Monday, May 10, 2021

Battling Skinks


These two five-lined skinks fought continuously on our deck for five minutes before one escaped over the edge.  You can see a little of the battle in this Youtube video.  Their orange heads identified them as males which were competing for territory.  Why the orange head?  In breeding season, the males develop their bright orange color, presumably as a way of attracting females.  They fight other males aggressively to defend their territory and the females within it.

This could easily be confused with mating behavior.  In courtship the male grasps the necks of a receptive female in his jaws after approaching them from the side. "Using the tail to align cloacal openings, males initiate copulation by inserting one of the two hemipenes into the female's cloaca. Copulation events typically last four to eight minutes." Wikipedia

In addition to sight, skinks rely on their vomeronasal or Johnson's organ to "taste" male chemicals.  This organ is located at the base of the nasal cavity in all lizards and snakes.  It is divided by the nasal septum, allowing the animal to know the "odor" comes from the right or left.  This is what a snake is doing when it is flicking its tongue in and out as in this video.  The tongue doesn't taste, it is transferring the odor to the Johnson's organ.


Freshly hatched five-lined skink

"Now where did I leave my tail?"

Young skinks have very prominent white stripes and a bright blue tail.  Like many other lizards, five-lined skinks will break off its tail when it is grabbed.  The tail will continue to thrash about vigorously, distracting the predator and allowing the lizard to escape.  You can see this in action in this Youtube video.  The skink will frequently regrow a smaller tail.

In the south, blue-tailed skinks are frequently referred to as "scorpions" and are believed to have a venomous sting. While this belief is completely false, maybe it will keep kids' hands off their tails. 


Female skinks are very attentive mothers, guarding and nursing their eggs. They will frequently coil their body above or around the eggs to warm them.  They will roll displaced eggs with their head and consume rotting eggs.  They even urinate in the nest and turn the eggs to maintain humidity.  No one has studied what the young skinks think of the last fact.

Friday, May 7, 2021

Skullcap Skeletonizer

 
  
SSM - INaturalist CC

Tonya Smith sent me this picture of a beautiful little moth which she identified on INaturalist as the skullcap skeletonizer moth (SSM), Prochoreutis inflatella.  Downy skullcap was growing at the Springfield Lake Boathouse right where she discovered the little SSM. The moth's wings have beautiful silver streaks with a wingspan less than half an inch. Adults are said to be on wing from June to September. but this was photographed in May.  There are several generations per year.


Downy Skullcap-Wikimedia

Downy skullcap, Scutellaria lateriflora, is a pretty wildflower in the mint family.  It is showy, a nice addition to a garden.  It also is packed with a lot of chemical punch. It produces many chemicals which have been promoted as herbal medicines for sleep or a mild sedative.  Cherokee women may have used it to induce abortion.  Because the foliage is bitter-tasting and possibly toxic, mammalian herbivores usually don't bother eating it.


Leaf skeletonized by SSM - Moths of North Carolina

The SSM larvae feed on Scutellaria species, including downy skullcap. They skeletonize the leaves, bending the leaf upwards and the edges together. They feed under slight webbing. The first larvae appear in March, only shortly after the host plant begins growth.  Pupation occurs in a fusiform, multi-layered cocoon of white silk. 

Skullcap Caloptilia leaf mines*
Another moth with a taste for skullcaps is Caloptilia scutellariella, the skullcap caloptilia moth. These larvae are leafminers, spending their childhood inside the lower side of the leaf epidermis.  They then crawl out to pupate in the rolled up leaf base.

*Leafminers are cool.  Spending their infancy crawling between the upper and lower surfaces of a leaf, they leave a trail of frass.  Charley Eiseman's Leafminers of North America is encyclopedic and takes no shelf space as a continually updated huge PDF, highly recommented.


Tuesday, April 20, 2021

Carpet Beetle

 

Barb found a tiny dark spot on her comb in our cabin.  It measured almost 1/10" (2.5mm) and under high magnification, to our surprise, it wasn't a tick.  INaturalist quickly identified it as a common carpet beetle, Anthraenus verbasci.  Their larvae feed on keratin and chitin in natural fibers like dead insects, animal hair and feathers so it must have been there for hair.

Carpet Beetle, aka A. verbasci - Wikipedia

That would have been the end of the story except for some interesting details in its lifecycle.  For starters, it is the first insect proven to have its lifecycle adjusted by temperature.  Both its incubation and pupation is 5 times longer with lower temperatures.  The adults live for 2 weeks, feeding on nectar and pollen while mating and laying their eggs in human habitation and bird nests.  The larvae then feed on natural fibers in houses, bird nests, and in museums where they can be a serious pest.

Woolly Bear, aka A. verbasci  -  Wikipedia
Head-on view - Wikipedia

The larvae are densely covered in large setae (hairs), and are commonly called "wooly bears" like our moth larvae.  These are defensive against its parasitoid predatory wasp, Laelius pedatus.  The female wasp will land on it and attempt to paralyze it with its stinger-like ovipositor.  The hairs will stick to the wasp, an annoying deterrence which rarely prevents the wasp from winning.  

