Random Insect: Midland clubtail dragonfly

Midland clubtail dragonfly (Gomphus fraternus, Gomphidae) photographed 06/07/2011 near Blissfield Michigan.

Yesterday I noticed several of these midland clubtail dragonflies (Gomphus fraternus, Gomphidae) near the River Raisin in southeast Michigan.  This species is concentrated around the Great Lakes and adults only appear for a few weeks in and around June.

Clubtails get their name from their obvious clubbed tails, but this feature isn’t present in all taxa (Triplehorn and Johnson 2005).  More subtle features of the eyes, mouthparts, and wings are also used to identify members of this family.

Dragonfly larvae (naiads) spend their time at the bottom of rivers and lakes ambushing other aquatic insects.  As they grow they may molt 9-17 times before leaving the water to molt into adults (Triplehorn and Johnson 2005).

Although the adults fly rather well, they seldom stray far from their aquatic nurseries (Triplehorn and Johnson 2005).  They continue the predaceous feeding habits of naiads, capturing other flying insects and often eating them in flight.  They’re considered very beneficial to humans since both the larvae and adults consume large numbers of insect pests, including mosquitoes (Triplehorn and Johnson 2005).

Literature cited:

Triplehorn, C.A. and N.F. Johnson.  2005.  Borror and DeLong’s Introduction to the Study of Insects.  Seventh Edition.  Thomson Brooks/Cole, Belmont, CA.

Plant-Insect Interaction: Flower fly on a Philadelphia fleabane

Flower fly (family Syrphidae) visiting the flower head of a Philadelphia fleabane (Erigeron philadelphicus, Asteraceae). Photographed 06/07/2011 near Blissfield Michigan.

Today I came across some Philadelphia fleabane (Erigeron philadelphicus, Asteraceae) being visited by a large number of insect pollinators.  In addition to some bees, the flower heads were attracting various flower flies (family Syrphidae).  Although these flies resemble bees, one obvious characteristic sets them apart.  Flies only have one pair of wings, while bees have two pairs.  Like bees, however, these flies visit flowers to feed on nectar and pollen.

Random Insect: Bouncing baby boxelder bugs

Eggs and first instar nymphs of eastern boxelder bugs (Boisea trivittata, Rhopalidae). Photographed 06/05/2011 near Blissfield Michigan.

In the past I’ve photographed adults and older nymphs of eastern boxelder bugs (Boisea trivittata, Rhopalidae).  Adding to that, yesterday I found some recently-hatched nymphs still hanging out near their empty egg cases.  These individuals were clinging to the front of a translucent greenhouse door in southeast Michigan.

Eggs and first instar nymphs of eastern boxelder bugs (Boisea trivittata, Rhopalidae). Photographed 06/05/2011 near Blissfield Michigan.

Boxelder bugs are hemimetabolous and they don’t pupate.  Instead the young nymphs resemble wingless adults, becoming more adult-like with each molt.  Boxelder nymphs go through five nymphal stages (instars) before reaching the adult stage (imago).  Now that I’ve found eggs and first instar nymphs, I’m pretty sure I’ve seen every stage in the life cycle of these insects.

Random Insect: Alderfly

Alderfly (Sialis sp., Sialidae) photographed 05/27/2011 near Blissfield Michigan.

I sometimes think of the insect order Megaloptera (fishflies, dobsonflies, and alderflies) as one of several “weird” orders.  They aren’t nearly as common as many other insects, and they don’t look quite like anything else.  Because of that I was happy to recently stumble upon this nearctic alderfly (Sialis sp., Sialidae).

Alderfly (Sialis sp., Sialidae) photographed 05/27/2011 near Blissfield Michigan.

Although adults like this may not feed, the larvae are predaceous.  They crawl around on the bottom of rivers and streams hunting down other aquatic insects.  They leave the water to pupate, but don’t form cocoons (Triplehorn and Johnson 2005).  Adult alderflies are poor fliers, and they’re usually found close to the water they grew up in (Bouchard 2004).  Since I found this individual along the River Raisin downstream of Blissfield Michigan, it probably lived in the river here as a larva.  Interestingly, this section of river is generally regarded as having poor water quality, but alderfly larvae are considered moderately sensitive to poor water (Bouchard 2004).

Literature cited:

Bouchard, R.W., Jr.  2004.  Guide to aquatic macroinvertebrates of the Upper Midwest.  Water Resources Center, University of Minnesota, St. Paul, MN.  208 pp.

