A Thousand Acres of Silphiums

Sawfly – Tenthredinidae – Dolerus neoagcistus

With some extra nature time last week, I hit the trails at Shaw Nature Reserve hoping to get some shots of Claytonia virginica (spring beauty) being visited by its pollinators – particularly the small solitary Halactid bees.  The problem I had on this day is that these bees don’t typically like to be very active on cloudy, grey days.  There were a few flies visiting the spring ephemerals, but they were much to flighty to bother with.  So, I decided to give some attention to the Lindera benzoin (spicebush) that were blooming in abundance along the river bottom trails.  My goal then became to document the pollinators that visit this early-blooming bush.

Sawfly – Tenthredinidae – Dolerus neoagcistus

One of the more obvious of these pollinators that I found was this sawfly.  This is my best guess on identification.  This sawfly was quite small and by the looks of it, is quite an efficient pollinator.

Sawfly – Tenthredinidae – Dolerus neoagcistus

Probably the most abundant pollinator I came across were these Tachinid flies (again, flies are difficult and I could be wrong).

Tachinid Fly?

The hair-like setae that probably serve to aid the fly in responding to changing air pressures also serve as nice holders to move pollen from flower to flower.

Tachinid Fly?

I also found a number of multicolored asian lady beetles (Harmonia axyridis).  Typically predators of aphids, these beetles are also known to feed on pollen.  This is what I figure was going on in the image below.  Since there are probably few aphids to be found during the early spring, with few leaves being available, pollen is the next best protein source.  I suppose there could be aphids to be found hiding within the flowers, but did not inspect closely enough.

Multicolored Asian Lady Beetle – Coccinellidae – Harmonia axyridis

Probably my favorite find of the day were several flies of the family Empididae.  These are fascinating flies that are primarily predatory, but a few taxa will visit flowers to feed on nectar or pollen.

Dagger fly – Empididae – Empis or Hilara genus

Within this family are at least a few where the females will not hunt themselves, instead relying on a “nuptial gift” of a prey item from a male.  Males of some species will wrap their gift in a silk wrapper.  In these taxa the sex roles will often be reversed – the females courting the males to get these gifts and the opportunity to mate.  In at least one species, the females will inflate themselves grossly with air to give herself the appearance of being bound with eggs and fecund, to trick the male into thinking she is a prime candidate to provide his gift and have the opportunity to mate with.

Dagger fly – Empididae – Empis or Hilara genus

At least one species has taken this system a step further.  The males no longer provide a prey wrapped in its decorative covering, but simply provide the silken covering, or balloon, giving them the name “balloon flies”.  The photo below provides a good look at the dagger-like moth parts that give these guys another of their common names.  Another overlooked beneficial fly.  Not only do these guys prey on mosquitoes and other potential pest insect species, but their larvae are also predatory, feeding on insects in the soil and leaf litter.

Dagger fly – Empididae – Empis or Hilara genus

I’ll leave you with one final image.  This one isn’t a pollinator of the spicebush, but potentially feeds on its leaves in summer.  What I believe this to be is a (Camptonotus carolinensis) Carolina leaf roller that was parasitized by one of the “zombie fungi”, potentially Cordyceps sometime last summer or early fall.  This poor cricket was infected with this fungi that took control of its “mind”, forcing it it to climb high up on a branch of the spicebush.  Once there, the fungi used the cricket’s resources to fruit and spread its spores from this higher location in order to reinfect others.

Zombie Cricket

Until next time…
-OZB