Bug of the Week – Fleas

Howdy BugFans,

 

The BugLady was sitting in an office watching someone scratching their leg the other day, and her first thought (occupational hazard) was “fleas.”  She hopes you enjoy this slightly reworked BOTW from four years ago.

 

Everyone’s heard a story about some poor soul who walks into their home after a two-week vacation and is immediately covered with fleas halfway to their knees (which is as high as the fleas could make it on the first leap).  This is called a “house infestation.”  The BugLady’s dog happily contributed this “single” flea (there’s actually no such thing as a single flea), and the BugLady popped it into the freezer to slow it down so she could photograph it.

 

Yes, for a variety of very good reasons they are major pests.  But, they are magnificently adapted pests, perfectly designed to live where they live (on mammals and birds) and do what they do (suck blood), and for this, they deserve a small (but grudging) round of applause.

 

Design specs: Fleas are very small and are laterally flattened – look at a flea head-on and it’s easy to miss.  Its slim body slips between the feathers or the dense fur of its host, and it’s covered with backward-pointing spines, so it’s hard to dislodge. Streamlined?  Its antennae are tucked away in grooves on a flea’s head, and it has no wings to get hung-up as it darts around.  Need to change hosts?  A flea can leap 7 inches vertically and 12 inches horizontally (200X its body length) from one warm body to the next.  Strong?  One source equates their strength to that of a human pulling 2 elephants around.  Swat-able?  Better swat hard; their exoskeletons are tough.  Bloodthirsty?  In aid of getting that all-important blood meal, flea mouthparts come equipped with 3 “piercing stylets.”

 

Fleas belong to the insect order Siphonaptera, from “siphon” (tube) plus “aptera” (wingless).  Fleas are secondarily wingless, meaning that the wings that their ancestors once had have since been lost.  Insects that are secondarily wingless have developed a lifestyle in which they are “better off” without wings.

 

Thousands of species of fleas have been identified worldwide, but the fleas that people most often encounter tend to be in the family Pulicidae.  They may have names like dog flea, cat flea, and human flea, but most don’t care about the taxonomy of their host as long as it’s warm-blooded.  The human flea, Pulex irritans, is more common on non-humans like pigs, rodents, deer, mules, and household pets, and the cat flea (Ctenocephalides felis) is the common indoor flea on both dogs and cats (cat fleas may bite us, but they don’t live on us).

 

A flea’s life cycle is also brilliantly fine-tuned for survival.  Flea larvae are tiny, blind, legless, wormlike scavengers that develop in dark, humid places like cracks on the floor, animal nests, bedding, etc.  There they eat organic matter including dead insects, dandruff, exfoliated skin, shed insect exoskeletons, plant material, and flea feces (a list that makes even the BugLady reach for the vacuum).  The feces of adult fleas, high in undigested blood, are the base of a larval flea’s food pyramid.  After a week or two as larvae, they spin silken pupal cases.  The silk is “tacky” and picks up debris, camouflaging the cocoon.  Fleas spend a week or two as pupae.  They may hatch immediately, or they may remain dormant in their pupal cases until they sense the approach of a host, whether by vibration, sound, heat or by the host’s exhalations.  If the host has been away from home for a while, all the pupal cases that await its return will contain adult fleas, and they’ll all pop out of the birthday cake at once.  Presto – instant infestation.

 

The (admirably) devious rabbit flea monitors the hormone level of its bunny host, and when her EPT kit indicates that the rabbit is about to give birth, the flea starts manufacturing eggs.  These she lays on the baby bunnies before migrating back to Mom and waiting for the next litter.  One reference said that humans are the only primate that entertains fleas, because humans are the only primate that beds down in the same spot night after night, allowing larvae the opportunity to return to their host’s body as adults.

 

An adult flea must “break its fast” within a week of emerging from its pupal case, but after that first meal, a flea can fast for months.  Without a blood meal, fleas can’t reproduce.  In other blood-sucking species, like mosquitoes, only the female must drink blood and the male is a vegetarian.  The BugLady didn’t find any mention of this kind of dimorphism in fleas.  A feeding flea uses its razor-sharp maxillae (mouthparts) to pierce the skin, administers a dab of flea spit which acts as an anticoagulant, and siphons out blood with tube-like mouthparts.  It may siphon blood for as long as 4 hours at a sitting, but most of that volume goes straight through it and out the other end, released onto the host’s bedding to nourish the next generation that is lurking there.

 

Fleas are disease vectors that can spread typhus, tularemia, dog tapeworms, and plague (or it may not be carrying any of those diseases).  Like mosquitoes, fleas may be more attracted to some people than to others.  If someone says that they are a flea magnet, it might be that fleas truly do seek them out based on their personal “aromatic signature,” or it may be that they are more sensitive to flea saliva and react more intensely to the bites.  At the very least, the bites can cause itching, and scratching can cause secondary infection.