Triplehorn, C.A. and N.F. Johnson.  2005.  Borror and DeLong’s Introduction to the Study of Insects.  Seventh Edition.  Thomson Brooks/Cole, Belmont, CA.

Random Plant: Pineapple weed

Pineapple weed (Matricaria discoidea, Asteraceae) photographed 05/27/2011 near Blissfield Michigan.

Pineapple weed (Matricaria discoidea, Asteraceae) is unique for a couple of reasons.  First, the flower heads lack the prominent ray florets typical of the aster family, possessing only cone-shaped aggregations of small disc florets.  Second, the finely-divided leaves produce a distinct pineapple-like scent when they’re crushed (Brandenburg 2010).

Pineapple weed (Matricaria discoidea, Asteraceae) photographed 05/27/2011 near Blissfield Michigan.

Despite these interesting traits, pineapple weed (also called disc mayweed) is often overlooked because it’s so common.  Native to the northwestern United States, it has spread over much of the continent (Brandenburg 2010).  It can usually be found in abundance in open, disturbed areas like trails, roadways, and fields.  These particular photos were taken along the edge of a farm field.

Literature cited:

Brandenburg, D.M.  2010.  National Wildlife Federation Field Guide to Wildflowers of North America.  Andrew Stewart Publishing, Inc., New York, NY.

Random Insect: Armored mayfly

Armored mayfly (Baetisca sp., Baetiscidae) photographed 05/28/2011 near Blissfield Michigan.

Imagine having no mouth and your only instinct is to spend the next few hours or days trying to mate before you starve to death or get eaten by fish.  Such is the plight of the adult mayfly (order Ephemeroptera).

Mayflies start out with a pretty comfortable life.  As hemimetabolous insects, the eggs hatch into naiads (aquatic nymphs) that vaguely resemble wingless adults.  Naiads spend several months to two years crawling around on the bottom of streams, rivers, ponds, or lakes feeding and growing (Triplehorn and Johnson 2005).  They molt often as they rapidly outgrow their exoskeletons.  It’s all relatively mundane.  Once they’re ready to leave the water, however, things get dramatic.

The naiads go to the surface of the water and molt into a winged sub-adult stage (the subimago).  It’s at this point that they suddenly become very attractive to freshwater fish.  Large numbers of these subimagoes are consumed by fish, for which they’re an important food source (fishermen refer to subimagoes as “duns” and often use live or fake duns as bait).

Subimagoes that survive the fish fly towards land, resting on plants for a short period before they again molt into fully reproductive adults (the imago stage, called “spinners” by fishermen). While they gain functional genitalia, they lose functional mouthparts.  Since they can no longer eat they then have a very limited amount of time to live, normally only a day or two (Triplehorn and Johnson 2005).  At that point mating is the only thing on their very simple minds.  Adults often emerge at around the same time and engage in mating flights (Triplehorn and Johnson 2005).  Shortly thereafter, females lay eggs in the water and the adults all die from starvation and exhaustion.

Some mayflies like those of the genus Hexagenia occur in plague-like numbers near lakes.  Mating flights can be dense enough to appear on Doppler weather radar, and they frequently blanket every surface near the shore.  I’ve walked along Lake Erie near Port Clinton and Sandusky, Ohio in May where you often crush scores of them with every step.

The individual shown above occurs in less impressive numbers, and farther from lakes.  I found it in a forest along the River Raisin in southeast Michigan.  By examining the wing veination and caudal filaments (the “tails”) I keyed this mayfly to the family Baetiscidae (armored mayflies).  In this family there is only one genus (Baetisca) that occurs in North America (Triplehorn and Johnson 2005).  They’re called “armored” mayflies because the naiads have enlarged and fused thoracic sclerites that cover part of their abdomens.

Literature cited:

Triplehorn, C.A. and N.F. Johnson.  2005.  Borror and DeLong’s Introduction to the Study of Insects.  Seventh Edition.  Thomson Brooks/Cole, Belmont, CA.

Plant-Insect Interaction: Sweat bee on stinking chamomile

Sweat bee (family Halictidae, possibly of the genus Augochlorella) on a stinking chamomile (Anthemis cotula, Asteraceae) . Photographed 05/29/2011 near Blissfield Michigan.

Sweat bees (family Halictidae) earn their name from the affinity for human perspiration that’s exhibited by some members of the genus Lasioglossum (Triplehorn and Johnson 2005).  It may be more accurate to call sweat bees halictids since many species lack this attraction to sweat.

