Friday, August 16, 2019

Another Jumping Spider

I saw what initially looked like a small ant slowly scouting the surface of a patio table.  It was less than a quarter inch long (5mm) and skittish when I got too close.  I was able to get these pictures with my cell phone, a bit blurry when blown up but good enough to ID it on INaturalist as a Common Hentz Jumping Spider, Hentzia palmarum.

It has impressive front legs that resemble a crab spider.  When I got too near it jumped several inches over the table edge and dangled by a trailing strand of silk before climbing back up.  Jumping spiders don't build webs but also use their silk to create a burrow to hole up into.

H. palmarum - Large central eyes - "The better to measure the jump on you with"  - Wikipedia
H. palmarum  David Hill - Wikipedia
They hunt by relying on their large eyes in front as they stalk their prey (See last month's blog for a discussion on their binocular vision).  The long front legs holds their prey while they inject their venom.  The black and white striped structures in this photograph are their pedipalps or jaws.  The large pedipalps and dark color generally identify this as a male.  There is a good video of H. palmarum in action at this Youtube link.

Female H. palmarum - Brandon Woo

There is a dramatic difference in appearance between the male and female, making them look like separate species.  According to Bugguide "Females are hairier, paler in color, often marked with forward pointing triangles along the center of her abdomen."

Brandon Woo's specimen looks warm and cuddly compared to the males, unless spiders aren't your thing.

Monday, August 12, 2019

Milkweed Munchers

Barb was dumping plant debris into the compost pile when she noticed this bug crawling around in it.  Lifting up some of the old scraps revealed even more of them.  They measured 3/8" (10 mm) and required magnification for final identification as small milkweed bugs, SMB - Lygaeus kalmii.

Box elder Bug
On first glance it resembles a smaller version of the box elder bugs that swarm later in the year. They tend to migrate into the house, occasionally using their plant-sucking proboscis to puncture the skin, causing slight irritation.

The distinctive coloration of SMB made the identification relatively easy.  It has a bright orange incomplete "X" on the back and the upper black marking is somewhat heart shaped.  The anterior edge of the pronotum (the plate covering the first portion of the thorax) has two small black spots.  L. kalmii also has a small red spot on the back of the head extending forward, visible only with magnification.

When I think of milkweed, I associate it with the poster child of lepidoptera, the monarch butterfly.    SMB feeds on milkweed seeds as well as the nectar from other forbs.  They can also predate on small insects when other food sources are depleted.

The adults lay their eggs on milkweed in the spring and the larvae require milkweed to grow.  They absorb and store the milkweeds toxin glycosides which are harmless to them but serve as a defense against predators.  Actually at least four other insects feed on milkweed without ill effect from the toxic chemical.

Large milkweed bugs - Wikimedia
The large milkweed bug, Oncopeltus fasciatus is nearly twice the size and has a different pattern of the same colors.  Both the adult and larval forms feed on milkweed juice and seeds when available.  O. fasciatus is commonly used in science due to ease of rearing and ease of dissection, a trait that is probably not of significant survival value to the bug but is a boon  to science and education. 

Milkweed beetle-Wikimedia
The milkweed beetle, Tetraopes_tetrophthalmus likewise stores the toxins and advertises its distastefulness.  All the above species share the black and orange aposematic coloration, as does the monarch, warning potential predators that they are toxic. After the eggs are laid on stems at or just below surface, larvae bore into stems, overwinter in roots, and pupate in spring.  The adults appear in the early summer to repeat the cycle.

Our final contestant lacks aposematic coloration.  The milkweed stem weevil,  Rhyssomatus lineaticollis, can be quite destructive of rare and endangered milkweed species.