 

The exterminator’s mantra is: “Treat the pet.  Treat the home.  Treat the yard.”  If you are “chemical averse,” one resource recommends sprinkling diatomaceous earth on the floor and vacuuming it up a week later.  It’s a natural product, but use it with caution – no dust is wholesome when inhaled.  It reputedly works by damaging the waxy cuticle of fleas and other floor-dwelling insects, causing them to dehydrate.  The BugLady knows someone who uses salt for the same purpose.  Lowering the humidity of the house also helps knock down the population of larvae, and regular vacuuming corrals the majority of adult fleas.

 

Who said that good things come in small packages?

 

The BugLady

It’s a High Flyer Bird City

On behalf of the Steering Committee for Bird City Wisconsin, our congratulations on successfully renewing your recognition as a Bird City for 2014 at the High Flyer level. It is an accomplishment that puts the Village of Newburg, with the help of the Riveredge Nature Center, at the absolute forefront of efforts to forge a statewide coalition of citizens and public officials who know that birds are more than beautiful — they are significant.

Congratulations to the Village of Newburg for achieving this great accomplishment! Riveredge Nature Center has partnered with the village to annually apply for this recognition.  This year is special, as the village is one of only 10 municipalities (out of 75 awards) who received the High Flyer recognition.

The Bird City Steering Committee wants to make special mention of the five steps taken to meet its High Flyer criteria:

  • The Ozaukee County Fish Passage Project has been working with a contractor to restore habitat in the area damaged by the removal of the Newburg dam in the summer of 2012. Numerous trees and other plants were added to the area over the last two years to help restore the shoreline.
  • The Riveredge Nature Center in Newburg is offering a cavity nester workshop for the public (including Scout groups) in March 2014.
  • To incorporate native hardwood trees in public landscaping, some 25 small oaks and tamaracks were planted in Francis Fritz Falkner Park. They’ve added biodiversity, bank stability and color to the park.
  • As part of Newburg’s registration as a bird-safe community on the Wisconsin Humane Society’s Wildlife Rehabilitation Center website, Riveredge minimizes or extinguishes night lighting between the hours of 11 p.m. and 7 a.m. during migration periods (mid-August through October, and mid-March through May). It also reduces perimeter lighting, uses solar reflective curtains and applies window clings and CollidEscape to windows to reduce daytime collisions.
  • To raise awareness of its bird assets, an osprey platform has been erected in the Francis “Fritz” Falkner Park at the site of the former Newburg dam. Several adult bald eagles have frequently been observed in this area including on the Christmas Bird Count on Dec. 21, 2013.
Carpathian walnut with grapevine

Plant a Tree for a Great Price!

The Ozaukee County Land and Water Management Department is holding their annual tree sale! The title is a little misleading as they you can also purchase shrubs, prairie grass, wildflower seeds, bluebird houses, and rain barrels too! Have you ever purchased trees from the county before?  They are a great buy – a wonderful, and economical, way to increase habitat and beauty on your property.   The deadline to order is February 28th – but order early to get the best selection.

Here’s the PDF order form with all the details.  Spring is coming!

Bug of the Week – Flat-Headed Poplar Borer

Greetings, BugFans,

 

The BugLady wishes she were reclining under a sea grape somewhere, but instead she is courting Brain Freeze here in God’s Country.  Please accept this revision of an earlier BOTW.

 

Before you dive into that, these two links were sent by BugFans Bill and Joe after last week’s BOTW about bumblebees:

http://www.nationalgeographic.com/features/140114-bee-native-macro-photography-insects-science/?utm_source=Facebook&utm_medium=Social&utm_content=link_fb20140124ng-bees&utm_campaign=Content

and

http://www.bumblebeewatch.org/contents/

 

The story of a metallic wood boring beetle may begin in a felled tree and end up in a palace.  Not a rags-to-riches tale (because it might also end up in your kitchen or den), but the story of a group of pretty spiffy beetles, many of whose larvae make their living in the timber business.

 

Today’s star is a metallic wood boring beetle called (probably) the Flatheaded Poplar Borer (Dicerca tenebrica) (unless it’s D. divaricata, the Flatheaded Hardwood Borer).  There are about 25 species in the genus, and the tips of their elytra (the hard covers that protect the flying wings) are longish, a tad blunt, and slightly separated or flared at their tips (reminds the BugLady of an old-timey men’s Morning Coat).  Adult FPBs are found by day on pine and aspen trees.  Eggs are laid on the twigs or bark (depending on who you read) of dead or dying big-toothed aspen, and the larvae chew zigzag trails (“galleries”) just under the bark, eating the protein and sugar of the sapwood for (officially) two to five years or (anecdotally) decades.  They pupate under the bark and chew their way out after emerging as adults, which don’t eat much.  Though it’s not as glamorous as some of its flashier cousins, let’s use the FPB to explore a few things Buprestid.  This BOTW contains a record number of links, scholarly and not-so-scholarly, for BugFans to follow – like one of those “Choose Your Own Adventure” books.

 

Metalic Wood Boring Beetles (family Buprestidae) have starred in these pages before, most notably in the form of the recently arrived and horrifically destructive Emerald Ash Borer.  The name Buprestid comes from the Latin “buprestis,” which comes from the Greek “buos” (ox) and “prethein” (to swell up”), which boils down to “a poisonous beetle that causes cattle to swell up.”  Your guess is as good as the BugLady’s.  Other names for the group are “flat-headed borer,” a nod to the blunt or flat appearance of the larva’s head and shoulders (http://bugguide.net/node/view/704263/bgimage) and “jewel beetle.”

