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Thalia geniculata

Marantaceae

Today I took a walk on the soggy side among one of my favorite Florida tropical marvels, Alligator-Flag (Thalia geniculata).   Everyone around here knows it whether they know it or not—big roadside ditch plant with “banana” leaves and paired violet flowers aloft on wands as tall as a truck .  They have a complex snap trap mechanical pollination system that would impress an orchid.    That was all written up in this blog, holy smokes, back in 2012.

https://treasurecoastnatives.wordpress.com/category/alligator-flag/

So, after a 13-year gap, it is time for Thalia Phase II:   co-habitant insects.     They are weird and poorly known.  The identities of the today’s Thalia companion species (in addition to the Canna Skipper) are handy thanks to a helping hand from bugnet.guide.

If you go look closely at Alligator-Flag inflorescences, which requires wet feet or a boardwalk such as Wakodahatchee Wetlands or Green Cay, you’ll probably find the True Bug Ischnodemus sallei scurrying, and mating immodestly,  on the branchlets among the flowers.   Related to the chinch bugs of suburban lawn dread,  Ischnodemus sallei feeds on Thalia sap.    The species has a special affinity for Thalia, at least in South Florida.

Below is the lion’s share of the knowledge of its distribution in Florida. Notice anything?  (The non-Thalia reports of this species I’ve seen have been on plants related to Thalia outside of Florida.)

And here is a tidbit from UF entomologist Dr. Susan Halbert:

Don’t want to bore you by getting too far into the weeds.   I just fancy a special relationship between one of our coolest wildflowers and its own bugs, even if they suck.    The Ischnodemus sallei abundance on Thalia is so bountiful locally,  I wonder if the insects disperse with floating plant parts of this shore-dweller.

Also abundant on Thalia,  and also poorly known, is a bigger, showier species of leaf-footed bug, Namacus annulicornis.    If you bother Ischnodemus sallei it disappears furtively into the spaces between the leaf sheaths and the stem. By contrast, when bugged, Namacus flies off in a huff, and seems to emit a stinkum on the way..  

Namacus

This bug appears to have Alligator-Flag as its sole host according to R. Barananowski and  J. Slater in their 1986 account in the Arthropods of Florida:

 

Eggs

Those bright red nymphs (below) look so much like Assassin Bug nymphs, I wonder if there is mimicry of some sort.

Funny how, when a flower has an “oh-my” pollination system, its more mundane aspects can  go overlooked.

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