Human sweat aside, members of this family spend their days digging nests in the ground, feeding on nectar, and collecting pollen for their young.  Pollen and nectar are collected from a variety of flowers, including this common stinking chamomile (Anthemis cotula, Asteraceae) .

Sweat bee (family Halictidae, possibly of the genus Augochlorella) on a stinking chamomile (Anthemis cotula, Asteraceae) . Photographed 05/29/2011 near Blissfield Michigan.

Based on the pointed apex of the marginal cell, pale green color, and reddish tegulae, this halictid appears to be a member of the genus Augochlorella.  As the literature suggests, it didn’t seem remotely interested in my sweat.

Literature cited:

Triplehorn, C.A. and N.F. Johnson.  2005.  Borror and DeLong’s Introduction to the Study of Insects.  Seventh Edition.  Thomson Brooks/Cole, Belmont, CA.

Random Plant: Ostrich fern

Ostrich ferns (Matteuccia struthiopteris, Dryopteridaceae) photographed 05/09/2009 near Blissfield Michigan.

Since I wrote about a relatively uncommon bladder fern the other day, I thought it would be prudent to back up and cover the common ostrich fern (Matteuccia struthiopteris, Dryopteridaceae).  Every year I find these ferns in a large congregation in a wet forest in southeast Michigan.  This location isn’t as frequently flooded as a floodplain forest, but it’s consistently wetter than a mesic southern forest.  This in-between zone seems ideal for their growth.

Ostrich ferns (Matteuccia struthiopteris, Dryopteridaceae) photographed 05/09/2009 near Blissfield Michigan.

These ferns are notable for their sheer size; they usually exceed three feet in height, and can grow up to about five feet.  Dense clusters like this give off a Jurassic Park vibe…among these ancient plants it’s easy to imagine dinosaurs just on the other side.

Ostrich fern (Matteuccia struthiopteris, Dryopteridaceae) photographed 05/09/2009 near Blissfield Michigan.

On a more mundane note, these are probably the most common ferns found in garden centers.  Since they’re so easy to come by they’re a relatively inexpensive and exotic addition to landscaping.  Just keep them out of full sun or they’ll burn to a crisp.  I’ve found that dappled part sun or shade work well.

Random Insect: A shy bumble bee

Bumble bee (Bombus sp., Apidae) hiding under a common mullein leaf (Verbascum thapsus, Scrophulariaceae). Photographed 05/29/2011 near Blissfield Michigan.

Yesterday I saw a bee’s behind (a bee-hind?) sticking out from under the edge of a common mullein leaf (Verbascum thapsus, Scrophulariaceae).  I thought this bumble bee (Bombus sp., Apidae) seemed shy, but it was probably just engrossed in some activity on the underside of the leaf.  What that activity was, I don’t know.  Normally they spend their time with their faces buried in flowers eating nectar and collecting pollen, not playing around on leaves.  I’ve heard that they sometimes lick up honeydew left by aphids (Aphididae), and perhaps that was what this bee was doing.

Bumble bee (Bombus sp., Apidae) hiding under a common mullein leaf (Verbascum thapsus, Scrophulariaceae). Photographed 05/29/2011 near Blissfield Michigan.

It eventually stopped what it was doing and turned around long enough for me to get a decent shot of its face.  Then it buzzed away.

Random Plant: Stinking chamomile

Stinking chamomile (Anthemis cotula, Asteraceae) photographed 05/27/2011 near Blissfield Michigan.

A common weed in disturbed areas, stinking chamomile (Anthemis cotula, Asteraceae) lives up to its name.  When the leaves are crushed they give off a pungent odor.  Personally I don’t find the smell to be too repulsive, but I could see how someone else might.

Like many invasive weeds this plant came from Eurasia.  Since being introduced to North America, it has spread across the entire continent.  It can often be found along roads, fields, and near buildings, like outside the greenhouse where this individual was growing.

Plant-Insect Interaction: Eastern carpenter bees on common marigolds

Eastern carpenter bee (Xylocopa virginica, Apidae) on a common marigold (Tagetes sp., Asteraceae), photographed 05/29/2011 near Blissfield Michigan.

Similar in size and appearance to bumble bees (Bombus sp., Apidae), the bee shown here is actually an eastern carpenter bee (Xylocopa virginica, Apidae).  You can tell them apart by looking at the top of their abdomens.  Bumble bees have fairly hairy abdomens that are usually colored black and yellow, while large carpenter bees (Xylocopa sp.) have upper abdomen surfaces that are mostly black and bare (Triplehorn and Johnson 2005).  You can see that the abdomen on the bee above is shiny and mostly hairless.