 

Buprestidae is a large family, with about 700 species in North America and 15, 000 worldwide, and they are happiest (most diverse) in the tropics.  They are sturdy-looking, bullet-shaped beetles that range in size from XS (about 1/8 inch) through XL (1 ¼ inch) with the FPB at the larger end of the spectrum.  Buprestids have short legs and short antennae and are strong flyers.  Because most larvae are borers in roots, stems, or wood, many native species have a bad reputation for damaging both standing and logged trees (a few are leaf miners and gall-makers).  The consensus is that most species don’t attack healthy trees, and some species target only fallen or logged trees, but the just-below-the-bark meanderings of the larvae ruin the top layers of saw logs.  Ecologically speaking, the holes made by exiting beetles let the water, fungi, bacteria, and small organisms that are the authors of decomposition into a tree that was already a goner.

 

Many Buprestids come in startling and iridescent colors, which suggests that at least some of their communication is visual.  According to Wikipedia, “The iridescence common to these beetles is not due to pigments in the exoskeleton, but instead physical iridescence in which microscopic texture in their cuticle selectively reflects specific frequencies of light in particular directions.  This is the same effect that makes a compact disc reflect multiple colors.”  Golden buprestids are a great example – http://bugguide.net/node/view/424597/bgimage.).move.

 

A Golden Buprestid beetle detour: The Olympic Spray Service, Inc. in the Pacific Northwest, says the following about the Golden buprestid beetle: “The golden buprestid beetle is often taken for a wood boring beetle that is causing damage to a structure.  It is, but its damage is usually restricted to the one board in which the beetle first laid its eggs.  Sometimes these will be discovered in an open beam in a living room.  This beetle requires no treatment.  It [av_the larva] can stay in the wood for 40 years. The eggs are laid in the wood when it is green or first harvested.  When it leaves it will not re-infest dry wood.  The eggs were probably in the wood when it was first put into the house.  It may be only in one board.   A Blog called “Nature in the City” told the story of a Golden buprestid beetle that emerged from a wooden cutting board that had been in someone’s kitchen for 29 years. A local expert theorized that as the cutting board (or exposed ceiling beam) dries, its wood becomes less nutritious and causes the larva to develop much more slowly.

 

Buprestids in Art – not images of beetles, but art produced using beetle wings.  Unfortunately, their shiny colors make some buprestids highly “collectable.”  Their colorful elytra are used, especially in the Orient, to create amazing beetle-wing jewelry and objects d’ art, some of which may be found on eBay, and they are regularly featured on postage stamps http://www.asahi-net.or.jp/~CH2M-NITU/tamae.htm.  The use of buprestids for and in art goes back several millennia; buprestids decorated King Tut’s tomb and a picture of an almost-4000 year old necklace with buprestid representations can be found at http://gtapestry.blogspot.com/search/label/Buprestidae.

 

A contemporary Belgian artist named Jan Fabre used Buprestid elytra to create art pieces large and small, including a ceiling at the Royal Palace of Brussels.  He is said to have chosen beetles as his medium because they’ve been around for a long time (though using 1,600,000 elytra for the Royal Palace might threaten that survival record).  Wikipedia’s entry on Jan Fabre shows one view of the palace.  Click on “A Bug-infested Ceiling” at the bottom of their entry for a few more views or go directly to http://www.odditycentral.com/pics/a-beautiful-bug-infested-ceiling.html.

 

Alas for the buprestids, they are marketed by the hundreds on ebay for our art project needs.

 

Buprestids go the movieshttp://www.ecouterre.com/charlize-theron-wears-beetle-wing-dress-in-snow-white-and-the-huntsman/. “Trimmed with thousands of discarded jewel-beetle wings from Thailand, where the insect is a delicacy.”

 

Buprestids in Textileshttp://www3.hants.gov.uk/museum/dress-and-textiles/beetlewing.htm and http://www.pinterest.com/elmsleyr/embroidery-beetlewing/.  The beetle-craft theme is continued in an article in the Cultural Entomology Digest (very readable for an article that manages to slip in words like “ethnoentomological”) on a website called Insects.org.  For a discussion of the use of beetles in religious, ceremonial and everyday garments, check out http://www.insects.org/ced2/beetles_tex.html.

 

Buprestids in Religion and Anthropology – BugFans who are interested in accounts of these topics can try http://www.insects.org/ced1/beetles_rel_sym.html.  The Egyptians may have admired buprestids because their emergence from trees echoed an incident in the life of the Egyptian god Osiris.  There are other anthropology-related articles listed in the table of contents of the Cultural Entomology Digest.

 

Buprestids in the News – Buprestid public relations hit a low point when a 2 inch long species of Australian buprestid was awarded the Ig-Nobel Prize” in September, 2011.  In this species, the male courts the largest female available.  Beetles were photographed courting and attempting to share bodily fluids with a newly-designed Australian beer bottle called a “stubby.”  Apparently, the compact size and brown color of the bottle and the stippling at the base acted as a “super-stimulus” for the males.