Milkweed stem weevil - Ken at Bugguides
"Adults initially feed on the apical leaves and then, after feeding, female weevils walk to lower parts of the stem and chew several sequential holes in the stem, creating a continuous scar. Females lay a single egg per hole and larvae complete development inside the stem while feeding on pith tissue."
A mastication of caterpillars
We have previously written about the Milkweed Tussock Moth.  There are lists of special names for groups of animals such as a "murder of crows."   The "official" name for the group of caterpillars is "an army of caterpillars" but I like Kevin Furth's naming of a "mastication of caterpillars."  They are enough to make crow vomit as seen in this blog.

All insects that have milkweed in their diet at some part of their life cycle are poisonous to their predators because of the toxic cardiac glycosides contained in milkweed sap.  Brightly colored or not, don't eat them!

MN Members:
Got Milk-weed seeds?  MDC is collecting them for monarchs.  Store them in a plastic bag and we will get them to MDC at a later time.

Tuesday, August 6, 2019

Becky's Decorated Moth

Find the caterpillar on a zinnia flower head - Click to enlarge - BS
Becky Swearingen sent us this photograph to identify a caterpillar feeding on the composite flower head of her zinnias.  We couldn't even find it until we had closeup macro views.  After zooming in on the photograph above, watch her video here to see it in action.

Dressed up for a date with a flower - BS
This cool cat is a waved-lined emerald larva, Synchlora aerata, also known at the camouflaged looper.  It decorates its back with fragments of the flower heads it eats, (Aster, Rudbeckia, Liatris, Solidago, etc.) changing its appearance depending on the host plant.  This gives more meaning to "You are what you eat."
The fresh fragments blend in with the flower head, concealing the caterpillar until it moves.

Loopers or inch worms are members of the Geometridae family, from the Greek meaning "measure the earth."  The earth may be a slight exageration but they certainly can pace off a flower head.  They come equipped with only two or three pair of legs on the back end instead of the usual five pair of other lepidoptera larvae.  They use the hooks on the front legs to hang on while bringing up their rear to clasp before stretching forward again.

Decorated cocoon - Wikipedia ES
When the larva molts, the decorations remain on the old skin (exuvia) and gives it a chance to develop a whole new look, as by then its decorations have dried and turned dull.  Likewise, when it forms its cocoon, the decorations remain, giving it some further camouflage.

Wavy-lined emerald moth - Wikipedia
The larva decorations are a unique trait among moth caterpillars, found only on
S. aerata and S. frondaria found along the east coast.  The technique is different from the bagworm moths, Psychidae, that spin their case of silk and leaf fragments, carrying it along like a light weight motor home.  There are a few other species of insects which decorate their backs, the subject of a future blog. 
Thanks to Phil Koenig from BAMONA for information on the genus Synchlora.  Also to Dr.  Becky Swearingen for the inspiration, the caterpillars and the photographs. 

Friday, August 2, 2019

Coffee Table Critter

I was sitting in the family room when I saw a little 4mm brown speck slowly patrolling the coffee table. With a few macro photographs and a trip to INaturalist, I came up with the ID, a broad-nosed weevil (BNW) named Pseudoedophrys hilleri.
Rosy maple moth caterpillar exuvia and a ballpoint pen
This is a species introduced from Japan, so what introduced it to our house in town?  Adults eat foliage of woody plants, especially maples and witch hazels.  I had just been photographing a dead maple leaf with an exuvia, the dried skin left when a rosy maple moth caterpillar molted.  Evidently the weevil had been laying unseen in the shell.

P. hilleri is a member of the beetle subfamily Entiminae, the broad-nosed weevils.  Weevils are small beetles, generally less than 6mm long, so you have to look closely at them or you will "see no weevil."*  They are herbivorous, eating a wide variety of plants and can be destructive to many crops.  The boll weevil is most famous, known in song for destroying cotton crops.
Click to enlarge

There are lots of photographs of P. hillerion on the web but virtually nothing about their lifecycle.  Ours is the first reported in INaturalist in Missouri.  Although they are native to Japan, the US distribution is predominately east coast.  Maybe they arrived when Japanese maples became a popular landscape plant?
123RF- cc

* I bet that you didn't know that the three wise monkeys of Japanese fame have names.  "See no evil" who covers his eyes is named Mizaru.

