Thursday, September 23, 2021

Hickory Tussock Moth


One of the stars of the field trip last Friday was this cute little hickory tussock moth, (Lophocampa caryae).  We found them on a variety of leaves, conveniently placed at the height of a WOLF Student.  The name is a bit confusing as it's host plants are hickory, pecan and walnut, but they will also feed on ash, elm, oak and willow.

Viewed from above
Just hatched- Charlie Eiseman

They are really cute when they first emerge, all yellow and juicy as captured by Charlie Eiseman.  Like most caterpillars, they munch on their eggshells to get a quick snack before eating their veggies.

Hickory Tussock Moth larva - Lophocampa caryae
 Gregarious young cats - Mathew Priebe









Now they get serious about their leaf diet, clustered together munching until there is a mere skeleton remaining.  Later instars wander off and are solitary like the ones we found today.  They will feed until ready to pupate in the fall.

While it looks cute and fuzzy, don't pet it.  The hairs cause a rash (called a contact dermatitis) in many people.  It is caused by a urushiol oil similar to that produced by poison ivy.  In addition, those hairs have microscopic barbs and if you get them on your hands and touch sensitive tissues like your eyes it can cause serious pain.

Hickory Tussock Moth - Tom Murray CC
Soon these caterpillars will wander off to form a cocoon where they will spend the winter in the leaf litter of the forest floor.  The adult moth will emerge in May, seek a mate and lay the eggs that complete the circle of their life.

Tuesday, September 21, 2021

Red Caterpillar

This red caterpillar led me on a long chase for an ID.  My friend Ben suggested it was a soft fishing lure from Bass Pro but he hadn't seen it move.  INaturalist called it a drab prominent moth larva (Misogada unicolor) but all the initial photographs of caterpillars I found were light green with tan or white racing stripes.  They did at least have the same dual exhausts!

Diving further into photographs in Bugguide I finally found some red lookalikes.  Apparently the caterpillars turn color when they are ready to pupate.  Looking closely at my photograph you can make out the pale racing stripe remnant down the back.  Measuring close to 2", it was a dramatic find.

Porch light moth- 2018
The name "drab prominent" describes the moth perfectly, so unremarkable that I forgot I had photographed it at the porch light at Bull Mills in 2018.  According to Bugguide, bronze scales on the tuft of the head are diagnostic in distinguishing the adult of this species as seen in the example to the right.  Their host plants are cottonwood and sycamore which is what we found this one on.

Finally, Misogada is a monotypic genus, meaning it has only one species.  That is my new word of the day.

Sunday, September 19, 2021

Leaf-foot Bug Birth

Several of these insects were found by WOLF students on Friday's field trip.  This is the very common and distinctive Acanthocephala terminalis, the leaf-footed bug (LFB).  The genus name comes from the Greek akanth 'thorn/spine' and kephale 'head', and refers to the spine on the front of the head.  Terminalis comes from the bright yellow-orange terminal segment of the antennae.  The "leaf-foot" is obvious on the hind leg tibia.

LFBs are commonly found on shrubs in the woods or field edges.  Nymphs and adults suck sap from various native plants, but unlike squash bugs, they don't harm our cultivated plants.  They are also found on bird droppings which they probe with their long proboscises.  This may be for nutrition or simply a case of bad taste. 

They overwinter as adults, mating in the spring and leaving clusters of eggs on leaves.  I found this small cluster of insect eggs on the underside of a leaf several years ago and stored them safely in a bug box, hoping to film their births. 

Egg - Click to enlarge
I gently moved the eggs onto the sticky part of a post-it note for handling.  We watched the eggs daily and noticed a change in color on day 16.  They were a little cloudy and had developed some red streaks.  This was a sign on maturation of the larvae. 

Ready to hatch- note legs-T. Smith

The eggs are so translucent that you can actually make out the body and curled up legs in the photo by Tonya Smith.



Empty eggs - Click to enlarge.


By the next morning the little stinkers had emerged overnight so I couldn't video the birth.  Now we could see the eggs with a lid cut out by the nymph.  The first instar is very distinctive with orange streaks that we had seen through the translucent eggs the day before.  

I was amazed that an infant that size can emerge from a tiny egg overnight, but my wife reminded me of how compact our children were packaged before she gave birth.  Once the bodies of these unfolded their size was mostly the gangly legs.  There are even better photographs on Buggtracks.

Newly emerged nymph

Later instar - Bugguide
The upward curve of the abdomen is common to a lot of different bug nymphs such as assassin bugs.  They go through 5 sequential molts. The later instars of LFB darken and develop a spiny back.  As all hemiptera (true bugs) they have incomplete metamorphosis, the nymphs resembling the adults.  There is a series of pictures of one molting at Bugguide.  The one on the right was initially misidentified as an assassin bug nymph.

