Bug Finds Food Using Infrared

Western conifer-seed bug (photo by Dawn Dailey O’Brien, Cornell University, Bugwood.org)

Back in 2008 a team of scientists made an amazing discovery: the western conifer-seed bug uses infrared sensors to find his favorite food.

Western conifer-seed bug (photo by David Cappaert, Bugwood.org)

The western conifer-seed bug (Leptoglossus occidentalis) is a North American sucking beetle that resembles a stink bug, though he’s not in the stink bug family. Ornately marked and 1/2 to 3/4 inch long (16-20 mm), he feeds on the sap of developing pine cones. This causes the seeds in the cones to wither which is only a minor problem in western forests but a big deal at pine seed orchards.

The seed bug used to be confined to temperate forests of the Pacific coast but has naturally expanded his range all the way east to Nova Scotia. In the past 20 years he’s been accidentally imported into Europe, Chile, and Japan so there’s international interest in how this bug finds pine cones at a distance.

The 2008 study led by Stephen Takács, Infrared radiation from hot cones on cool conifers attracts seed-feeding insects, found that pine cones emit infrared light at all levels and the western conifer-seed bug can “see” it.

Pine cones emit infrared light because they’re warmer than the rest of the tree by almost 60 degrees F. These photos from the study, taken in normal and infrared light, explain: “The temperature bar to the right of the paired images reveals that cones are up to 15°C warmer than foliage under high-cloud conditions.”

Conspicuousness of western white pine cones in mid-range and long-range IR spectrum thermographs. (a) visual spectrum photographs (b) thermographs (image from Royal Society Publishing 2008.0742)

To prove that the bug is attracted to infrared, researchers set up infrared emitters shaped like pine cones (photos below). Did the bug approach them? Yes, it did. Could the bug find the cones when his IR sensors were experimentally blocked? No he could not.

As the study explains:

Here, we show that the western conifer seed bug, Leptoglossus occidentalis Heidemann (Hemiptera: Coreidae), a tissue specialist herbivore that forages during the photophase and feeds on the contents of seeds within the cones of many conifers (Blatt & Borden 1999; Strong et al. 2001), uses IR radiation from developing cones as a long-range foraging cue. We present data revealing that (i) cones are warmer and continuously emit more near-, mid- and long-range IR radiation than needles, (ii) seed bugs possess IR receptive organs and orient towards experimental IR cues, and (iii) occlusion of the insects’ IR receptors impairs IR perception.

Infrared radiation from hot cones on cool conifers attracts seed-feeding insects, Stephen Takács et al, Royal Society Publishing

Apparently the world looks very different to a western conifer-seed bug. For him the pine cones really stand out while the rest of the world is boring.

postscript: NOTE that the western conifer-seed bug (Leptoglossus occidentalis) is not the scourge of our western pine forests. The forests are being killed by a completely different native bug — the mountain pine beetle (Dendroctonus ponderosae) — whose larvae make galleries under the bark and kill the tree from inside. Below: Pines killed by the mountain pine beetle, Galleries under the bark, and the mountain pine beetle.

Mountain pine beetle (Dendroctonus ponderosae) and its damage (photos from bugwood; see citations and links below)

photo credits: Click on the captions to see the originals.
* Infrared images from study at Royal Society 2008.0742, Creative Commons license
* Western conifer-seed bug photos from Wikimedia Commons
* Mountain pine beetle row of photos:
#5540352: Kill at Deadman Road, CO, William M. Ciesla, Forest Health Management International, Bugwood.org, #UGA1254003, Galleries, William M. Ciesla, Forest Health Management International, Bugwood.org, #UGA1306005, mountain pine beetle, Dendroctonus ponderosae, Ron Long, Simon Fraser University, Bugwood.org

This topic was inspired by a 2008 article from Nature’s Crusaders blog: Pine Beetle Uses Infrared to Find Next Meal

Blue Jay Fools A Young’un

Like other members of the Corvid family, blue jays (Cyanocitta cristata) are very intelligent and have strong family ties. Some of their intelligence and social awareness is put to use to fool each other, especially where food is involved.

Watch the video above by Lesley The Bird Nerd to see how an adult blue jay played a trick on a young one that was planning to steal his food.