 

The BugLady

Bug of the Week – Celebrating Bumblebees

Howdy, BugFans,

 

It looks like fun to be a bumblebee, and the BugLady can hardly pass one by without taking its picture.  A BOTW in 2008 covered the lifestyle of bumblebees, and another in 2009 showed bumblebees negotiating Bottled gentian flowers http://www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/bumblebee.cfm and http://www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/bumble-bee.cfm.  BugFan Andy, who is also a bumblebee fan, wrote and suggested an update.

 

Here are some Fun Facts about Bumblebees:

 

  • As a group, BBs are northern bees, tough enough to survive north of the Arctic Circle.  They can “thermoregulate;” – producing heat by “shivering” their flight muscles without beating their wings, and retaining it via their thick, insulating hairs.  They need an internal temperature of 86 degrees before they can fly.  In chilly weather, queen BBs use the same “isometric” trick to incubate their eggs, warming the thorax and then sending heat to a bare spot on the underside of the abdomen; in hot weather they can get rid of excess heat that way.  They have to override a built-in system to do that; BBs are designed so that the heat that’s produced in the thorax, stays in the thorax.
  • Besides noting that BBs were able to pollinate certain tubular flowers that other insects couldn’t, Charles Darwin linked BB, field mouse, and cat populations (he called them humble bees, common usage in England at the time).  Mice raid BB nests (which are often located in old mouse tunnels), and Darwin wrote that if cat numbers were high, mice were kept in check, and BBs throve (and so did flowers).  And vice versa.
  • A BB’s buzz is produced by the vibrations of its flight muscles as it flies.
  • Small wings on a bulky body do not make for a very efficient flying machine.  The un-aerodynamic BB essentially muscles its way through the air, flapping its wings about 200 times per second (a little slower than a honeybee’s 230 beats per second and half the speed of a mosquito).
  • Honeybees (which were brought across The Pond from Europe in 1622) are key pollinators of agricultural crops, but the importance of BBs and other native bees as pollinators of a variety of beans, squashes, berries and orchard fruits is increasingly recognized.  BBs pollinate 15% of US crops (they fly in cooler and damper and darker weather than honeybees do), and they are now raised commercially and moved around internationally (colonies are also removed from the wild).
  • And then there’s “Buzz pollination.”  BBs approach a downward-facing flower, grab it, and give a little shiver while simultaneously buzzing at approximately “Middle C.”  It sounds different than their in-flight buzz.  The 400Hz vibration loosens the pollen grains and sends them raining down onto the BB’s furry little body.  One researcher calls them “living tuning forks.”  Life is Physics.  Turns out BBs are the ideal pollinators for tomato, cranberry and blueberry flowers, and they’re commonly introduced into greenhouses (previously, greenhouse growers used a small hand-buzzer to imitate nature while pollinating tomatoes).  Honeybees are buzz-pollination-challenged.
  • Continuing in the “Life is Physics” category, as a bee flies through the air, the resistance/friction it encounters causes a small, positive electric charge to build up on its body.  When it lands on a flower, the pollen grains, which have a slight negative charge, are attracted to the bee and will attach to its hairs even if the bee doesn’t actually brush against them.
  • Wisconsin hosts more than 500 species of native bee, including 13 BBs.  Nationwide, BBs represent 49 of about 4,000 different kinds of wild bees.
  • BBs provide “Ecosystem Services.”  They pollinate many wildflowers and wild fruits and berries.  Although BBs themselves are generalists, some of the flowers they pollinate can’t be accessed by other bees, so their actions affect ecosystem diversity and integrity.  The resulting fruits and seeds, the BBs themselves, and other invertebrates attracted to the plants, are eaten by wildlife.

But, as Joni Mitchell used to sing, “Don’t it always seem to go, that you don’t know what you’ve got till it’s gone.”  There are some Not-So-Fun Facts about bumblebees, too.

 

  • While the woes of honeybees and Colony Collapse Disorder have received public attention and outcry, native bees are also disappearing.  The list of adverse factors includes diseases and parasites carried by domestic bees (including imported BBs), air pollution (a University of VA study showed that gasses from cars bond with the scent molecules of flowers and make it harder for pollinators to “follow their noses.”), climate change (some may like it hot, but not BBs), pesticide use, and habitat loss and fragmentation (the current trend toward “agricultural intensification” – the removal of fence rows and natural borders – deprives bees of feeding diversity and of nectar corridors).
  • Because there have been few baseline population studies of native bees, it’s hard to say how rapidly they are vanishing.  It is believed that at least four or five species of BBs have experienced a severe decline.  The same thing is happening in Europe.
  • Some surveys do exist – in 1890, an insect enthusiast meticulously cataloged the insects around his southern Illinois home.  100+ years later, researchers could find only 54 of the 109 species of native bees he recorded.
  • According to an article in a 2009 Wisconsin Natural Resources magazine, 93% of BBs found in a 1993 survey of northern Wisconsin’s cranberry growing area were Yellow-banded BBs.  Less than 20 years later, YbBBs represented 1% of the BBs in the area, and the small populations seen at three Wisconsin sites were the only recorded populations in the Midwest.

