A Neotropical Savanna

The weevils that swarmed on the sandpaper plant when it was in bloom have been identified. I received this email from Dr. Henry Stockwell, who kindly performed the identification during his recent stay at the Smithsonian Tropical Research Institute.

The weevils that you sent me are named Solaria curtula, of the subfamily Baridinae. As I mentioned to you on the phone, the larvae have their development in stems near the ground of poor nutritional value and must make an effort to find pollen after they emerge from a brief pupal stage. This is one of the very few weevils that is found on a fern, Dicranopteris. This fern is very common and forms a mat of vegetative growth on bare red-clay slopes. The individual single plant may cover several square meters. It is the first plant to reclaim bare hill-sides after a land-slide. Can’t think of a plant that might be poorer nutritionally.

Someone had suggested to me that the weevils might be laying their eggs in the pistils of the sandpaper plant so that the larvae could develop along with the fruit. Dr. Stockwell said on the phone that such behavior would be extremely unlikely because of the known life cycle of this species, which he then described in the email, above.

I should also add that although I saw the weevils mating during their pollen-eating swarm, I did not see them laying eggs, nor did I see them spending much time near the greenish pistil of the flower, which is where they would have had to lay their eggs.

Thank you, Dr. Stockwell.