(video by LesleyTheBirdNerd on YouTube. Click here for her YouTube site.)

From Hawaii to Alaska

Bristle-thighed curlew, Midway Christmas Bird Count, 2012 (photo by Bettina Arrigoni, Creative Commons license on Flickr)

Bristle-thighed curlews are so rare and hard to find that they’ve been called the birders’ Holy Grail. The word “Tahiti” in their scientific name, Numenius tahitiensis, tells us why. These birds are Pacific Islanders. Their remote breeding location in Alaska was not discovered until 1948.

Adult bristle-thighed curlews spend only two months on their breeding grounds at the central Seward Peninsula and Yukon Delta. They arrive in late May and begin nesting almost immediately.

Bristle-thighed curlew in Alaska, June 2016 (photo by Aaron Budgor, Creative Commons license on Flickr)

When the eggs hatch in June, the chicks are precocial and soon walk off the nest. At 3+ weeks old they learn to fly but they aren’t independent yet. At 5 weeks their parents leave them with a few caretaker adults and depart for the staging grounds at the Bering Sea.

Bristle-thighed curlew chick in Alaska, July 2014 (photo by T.Lee Tibbitts USGS via Wikimedia Commons)

There they fatten up for the first leg of their journey home — a non-stop 2,500 mile flight to Laysan, Midway Atoll in the Hawaiian islands. For some curlews the final destination is much further, as shown on the map below. (Red spots are breeding range, white arrow is first stop, blue circles are wintering locations.)

Bristle-thighed curlew range (base map from Wikimedia Commons)

Young curlews follow the adults a few weeks later. They won’t return to Alaska until they’re three to four years old.

This year I happened to visit Hawaii and Alaska on the same schedule as the bristle-thighed curlews. My Life Bird curlew was a fly-by at Kahuku Golf Course, Kauai on February 28, photographed here by Michael McNulty. Then I saw curlews again near Nome, Alaska in June.

Bristle-thighed curlew at Kauai, 28 Feb 2019 (photo by Michael McNulty)

Every year the curlews travel from Hawaii to Alaska. With a worldwide population of only 7,000 birds and sea level rise due to flood their home islands, this amazing bird is vulnerable to extinction.

p.s. Bristle-thighed curlews are closely related to whimbrels, whom they resemble. We saw and heard both species in western Alaska.

(photos by Bettina Arrigoni, Aaron Budgor, Michael McNulty and Wikimedia Commons; click on the captions to see the originals)

Chocolate Lilies And Other Delights

Chocolate lily, 18 June 2019 (photo by Kate St. John)

Last month we found chocolate lilies and other delightful wildflowers while on PIB‘s Alaska birding tour. Here are the best of them, mostly found at Turnagain Pass Rest Area on 18 June 2019. Please leave a comment to help me identify the ones I’ve labeled “mystery” flowers and correct any I’ve misidentified. Thanks!

At top, the chocolate lily (Fritillaria camschatcensis) is a gorgeous small flower that resembles a Canada lily (Lilium canadense) except that it’s the color of chocolate. What a treat!

Below, clasping twisted-stalk (Streptopus amplexifolius) has delicate bell-shaped yellow flowers that hang under the leaves. They remind me of Solomon’s seal.

Clasping twisted-stalk, near Anchorage, 13 June 2019 (photo by Kate St. John)

Nootka lupine (Lupinus nootkatensis) starts blue, becomes white at the tip.

Nootka lupine, 18 June 2019 (photo by Kate St. John)

Devil’s club (Oplopanax horridum) is covered in spines that are hard to remove if they get in your skin. Don’t touch!

Devil’s club near Anchorage, 13 June 2019 (photo by Kate St. John)

Woolly geranium (Geranium erianthum) looks like Pennsylvania’s wild geranium. The flowers and leaves are larger, though.

Woolly geranium, 18 June 2019 (photo by Kate St. John)

We saw liverleaf wintergreen (Pyrola asarifolia) in Seward.

Liverleaf wintergreen in Seward, 18 June 2019 (photo by Kate St. John)

What is the yellow flower shown below? It looks like a cinquefoil to me but the leaves are so big. (The flower is about the size of the first joint of my thumb.)