Can we help BBs and other native bees?  We certainly can.

 

We can census them by participating in Citizen Science efforts like the Great Sunflower Project’s Backyard Bee Count – http://www.greatsunflower.Org/ and by checking http://Www.xerces.org/pollinator-conservation/ to see if they have other surveys in the area.

 

We can plant clumps of bee-friendly, native plants that have different heights, shapes, colors and blooming seasons.  Plant enough, and you’ve created a habitat, and butterflies and birds will be happy, too.

 

Heard of bird houses and bat houses?  Here are two plans for DIY bee shelters from Dragonfly Woman: http://thedragonflywoman.com/2012/04/30/a-new-bee-house/  http://thedragonflywoman.com/2011/04/22/bee-house-from-recycled-wood/.

 

Many native bees nest in the ground or in dead trees.  Can you spare a patch of lawn?  Rototill or spade up a small area on the lawn’s edge and see what comes in.  Leave a dead tree standing.

 

See http://www.fs.fed.us/wildflowers/pollinators/documents/BumbleBeeGuideEast2011.pdf and http://homepages.cae.wisc.edu/~oliphant/bees/bombus/species.shtml to try your hand at BB Identification.  The BugLady’s BB IDs are tentative (but she’s blown away by the big Black and Gold BBs (maybe) with the crew cuts).

 

For more information about bees: http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5306468.pdf.

 

The BugLady wishes that she had a dollar for every bumblebee she saw on wildflowers in southeast Wisconsin in 2013, but BugFans Tom and Joe reported a scary lack of bumblebees and other hymenopteran pollinators last summer at their locations south of the Mason Dixon line.  Imagine goldenrods empty of bumblebees and windfall apples with no yellowjackets on them.

 

Waiting for BB weather,

 

The BugLady

Bug of the Week – European Elm Bark Beetle

Salutations, BugFans,

 

The BugLady loves finding these runes, inscribed by long-departed insects (they are also reminiscent of a diagram of meiosis from the BugLady’s past).  The tale that they tell is one of lust and fertility and survival (OK – a little florid, but it’s snowing.  Again).  Turns out that there was much more to the story of the European elm bark borer than first meets the eye.  Put your feet up – it’s an epic tale.

 

There are a number of beetle families whose larvae burrow beneath the bark.  The offspring of the prominent and showy Buprestids (metallic wood borers like the infamous Emerald ash borer) and Cerambycids (Long-horned beetles) are borers.  Bark beetles, in the weevil family Curculionidae, are small and seldom noticed, and they tunnel as both adults and larvae.

 

Older books and internet sites list them in their own family, Scolytidae, but with the constant review and reshuffling that is scientific taxonomy, they are now grouped with the weevils.  Their subfamily, Scolytinae, gives a nod to their former classification.  There are about 6,000 species of Scolytini worldwide; 525 in North America.  They look a lot alike, and one way to narrow down the species is by noting the type of tree, the location of larval feeding, and the shape of the larval galleries (tunnels) (Scolytinae also includes a group called the Ambrosia beetles, who plant fungal spores in their tunnels and then eat the plant tissue that is softened by the growing fungi.  The larvae of European elm bark beetles tunnel, but they do not farm).

 

There are a number of serious pests, both native and introduced, within the Scolytinae, like the several species of extremely worrisome pine beetles that are impacting trees in western and southeastern North America.  The European elm bark borer (Scolytus multistriatus), a.k.a the Dutch elm weevil, a.k.a. the Smaller European elm bark beetle, is an alien that was first observed in the US in 1909, though it undoubtedly arrived earlier.  Surveys in 1933 found the beetles clustered around the seaports of Boston, New York City, and Philadelphia.  Look for them today across the US, north into Canada and south into Central America, wherever elms grow.  Look sharp, because they’re tiny – only 2 or 3 mm long (1/8 inch) long http://www.eakringbirds.com/eakringbirds5/insectinfocusscolytusmultistriatus.htm.

 

For EEBBs, feeding and breeding are interwoven.  Long story short – newly-emerged adults seek food, preferring to feed in the top half of healthy elms in a twig crotch, at the twig-leaf connection (axil), and sometimes on the buds.  When they are sated (or when, as one source implied, they have seen enough of the sun), they look for a cut, diseased or compromised elm.  The female EEBB burrows under the bark and creates a long (up to four inches), straight tunnel parallel to the grain of the wood (in one of the BugLady’s pictures, Mom’s tunnel curved when she encountered the tough wood of a knot).  A widened cup at one end serves as a mating chamber.

