If you plant it, they will come

Volunteers planting marsh violets in the Shropshire Hills to support recolonization by Small Pearl-bordered Fritillary [photo National Trust/Paul Harris]

In the UK’s Shropshire Hills, Britain’s ambitious project to restore habitat for the Small Pearl-bordered Fritillary will see some 20,000 marsh violets planted to provide food for the rare butterfly’s caterpillars.

Led by the National Trust, and funded by the Natural England Species Recovery Programme, this ambitious planting is part of the Stepping Stones Project to restore habitat connectivity across the whole landscape and create a sustainable home for not only Small Pearl-bordered Fritillary butterflies but also willow tits, hazel dormice and otters. The National Trust is working closely with Shropshire Wildlife Trust, Natural England and the Shropshire Hills National Landscape Partnership, along with various landowners, the conservation organization says.

As with most true fritillaries, Small Pearl-bordered Fritillary butterflies have only one plant that their caterpillars can eat: violets. In the case of this species, it’s marsh violet, Viola palustris. The species name palustris means swampy or marshy, and gives a good clue of where to find both the violet and the fritillary — wet woodlands. Habitat loss has been among the worst problems facing the butterfly and its host; restoring large intact landscapes offers the best hope to preserve the dwindling butterfly.

Caroline Uff, Ecological Consultant to the National Trust, said: “Currently, these striking butterflies are hanging on in fragmented colonies. Through this new mass planting and habitat restoration the plan is to give these butterflies the space to move and flourish. New areas could start to re-colonise within a couple of years. “But this project is not just about one butterfly – it will also create habitats for many increasingly uncommon species such as snipe, curlew and devil’s bit scabious.”

Sourcing locally and then planting locally is key, with everything done within a 20-mile radius. Last winter volunteers also helped cut back rushes and bracken to open up these wetland areas and make space for the new arrivals, according to the National Trust.

To give these butterflies a helping hand, volunteers are planting out the first ‘clumps’ of marsh violets this spring, with the rest to follow in the autumn. Approximately 50 plants each are being planted together in 1x1m squares scattered in the habitat, creating 400 separate areas for the violets to thrive.

Ben McCarthy, Head of Nature and Restoration Ecology at the National Trust said: “Targeted interventions such as these can make a huge difference in reversing the decline to our once charismatic wildlife. The delicate marsh violet and small pearl-bordered fritillary were once widespread and common, but have both suffered from land drainage and inappropriate management of our wetlands.

“This hugely ambitious project to propagate and enhance the local population of marsh violets will help rebuild richer eco-systems – with the flower being the critical food source for the caterpillar – that is core to tackling the nature crisis.

“By making our sites bigger, better and more connected we are making space for nature and restoring populations of other threatened species as well such as the willow tit which thrive in these wet and complex wet woodlands.”

It’s a problem not unlike that faced by reintroduction efforts for the Baltimore Checkerspot in the mid-Atlantic, whose young caterpillars require white turtlehead plants. These plants typically thrive in palustrine, or wet, meadows, and historically were associated with beaver ponds and beaver-flooded landscapes. With the near-extermination of beaver across the eastern U.S., such habitats rapidly reverted to overgrown tree and shrub habitats. Others were converted into housing and commercial land use.

Each spring, plant nurseries sell hundreds of turtlehead plants with the promise that they will attract checkerspots. In reality, the iconic butterfly — Maryland’s state arthropod — needs the entire habitat to thrive; no amount of turtleheads in home or school gardens is going to do the trick. Maryland could take a page out of the National Trust playbook.

New mechanism for sex determination in butterflies uncovered

University of Liverpool researchers studying the Squinting Bush Brown discovered a novel genetic pathway for how butterfly embryos become male or female [photo credit: University of Liverpool]

A news release below from our colleagues in the University of Liverpool news office:

In a study of a species of African butterfly, researchers have discovered a previously undescribed molecular mechanism of how the sex of an embryo is initially specified.

Across species, a molecular switch is required to initiate development of a newly formed embryo into a female or a male. The genetic identity of this molecular switch, and how it actually works, differs widely across animal groups, which implies that over evolutionary time the sex determination mechanism is under pressure to change.

In insects, the identity of these primary signals, and how they function, has been described in only a handful of species.

In butterflies and moths, it is the females that determine the sex of offspring. The most common sex determination switch is thought to be a gene (Feminizer) on the female-specific W chromosome, which initiates the female pathway by inhibiting a gene (Masculinizer) on the sex (Z) chromosome that initiates the male pathway.

Working on a species of African butterfly, the Squinting Bush Brown, researchers from the University of Liverpool have discovered a radically different molecular switch that does not require a sex-limited gene or chromosome. Instead, it relies on recognition of sequence differences between the two copies of Masculinizer within genetic (ZZ) males, to produce healthy males.