Sunday, July 28, 2019

Copperhead and Cicada

A story in the Springfield News Leader reported on the mid-summer cicada season where they provide a buffet for copperheads.  John Miller of MDC had always referred to them as "copperhead M&Ms" and here is photographic proof.

Charlton McDaniel had been floating on the Mulberry River in Arkansas where he saw several cicada's that were starting to emerge from their pupae.  They emerge from their winter quarters in the ground this time of year.  They typically climb up on to a tree trunk where they begin their struggle to leave the pupae and dry out before find mates.

At this stage they are helpless, their wings not expanded, their bodies not yet hardened.  And the copperheads know this.  McDaniel's fantastic photographs at document what happened next.

It was nearly the same date seven years ago that our friend Sheila called to report an invasion of copperheads in her front yard.  We described her encounter at length in a blog listed below.*  While patrolling her front yard the next evening she found several looking at her from eye level.  They had wiggled straight up on tree trunks to where their treats were hanging on.  And where there is one cicada, there are frequently several, even enough to stage a copperhead banquet.  A similar event occurred at Pine Ridge Church and its "Copperhead Capitol" designation described here.  This is not a unique story.
"Reports of mid-summer clusters or irruptions of copperheads are not just from Bull Creek.  A mid-summer 2005 gathering of 100 copperheads under a cedar tree in Marion County, Arkansas was investigated by an Arkansas State University zoologist with no apparent cause found.   Recent accounts tell of gatherings occurring in Southwest Missouri and Texas.  In summer of 2011 a man in Georgia reported 30 copperheads in his yard."
Don't worry about going for an evening walk....but you might want to take a flashlight.  If you see a copperhead, leave it alone unless it is a direct threat to your friends and family.  Remember, it is part of nature and this is its Halloween search for candy.  Then it has to return to its usual diet of mostly mice.
* The story behind the copperhead clusters is all told in this blog.

Thursday, July 25, 2019

Mothing on Bull Creek

We held a Master Naturalist Mothing last week.  If you have never been a "moth-er" I will explain the joys and annoyances of a session.  First let's set the scene.  Imagine a white sheet on a frame with a bright mercury vapor lamp casting a strange glow.

Owlfly with mayflies and a leaf hopper
Moths, other insects and hundreds of tiny mayflies are drawn to the light, preferring this wavelength to a normal light bulb.  Why, no one knows, although a lot of theories are discussed at Live Science.  One of my favorite insects was this owlfly above, identified by the large eyes and the knob on the end of its antennae.

The only large silk moth we found was the imperial moth.  This species is also the only silk moth coming to our deck light so far this year.  For us, this was the chance to see a moth up close and personal.  The big feathery antennae identify it as a male (no surprise there!)

Bisected honey locust moth - Sphingicampa bisecta
The honey locust moth above was a new species for Bull Mills.  The first site I looked for it showed no sightings in Missouri although they were seen in surrounding states.  Other maps show it is common here, the food for another blog.  Meanwhile, I put it in a bug box to confirm its identity and an hour later found over 120 eggs.  I can just imagine her saying "Thanks, I really needed that."

Luciana underwing - Catocala luciana
Grape leaf folder moth

Banded tussock moth - Halysidota tessellaris

The mercury vapor lamp casts an eerie glow on everyone.  In addition to the ubiquitous mayflies there were lots of other tiny flying insects on the sheet, our clothes, in our hair, and more intimate locations.  This is only if you get close to the light so there are generally three strategies.  1) Ignore the tiny bugs and mayflies crawling on you and plunge in to find critters.  2)  Hang back and come in just when an interesting find is announced.  3) Flying bugs?  No way!