 

At intervals along the sides of her tunnel she carves little alcoves, each a repository for an egg, and when she is finished ovipositing, she remains in the tunnel to protect her young and keep the tunnel clean (her offspring aren’t as tidy, and their tunnels are packed with frass (bug poop)).  When the eggs hatch, the larvae chew outwards “with the grain,” at right angles to the maternal gallery, eating their way through the living vascular tissue (cambium and phloem) under the bark.  Unless population densities are high, larval tunnels don’t intersect, and as a larva fattens, so does the circumference of its tunnel.  It will pupate in the outer bark at the far end of its excavation.  There may be several generations in a summer, and the fall larvae overwinter under the bark as larvae, to metamorphose when elm leaves appear in spring.  When a cohort of adult EEBBs emerge, they leave the bark with a “birdshot” appearance.

 

Ah, but the devil’s in the details, and the escapades of the adults are a testament to Better Living through Chemistry [av_side note – check out the etymology/origins of the saying “the devil’s in the details” in Wikipedia].  Hungry adults may locate healthy elms via the elm’s airborne scent, or they may have to land on the tree to “scratch and sniff.”  Receptors on their antennae allow them to “smell.”  These tree odors act as feeding stimulants, and as the beetle chews on the twig, more elm “volatiles” are released and more beetles come.

 

The EEBB locates its brood tree in the same way.  Damaged elms give off a number of chemicals, one of which is similar to vanilla and another that smells like “sweet and spicy apples.”  As they excavate their brood tunnels, virgin female EEBBs release “aggregation pheromones” (airborne chemical attractants) at the entrance to the breeding chamber that invite both sexes to the party (even her frass is scented).  The brood tree ends up as a beetle mecca (EEBBS prefer trees that have other EEBBS in them), which results in more egg-laying (a “breeding attack”), which wears down the tree’s defenses.  There’s a tiny, parasitic wasp that follows its nose to the EEBBs, too.  Pheromone traps offer a way to control EEBBs.

 

This tunneling by EEBBs damages their (already ailing) host trees mechanically because the centipede-shaped galleries of the larvae interrupt the transport of nutrients throughout the tree, but EEBBs pack a one-two punch.  The first recorded case of Dutch Elm Disease (DED) in the United States was recorded in 1928, and in 1937, a report from the Massachusetts Agricultural Experiment Station states that the EEBB is “now considered to be the most important insect carrier concerned in the spread of the causal fungus [av_for Dutch elm disease] in the United States.”  DED first appeared in Europe (in a significantly milder form) in 1910, and having made landfall here in the late 1920’s, it arrived in Chicago and St. Paul by 1960 and California by 1973.

 

Dutch elm disease in the US is caused by two fungi, Ophiostoma ulmi and Ophiostoma novo-ulmi, and it’s transmitted by the EEBB, by a native elm bark beetle and by the alien Asian/Banded BB, a 2003 arrival that’s in the same genus as the EEBB.  If the dead or dying tree chosen by Mom for the natal chamber was infected with the Dutch Elm Disease (DED) fungus, the new adults will be coated with spores when they emerge and may also have spores in their guts.  They will inoculate both the healthy trees they feed on and the trees they lay eggs in.  Because of differences in the phloem tubes over the growing season, elms are more susceptible to DED at the beginning of summer, when the first brood of EEBBs appears.  Ironically, damage from DED occurs when the tree plugs its own xylem/water-transport tubes in an effort to isolate the fungus.

 

The BugLady found a study in which Webber, et al demonstrated that in the early stages of their lives, EEBB larvae can’t tolerate the DED fungus (and possibly other kinds of fungi, either); if they are surrounded by fungus-infested tissue, they don’t make galleries.  Older larvae can eat fungi with impunity.  There is, apparently, a window on the usefulness of a declining elm.

 

Are trees helpless against the beetles?  Plants often mount a defense against their attackers by producing insecticidal/fungicidal/nasty-tasting/toxic substances, thorns, or sticky sap.  When it comes to EEBBs, not all elms are created equal.  The BugLady read one account of a Chinese elm that thwarted the beetles with its gluey sap.  The fungus transmitted by beetles may be their counterattack against the trees’ defenses, and more distressed an elm becomes, the more nursery trees are produced.

 

And then there’s the phoresy.  The BugLady is always blown away when she comes across examples of phoresy (benevolent hitchhiking), a stunning indication of how profoundly complicated things are in Nature.  In a European study, both mites and nematodes (roundworms) were discovered in EEBB galleries (nematodes are found everywhere in Nature), and mite associations have also been observed with American EEBBs, as early as the 1930’s.

Although their ecological roles are unknown, scientists hypothesize that the mites move with the adult EEBBs from their natal tree to the tree where eggs will be laid.  When they hop off of their transport, mites spread fungal spores in their new location.

 

The BugLady recommends A Guide to Nature in Winter by Donald W. Stokes, and Tracks and Signs of Insects and other Invertebrates by Eiseman and Charney.  Both will help BugFans make sense of the clues that insects leave behind.

 

FYI, the internet rhyming site was stumped when it came to a rhyme for Scolytus multistriatus.  Go figure!  Hiatus?

 

The BugLady

Bug of the Week – Chickweed Geometer Moth

Salutations, BugFans,

 

This lovely little Chickweed geometer moth appeared on the BugLady’s tomatoes (the male, note the fuzzy antennae) and her front porch (the female – note the plain antennae).  She blames her lamentable inattention to small moths for not noticing them before, because they are allegedly pretty common.