There’s another difference regarding their nesting sites.  Bumble bees usually nest in the ground, while large carpenter bees excavate nests in solid wood (Triplehorn and Johnson 2005).  Large carpenter bees are sometimes considered pests since they’re capable of weakening bare structural timbers.

Eastern carpenter bee (Xylocopa virginica, Apidae) on a common marigold (Tagetes sp., Asteraceae), photographed 05/29/2011 near Blissfield Michigan.

I found quite a few of these bees feeding on the nectar of common marigolds (Tagetes sp., Asteraceae) in a southeast Michigan greenhouse.  Based on the very large eyes and yellow facial marking, the bee in the second photo appears to be a male.

Literature cited:

Triplehorn, C.A. and N.F. Johnson.  2005.  Borror and DeLong’s Introduction to the Study of Insects.  Seventh Edition.  Thomson Brooks/Cole, Belmont, CA.

Plant-Insect Interaction: Leaf mining larva on an American elm

Feeding tunnel in an American elm leaf (Ulmus americana, Ulmaceae), created by an unknown leaf miner. Photographed 05/27/2011 near Blissfield Michigan.

While out along the River Raisin I came across an American elm leaf (Ulmus americana, Ulmaceae) showing characteristic leaf miner wounds.  Leaf mining insects have larvae that feed within leaves, eating the soft tissues while remaining relatively safe from predators.

Feeding tunnel in an American elm leaf (Ulmus americana, Ulmaceae), created by an unknown leaf miner. Photographed 05/27/2011 near Blissfield Michigan.

I carefully pulled the mine apart to find the culprit:

Unknown leaf miner on an American elm leaf (Ulmus americana, Ulmaceae). Photographed 05/27/2011 near Blissfield Michigan.

I suspect this is the larva of a fly (order Diptera).  The damage pattern and host plant seem to suggest this could be an elm agromyzid leaf miner (Agromyza aristata, Agromyzidae).

Random Insect: Leaf mining hispine beetle

Leaf mining hispine beetle (Sumitrosis inaequalis, Chrysomelidae) photographed 05/11/2011 near Blissfield Michigan.

I came across this beetle a few weeks ago in a floodplain forest in southeast Michigan.  The poor thing doesn’t seem to have a common name, so I’ll just generically refer to it as a leaf mining hispine beetle (Sumitrosis inaequalis, Chrysomelidae).  The larvae apparently feed on plants in the families Asteraceae (asters) and Fabaceae (legumes).  This adult happened to be on neither.

This beetle bears a strong resemblance to the basswood leaf miner (Baliosus nervosus, Chrysomelidae), which I’ve covered once or twice before.  Both beetles are in the same tribe (Chalepini) within the same subfamily (Cassidinae).

Random Plant: Bladder fern

Bladder ferns (Cystopteris sp., Dryopteridaceae) photographed 05/07/2011 near Blissfield Michigan.

According to Michigan State University there are a number of ferns that are present in Michigan floodplain forests.  They include the ostrich fern (Matteuccia struthiopteris, Dryopteridaceae), sensitive fern (Onoclea sensibilis, Dryopteridaceae), royal fern (Osmunda regalis, Osmundaceae), New York fern (Thelypteris noveboracensis, Thelypteridaceae), and the rare log fern (Dryopteris celsa, Dryopteridaceae).  While I’m familiar with most of these (especially the common and rather large ostrich fern) I recently came across a fern MSU didn’t mention:  a bladder fern (Cystopteris sp., Dryopteridaceae).

Bladder ferns (Cystopteris sp., Dryopteridaceae) photographed 05/07/2011 near Blissfield Michigan.

These ferns were relatively small, with fronds less than a foot in length.  They were growing just above the River Raisin on a steep north-facing bank.

Bladder fern (Cystopteris sp., Dryopteridaceae) photographed 05/27/2011 near Blissfield Michigan.

Unlike seed-producing plants like angiosperms and gymnosperms, ferns are more ancient and spread via spores.  The undersides of some leaves have structures called sori that are collections of spore-producing sporangia.  In bladder ferns, each sorus is enclosed in an inflated membrane called an indusium.  This layer ultimately ruptures and releases the spores.

Plant-Insect Interaction: Basswood leaf mining beetles on an American basswood

Basswood leaf mining beetle (Baliosus nervosus, Chrysomelidae) on an American basswood (Tilia americana, Tiliaceae). Photographed 05/27/2011 near Blissfield Michigan.