When an embryo has one Z chromosome, and therefore one copy of Masculinizer, it develops into a healthy female (even in the absence of the W chromosome). However, a cost of this mechanism is that ZZ (genetically male) embryos with identical copies of Masculinizer are sent down the female developmental pathway and die as embryos because of imbalances between the expression of genes on the Z chromosome and autosomes (non-sex chromosomes).

Butterflies who mate with an individual that shares an identical copy of Masculinizer produce 50% fewer sons than non-identical pairings. This makes it highly advantageous to be a rare variant (allele) of Masculinizer, resulting in very large numbers of alleles in these butterflies.

Corresponding author the University of Liverpool’s Ilik Saccheri, Professor of Ecological Genetics said: “Nature has devised many ways of producing males and females. Our discovery of this primary switch highlights the fascinating diversity of sex-determining mechanisms and underlying evolutionary drivers. We suspect that this alternative mechanism evolved as a response to male-killing bacteria that are known to subvert sex-determination machinery in order to promote their own transmission through host females. In the future, we would like to reconstruct where on the evolutionary tree this alternative sex determination mechanism evolved, explore whether structurally similar mechanisms have evolved independently in other butterflies and moths, and figure out how the Masculinizer same/different mechanism actually functions.”

The full study is available here: https://www.science.org/doi/10.1126/sciadv.adj6979

New at Timber Press–The Insect Artist

I can’t pretend any artistic expertise, entomological or otherwise. But one can always hope, if there’s a good guide to help me figure out how.

Check out this new release from Timber Press. The Insect Artist: How to Observe, Draw, and Paint Butterflies, Bees, and More by Zebith S. Thalden, $27.99

Sources for collecting and rearing supplies

Entomological equipment in the 18^th Century from Elementa Entomologia (1766) by Jacob Christian Schaeffer (1718-1790). Courtesy Simon Leather’s blog, Don’t Forget the Roundabouts.

With the demise of BioQuip in 2022, the lep community — and ecologists in general — lost one of the best stocked and most dependable suppliers of field and collection tools and resources available. A number of new and established vendors have stepped in to fill this void, and Caitlan LaBar has thoughtfully updated her list of entomology equipment suppliers on the Northwest Butterflies blog.

And just in time for the temperate zone butterfly season, too!

Butterflies clue into predator vocalizations

Heliconius melpomene plessini [photo courtesy Wikimedia Commons]

The lep community has known for quite some time that moths are capable of detecting and taking evasive action when they hear the vocalizations of predators, especially bats. And while scientists have found auditory sensing organs on some butterflies as well, if and how they use these has not been as extensively studied.

Researchers from the University of Arkansas and their colleagues, however, have discovered that males of the Postman butterfly, Heliconius melpomene, detect and take evasive action when the calls of one of their resident bird predators are played.

Rufous-tailed jacamars are widespread and common insectivorous birds in the range of Heliconius melpomene plessini, the subspecies the researchers studied. The birds look like a forest version of a kingfisher, with long pointed bills that they use to capture insect prey, especially wasps. But butterflies and dragonflies are also on the jacamar menu in the Central and South American habitats where the Postman flies.

Heliconius butterflies generally have evolved a wide rage of defense mechanisms against predation, the research team noted. They are toxic, unpalatable, display aposematic colouration, form Müllerian mimicry rings, and roost communally to avoid bird and bat predation. This might suggest that they don’t really need much extra predation defense from jacamars.

Nevertheless, when the scientists played jacamar calls in the greenhouse where the Postman butterflies were raised, the males immediately changed behavior, increasing their fluttering and walking instead of flying during the jacamar playback and for a short period (about 3 minutes) afterwards. There was no longer-term behavior change, nor did females show any reaction to the jacamar calls.

Nor did they react to background noise played in the greenhouse, or to the calls of two other migratory predators in their range — eastern and tropical kingbirds. And even the calls of the jacamar failed to change the butterflies’ intersexual behavior.

“Heliconius melpomene plessini butterflies changed their behaviour in response to predatory rufous-tailed jacamar calls but did not change their behaviour in response to predatory Eastern kingbird or tropical kingbird calls,” the team concluded. “We found a sex-specific difference in behaviour, where males, but not females, increased their fluttering and walking behaviours during the playback of the rufous-tailed jacamar calls. The observed behavioural changes in response to rufous-tailed jacamar calls are short-term and do not persist over an extended duration of time.”

The researcher posit two possible reasons for why the butterflies reacted to jacamars but not kingbirds. One, the jacamars are a year-round threat, while the kingbirds are migrants that also eat a lot of fruit during their winter sojourn in the tropics where the Postman is found. Overall, the scientists suspect, predation pressure from the kingbirds could be much less than from jacamars.

Two, the calls of the two kingbirds are in a much different auditory frequency than the jacamars, and it’s possible the auditory organs of the butterflies can “hear” the jacamar but not the kingbirds.

That the butterflies are only reacting to predatory bird calls was studied by playing recordings of toco toucan calls in the greenhouse. The toucan calls are in the same frequency range as jacamars, but toucans don’t eat the butterflies. The butterflies had no reaction to the toco toucans.