 

Chickweed geometers are members of the family Geometridae.  As BugFans will recall, geometer caterpillars are called inchworms – they are missing several sets of prolegs in their midsection and that causes them to “inch” (hike their rear end toward their front) rather than “undulate.”

 

Proceeding on the assumption that scientific names are not just meaningless tongue twisters, the BugLady loves to find out the etymology of insect names.  Geometer means “earth measurer.”  Bugguide.net says that the genus part of a Chickweed geometer’s scientific name (Haematopsis grataria) comes from the Greek “haima” or “haimatinos,” meaning “blood/of blood,” probably refering to the pink markings on the wings, which can approach blood red in some individuals.  On-line dictionaries attribute the species name, “grataria,” to a Catalonian word (Catalonia is a region of Spain) meaning “to scrape, itch, squawk or scratch.”  The BugLady is going to have to chew on that one for a while.  According to Donald Borror’s Dictionary of Word Roots and Combining Forms, the prefix “grat,” from the Latin, means “pleasing” or “favor.”  A choice between grace and irritation.

 

Except for the far east and west coasts, CGs are found from the Rio Grande well north into Canada, especially in the eastern half of the US.  Because their larvae eat the leaves of chickweed (and clover and smartweed and other low plants) and because lawns may be hotbeds of chickweed and clover, CGs are often found in manicured situations, where their presence is welcomed.  Adults may sit on flowers, and they may pollinate flowers, but they probably do not eat.  They are eaten by predators, but Sogaard, in Moths and Caterpillars of the North Woods, wonders if their cheery colors signal that they are distasteful.

 

CGs are another “not much else looks like this” species.  Males and females are similar, with wingspreads just under an inch.  Because they are colorful and diurnal (day-flying), and they perch with their wings spread flat, they are often mistaken for butterflies.  Geometridae is a huge family, but Haematopsis is a tiny genus, with only this species in it.

 

CGs are seen throughout late spring and summer, until the first frosts.  The larvae develop quickly (a month as larvae; two weeks as pupae), there are several broods throughout its range.  The caterpillars from the first brood pupate briefly in a cocoon that they spin.  Larvae of the final brood overwinter as pupae.

 

The BugLady

Bug of the Week

Howdy, BugFans,

 

Here are two pretty beetles to remind us of summertime.

 

SHINING FLOWER BEETLES appeared in the first half of August, covering goldenrods and a few other members of the Aster/Composite family as though scattered from a cosmic pepper grinder.  Tiny, shiny, round, black dots that were, just as suddenly, gone.

 

SFBs in the genus Olibrus are in the Shining flower beetle family Phalacridae (from the Greek for “shining” and “circle”), and, first off, they’re misnamed (more about that shortly).  The SFBs are a small family, with about 125 species in North America and fewer than 650 species worldwide.  Olibrus is the largest of the 50 or so genera in the family.  Since they’re in the one to three millimeter size range, keying them to species requires scrutinizing their hind feet, antennae or, as Monty Python would say, their “naughty-bits” under good magnification.

 

Most members of the extended SFB family dine on fungus spores or hyphae (the threadlike filaments that make up the fungus’ support system).  As adults and as larvae, Olibrus SFBs are found on flowers.  Olibrus adults feed on pollen (one author wondered how, with SFBs so numerous, the goldenrods had enough pollen left to reproduce), and the larvae, buried deep in the flowers, drink only sap (they chew through flower buds and seeds to get the plant juices flowing, but apparently they spit the solids out and start sipping).  Because Olibrus SFBs are so conspicuous and easily collected, they have become the poster-beetles for the whole family, so while some sources refer to the family as Shining Mold beetles, most call this group of fungus-eaters the Shining Flower beetles.

 

Olibrus SFBs produce a single generation a year, timed to coincide with the flowering of their favorite composite.  In fall, the larva falls from the plant and tunnels into the soil, where it spends the winter as a pre-pupa; it will pupate the following spring or summer.  The beetles’ domed shape allows them to practice the stop-and-drop response when alarmed.

 

When the BugLady encountered these lovely black beetles with red epaulettes and derrieres, they were helping to control the sumac population.  With no common name in sight, the BugLady hereby dubs them the BLACK AND RED SUMAC LEAF BEETLE (Cryptocephalus quadruplex) (probably), though they are polyphagous (which means that they eat a bunch of different plants including sumac).  According to reports from the late 1800’s and early 1900’s, their taste for raspberry and blackberry leaves, got them blacklisted as pests.

 

Their genus name, Cryptocehpalus (“hidden head”) refers to the fact that the beetle’s head is recessed or tucked/tipped down into its thorax (quadruplex sounds like a movie theater with four screens, but according to bugguide.net, it is from the Latin for interwoven or network. The BugLady doesn’t get it, either.).  BaRSBs are one of about 80 species in the “case-bearing” leaf beetle bunch, beetles whose larvae travel about in cases made from their own fecal material.  Females oviposit in the leaf litter, the larvae eat dead leaves and grow there, and the almost-grown larvae spend the winter deep under the insulating leaves and are ready to emerge as adults by the end of May.  At 4 mm in length, they are giants next to Olibrus SFBs.

