About the aphid
Next up is Sitobion avenae, also known as English Grain Aphid. The lead picture of a single alate (winged aphid) is one of my favorites I have taken so far and made an appearance in my introductory post. S. avenae is a widely distributed aphid that primarily feeds on grasses. It is notable for being a pest on wheat and other cereals around the world. We raise this species and a number of other grain aphids on barley. While all the individuals in our colonies and pictured here are yellowish green, they can also be found in a reddish brown color. S. avenae is a medium-large sized aphid and fairly easy to spot on leaves and stems.
About the photos
A number of these photos have a dark or black background. This is simply due to the flash coming from overhead, illuminating the aphids much more than the background behind them. There is no special backdrop behind them. If the flash was pointing straight at the aphids from the same direction that the camera sees them, you would see rows of large growth chambers in the basement room where these were taken. The lights were on in the room, but are just much lower intensity than the flash. Since barley leaves and stems are so narrow, it is easier to get a lower angled “eye-level” with these aphids than others on broader leaves.
I tried holding a piece of white paper behind the aphids but was not satisfied with how it turned out grey like this photo of an alate about to take flight.
It is still an interesting action shot, but I think the grey color takes away from it. To get a true white background I think I would have to have more light pointed straight at the paper, or have the paper much closer to the subject. Also a green or blue background could be interesting. Maybe something to try in the future.
Shorter post this time, but more photos. I also took some pretty nice photos of a couple green lacewings (Neuroptera: Chrysopidae) yesterday, so may have to take a detour for the next post before getting back to more aphids.
About the aphid
Myzocallis asclepiadis is the first species I tried taking pictures of with my new camera setup. It is a very pretty and relatively little-studied aphid that is believed to be a strict specialist on common milkweed Asclepias syriaca, which it is seen on in these photos. Interestingly, almost all other known Myzocallis species specialize on shrubs and trees, especially oaks. In Minnesota, M. asclepiadis are easiest to find in mid and late summer on the undersides of milkweed leaves, typically evenly disbursed instead of forming tight colonies. Males have never been recorded, all adult females are winged, and they are only known to reproduce by live birth through parthenogenesis. They are usually paler in color early in the season and when immature. I do not believe their overwintering strategy is known.
One particular bit of info about this species that you may not hear elsewhere is how it interacts with parasitoid wasps. In laboratory host range tests of parasitoids being considered as biological control agents against soybean aphid in the Heimpel Lab, adult wasps were often found dead after contacting M. asclepiadis. After two undergraduate research projects that I helped advise (by Michael Oxendine in 2010 and Mattea Allert in 2012), we can say that adult M. asclepiadis does indeed seem to cause premature death in at least two species of Lysiphlebus parasitoid wasp adults. The exact mechanism is still under investigation. Many aphids defend themselves against their attackers, but this is an extreme case.
As will be the case with all of these posts, the species info is a combination of personal observations, things I have retained over the years from reading papers and books, and information gleaned from easily accessible web sources such as Influential Points and Aphids on the World’s Plants. I think I will skip having formal citations for everything since this is just for fun. This entry is long since it is my first real post and covers an aphid I have more experience with. Others may be much shorter.
About the photos
Settings on the camera and lenses for these shots are manually set to: aperture between f/22 and f/32 on the main macro lens and focus set to maximum magnification, f/1.8 on the reversed lens and focus set to inifity, 1/400-1/500 shutter speed, 100-200 ISO, and auto white balance. Flash is triggered by the camera at -1EV, handheld very close to the subjects. There probably are much better ways to do it, this is just what I found to work reasonably well with this setup.
As you can see, these are very colorful aphids and stand out quite nicely from the leaves they live on. This first photo is what they look like with a regular macro lens at 1:1 magnification.
Once I add the 50mm reversed lens, I can get something like this shot of an adult aphid and a very young nymph in focus with a few others scattered around. This first shot is uncropped and unretouched.
Once I get an image like that off my camera and into my computer, I zoom in quick to make sure there is enough detail to crop in closer. Then I boost the contrast, adjust the exposure (in this case, increased by 0.50 stop), and tweak a few other things as needed to get the colors and detail to where I want.
Finally, since I am most interested in the adult and immature aphid in focus in the center of the image, I crop and level to highlight them while keeping a couple other out of focus individuals in the frame for context. I am cropping pretty tight to show detail for this blog, but for other applications I might leave a bit more background or do a better job of abiding by “the rule of thirds” in terms of framing. Total imagine editing time is around or under two minutes. Here is what I will call my finished product:
A note about light
I quickly discovered that supplemental light of some form is essential for getting decent photos with this lens combination. Also, the plane of focus is so close to the front of the lens that I cannot just have a flash at the top of the camera and make the light actually hit the aphids. When I am taking these photos, I am usually holding an external flash with my left hand close to the end of the lens while simultaneously trying to steady the camera. It certainly helps when I can rest my elbows against a table or otherwise brace myself against shaking too much. Since I am using just a single flash with a little plastic diffuser and sometimes a small white bounce card taped to the top, location has a huge effect.
In these three photos I tried moving the flash from the far left in the first one, to the far right in the second (by crossing my arms and looking even more ridiculous than usual in the process), to mostly overhead and just a bit to left in the third. I am not particularly thrilled with any of these three in terms of composition, but they do illustrate how big of an effect light direction can have on the resulting image. Maybe some day I’ll get into trying multiple light sources, but that day is a long way off.
MC Kaiser Blog
Photographs of aphids by an enthusiastic amateur.
Images free for educational use with attribution.
Please contact me for any other uses, or visit my portfolios at Shutterstock and Dreamstime
First post and introduction here
If you are trying to identify live aphids from pictures, I highly recommend the website InfluentialPoints.com
For ID keys and a quite comprehensive catalog of aphids and their host plants see Aphids on the World's Plants
There is always the chance of one of our colonies getting contaminated and me posting a misidentified aphid. These images therefore should not be used to make formal identifications.
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