 

 

Laelius pedatus - only 2 mm long - Tom Murray CC

It will then observe the larva for up to 24 hours, repeatedly biting it to assure paralysis while removing the irritating hairs from its body before inserting its egg into the helpless victim.  The egg hatches and a week later the wasp larva will have consumed the woolly bear and formed a pupa.

Carpet beetles are considered a major pest in English museums, often destroying insect collections.  Their most likely entrance is from nearby nests of the same English Sparrows which have achieved a pest status here in the US.  Poetic justice, anyone?

Friday, April 16, 2021

Acorn Weevil's Wasp

Last fall I found this long-nosed beetle in a patch of oak trees.  Although it looks dangerous with a long curved snout, you should "fear no weevil," for it attacks only plants.  With its long slender beak and its sharply elbowed antennae, it is identified as a nut and acorn weevil, a member of the genus Curculio with over 30 species on our continent.  Many of these make their living only on oaks.

Curilio female weevil.  Females have beaks longer than their bodies.

I collected some acorns and sealed them in a ziplock bag and 24 hours later I found a Curculio larva in the bottom of the bag adjacent to a newly drilled acorn.  Once out of the bag, it laid still for a minute and then started to make its getaway, looking for some nice soil to pupate for a couple of years.  It was slow moving so I had lots of time to set up for this macro movie to document its progress.

Inserting the egg -click to enlarge- USFS

Life begins for a weevil when a female bores into a green developing acorn and deposits a single egg.  She seals up the tiny hole with her fecal material and the larva will emerge from the egg to find shelter and sustenance.  After consuming most of the nut's contents, it carves out a round hole and struggles out of the acorn.  The larva will then crawl off into the soil to pupate.  The whole process is shown in this short National Geographic video.

 

Larva emerging from an acorn - Jay Barber
Taking off from Antlab video    

The pupa may not emerge for over a year, coming out as an adult in the summer, hopefully at the time the acorns are greening up.  After mating, the female begins a long journey up a mature oak to start the cycle again.  She flies, although you would never guess it from this photograph.  Watch the sequence in the first 90 seconds of slow motion here, but watch the reswt for other cool insect flights.

C. halone carrying weevil -  Tom Murray CC
C. halone in the nest- Tom Murray CC

As if life wasn't hard enough, here come the weevil wasps, Cerceris sp. that specialize on acorn weevils.  Cerceris halone attacks only oak acorn weevils.  The female wasp stings the weevil and paralyzes it.  The immobile weevil is then brought back to the previously prepared underground nest and stuffed inside a cell where it remains alive, but paralyzed. A hatching wasp larva immediately begins feeding on the living, paralyzed weevil. Once the wasp larva has grown, it will pupate into its adult form and leave the nest and the now dead weevil larva.

Larva in acorn - USFS

A fun fall activity is to collect acorns and crack them open to find weevil larva.  Put them in a pan of water and save the ones that float to crack open for the larva.  The space that the larva has chewed out makes them buoyant.  On the other hand, if the acorns sink "you will see no weevil."  Sorry......no, not really.

Saturday, April 10, 2021

Whoops, It's a Plasterer Bee



Last week I posted a blog on this bee that we tentatively identified on INaturalist as a Orange-legged Furrow Bee.  The fuzzy photograph is a frame grab from a 7 second video sent by Patty Hatcher.  I sent it in to Bugguide and just got back this expert identification of an Unequal Cellophane Bee (UCB), a name that even I couldn't make up.  UCB has an official name of Colletes inaequalis.

I sent this different view of the same bee back to INaturalist and it's first choice was also a UCB.  There are several lessons here. The first photo above is fuzzy beyond the normal of the bee's body. The view to the right shows more details including the legs which were important in the identification.  Finally, when in doubt, submit to Bugguide.

I edited Patty's original 7 second video of the scuffle in a quarter speed replay at the end in this video version and asked her to describe her experience.

"I saw a bunch of these little bees poking their heads out of the ground at Busiek. While watching them one was all the way up when a second bee walked up to it and they started fighting. The tussle only lasted a few seconds and they went off in opposite directions, nobody hurt. I didn’t see them nectaring on anything specific. It was early, the 20th of March so maybe they were just venturing out of the ground into the sun."

Ground nesting bees make up 70% of all bee species world wide.  They make solitary nests although they may be gregarious, having many neighbor nests of the same species in a small area.  Building a nest with a open tunnel and no roof means their offspring are in danger of flooding and wet soil.  Most species overcome this by creating a glandular secretions that they brush on the cell walls.  This lining is a secretion product of the Dufour's gland, located at the base of the sting in female bees.  They then spread this transparent, waxy coating around the brood cell, with their mouth, protecting the larva from flooding and spoiling of their nectar and pollen provisions.

