The flower and the fly

Pretty things.

I’m in the middle of prelims and also a rather prolonged fever but I thought I’d check in before November ended.

Plus now I can stare at this pretty flower and the stripey fly I saw in Argentina.  I don’t know what kind of fly it is but it’s very striking.  Looks like it’s a nectar feeder.  VanEngelsdorp and Mexner recently estimated the global value of insect pollination at US$ 212 billion, or about 10% of the global value of agricultural production (2010).  There, I even included an insect fact.

Shh, only pretty flower-flies now.

*edit* Thanks kindly to Morgan Jackson and Joel Kits in the comments for identifying this as a bee fly (Bombyliidae) in the genus Poecilognathus.  Bee flies are really really cool little flies whose young generally parasitize other insects.

Two Weevils

A small black weevil feeds on a flower.

For a long time the extent of my knowledge about weevils was that joke.  You know the one.  (Or possibly you don’t.  My dad has a terrible addiction to bad puns.)  My mental conception of weevils was ‘some kind of buggy thing that gets in food.’  But now, as an entomologist, I know that they are a type of beetle thingy that gets in food.  And, you know, other stuff.   Weevils (and snout beetles) belong to the family Curculionidae, from the latin Curculio or “corn worm.”  I just think of curlicues.  With more than 40,000 species, weevils are the largest family of beetles, while beetles themselves are the most speciose order in Animalia.  Basically, this means there may be more species of weevils than any other animal on Earth.*

*Conceptions of species distributions are a rapidly changing field, and one strongly influenced by both ability and motivation to identify cryptic species.  For example, the wasp family Ichneumonidae currently has about 15,000 described species but estimates place the actual species count as high as 60,000. (Townes 1969)

A weevil (Curculionidae) on a fingertip.

Whatever the case, it is clear that this group has been very successful.  Why?  How about the advantage of a novel adaptation?  Most weevils are characterized by a unique, snout-like beak.  Despite appearances, this is not a piercing-sucking mouthpart.  Instead, the chewing mandibles are placed at the end of a long, tubular beak which gives them the reach to bore in to fruit, seeds, flowers, trees, etc.  Of course, a long snout like that requires other adaptations.  For one thing, most weevils have elbowed antennae that can fold back into a groove on the snout while feeding.  (For an example check out Ted MacRae’s excellent pictures.)  Another contributor to their success?  Well, as stored products pest these guys are extremely hardy.  We have a glass jar of corn and weevils that we use as part of our live insect display at outreach exhibit.  It has not been opened in years.  The corn is mostly powder but the beetles are chugging along.  Go weevils!

Pollinator

Pollen-covered fly feeding at a flower (Presidio la Bahia, TX).

I noticed recently that when I see pictures of flowers without bugs on them I find myself thinking that they are lacking, as if the photographer has left something out of the composition.  Yes, that’s a lovely flower– but it would be more interesting with bugs.

Look how pretty that fly is up there.  Much better.

I can’t see the subscutellum, but I’m going to place this fly as a tachinid anyway, using my go-to “look how bristly it is” method.  I’m a lazy taxonomist.  Tachinidae is an interesting family, as its members are parasitoids of other arthropods.  House flies and fruit flies lay their eggs on rotting meat or fruit.  Tachinids lay their eggs on or in another living arthropod (most commonly caterpillars).  The young maggots feed on their living host from the inside, Alien-style.  Adults live more mild-mannered lives, feeding on flower nectar, pollen, decaying material, or nothing at all, until the time comes to find a host for their young.  A beautiful, science-fiction circle of life.

Tag:  Bugs on flowers

A day in the life of a butterfly

A story in three parts.

Part 1.

Part 2.

Part 3.

The End.

Spider Waits

A spider waits on a flower in Argentina.

Here is the traditional holiday spider for your enjoyment.  Merry Christmas, all.  May delicious prey come your way.

♥

Alison

Swallowtails

Pipevine swallowtail feeding at flowers at Presidio la Bahia

Just got back from the ESA conference in San Diego!  It was fun.

Here’s some pictures I took last spring at the gorgeous flower field outside La Bahia (Goliad, Texas).  Two common varieties of Texas swallowtail butterflies, family Papilionidae, feeding in the flowers.  Swallowtails take their name from the long ‘tails’  common on the wings of butterfly species in this family.  Butterflies feed through siphoning mouthparts in the form of a long, coiled tube, called a proboscis.  As lepidopterans metamorphose from caterpillars to butterflies their mouthparts change drastically from leaf-chewing mandibles to a nectar-sipping tube.  This change is mirrored in their digestive tracts, which in caterpillars take the form of a fairly simple tube, and in butterflies becomes much more complex.