Two-lined spittlebug

"Mothing is like a box of chocolates." (Jay Barber)

Meanwhile, back at the lamp, we were finding lots of non-moths, ranging from 5/5 inch (70 mm) Eastern Dobsonflies to tiny 4mm leafhoppers, the Two-lined Spittlebug.  We were fortunate to have guest lepidopterist/entomologist Kevin Firth and daughter Lindsey with us to sort them out.  There is a lot more to see in this Flickr album.  We even had enough mayflies that everyone who stayed close to the sheet could take some home on and in their clothes!

Did I mention there were lots of mayflies?

Sunday, July 21, 2019

Two-lined Spittlebug

 Our Master Naturalist Mothing last Friday included lots of non-moths like this Two-lined Spittlebug, Prosapia bicinctaIt is really a beauty as bugs go, spittlebug but it retains the spittlebug name because of its misspent youthful habits.  You probably have seen hundreds in their childhood.

Home sweet home.
Spittlebug are common in grasslands.  As all true bugs in the Order Hemiptera, they have sucking mouth parts to extract juice from grasses.  Most people have seen the signs of them but few have bothered to search out the bug, a somewhat distasteful endeavor, so  I will save you the time and the mess.

"No spit!  I really feel naked."
Spittlebugs that we find are actually the nymphs of froghoppers, in the order Hemiptera, a diverse group that includes shield bugs, planthoppers, leaf hoppers, aphids and cicadas.  Froghoppers leap from plant to plant with amazing agility, with some jumping over 2 feet straight up.  They resemble treehoppers with minor differences that only an entomologist or another froghopper would notice.
Prosapia bicincta Kaldari.jpg
Two-lined spittlebug - Wikimedia- Kaldari
Many adult froghoppers can "bleed" from their tarsi (distal legs), exuding a hemolymph that is distasteful.  It is likely that their bright color as seen above send that warning message to predators considering a snack.  The adults feed on the underside of hollies.

Meanwhile back to the nymphs who are covered with froth like you might find on top of a fine ale.  You don't want to know where it comes from, but here I go anyway.  The nymphs always feed head down, an important skill if you want to cover your body from the end that is up.  They feed on sap which they pump through their intestine and out the anus at a rapid rate.  It is said to have an acrid taste, protecting them from predators.  As far as I know, the scientists who reported this have never tasting it.  To me it was tastless, but then Barb has always said I have no taste.
Feeding head down on the stalk
Now the froth.  It is thought to protect the nymphs from dehydration, heat and cold, and to hide them from predators.  In addition to housing several larvae, a glob of spittle may hold an inquiline species, another species that lives in there without contributing or harming the spittlebugs.
Stenotus binotatus
Stenotus binotatus

Wiping spittle on one blade of grass below, I uncovered several spittlebugs and a common plant bug, Stenotus binotatus.  This is a European invasive species that feeds on grasses and can be a pest on wheat.  There are no reports of it in association with spittlebugs, so it may have just been passing through.

How to explain the bubbles?  Here is one possible explanation from
"The bug feeds standing on its head and excretes excess fluid from its anus. This fluid runs down and coats the spittle bug’s body. Specialized glands mix in mucilaginous compounds that increase the viscosity of the fluid and also stabilize the bubbles.  The nymph sucks air into its abdominal breathing tube and then forces it out to blow bubbles while pumping its abdomen up and down. As bubbles form, it uses its legs to pull the froth over its body. Safe within this foamy bath, the nymph grows and molts a few times, finally emerging as an adult. "
I find it interesting that the larva is sucking up xylem, the fluid coming up from the roots, delivering minerals like nitrogen incorporated in amino acids. The fluid is more dilute and not as nutrient rich as the phloem (memory tip: phloem=food flowing down) that is coming down from the leaves with nutrients to feed the roots. The larva must process lots of fluid to obtain its nutrition, expelling it continually. Some evidence suggests that they preferentially feed on legumes and nitrogen fixing grasses. Certainly it means the nymph has to suck a lot of lymph to get its nutrition. No wonder it is pushing it all out quickly!

The head down feeding is important in getting the foam to cover up the nymph.    I suspect that predators know they are all hiding in there but have heard the reports above of the acrid taste and don't bother trying.