Saturday, July 23, 2016

Restoring Bottomland Prairie: A Tale of Two Julys (2015 vs. 2016, Part 2.5)

Okay, so I'm not seeing the same pollinators I saw last July--but I am seeing some new ones.   New to me, anyway, are the Tachinid fly shown in this video and the Vespid wasp, both appearing in the Creek Field at the beginning of July 2016, on the blossoms of White Sweet Clover:  



Wouldn't you know, these two pollinators had to appear on a non-native plant, White Sweet Clover (Melilotus alba), a biennial introduced to North America in the 1700s.   So far I haven't worried about non-native annuals or biennials in the Creek Field.   As the the native perennials advance, they have pushed the more shallowly-rooted, short-lived invaders aside.  But White Sweet Clover has a reputation for being weedy, so I guess I'd better keep an eye on it.  On the other hand, keeping an eye on it has shown me that pollinators like it.   Beekeepers find it a good source of pollen for their honeybees. 

A presenter at this year's convention of the Kansas Native Plant Society told about her surveys of pollinators in prairie restorations. She found that pollinators were preferentially using many non-native biennials & annuals.  Her conclusion:  We should include more native annuals & biennials in our seed-mixes, as clearly from the pollinators' perspective the native plants are leaving some niches unfilled.  

In the meantime, I will tolerate a discreet non-native plant or two, especially if they're loaded with pollen!

Gathering pollen seems like a lovely occupation--of benefit to the plants as well as the insects.    

But my insects have other habits as well, some of them not so pretty.  The  Tachinid shown here is a "parisitoid"--one that kills its host from the inside out (as opposed to a straight-out parasite, that just lives off its host).  This fly lays eggs in caterpillars, and the larvae eat their way out, killing the caterpillars.  Tachinid flies provide important control of tent-worm caterpillars and some agricultural pests.  However, Tachinids also enjoy caterpillars of many species, including those that turn into beautiful butterflies.  


The wasp shown in the video is a Vespid wasp, one of the potter, mason, and pollen wasps, most likely Monobia quadridens.  This wasp is a pollen-eater, but a connoisseur of caterpillars as well.  M. quadridens provisions her nest with caterpillars!

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