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Just hanging around

If you walk around your house you may notice small brown spindle-shaped objects attached to walls, fence posts, or just about anything stationary with a vertical surface. They look like mini scrap-piles of dried grass, twig and bark.

mini-bagworm larvae cling to the side of a structure

Mini-bagworm (Astala confederata) larvae make their homes on the side of a structure. The larvae ultimately will become tiny moths, just some 20 mm long.

These are the tiny homes belonging to the larval stage of Astala confederata, a tiny moth less than 20mm long and commonly referred to as the mini-bagworm. The larvae use pieces of debris that they find to build their homes and help camouflage the insects. They will glue themselves to a substrate using fine strands of spun silk just before they start to pupate, the last stage before becoming an adult.

It is very difficult to dislodge the bag with a normal water spray from the hose, but they can be removed fairly easy by using a power washer or picking them off by hand.

These moths eat pieces of debris and grass, but do not cause any noticeable damage as we see with sod webworm or their larger cousin, the Evergreen bagworm. No insecticide sprays are necessary to use against the moth or larvae. The wingless female spends her life in the bag, it is the male that comes to her to mate. She then lays her eggs in the bag after fertilization.

If you handpick the bags they can be collected and thrown in the garbage or placed in a bucket of soapy water to kill the insect. Handpicking is most effective from late fall to early spring before adults reproduce and new bagworm larvae disperse.


4 Comments on “Just hanging around

  1. I don’t recall seeing them until the last year or so and I’ve lived here for 26 yrs.
    Are they indigenous to the US ?
    The little extra work getting ride of them doesn’t bother me much except for when they attach to screens, especially my pool cage. I work full time, so it is hard to always check, but if left unchecked, birds swoop in to check out this possible food source and poke holes in the screen.
    Thanks for all you folks do !

  2. Thanks! I’ve long wondered what moth makes those cocoons. There are always lots of them on the walls of my house in Tavernier, FL.

  3. Thanks, very helpful as I don’t want to bother the moth population but they are kind of disgusting when all over the house, front door, pool cage etc.