A few weeks ago I wrote about some basswood leaf mining beetles (Baliosus nervosus, Chrysomelidae) that I discovered in some forest leaf litter.  They had apparently awoken from overwintering and were just starting to become active.

Yesterday I was out in the same mesic southern forest in southeast Michigan and I came across a young American basswood tree (Tilia americana, Tiliaceae).  I got a bit excited, hoping to find some evidence of these leaf mining beetles.  I was not disappointed:

Basswood leaf mining beetles (Baliosus nervosus, Chrysomelidae) on an American basswood (Tilia americana, Tiliaceae). Photographed 05/28/2011 near Blissfield Michigan.

In the photo above you can see at least four adult beetles and some skeletonized basswood leaves.  In my initial post I pointed out that leaf mining insects have larvae that feed within the leaf tissues, creating “mines” in the leaves (example).  The interesting thing here is that this leaf damage doesn’t seem to be caused by larvae, it’s more consistent with chewing damage caused by adults.

Basswood leaf mining beetle (Baliosus nervosus, Chrysomelidae) on an American basswood (Tilia americana, Tiliaceae). Photographed 05/28/2011 near Blissfield Michigan.

I also found adults that appeared to be in the process of eating:

Basswood leaf mining beetle (Baliosus nervosus, Chrysomelidae) on an American basswood (Tilia americana, Tiliaceae). Photographed 05/29/2011 near Blissfield Michigan.

So in addition to the larvae mining the leaves, the adults appear to eat them as well.  That wasn’t all they were doing, however:

Basswood leaf mining beetles (Baliosus nervosus, Chrysomelidae) on an American basswood (Tilia americana, Tiliaceae). Photographed 05/29/2011 near Blissfield Michigan.

A lot of them were mating, and I imagine the females will soon lay eggs on the leaves.  After hatching, the larvae will inevitably start chewing their way through the foliage.  After getting fat and pupating, they’ll overwinter in the leaf litter on the ground and start it all again next year.

Random Plant: Virginia creeper

Virginia creeper (Parthenocissus quinquefolia, Vitaceae) photographed 05/11/2011 near Blissfield Michigan.

Virginia creeper (Parthenocissus quinquefolia, Vitaceae) is probably the most common vine I find in southeast Michigan forests.  I suspect it’s equally common in woodlands throughout its range in eastern North America.  I see it all the time, climbing trees to heights of maybe 30-40 feet.  The alternate, palmately compound leaves of five are pretty distinct.

Virginia creeper (Parthenocissus quinquefolia, Vitaceae) photographed 05/11/2011 near Blissfield Michigan.

This time of year the new foliage is a shiny bronze color.  The leaves will turn dark green in the summer, and then in the fall they’ll turn various shades of red and purple. The unimpressive summer flowers give way to small blue fruit, which stand in stark contrast to the bright red pedicles.

Virginia creeper (Parthenocissus quinquefolia, Vitaceae) photographed 05/28/2011 near Blissfield Michigan.

The color variation throughout the year makes Virginia creeper rather interesting and attractive.   For this reason it can be desirable as an ornamental in home gardens.  In addition to its beauty, it’s tolerant of a wide range of conditions (wet-dry, sand-clay, sun-shade) and can be grown easily.  Perhaps a little too easily.  Judging from its rampant growth in the wild, I suspect it may be hard to control.

Plant-Insect Interaction: Caterpillar on a boxelder

Caterpillar (order Lepidoptera) feeding on a boxelder (Acer negundo, Aceraceae). Photographed 05/11/2011 near Blissfield Michigan.

Boxelder trees (Acer negundo, Aceraceae) tend to be common in floodplains, including one in southeast Michigan where these photos were taken.  These maples have a preference for ample water and sunlight, so they grow readily in these disturbed areas.  They’re tolerant of a wide range of conditions, however, and easily colonize any disturbed area.  Because of that they’re commonly found on developed property and along ditches, fields, and roads.

Boxelders are often considered undesirable for a number of reasons.  They’re weak, easily damaged by weather, relatively unattractive, and short-lived.  The wood is of poor quality and of little use as lumber.  The trees also attract large numbers of boxelder bugs, which can be a nuisance to people.  I’ve heard people refer to boxelders as “trash” trees since they tend to grow like weeds anywhere they can.

Caterpillar (order Lepidoptera) feeding on a boxelder (Acer negundo, Aceraceae). Photographed 05/11/2011 near Blissfield Michigan.

