5 August 2026

This very large green caterpillar is a tobacco hornworm (Manduca sexta). Though its name suggests it feeds only on tobacco, its hosts include many plants in the Solanaceae family including tobacco, tomatoes, Datura (ex: jimsonweed), bell peppers.

From hatch to full-grown, the caterpillar feeds for two to three weeks before it begins to wander, looking for a place to pupate underground in loose soil. 7 to 10 days later it emerges as a large moth, the Carolina Sphinx moth also called the tobacco hawk moth.

(video embedded from entomology_1 on YouTube)

The Carolina sphinx moth is famous for its ability to hover like a hummingbird as it drinks from deep flowers. Here it is in slow motion in a wind tunnel.

When it’s time to lay eggs this moth must find a host plant that doesn’t smell sweet. How do they find it?

In a recent study, researchers examined the tiny hairs on the wings of Carolina sphinx moths (tobacco hawk moths) and found they have a sense of smell!

Looking at tiny wing hairs with both light and scanning electron microscopy, [researchers] found the hairs were porous: a telltale sign of olfactory function. …

The team placed the delicate detached wings between two electrodes and wafted odor molecules representing various chemical classes over them, hoping for a response. They reacted to … two amines—a group of smelly organic compounds derived from ammonia)—called pyrrolidine and piperidine … found in pungent, rotting smells, but also in the olfactory bouquet of tobacco plants..

— Science: These moths smell with their wings

These same compounds are part of the “smell” of tomato plants and probably other members of Solanaceae.

So when a Carolina sphinx moth flies past your tomato plants, its wings smell a place to lay eggs.

Read more at the Journal of Experimental Biology: Tobacco hawkmoth wings have a sense of smell. Watch a tobacco hornworm develop from egg to adult in this 6-minute video: Manduca sexta, from egg to adult on YouTube.

25 July 2026

July is Bug Season. This week they took center stage at Raccoon Wildflower Reserve, Frick Park and Aspinwall Riverfront Park (a.k.a. Allegheny RiverTrail Park).

Butterflies are hard to photograph with my cellphone but I managed to capture images of a pearl crescent at Raccoon Wildflower Reserve.

Looks like a bee but this is a fly — a bee-fly on Queen Anne’s lace at Aspinwall.

I also found evidence of tiny wasps and chased a Great-sized wasp from flower to flower.

At Frick Park we found a red misshapen gall on a blackberry stem. Not only did the gall look like an infection but the stem looked like it had broken at the site of the gall. This is evidence of a blackberry knot gall wasp (Diastrophus nebulosus).

The wasp is a blackberry stem specialist. It doesn’t use other plants.

Inside the gall are the tiny larvae of Diastrophus nebulosus that irritate the plant so much that it produces a big gall. The adults are tiny too — a little smaller than a sesame seed.

On the high end of the size spectrum are great digger wasps. I found a great black digger wasp (Sphex pensylvanicus) at Aspinwall Riverfront Park. Though “Pennsylvania” is in their name these wasps have a wide range in North America.

Like most wasps, great black digger wasps are solitary.  The female makes her nest by digging a hole with lateral chambers.  To provision the chambers she captures and paralyzes a katydid or grasshopper and then lays an egg on it. When the egg hatches the larva feasts on the paralyzed (live) insect and emerges as a wasp.  Read more about it here.

There are other colors of digger wasp. I saw a great golden digger wasp 13 years ago at the Montour Trail. Late July seems to be their favorite time in southwestern PA.

22 July 2026

In June I had no mosquito bites and was congratulating myself for being careful, but in fact there must have been fewer mosquitoes. Yesterday at Nine Mile Run they whined around my head and turned my hands into itchy pincushions.

If mosquitoes are present they find me. I must be one of the estimated 20 percent of people that mosquitoes bite more often on a consistent basis. Why do they feast on me — and maybe you — more than other people? It comes down to attracting them.

Mosquitoes find us by scent and sight.

CO2 in our breath attracts them from as much as 100 feet away. People who exhale more CO2 are more attractive. Don’t exhale? Not an option.

