ambient light as well as diffused flash - as these highly reflective pupas are a huge challenge to photograph. As i set my equipment up i noticed these tiny parasitic wasps start to emerge, normally one at a time, but as i waited and took multiple pictures i was rewarded with two emerging and one about to fly off, and another perched above. This is a truly unique moment as i had heard of this behaviour but never before witnessed it. The tiny parasitic wasp that laid its egg was likely Chalcidoidea or Ichneumonidae and they normally lay just one egg, which can then divide into many identical embryos, called “polyembryony” which is the title of the photo.

It has been my only chance over many years to capture parasitism — the unseen fate of many pupae, yet it is estimated well over half of pupae die from parasitism in the wild. This image is both beautiful and scientifically significant.

The highly reflective surface means the two off camera flashes were set to manual at about 1/64 power, and I used large  (home made) foam diffusers on both of the off camera flashes. the other challenge was how to make the wasps lighter, which i did with the aid of a small hand torch. Unable to stack due to the movement i used f16 to get a decent depth of field given how close I was to the subject for a full frame shot, and a tripod. This was shot around 5pm in mountains behind Sai Kung, where it was 30degrees and 80% humidity, so I was dripping with sweat as I took this, using a cable remote to stop any camera movement and a fast enough shutter speed to freeze the emerging wasps. These are the tiny wasp parasites emerging from the amazing golden chrysalis of a crow butterfly.

The best way to spot these golden sculptures is out at night, where their highly reflective surface shines bright in the torchlight. I have seen them on railings on the Peak and on Lung Fu Shan, and in more forested areas, under leaves, on a forest path. Always a wonder to behold, and very tricky to photograph, as it shines in the flash.