Mystery: Is this a cinquefoil? (photo by Kate St. John)

I believe this is salmonberry (Rubus spectabilis). Am I right?

Is this salmonberry? 18 June 2019 (photo by Kate St. John)

Threeleaf foamflower (Tiarella trifoliata), found in Seward.

Threeleaf foamflower in Seward, 20 June 2019 (photo by Kate St. John)

I couldn’t identify this flower at first, but thanks to Janet Campagna’s comment I think these are yellow marsh marigold (Caltha palustris), seen at Turnagain Pass Rest Area, 18 June 2019.

Yellow marsh marigold at Turnagain Pass Rest Area, 18 June 2019 (photo by Kate St. John)

And finally, dwarf fireweed (Chamaenerion latifolium) was easy to find along the Teller Road northwest of Nome.

Dwarf fireweed by the Teller Road outside Nome, Alaska, 21 June 2019 (photo by Kate St. John)

Please let me know if I’ve misidentified any of these. The solo yellow flower, 7th photo, remains a mystery.

(photos by Kate St. John, all of them taken with my Pixel 3 cellphone)

Ghost Flower

Indian pipe, Schenley Park, 11 July 2019 (photo by Kate St. John)

I found a ghost flower blooming in Schenley Park last Monday.

Indian pipe (Monotropa uniflora) looks ghostly because it has no chlorophyll. Instead it’s symbiotic or parasitic on fungi that have a symbiotic/parasitic relationship with tree roots. This makes Indian pipe a parasite on a parasite … sort of.

Though it’s a perennial member of the Heath family, Indian pipe only grows when conditions are perfect and these are so impossible to replicate that the plant isn’t cultivated.

Its stems and flowers grow and bloom in a couple of days. The flowers are pollinated, in part, by long-tongued bees and fade within 1-2 weeks. After pollination the developing fruit makes the flower head stand up. Click here to see.

Later this month I’ll return to see the fruiting stems and will look for remnants of the bizarre truck accident that was in progress when I found the flowers.

Tri-axle truck falls over the hill, 8 July 2019: I found Indian pipe while on a shortcut past the paving project on Serpentine Road. My normal route was closed because a huge tri-axle dump truck had pitched over the hillside, dumped its load of asphalt and was lying on its side. On Tuesday July 9 they winched the truck out of the valley. Unfortunately, as of Friday July 12 the asphalt is still on the hillside. 🙁 Click on the embedded news links to see what the accident looked like.

(photo by Kate St. John)

High Tide On The Allegheny

High water at Highland Park Dam, 11 July 2019, 4pm (photo by Kate St. John)

Yesterday morning heavy rain caused flash floods, road closures, landslides, basement and first floor flooding, and car accidents in Pittsburgh.

The rain gauge at the airport measured 2.32″ for the day. All but .01″ of it fell in just four hours.

Precipitation at Pittsburgh International Airport, 11 July 2019 (graph from National Weather Service)

There were three huge rain events so thick that you couldn’t see to drive.

  • Half an inch (0.53″) in 50 minutes, 7:05a-7:50a
  • More than a third of an inch (0.38″) in 25 minutes, 7:55-8:17a
  • 1.4 inches in an hour, 10:05a-11:05a

If you want to see what it was like, click here for great footage from WPXI.

Hours later, at 3:30pm, a friend and I made our way from Indiana Township (between Fox Chapel and Cheswick) to Churchill. It took over an hour to get there. The traffic was horrendous and the roads that were open were littered with debris. Nadine, Sandy Creek, and Washington Boulevard were all closed.

But I got two photos of the river in flood.

High tide on the Allegheny!

p.s. This rain didn’t even set a record at the airport though there may have been localized records. My friend Julie had 4″ in her rain gauge in her Squirrel Hill backyard. Sue Vrabel commented below that she had 4.5″ in Churchill.

(photos by Kate St. John, rain graph from the National Weather Service)

Get Thee To A Shrubbery

The “ultimate green square,” Leylandii enclosing a tennis court (photo from Wikimedia Commons)

Even when a species is invasive, nurseries sell it and people plant it until it’s banned. Consider the case of Leylandii trees, sold as shrubs in the U.K.