Mosquitoes are visually attracted to red, orange and black. Don’t wear those colors outdoors.

At 1 meter, 3.2 ft, mosquitoes can smell your skin and are attracted to a combination of lactic acid, ammonia and other substances in human sweat. They like sucrose (sugars) and salt but not bitter.

At close range — swatting distance — mosquitoes are attracted to heat. Long pants and long sleeves deter them. An exposed hand will attract them. Here’s a thermal image.

There are a few more things that attract them, most of which we cannot control.

• Alcohol makes your skin smell delicious to mosquitoes. Don’t drink if you’re going to be near them.
• Type O blood is the most attractive to mosquitoes.
• Genetics: Studies of identical twins show that being attractive to mosquitoes runs in families.

The good news is that repellent works. If your skin tastes bitter mosquitoes won’t bite. Some people use DEET. There are also a host of natural repellents tested and listed at NIH: Plant-based insect repellents: a review of their efficacy, development and testing. #1 on the list is lemon eucalyptus.

Find out more about mosquitoes’ preferences in Smithsonian Magazine: Why do mosquitoes bite some people more than others?

(timelapse photos of Photinus pyralis in flight. fly left, fly right from Wikimedia)

14 July 2026

Last night after sunset I sat on a park bench and watched fireflies (a.k.a. lightning bugs) in my city neighborhood. I could tell by their flash patterns that they were Photinus pyralis, the common eastern firefly, because the males glowed while ascending in a J shape. Females flashed from the tips of grasses to attract a mate.

You can see both behaviors in this video by Radim Schreiber at fireflyexperience.org.

The lightning bug’s flash is generated by a light-producing enzyme called luciferase. Close up the flash looks like lightning in a cloud.

The combination of color, flash and pause pattern, and flight path are unique to each species(*). Notice how different the flashes are for this species, the cypress firefly.

Watching fireflies is such a peaceful activity. Enjoy the summer night with fireflies.

(*) The pattern and length of pauses and flashes is unique to each species except … Females in the predatory firefly genus Photuris can mimic the lights of smaller species in order to attract and eat a male. Pennsylvania’s State Insect, Photuris pensylvanica, is in this predatory genus. It was chosen because it has Pennsylvania in its scientific name.

9 July 2026

Now that Bug Season is in full swing it’s fun to find the bugs in camouflage.

Planthoppers are parasites that suck the juice from plants, though they rarely reach the pest level in their native range. They barely move when perched but if you jostle them they jump like grasshoppers. Plant.Hoppers. Every life stage uses camouflage to hide from predators.

Google Lens identified the bug at top as an Acanalonia planthopper that sucks the juice of woody plants. Usually green in color, the adult is trying to look like a leaf.

Some species of flatid planthoppers are white so how are they camouflaged?

The adult females secrete a white waxy substance to protect their eggs and young. The adults resemble moths as they hang out in a white fuzz zone.

Their tiny nymphs are ghostly white with fuzzy, wispy tails. 

Planthoppers are parasites who are parasitized by a moth.

This well-camouflaged planthopper parasite caterpillar (Epipyrops exigua) feeds on the body fluids (haemolymph) of planthoppers and cicadas.

After he transforms into an adult, he is still camouflaged.

I’ve never seen the caterpillar and moth but I’ll look more closely now when I find planthoppers.

7 July 2026

At last the heat has broken and we’re able to enjoy the outdoors again, but don’t get too cocky. Tick bites are way up this year and they are TROUBLE.

For most of the country, weekly emergency visits for tick bites are at the highest rates for this time of year since 2017, according to the CDC.

— Allegheny Front: Tick bites up in U.S., Pennsylvania, this spring, prompting renewed emphasis on prevention

This means that even on vacation you’ve gotta watch out for ticks.

The bites of two species can make you very sick: black-legged ticks and lone star ticks. This diagram shows their relative size and shape, shown with the familiar dog tick for comparison.

