What's That Bug? does not endorse extermination

Subject: Caterpillar swarm in Costa Rica
Location: Costa Rica higher elevation
October 31, 2014 9:12 am
These caterpillars(?) appear seasonally in the higher elevations in Costa Rica. (1500m/5000′ MSL). They are 3-4″ long and appear to burrow as a group in the ground (in our yard and surrounding farmlands).
We don’t know what they are (or whether they are a problem?) but they have a marvelous locomotion. They crawl on top of each other for awhile, then they all pause as if catching their breath, then resume. This video was taken on the road outside our house.
What are they and do they benefit or damage the plants and animals?
Signature: Bugged in Costa Rica

Sawfly Larva

Sawfly Larva

Dear Bugged in Costa Rica,
We do not believe these are Caterpillars.  We believe they are Sawfly Larvae, relatives of wasps and bees.  There are Australian Sawfly Larvae known as Spitfires that look similar.

Aggregation of Sawfly Larvae

Aggregation of Sawfly Larvae

What's That Bug? does not endorse extermination
Location: Costa Rica

One Response to Possibly Sawfly Larvae from Costa Rica

  1. Bugged in Costa Rica says:

    Amazing. A 3″ larvae, assuming that is what they are, traveling in packs (pods? herd? pride? swarm?) of dozens… then each turning into a “sawfly”…

    None of the flies we have here (except flying beetles) are a fraction of their size. From other reading I see that they can be destructive in larval stage. I guess I’ll relocate them out of the yard…

    Sorry that video files were not supported. Their locomotion is fascinating… Perhaps I’ll post to Youtube…

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