Giant swallowtail in the flowers at La Bahia, Texas.

Tumbling Flower Beetle

Tumbling flower beetle on daisy (Welder Wildlife Refuge, Texas).

This little beetle is a tumbling flower beetle, a member of the family Mordellidae.  Although small and easily overlooked, tumbling flower beetles can be identified relatively easily by their characteristic wedged body shape, with a humped back and pointy abdomen which extends beyond the wing case.  They are frequently black, but may also have colorful patterning.  As their name would suggest, tumbling flower beetles are generally found on flowers on which they feed as adults, although a few species also bore in dead wood.  They take their common name from their defensive behaviors.   Like many insects, when disturbed they will frequently drop from their plant perch to the ground, a maneuver which helps them avoid predators and entomologists with cameras.  They will also ‘tumble’ and gyrate about when cornered.

Lacy Wings

A green lacewing perches on a flower stem.

I caught this little guy right before he took off from the tip of a flower stem.  Lacewings are members of order Neuroptera,which includes both green and brown lacewings mantispids (mantisflies), and antlions.  Neuroptera means ‘nerve-winged,’ in reference to the intricate venation of the members’ wings.  They are closely related to, and are sometimes classified with, the orders Megaloptera and Raphidioptera, the dobsonflies, fishflies, and serpentflies, all of which also share similarly complex wing venation.

The green lacewing family, Chrysopidae, takes its name from the greek word “chryso” for “gold” for the nearly metallic toned eyes were are often conspicuously golden.  The macrophotography blog Four Ages of the Sand has a gorgeous close up of a lacewing eye. Somewhat like dragonflies, lacewings and other neuropterans are predatory, both as larvae and adults.  Because of this they are popular for pest control, and eggs are often purchased and distributed in large quantities in greenhouses or agricultural fields.  On the other hand, in some situations this same quality may make them a pest insect themselves.  For instance, some scale insects are used for commercial red dyes, and lacewings may prey on farmed populations of these insects.

Inching Along – Geometridae

An inchworm (family Geometridae) climbs flowers at the Welder Wildlife Refuge, in Texas

Inchworms (also called loopers and spanworms) are a type of caterpillar that take their name from their unique method of moving.  Rather than crawl along leg by leg, these caterpillars have adapted to take advantage of the length of their bodies and “inch” along, contracting the front and back portion of their bodies.  Even the placement of the prolegs (false extra appendages found in some insect larvae) has adapted to this behavior–inchworms lack prolegs in the middle of their body.  Inchworms are typically colored in greens or browns to blend into their environment.  Some, such as the caterpillar below, may have extra filaments to aid in their disguise.  Caterpillars may strike poses to resemble twigs, stems, or even bird poop!

A filament bearing geometrid on a plant stem (Flynn, TX).

The “inchworm” style of movement has independently evolved in several lineages of caterpillars.  However, by far the most abundant and diverse group are the caterpillars of the geometer moths, in the family Geometridae. This family name literally means “earth measurer” and these moths are often better known for their caterpillars than their adults.

Inchworm inching along.

Sunny Suckers

Aphids nestle under the base of a flower in Sam Houston National Forest.

Anyone who has spent much time around plants will be familiar with this classic gardener’s pest, the aphid.  Aphids use their piercing-sucking mouthparts (a characteristic of the order Hemiptera)  to drink the fluids of plants.  Fluid uptake occurs passively via the pressure generated by the plant’s own circulatory system.  In fact, the aphid’s mouthparts actually contain valves to limit the flow.  Without such systems the aphid would literally be blown off the plant.  It is more the equivalent of attempting to drink from a firehose than sucking from a straw.

Aphids are gregarious insects which live in small subsocial colonies on plants.  Reproduction varies among aphid species and may be sexual or asexual.  Many aphid species give live birth to young.  In the picture above and below, a few white and shriveled cast off exoskeletons are visible from developing aphids.  These skins, called exuvia, can become quite numerous as colonies grow and become crowded.  Overcrowding on plants generally triggers the production of winged aphids, which disperse to new host plants where they found new colonies.

Aphids coat a plant stem in Argentina.