Pollinators of Spicebush

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

 

 

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Fragrant Water Lilies

Fragrant Water Lilies - 1
Fragrant Water Lilies – 1

Here is a series of the freshly blooming Fragrant Water Lilies (Nymphaeaceae – Nymphaea odorata) taken at Shaw Nature Reserve this past summer.  I converted these to look like oil paintings using Photoshop CS6.

Fragrant Water Lilies - 2
Fragrant Water Lilies – 2

This plant uses an interesting pollination strategy.  Insects are attracted to the flower and land on the concave tip of the ovary which contains a small amount of liquid.  If the insect has visited another lily flower previously, then the pollen it is carrying gets washed off in this fluid and pollinates the flower.  Often, the insect pollinator (usually small, native bees) will not be able to escape this small pool before the flower closes for the night and will therefore drown.  See Steyermark’s Flora of Missouri by George Yatskievych for more details on these interesting wetland plants.

Water Lilies - 3
Fragrant Water Lilies – 3

Thanks for visiting…
-OZB

A Straight-snouted Weevil

Baptisia alba
Baptisia alba Seedpod

Almost reflexively, I pull the baby rattle-shaped seed pod from the stately White Wild Indigo (Baptisia alba) as I meander through Shaw Nature Reserve’s prairie trails.  I can’t help it.  I make sure the pods are always black, mature and any seeds left unravaged I simply help to disperse along my walk.  But in doing this so often in the late summer and autumn for so many years I have come to notice that this common forb cannot disperse many seed.  Because, inside the seed pods, like the one pictured above, I usually find multiple seed predators – the short-snouted weevils, Trichapion rostrum (Family Brentidae).

Trichapion rostrum
Trichapion rostrum

Baptisia seed are favored among other insects as well, but what they may lose in this stage of life, they pick up as they grow, for the false indigo are long-lived, drought-tolerant perennials that contain large amounts of secondary compounds that make them absolutely unpalatable to grazing mammals.  The photo below shows these tiny beetles (3.0 – 3.5 mm) among the husks of a number of seeds.  I have not been able to find a source that suggests if both larvae and adults feed on these seeds, or just one of the growth stages.

Trichapion rostrum
Destroyer of Seeds

Here is an image of a couple, shortly after I split their double-wide…

It's the Visitors, Martha!
It’s the Visitors, Martha!

These little one have been a source of fascination for me.  I hope to learn more about them someday.

-OZB

The Bee Wolves

Bee Wasp
Bee Wolf

I was thrilled when I took my camera inside from shooting in my wildflower garden on a past summer day and identified this hymenopteran as a Bee Wolf.  Philanthus gibbosus (Family Crabonidae) is what I am calling this one.  Bee Wolves get their name from doing what you expect, feeding primarily on bees.  These solitary wasps will load their brood chambers with pretty much any bee or wasp smaller than themselves that they can catch as a provision for a single egg they deposit prior to sealing the chamber shut.  Some taxa have specific bees they prefer to catch and this can aid in identification.  This poor thing was quite beaten up as you can see in the photograph below.  Missing a few legs, it probably escaped a bird or larger insect, and was not happy to have me and my camera in its face.  In the photo above I captured it doing a rapid vibration of its wings, something I read that these guys are known for doing as a communication.  I can’t imagine what she may have been trying to tell me…

Bee Wolf
Bee Wolf

I believe the insect below to also be a species of Bee Wolf, but have not yet been able to put a name with this one.  I photographed this one having a drink in a wet area of Shaw Nature Reserve early one morning.

Bee Wolf?
Bee Wolf?

-OZB

 

False Milkweed Bug

False Milkweed Bug
False Milkweed Bug

The False Milkweed Bug (Lygaeus turcicus) is a seed bug that, although quite similar in appearance to the Small Milkweed Bug (Lygaeus kalmii), is not strongly associated with milkweed.

False Milkweed Bug
False Milkweed Bug

As can be seen in the photograph above, the False Milkweed Bug is most often found feeding on yellow composites (Family Asteraceae).  These bugs were all photographed at Shaw Nature Reserve on what seems to be this insect species’ favorite food plant, the False Sunflower (Heliopsis helianthoides).

False Milkweed Bug
False Milkweed Bug

There are several members of the Lygaeidae family that are aposematically colored and found in North American prairies.  As mentioned, it seems that the False Milkweed Bug does not typically utilize milkweeds.  The Small Milkweed Bug feeds on milkweeds as well as other plant taxa.  The Large Milkweed Bug feeds exclusively on milkweed.  There is obviously a great case of Mullerian mimicry (distasteful organisms appearing similar to one another to benefit from a an easily identified color or body type) going on here, but it gets pretty complicated.

