Baileya multiradiata and Trigonorhinus fungus weevils
When collecting seeds of desert marigold (Baileya multiradiata for you latin fans) I more often than not run across fused clumps of seeds in the seedheads that have been partially eaten and abandoned leaving a chamber and frass behind. This week as I was gathering some I found larvae and later adult fungus weevils (Trigonorhinus) in those chambers. The best match looks to be Trigonorhinus griseus, but being out of my field I'm reluctant to call a species.
As noted the chambers are quite common. This morning I collected and dissected ten likely seedheads (well-dried and shedding old flowers), and found the following:
Larva 2
Pupa 0
Adult 5
Empty chamber 2
No chamber 1
Nine of the ten had chambers. Larvae and adults were alive and were returned to their hosts.
If you have access to plants with mature seedheads (see attached photos), I'd be interested in a count of ten looking for evidence of a chamber (some of the seeds firmly clumped). If you want to go further and open them looking for occupants all the better.
Observations
Photos / Sounds
What
Genus TrigonorhinusObserver
stevejonesDescription
Larval beetle in Baileya multiradiata seedhead. Adult of presumably the same beetle species here. Both found in mature seedheads.
Photos / Sounds
What
Genus TrigonorhinusObserver
stevejonesDescription
Adult beetle found in Baileya multiradiata seedhead. Larva of presumably the same beetle species here. Both found in mature seedheads.
Photos / Sounds
What
Desert Marigold (Baileya multiradiata)Observer
stevejonesDescription
Old flowerhead with flowers and seeds (two layers); Trigonorhinus fungus weevil below. Second photo shows old flowers, third the seeds below. Fungus weevil larvae and adults frequently found in chambers within Baileya seed layer.
Comments
Detailed observations like this, focused on most every native plant, are bound to pick up the many organisms that use or inhabit it. Its the great fun in observing again and again the same plants and other biota.
Loved learning about this weevil! Excellent photos.. Thank you :-)
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