Note leaf shaped tibia and long proboscis

Unlike beetles with their chewing mouth parts, bugs have a proboscis that resembles a hypodermic needle. Their feeding is more complex than just sucking up juices. They first inject their saliva with enzymes into the tissue, then suck up the digested liquid. Assassin bugs attack insects and other prey, while plant bugs like our LFB suck the juices of leaves and fruit. Although some leaf-footed species can be listed as agricultural pests, our LFB (A. terminalis) is not a problem

Assassin bug

It can be difficult to separate some plant bugs from their assassin bug brethren so it is best not to pick them up with bare hands if you aren't sure.

Sunday, September 12, 2021

Raising Polyphemus

My granddaughter spotted this Polyphemus moth, clinging below a rock shelf by a little waterfall. It was in the shade all day, had a cooling mist off the waterfall and was out of reach to most of its normal predators.  Its wingtips were barely an eighth of an inch above the water but the view must have been worth the risk.  This was 10 years ago without a waterproof camera but the shot was worth the risk.

This moth probably was tired after a long night of courting.  Unlike most other lepidoptera, its lacks a functioning digestive system and never feeds.  It exists to breed and lives only six days, so it probably earned a rock with a great view.

Polyphemus, Antheraea polyphemus, is the second largest moth in Missouri.  Named for the one-eyed cyclops giant in Greek literature, it has a single large eye spot on each hind wing.  Wikipedia gives a lot more information on these giant silk moths

A Polyphemus moth caterpillar can eat 86,000 times its weight in a little less than two months!  Chris Barnhart raised them for the Butterfly House and Insectorama, a prodigous task as seen here.

They have several broods between May and August, its caterpillars feasting on 20 different tree species including maple and oak.  The caterpillar usually wraps a host plant leaf around its cocoon.  

Males can be distinguished by their feathery antennae,  which are more plumous than the females.  Yes, I know- I had to look it up too- its Latin for "full of down or feathers".  (see photograph below)

Polyphemus male with plumose antennas
The females emit pheromones which the male can detect through its large, plumose antennae.  The pheromones are released at a species-specific time, referred to as the "calling time". This “calling time” can help prevent moths with similar pheromone chemicals from finding the wrong mate.  (MDC)  Polyphemus' calling time is between 11 PM and 1 AM, and again from 3 AM to dawn.*  

Males can fly for miles in order to reach a female. After the moths mate, the female spends most of her remaining life laying eggs, while the male takes off and may mate several more times.  Editors note: No surprise there! 

This year the Insectorama was cancelled due to Covid.  With 40 + cocoons and no one to give them too, we distributed them to WOLF School students to raise and release.  One of the students noticed that after emerging, a female moth began laying eggs.  Unmated females will deposit eggs after a while and with their short life span they are unlikely to get a second chance at mating.

These eggs look at first glance a lot like a hamburger, possibly because I am hungry as I write this.  The upside down egg on the right shows the ragged dark ring where it was glued to the surface of the cage.  Thanks go to Kapri for bring me the find.

Friday, September 10, 2021

Planthopper Parasite Moth

Once again Gala Keller sent me down a rabbit hole.  This began innocently enough with the photograph above of a white spot on a leaf.  Even seen close up with a cellphone photo, it is hard to identify but INaturalist suggested it was a larva of a Planthopper Parasite Moth.

Turned over in her palm, it isn't any more impressive but it does resemble the better examples on the internet.  The one below is a better view.  If you still aren't convinced this is a larva, watch it wiggle its legs in Gala's video.

Fulgoraecia exigua  on a planthopper-   Matt Bertone CC
The Epipyropidae comprise a small family of moths. This family and the closely related Cyclotornidae are unique among the Lepidoptera in that the larvae are ectoparasites, the hosts typically being fulgoroid planthoppers, thus the common name planthopper parasite moths. (Wikipedia)

That is a lot of blog for a little fluff.

Wednesday, August 25, 2021

Hummingbird Moths and Other Hawkmoths

Snowberry clearwing moth - REK

These hummingbird moths are a common sight around a flower garden this time of year.  People love to see them hover, slurping up nectar through their long proboscis as they flit between blossoms.  We have two hummingbird moth (HM) species, snowberry clearwings (Hemaris diffinis) and hummingbird clearwings (Hemaris thysbe).  Their ranges overlap in Missouri as seen here.

Clearwing at rest - REK

We heard from several friends the last week, concerned that when they are finding large green hornworm caterpillars that these are HM babies eating their tomato plants.  These moths are not the same species although they are relatives.  There are many web sites that add to the confusion by calling hawk moth caterpillars by an alternate common name of hummingbird moth, demonstrating the importance of scientific names.

H. diffinis on tubular flower - J. Motto

Our friendly HM feed in daylight hours although they may stay out for a late supper if they find a great menu. They are especially adapted to sip from tubular flowers, just like a hummingbird.  Their larvae feed on honeysuckle family members - buckbrush, snowberry, horse gentian, Lonicera spp and dogbane including Amsonia (blue star). H. thysbe cats also eat viburnum, hawthorns, cherry and plum.