What has happened to the False Milkweed Bug?  Is this a case of a species that once fed primarily on milkweed and developed aposematic coloration but has since switched food preference?  Or, is this a case of a palatable species mimicking (Batesian mimicry this time) the aposematic coloration of a truly noxious species?  Thinking about this, it is easy to see the selective advantages that could result from either possibility.

First, a little background…
Some insects that feed on milkweed benefit by concentrating chemicals called cardiac glycosides that are toxic irritants to vertebrate predators.  Cardiac glycosides are an irritant to vertebrate herbivores (livestock) and vertebrates that feed on insects that feed on milkweed and store these compounds in their tissues.  However, they are not a significant problem for insects that feed on milkweeds – they simply pass through their guts (insects that store these specific toxins, for example the monarch, must have biochemical changes to avoid toxic effects).  The milkweed’s primary defense against the seed bugs and other herbivorous insects is the milky sap that gets forcefully pumped from any mechanical damage that is inflicted on the plant.  For this reason the milkweed is a pain for an insect to feed on.

For a seed bug, with its piercing-sucking mouth parts, feeding on the gummy sap of a milkweed is a significant hurdle.  Assuming the False Milkweed Bug once fed from milkweed primarily and gave it up would be a significant advantage.  Keeping the aposematic coloration, which would allow it to gain the benefit from its vile-tasting, similarly colored cousins, still feeding on milkweed, would be advantageous as well.  With my brief observations, the False Milkweed Bug still behaves conspicuously – feeding and doing everything else it does out in the open, suggesting that the aposematic coloration is still working in this mimic-model system, whatever the source history ultimately may be.

-OZB

Plant Parasites

Dodder on Rosinweed
Dodder on Rosinweed

Most of us are familiar with many of the parasites that infect animals, since we, as animals, are susceptible to many.  Tonight I am sharing a few easily spotted and recognizable forms of parasitism in the plant kingdom.  The photograph above was taken, as were all in this post, at Shaw Nature Reserve and shows a relentless parasite that can infect a number of prairie plant species.  Dodder (Cuscuta sp.) is an obligate parasite, meaning it must find a specific living host plant to infect in order to survive and reproduce.  One can see by the orange coloration, this plant does not contain chlorophyll and must pull the necessary nutrients from its host plant.

Silphium Gall Wasp
Silphium Wasp Gall

The next parasite is of a form that I am just beginning to study and am finding quite interesting.  Plant galls are simply growths of plant tissue, formed not by the host plant, but by other organisms.  The variety of gall former as well as gall formation is astounding, to put it mildly.  Insects are the primary organisms that cause gall formations, but other arthropods, fungi, bacteria and viruses form galls as well.  Researchers are just beginning to learn the basics behind how these parasites cause the formation of such specific, and often beautiful galls.

The particular gall that is found on this poor Rosinweed plant pictured above is caused by a Silphium Gall Wasp (Antistrophus sp.).  One of the gloriously interesting facts about galls, much like other forms of parasitism, is the specificity most commonly found between host and gall former.  Most often a gall former can infect only one species of plant, or sometimes a group of closely related plant taxa.  Such is the evolutionary arms race between host and its necessarily specific parasite.  In the case of so many prairie host and gall former relationships, the outcome is sad for both.  The near elimination of this habitat has caused dramatic reductions in the variety and abundance of prairie plant species, and accordingly, has had similar effects on the insects that form galls on these plants.

Silphium Gall Wasp
Silphium Gall Wasp

Having observed these galls for so many years, I decided to cut one open to see the developments within.  A single gall can host many developing was larvae.  In this small section I was able to count no fewer than five wasp galleries, each harboring a developing wasp.  The two examples of parasites presented above are just a small example of the number of parasitic species that the Silphium support.  A number of other insects/arthropods use Silphium for food and shelter.  Birds love the seed and use the plants’ long strong stems for perches.  In many ways the Silphium are keystone species and can be considered as important to the prairies as trees are to the forests.

Grape Phylloxera
Grape Phylloxera

Grape Phylloxera is caused by an aphid-like insect and is a parasite to native grapes.  In the mid-1800s this species was accidentally released in Europe and nearly destroyed the French wine industry.  The life cycle of this insect and its relationship to its host is mind-boggling.  As many as 18 different life stages have been identified – from sexual to asexual, winged, foliage feeding to root feeding.  This complexity, as with so many other multi-stage, specific host-parasite relationships creates major problems in man’s attempt at developing commercial controls.  To date, this parasite cannot be controlled with any pesticide solution; the only remedy is still resistant stock that nature has developed in this host-parasite arms race.

-OZB