Geographic location of the bug: Mount Washington, Los Angeles, California
Time: 04:20 PM EDT
Your letter to the bugman: That’s definitive, but what are they doing rolling around those sacks, and some of the sacks have been hung up?
How do you want your letter signed: Mel Frank
Ed. Note: We met recently with noted author Mel Frank (see Amazon) and we correctly identified what he thought were Assassin Bug nymphs found on Cannabis as Leaf Footed Bug nymphs, probably in the genus Leptoglossus, based on BugGuide images as well as images from our own archives, and he wrote back wondering about this unusual activity.
Hi again Mel,
As we stated earlier, these Leaf Footed Bug nymphs are phytophagous, meaning they feed on plants. Like other members of the True Bug suborder Heteroptera, they have mouths designed to pierce and suck fluids, and members of this genus are frequently found on plants like tomatoes, pomegranate and citrus, and they damage fruit. BugGuide notes: “some are extremely polyphagous” indicating that they will feed from many types of plants. Some typically plant feeding True Bugs are known to feed on dead and dying insects, including members of their own species, but that is opportunistic behavior and not true predatory behavior. What you witnessed and observed over time, the nymphs “rolling around those sacks” and then hanging them up, sounds like the behavior of a predator storing food the way spiders wrap up prey with silk. We wonder, perhaps, if while feeding by sucking the fluids from your Cannabis, these Leaf Footed Bugs ingested cannabinoids resulting in altered “mindbending” behavior similar to experiments on a Spider’s ability to spin a web after exposure to drugs (see Priceonomics). We have not clue at this time exactly what is in that sack these nymphs were rolling around, or why they were rolling them around and hanging them up. It is a mystery. We will contact Eric Eaton to see if he knows anything about this type of behavior in Leaf Footed Bugs from the family Coreidae. We can’t help but be reminded of “Invasion of the Body Snatchers” and the aliens using pods to generate simulacra of humans.
Update April 25, 2018: Eric Eaton provides information.
So the plant they are on is marijuana? In any event, yes, these are Leptoglossus nymphs, which typically feed on seeds or seed pods, and that is what the “sacs” are. I’m a bit perplexed by the “webbing” around them. The nymphs may be maneuvering the seeds to find a good place to pierce them so they can suck out the juicy contents.
author, Kaufman Field Guide to Insects of North America
Pomegranate is one of the primary host plants for Leaf Footed Bugs in the Los Angeles area. You frequently find numerous individuals feeding on a single pomegranate. The “sacs” look somewhat like unripe pomegranate seeds.