Snowberry clearwing hornworm caterpillar

Their larvae are equipped with a horn on the end, thus a"hornworm."  This is another cause of confusion as the hated tomato and tobacco hornworms that decimate tomato plants are similar although much larger.

Tobacco hornworm

Tobacco and tomato?  How can that be a common food plant between these hawkmoth larvae?  Science Daily sheds some insight.

"The Solanaceae is a family of flowering plants, many of which are edible, while others are considered poisonous.  The family is informally known as the nightshade or potato family. The family includes the Datura or Jimson weed, eggplant, mandrake, deadly nightshade or belladonna, capsicum (paprika, chile pepper), potato, tobacco, tomato, and petunia.

The Solanaceae are known for possessing a diverse range of alkaloidal glucosides, or simply alkaloids.  As far as humans are concerned, these alkaloids can be desirable, toxic, or both, though they presumably evolved because they reduced the tendency of animals to eat the plants."

Manduca sexta - Lyle Buss UFL

The tobacco and tomato hornworms hawkmoths are in the genus Manducae.  Unfortunately they are called hummingbird moths in some references.  They can hover like a hummingbird but they are mainly crepuscular, flying primarily at sunset and sunrise. 

A frequent question a naturalist hears are "what good are fill in the blank?"  Even mosquito larvae feed a number of aquatic species.  In this case, you can take comfort in this long answer from the Featured creatures of

"Tobacco hornworms have several natural enemies, including vertebrate species that feed on caterpillars, such as birds and small mammals, and insects like lacewing and lady beetle larvae that consume the eggs and early instar larvae. Wasps are a common predator of hornworms. Paper wasps and other insects that provision prey for their young will take hornworms from the host plant, paralyze them, and place them into the nest cells containing the wasp’s eggs as a future food source. 

Parasitoid wasps, like Cotesia congregata, use hornworms as a food source for their developing young. These wasps deposit their eggs inside the hornworm’s body and the larval wasps develop within the caterpillar, feeding on it as they progress through their life cycle. When pupation takes place, the immature wasps spin small, white, silken cocoons that protrude from the body of the still-living caterpillar. The cocoon-covered hornworms are a sight of great interest in the garden, and many fear that the parasitized caterpillars will have a negative impact on their garden. In fact, the opposite is true because the hornworm will eventually die and several adult wasps will emerge, mate, and seek out additional hornworm hosts for their eggs."

Revenge of a parasitoid wasp - REK

So fear not, defend your tomato plants with a clear conscious.

Saturday, August 21, 2021

Cicada Emerging

Not an Alien  -  Frank Johnson

There are two predictable events in August, cicada appearance and the emergence of their photographers.  Frank Johnson started this year's cycle with his dramatic photograph above of cicada eclosing, looking like it came out of a space movie.  Most species are green the first few hours, darkening as the air dry their wings and bodies.

Next Su Lyn Rogers sent me this beauty.  When she initially found it on a 10 PM dog walk, it was a newly-emerged cicada crawling on the sidewalk. She says:

"Under the porch light, I could see that it was still wearing some of the soil from its underground stage that had lasted for at least two years. I recorded some videos, then left it outside on a birdhouse on my bench intending to check on its progress later."

She sent this video as it crawled around, looking for a place to eclose.

Freshly eclosed  - Su Lyn Rogers

When she returned later it had completed molting.  MDC Discover Nature has descriptions of the different annual species which we can't identify with this fresh specimen until it dries out.

These are called annual cicada as they appear every August and September, unlike the 13 and 17 year periodic cicada which get all the glory in the press.  This however is deceiving as the life cycle of an individual is over two to five years.  

Also known as "dog day cicadas" they are members of the genus Tibicen, named for their abundance in late August through September in the hottest times.  They make a buzzing sound when they take off on short flights when disturbed and create a loud grating sound when held.  Only the males sing and each species has a distinctive sound, giving them names like "buzz saw" and "scissor grinder" which you can hear at this link.
Like their periodic cousins, they lay their eggs on twigs and the larvae emerge, leap off into space and land on the ground where they dig in.  They then burrow into roots to suck sap for the next few years until they mature and emerge, crawling up a tree or post and hanging on tight while the adult emerges and flies off, leaving the empty shell of dried skin to puzzle or delight a lucky child.  These cicada appear to be annual because each year some are emerging and mating.
Cicada Killer - Larry Wegmann
They are soft and juicy when they first emerge, hardening over 30 minutes.  As they hang on trees they are vulnerable to a specialized predator, the cicada killer wasps.  This is Sphecius specious, the largest wasp in North America.  Although fearsome in appearance, it saves its sting for a cicada to haul off to feed its young as described
in this past blog.  The female can carry a cicada twice its size!

Copperhead fast food - Charlton McDaniel in Tulsa World
Cicada's also face another predator, copperhead snakes.  They will climb trees to find these tasty morsels.  This blog has more information and these incredible photos like the one above from the Tulsa World  are worth a visit.