Congratulations to those of you who correctly guessed the identity of the “subject” in ID Challenge #16 as the ladybird beetle Eriopis connexa (family Coccinellidae). This is one of the most common ladybird beetles in Argentina, and during the past few weeks I have seen large numbers of these beetles in the soybean fields that I have been visiting. Coccinellids in Argentina are among the easier the groups to identify to species thanks to the excellent website Coccinellidae of Argentina. Identifying the “meal,” however, proved to be a little more difficult. Most people guessed aphids, a natural choice, but soybean aphids have not yet made it to the soybean fields of South America (thankfully!), so the victims of these predaceous beetles must be something else. There was a clue in the challenge photo that at least one person picked up on (but didn’t make the connection) in the form of small black globs stuck to the hairs of the plant on which the beetle was sitting. These are actually the fecal deposits of the bean thrips, Caliothrips phaseoli (order Thysanoptera, family Thripidae) (which I covered a year ago in A thrips is a thrips…), which for the past two seasons now has built up large populations on soybeans in Argentina. In fact, an adult bean thrips (yes, “thrips” is the correct singular form) can be seen in the above photo (which I did not notice while I was taking the photo). I’ve not yet witnessed these beetles actually feeding on a thrips, but the large numbers of thrips and beetles and near absence of any other suitable prey item makes the association almost a given.
Not only are the adult beetles numerous on the plants, but eggs and larvae as well. Larvae are every bit as brightly colored as the adults, with a color scheme that leaves little doubt regarding their association. In the case of this larva, I watched it roam back and forth across the soybean leaf, pausing momentarily and apparently eating something—thrips eggs I presume.
Congratulations to Mr. Phidippus and Dennis Haines, who tie for the Challenge win with 14 points each, while Gustavo and Dave tie for the final podium spot. Mr. Phidippus, however, easily takes the overall win in BitB Challenge Session #5 with a whopping total of 57 points. Mr. Phidippus—contact me for your loot! Dennis Haines and Tim Eisele take 2nd and 3rd overall honors, and full standings for BitB Challenge Session #5 are shown below.
Copyright © Ted C. MacRae 2012
7 thoughts on “Eriopis connexa on soybean in Argentina”
Oh geez, I even *found* the Coccinellidae of Argentina site, but didn’t look at the right part of it! Ah well. That’s how it goes, I guess.
Yes, I noticed that the red was gone in all of the prepared specimen photos – gives them quite a different appearance.
Still, I deliberately included ‘Argentina’ in the tags, so if it were me I would have gone through every photo at the ‘Coccinellidae of Argentina’ site 🙂
Hey, you made the final podium, and there isn’t much difference between 3rd overall and 2nd – Spider Man already had the overall win locked up.
Congrats to Mr. Phidippus,
I can see that I need to spend some time looking at critters under a microscope if I want to push higher up the table – two zeros for the crop-challenges.
Persistence is the key to these challenges 🙂
Your comment reminded me that I was considering offering awards to the top 3 finalists at the end of each session – hopefully that will create some additional incentive.
Congrats Mr. Phidippus, Dennis Haines and Tim Eisele!!! And This is the first time I noticed the links. The Springtails are super photos (i have to go back and read some more – how did Mr. Phidippus get these photos) and the Arthropods in the Backyard are also awesome! I have to check everyone’s pages and/or photos. And we all get to look for the early buggers in this unseasonably warm weather here in the Midwest this year! —Dorian, just back from some time spent in the Black Hills
I love the Black Hills – although my one trip there did include a rather unnerving encounter with a prairie rattlesnake: Rattled in the Black Hills.
Thhanks for posting this