Blacklegged tick (Ixodes scapularis)

Black-legged (or “deer”) ticks are at the top of the danger list. They are exceptionally plentiful and they spread Lyme disease.

Don’t let this tick get on you!

Just about anywhere you’d want to vacation in the Northeast and Great Lakes States is prime territory for black-legged ticks. Planning a beach vacation? Notice that this tick is there too.

Pennsylvania has the highest number of Lyme disease cases in the U.S.

Lone star tick (Amblyomma americanum)

The Lone Star name has nothing to do with Texas. In this case the lone star tick is named for the white dot on the female’s back.

These ticks are especially plentiful in the Southeast and have begun moving into PA. When they bite they transmit a protein in their saliva that causes an allergic reaction to mammalian foods — meat and dairy products — called alpha gal syndrome.

There are a plague of these ticks on Martha’s Vineyard. So many people have alpha gal syndrome that restaurants and farmer’s markets have changed their product offerings.

What can you do to protect yourself?

#1. Don’t let ticks get on you. Word to the Wise: Spray your clothes before you go out.

#2. Field check for ticks. Brush them off before they bite!

#2. If a tick is biting you, use tweezers to remove it. Do not wait to remove a tick. The longer it’s on you the more disease it can give you.

Learn more on The Allegheny Front: Tick bites up in U.S., Pennsylvania, this spring, prompting renewed emphasis on prevention

30 June 2026

Last Sunday in Schenley Park we discovered that right now it’s Millipede Mating Season in Pittsburgh. Millipede mating habits are so fascinating that I had to look into it.

First off, millipedes are not insects; they have a lot more than six legs. Their class Diplopoda contains 13,000 species, all of which have two pairs of jointed legs per body segment. The number of body segments varies a lot from short pill millipedes to Eumillipes persephone which can have over 1,300 legs.

Their name literally means “thousand feet” but most millipedes have far fewer. Count the body segments (but not the head) and multiply by 4. The ones in my photos have less than 100 legs.

They appear to be greenhouse millipedes (Oxidus gracilis) which were originally from Asia and are now invasive in North America. The name “greenhouse” comes from the fact that they thrive in greenhouses where they become pests. They can also live in cool moist woods where they feed on decaying plant matter.

When millipedes mate, copulation happens in the first seven segments but courtship involves all the segments. First they have to find each other, complicated by the fact that greenhouse millipedes cannot see — they don’t even have eyes. The males emit sex pheromones to attract the females.

After they find each other by scent and touch, the male walks on her back to stimulate her with rhythmic movements of his legs. It also calms her so she won’t reject him or curl up in a defensive posture.

Here are a male and female in a mating embrace on the tufa bridge over Phipps Run. Once we started looking we found many millipedes in the tufa crevices.

In this marked up photo you can see which one is the male — he’s shorter. There’s also a second couple nearby.

The male has to cling to the female for the next step, all of which was a mystery to scientists until the Field Museum did a study in 2020.

In most millipedes, including Pseudopolydesmus, the male’s testes are located in the body starting behind his second pair of legs. But his gonopods, the specialized pair of legs used to insert sperm into the female, are way back on his legs of the seventh body ring. “He has to ejaculate and then dig his seventh-ring gonopods into that ejaculate,” she explains. “It’s a blue-ish liquid.”

Once the male has gotten his gonopods covered in blue ejaculate, he’s ready to insert them into a female’s vulvae. “She has two openings, one on each side between her second pair of legs,” says Sierwald. …

After mating, the female’s vulvae get sealed up with a gooey secretion, trapping the sperm inside. Later, when she lays her eggs, they get coated with the stored sperm on their way out of her body.

— Field Museum, Feb 2020: Scientists finally figure out how millipedes actually do it

The females lay 40-50 eggs in cool, dark, moist soil. The tufa bridge looks like the perfect place.

If you’re curious about Millipede Mating Season check out the tufa bridges in Schenley Park or read more here Field Museum, Feb 2020: Scientists finally figure out how millipedes actually do it.

Will this week’s humid heat wave shut down their activity? Or will their tropical origin make them happy that it’s hot?