UCB Emerging in spring - see  Bug of the Week - MJ Raupp

UCB is a common species of plasterer bee (family Colletidae), native to North America.  Like other species in the genus, it lines the cells of the underground nests Dufour's gland secretion but they mix it with their saliva.  This dries to a smooth  cellophane-like lining, giving them an alternate names of Polyester or Cellophane Bees.  Cornell.edu has a lot more information including an explanation of what Patty was observing during the little clash of neighbors.

"One of the most abundant ground nesting bees in northeastern and midwestern region of North America is Colletes inaequalis. Even though this bee is solitary, meaning that every individual female builds her own nest, it is also a gregarious nester. Many females (hundreds and sometime thousands) build their nests next to each other. The nests are obvious above ground because of the conical piles of dirt with a hole in the middle."

Unlike social bees and wasps, solitary species are not aggressive insects.  Females do have a stinger but will not attempt to sting humans unless handled. Most activity at nest sites in early spring is of males looking for females to mate with.  So Patsy's observation was probably just boys being boys.

Discover Life has a lot of high quality photographs of the UCB nectaring.

Wednesday, March 31, 2021

Spring Ephemerals

Harbinger of Spring - Erigenia bulbosa

"True Rue"
This first warming period is when the spring ephemeral wildflowers wake up.   The Harbinger of Spring is the first up, a week or more before the rest.  They are so tiny that we have to get low and concentrate to find them in the leaf litter of winter, their leaves struggling to reach the light.

Next up usually are the Rue Anemones, false and true.  The "True Rue," Thalictrum thalictroides, has 4-8 petals while the false, Enemion biternatum, has five and tends to grow in clusters.  

Spring ephemerals have developed a strategy to survive along our shaded lane.  With the first warmth of Spring, they pop out before the trees leaf out and block the sun from the forest floor.  After gathering energy from the sun in a few weeks, many of these species their leaves and flowers.  They are perennials that survive the rest of the year as underground modified stems such as rhizomes and bulbs.

Common Flower Fly - Syrphus ribesii
Out early to greet these early blossoms was this Common Syrphid Fly,  Syrphus ribesii.  It was hovering above, then dropping down to the petals for a few seconds before darting to the next one. 

Another name for it is a hoverfly.  The "common" in its name refers to its range in the US, across Europe and scattered reports in China and South America.  Not only does it pollinate but its larvae feed on aphids, an added bonus. Its aposematic colors suggest it could sting, just a big bluff from a little 10 mm fly.

Bloodroot - Sanguinaria canadensis

One of our favorite ephemerals is the Bloodroot, nestled here in the thick dry leaves.  Its leaves and roots have bright red sap that can stain your fingers.  Pictures of the sap and the story of how it is planted by ants are in this previous blog.

Wake Robin - Trillium sessile
Read no further.  Finish up your work and get out into nature this glorious spring but keep your eyes focused on the ground.

 





Monday, March 29, 2021

Moss on the Rocks

Woodland Stonecrop on a moss covered rock

Warming weather and spring rains brings the rocks to life along Bull Creek.  Beneath the rock ledges, the mosses awaken from their winter slumber.  Wikipedia calls them  "small, non-vascular flowerless plants that typically form dense green clumps or mats," hardly a flattering description.  Up close after a shower they are much more, providing beauty and a home for insects and plants on boulders and rotting logs.  Here we see the delicate leaves of the woodland stonecrop (Sedum ternatum) growing on what would otherwise be just a rock.  In the words of Wikipedia:

"It has white flowers, blooming April to May. This shade-tolerant species is often found in the forest understory, although it can also grow in sunnier locations when sufficient moisture is present. Its common name of "stonecrop" evokes its ability to thrive atop boulders, where its succulent leaves help it to retain moisture in shallow soil. It adapts well to garden use."

Woodland Stonecrop flowers - Wikipedia
It is able to grow on these rocks because of the moss.  In the words of The Beatles   "I get by with a little help of my friends," I too need a lot of help, in this case from bryophytologist, Nels Holmberg.  He identified this green cover as Common Tree-skirt Moss, Anomodon attenuatus.   Illinois Wildflowers says:

"The dense mats of foliage provide cover for small insects and other invertebrates. The foliage of Common Tree-skirt Moss was often used as construction material for the nests of the Prothonotary Warbler (Protonotaria citrea). Because of this kind of activity, songbirds may be responsible, in part, for spreading this moss from one tree or area to another, as it rarely produces spore-bearing capsules."
 

The minature garden of lichen above is growing in a field of moss.  Nancy Schanda described these for us in the past.  "These are Pixie Cup lichens, Cladonia sp, which are found growing on soil and mosses and look very much like goblets for wee folk. These lichens display two of the main growth forms that are used to help identify lichens - squamulose and fruticose."

Glossy moss

The moss with capsules, each on the tip of a seta is most likely glossy moss, Entodon seductrix. Some birds use this as nesting material. In our bluebird boxes, finding this is a sign of a chickadee nest.


Chickadee eggs - click to enlarge
As Spring is sprung, no glossy moss is safe from the birds.  The good news is that carrying the strands spreads the spores, a free ride to a new location and maybe a lonely rock.

For a good and quick overview of moss, lichen and liverworts, check out this link.