Subject: Stinbug sucking on a monarch caterpillar.
Geographic location of the bug: Western New York State
Time: 09:17 PM EDT
Your letter to the bugman: My wife was so excited to see a monarch caterpillar in our garden today (8/9/2018), only to discover that its “friend” was sucking its insides out. I could tell the vampire was a true bug, but I had thought they mostly drank plant sap. How specific are they? Does it specialize in monarchs or does feed other larvae? Thanks! You guys are awesome!
How you want your letter signed: Mark VanDerwater
While most Stink Bugs feed on fluids from plants, one subfamily, Asopinae, is predatory. We believe we have correctly identified your Predatory Stink Bug as Apoecilus cynicus thanks to this BugGuide image. According to BugGuide: “mostly feeds on caterpillars” but luckily they do not limit their diet to solely Monarch Caterpillars so relocating the Predatory Stink Bug far from the milkweed, perhaps in the vegetable patch, would be our solution to repeating this scenario in the future.
Thank you Daniel! I was poking around insect sights too and came up with the spined soldier bug, Podisus maculiventris. Known to prefer lepidoptera larvae. Also has the dark abdominal tip.
We agree that you have provided us with a correction. The Spined Soldier Bug is another member of the Predatory Stink Bug subfamily, and this BugGuide image is a good match, and the BugGuide description “Black streak on wing membrane + spined humeri are diagnostic” matches your image. Thanks for bringing this misidentification to our attention.