 

Other than their presence on the lists of many state museums and nature areas, these are small, pretty, “unsung” leaf beetles in the huge family Chrysomelidae.  BaRSLBs live within a giant area running from Maine to Georgia to New Mexico to Montana, spilling over into Canada.

 

The BugLady

Discovering Snowflakes

Our featured finding this month is….snow!  With all the snow in our area this year, its a great time to get outside and explore.  Our education staff put together a fun activity for members of any age.

Make Your Own Snowflake ID Book

Have you ever looked at snowflakes up close?  Are there really no two alike?  Create a snowflake ID key and find out more about the snow all around you.  This is a great activity for everyone in the family.

There are seven common snowflake shapes: Hexagonal Plates, Stellar Crystals, Hexagonal Columns, Needles, Spatial Dendrites, Capped Columns and Irregular Crystals.  You can use the chart below or do some research on the internet to easily create your own key.  You’ll find different snowflake shapes as the temperature and humidity levels change – so go outside with each snowfall to see if you can eventually find all seven shapes!

After you have created  your key, attach black felt to the left side of the paper with glue.  This will allow you to “catch” your snowflakes right next to your key for easy identification.  Make sure to put your key outside or in the freezer before catching snowflakes – that way they won’t melt right away!  How many different snowflakes can you catch?

snowflake chart

Bug of the Week

Howdy, BugFans,

This is a rerun (with a little tweaking) from the Christmas season of 2009.

Ah, the surprising American Pelecinid wasp!

Surprising because it is an impressive insect to see flying through the air; because despite similarities in size and shape, it is not a damselfly; because it appears to have a fierce stinger but appearances can be deceiving; because it is the lone remaining genus in its family; and because it’s got that parthenogenesis thing going.

The BugLady is always happy to see this startling wasp, and she saw more of them than usual in the summer of 2013. American Pelecinid wasps (Pelecinus polyturator) belong in the family Pelecinidae, and they are a New World wasp (with distant, fossilized/amber-ized relations from the Old World). APWs are relatively common in woodlands, grasslands and gardens from Argentina through Canada, where they are seen from mid-summer to early fall. Two other PW species occur exclusively south of the border. APWs are whip-thin, shiny, and black, with extra-long antennae and a long, curved abdomen. A female may measure almost 2 ½ inches long (five-sixths of her length is abdomen), but males are only about an inch long. Pelecinids have short wings for their length and are slow flyers as a result (except when you’re stalking them with a camera).

The diet of adult APWs is nectar, perhaps supplemented by some pollen and water. APW larvae follow the parasitoid path. Mom reaches down into the soil with that wonderful, jointed, flexible abdomen and determines the presence there of a May/June beetle larva (grub). She deposits her egg directly into/onto the beetle grub and goes her merry way, and when her larva hatches, it dives into the grub. Its feeding kills the grub, and the APW larva continues to feed/scavenge on grub’s tissue until the immature wasp is ready to pupate, right there in the soil. Biologists who gather June bug larvae to rear for experiments often find themselves with wasp collections instead.

A further word about parasitoid(ism). Parasites find it counterproductive to kill their hosts; parasitoids live to kill their hosts/kill their hosts to live. The only question is – how fast. Some parasitoids prefer live food and eat around their host’s vital organs until it’s time for the End Game. APWs do the deed quickly because they don’t mind eating dead tissue. The term necrotroph (from the Greek nekros- “dead body” – and trophe – “nourishment”) applies. According to Frost, in Insect Life and Natural History, parasitoids are plunked down on the continuum between parasites and predators. Their habit is considered highly evolved, and they’ve often co-evolved with their hosts. Only insects with complete metamorphosis (egg-to-larva-pupa-to-adult) need apply for the parasitoid lifestyle, and only the larvae have the ability to do it, though their victims may come from any stage of life. Some parasitoids specialize on a single host species and others are less picky. Along with the label parasitoid, APW larvae are also classed as endoparasites (endo meaning that the larva is feeding from the inside).

With a nod to their long, curved abdomens, these beauties are sometimes called scorpionflies. Common names rarely reflect an organism’s actual biological family tree, and APWs are not related to the family Mecoptera, the home of the true scorpion fly. Is that long, pointy abdomen as dangerous as a scorpion’s? It does culminate with a stinger, which Ms. APW will use to probe the fingers of anyone handling her, and there are reports of “pin prick” stings being administered. As wasps go, these are docile and harmless

Their parthenogenesis (from the Greek parthenos, meaning “virgin” and the Latin genesis, meaning “genesis”) results from the fact that north of the Rio Grande, males are so rare that females have developed the ability to reproduce without them. Or is it the other way around? Parthenogenic females tend to produce more females. Male APWs may be absent from our landscapes, but they are present in the more torrid climes. South of the border, it does take Two to Tango. Not just parthenogenesis, but “geographic parthenogenesis.”

The BugLady