Despite the prevalence of boxelders and their negative reputation, some organisms find them valuable.  A number of butterfly and moth larvae (order Lepidoptera) are known to feed on the leaves, including the caterpillar shown here.

Random Plant: Hawthorn

Hawthorn tree (Crataegus sp., Rosaceae) photographed 05/11/2011 near Blissfield Michigan.

When it comes to thorny trees in southeast Michigan floodplain forests, the most impressively thorny is easily the honey locust (Gleditsia triacanthos, Fabaceae).  It’s not the only thorny tree I find, however.  Just as common are hawthorns (Crataegus sp., Rosaceae).

Thorns of a hawthorn tree (Crataegus sp., Rosaceae) photographed 05/11/2011 near Blissfield Michigan.

While not nearly as thorny as honey locusts, hawthorns make up for it by producing large numbers of showy white or pink flowers in April and May:

Hawthorn tree (Crataegus sp., Rosaceae) photographed 05/11/2011 near Blissfield Michigan.

The flowers are very similar to those of other members of the rose family, including apples, cherries, pears, and plums.  Among these some wild plums (Prunus sp.) also have thorns, but the lobed leaves shown here are distinctively those of hawthorns.

Fruit of a hawthorn tree (Crataegus sp., Rosaceae) photographed 10/19/2009 near Blissfield Michigan.

Also like many other members of the rose family, hawthorns produce fruit that are pomes, much like small apples.  After the flowers are pollinated in the spring, the fruit grow through the summer and drop from the trees in the fall.

Plant-Arachnid Interaction: Comb-footed spider on a spotted ladysthumb

Spotted ladysthumb (Polygonum persicaria, Polygonaceae) photographed 05/11/2011 near Blissfield Michigan.

While out in a floodplain forest in southern Michigan, I came across a lot of spotted ladysthumb (Polygonum persicaria, Polygonaceae).  Introduced from Europe, this invasive plant is very common in this area.  While photographing the foliage, I noticed several leaves that were curled up in a peculiar fashion:

Spotted ladysthumb (Polygonum persicaria, Polygonaceae) photographed 05/11/2011 near Blissfield Michigan.

Intrigued by these dome shapes, I turned over a few of the leaves in search of a cause.  It turned out that members of a certain species of comb-footed spider (family Theridiidae) were using them as homes:

Comb-footed spider (family Theridiidae) residing under the leaf of a spotted ladysthumb (Polygonum persicaria, Polygonaceae). Photographed 05/11/2011 near Blissfield Michigan.

It seemed that they had used their webs to pull the sides of the leaves together to create their domiciles.  I imagine that once insect prey were snared in their webs, they brought them back to these dark, quiet locations to feed in peace.  The dark spots on the spotted ladysthumb leaves may have offered some additional shade.

Comb-footed spider (family Theridiidae) residing under the leaf of a spotted ladysthumb (Polygonum persicaria, Polygonaceae). Photographed 05/11/2011 near Blissfield Michigan.

I can’t tell what the spider in the first photo is eating, but the second spider seems to have a common midge (family Chironomidae) on its dinner table.

Random Plant: Cleavers/stickywilly/catchweed bedstraw

Cleavers/stickywilly/catchweed bedstraw (Galium aparine, Rubiaceae) photographed 05/20/2011 near Blissfield Michigan.

There are a lot of common names for the native weed Galium aparine (Rubiaceae).  They include cleavers, stickywilly, and catchweed bedstraw.  Although I find some humor in the name “stickywilly,” “catchweed bedstraw” is probably more fitting since members of the genus Galium are called bedstraws.

Cleavers/stickywilly/catchweed bedstraw (Galium aparine, Rubiaceae) photographed 05/20/2011 near Blissfield Michigan.

Words like “sticky” and “catchweed” in the common names were inspired by the hooked hairs that cover the stems, leaves, and fruit.  When you run your fingers up the plant’s surface, these hairs give it a sticky feel.  The hairs allow the plant to cling to other plants and objects, providing support for the weak shoots.  They also have a role in seed dispersal if they stick to passing animals  (Burrill 1992).

Cleavers/stickywilly/catchweed bedstraw (Galium aparine, Rubiaceae) photographed 05/20/2011 near Blissfield Michigan.

Side note:  I think the tiny insect on the plant above may have been a shining flower beetle (family Phalacridae) but he got away before I could catch him.

Literature cited:

Burrill, L.C.  1992.  Catchweed Bedstraw.  PNW (Pacific Northwest Extension Publication) 388.