At the garden center, the homeowners say, “I want something that grows quickly and provides some privacy.” They bring home these cute little shrubs.

Just planted, a cute little Leylandii shrub (photo from Wikimedia Commons)

But Leylandii grow three feet a year. Eventually the shrubs are so tall they have to be trimmed using ladders, like the “ultimate green square” in the photo at top.

The hedges eat the bus stop …

Leylandii eat the bus shelter (photo from Wikimedia Commons)

… and engulf the lane.

Leylandii crowd a lane (photo from Wikimedia Commons)

On Throw Back Thursday read how these “privacy” shrubs can spark fights among the neighbors in this vintage post: Plant A Shrub, Start A Fight.

(photos from Wikimedia Commons; click on the captions to see the originals)

p.s. Shakespeare fans will recognize my allusion to Hamlet’s madness.

The Measure Of A Mouse

What size of a hole can a mouse get through? If you have ingenuity, time, and tools you can find out.

Matthias Wandel of woodgears.ca takes an engineering approach to woodworking. When a mouse got into his woodshed he made a wooden gauge to find the smallest hole the mouse could squeeze through. His seven-minute video, above, became an Internet sensation.

The mouse tried many holes but gave up quickly if they were too small. What limits the mouse from squeezing through? It’s the size of his skull, not the size of his belly that stands in the way.

Near the end of the video a shrew appears. What limits the shrew?

(video by Matthias Wandel of woodgears.ca. click here for more of his videos)

Prankster on Camera

Last week Colin Roberts tweeted this video from one of his forest trailcams in southwest Scotland. His cameras record the activities of pine martens but the view is sometimes dominated by another species, the Eurasian jay.

Eurasian jay (photo by Pierre Dalous via Wikimedia Commons)
Eurasian jay (photo by Pierre Dalous via Wikimedia Commons)

Eurasian jays (Garrulus glandarius) are intelligent, curious, and very vocal mimics. This particular jay punctuates his visits with the sounds of a squeaky tree, a tawny owl, and an amazing Star Wars riff.

Then he gets really close to the lens and … oh my!

(tweet and video by Colin Roberts @PinetenColin, photo from Wikimedia Commons)

Remembering Louie: 2002 – 2019

In late June, after five young peregrines fledged from Pittsburgh’s Third Avenue nest, their father Louie was found dead at age 17. He was exceptionally old for a wild peregrine but longevity was in his genes.

Louie hatched in 2002, the son of Dorothy and Erie during their first successful year at the Cathedral of Learning. Dorothy fledged 43 young at Pitt before she disappeared at age 16.5.

Dorothy was the daughter of Sibella and Bill who were both part of The Peregrine Fund‘s Midwest Peregrine Recovery Program. Sibella nested at the First Wisconsin Building in Milwaukee through her 15th year. With a long-lived mother and grandmother it’s no wonder Louie made it to 17.

Louie started breeding early. In 2003 he was one year old when he won Pittsburgh’s Downtown territory. It was a tumultuous spring with two females and two males vying for the Gulf Tower nest. In the end Louie fought and killed Boris at the nestbox and became Tasha’s mate.

From 2003-2009 Louie fledged 24 young with Tasha. In her last breeding year he was especially protective of her on Banding Day.

The next year, 2010, was Louie’s chance to shine. In late March Dori defeated Tasha and became a first-time parent. Louie showed her the ropes as described in the links below:

Louie was versatile. In their years together he and Dori moved their nest from year to year using three sites to fledge 39 young.

In 2012 they chose a cubbyhole on 3rd Avenue where they’ve nested 5 times. In 2015 they nested at Macy’s Annex. In 2014 and 2017 they returned to the Gulf Tower.

2018 ended sadly at Third Avenue when the Keystone Flats development was granted a Special Takings Permit and had their chicks removed. This year they were back at Third Avenue to raise and fledge five young. Louie was a good dad to the end.

All told Louie fathered 63 young peregrines. Like his mother Dorothy, Louie was the head of a dynasty.

(photos by Brian Cohen, Ann Hohn, Lori Maggio, Maria Ochoa, Matt Orres and the National Aviary falconcam at Gulf Tower)