The authors suggest this might be similar to the scenario where “aposematic striped skunks (Mephitis mephitis) perform anti-predatory behaviour in response to the calls of the great horned owl (Bubo virginianus) from which they are not chemically defended, but not in response to the calls of the coyote (Canis latrans), from which they are chemically defended.”

As to the sex-specific behavior change, the authors note that the males of a number of other species across the animal kingdom react differently than do females. “This male-specific response to predators is similar to that found in other species, and may reflect sexual dimorphic predation pressures,” they surmise, since males range widely through the middle of the forest landscape while females are mostly in the understory near their larval/food host plants. Since jacamars are “hawking” feeders — they dart out from perches to snag passing insects — they might pose more of a risk to male Heliconius butterflies than to females.

The paper is currently available as a preprint that has not yet been reviewed on bioRxiv.

Alternatively, you can read a PDF version in the LepLog library:

behavioural-changes-in-aposematic-heliconius-melpomene-butterflies-in-response-to-their-predatory-bird-callsDownload

Butterfly big bucks on the black market

Cairns Birdwing Butterfly, Ornithoptera priamus euphorion, Queensland, Australia

[From the Associated Press 2024 Feb. 28]

A Long Island man has pleaded guilty to illegally trafficking birdwing butterflies and other rare insects, according to a plea deal filed in Brooklyn federal court Tuesday.

Charles Limmer, 75, of Commack, pleaded guilty to a charge of conspiracy to smuggle wildlife into the country and agreed to pay a $30,215 penalty as well as hand over his collection of roughly 1,000 butterflies, moths and other insects. He faces up to 5 years in prison when sentenced.

Some of the dried specimens include birdwing butterflies, which are among the rarest and largest in the world.

Limmer was indicted last year on six counts related to wildlife smuggling, including violations of the federal Lacey Act’s prohibitions on falsely labeling and trafficking in wildlife. He could have received a 20-year sentence if convicted at trial.

They said Limmer circumvented U.S. laws by labeling shipments as “decorative wall coverings,” “origami paper craft” and “wall decorations.” He sold some of the dried lepidoptera specimens through an eBay account under the name “limmerleps,” pocketing tens of thousands of dollars.

Federal prosecutors said Limmer worked with overseas collaborators to smuggle some 1,000 lepidoptera, including some of the most endangered moths and butterflies in the world, even after his import/export license was suspended in Oct. 2022.

Federal law prohibits the commercial export or import of wildlife without permission from the U.S. Fish and Wildlife Service.

If not for the butterflies, do it for yourself

Bryce Canyon National Park (Utah) 2022 annual butterfly count [photo credit National Park Service]

If you haven’t yet figured out a good reason to participate in our spring and summer North American Butterfly Association (NABA) butterfly counts, here’s one: It’s good for you.

A team of scientists from the University of Derby in the UK says that it’s been long established that citizen science activities like butterfly counts improve “nature connectedness,” behaviors and values that support biodiversity awareness and conservation. But, they wondered: What’s in it for the counters?

The researchers identified a sample of more than 300 participants in the UK’s 2022 Big Butterfly Count, a mass-participation citizen science effort that regularly engages some 60,000 people each year. The team told their subjects that they would be completing three surveys at pre-, post- and follow-up time points, and the participants gave their consent to receive the invitations for subsequent surveys when agreeing to take part in the research.

Characteristics that the Derby team analyzed included nature (inter)connectedness; health and wellbeing (including self-rated health, mental well-being, and personal well-being); nature noticing; and emotional experiences related to the Big Butterfly Count experience. The first survey opened during Big Butterfly Count sign-up and closed just before the Count(s) began, the second survey was sent within the two weeks after the end of the Count period, and the final survey came about three weeks after the second survey closed.

The researchers observed that the most widely reported experience was one of enjoyment, with people reporting that they liked, loved, enjoyed, ‘always looked forward to’ taking part in the count, or that it was fun, lovely, and a pleasure. For some participants, the basis for their enjoyment and pleasure was the opportunity ‘to just sit quietly’, which allowed them to relax, take their mind off other things and into a ‘peaceful place.’ Some compared it to meditation or mindfulness and ‘being totally in the present moment.’

Many participants reported lower anxiety and increased well-being. Some even credit

Taking part in the count with helping them through difficult times, and many people commented on wellbeing benefits:

Going away from my house to look for butterflies has been a huge solace for me these past few weeks (…) counting the butterflies and watching their activities absolutely helps my wellbeing.

We often hear the same feedback from our NABA counts in Maryland.

The strength of the association was also correlated with positive emotions or experiences during the count, the authors said. This may account for the fact that other researchers didn’t find as strong a correlation between citizen science activities and various aspects of wellbeing. The butterfly count researchers note  Lynch et al. (2018) found no significant change in nature relatedness amongst a small sample of citizen scientists involved in a range of entomological studies, although interviews revealed participants’ increased awareness and appreciation of insects. Similarly, Ganzevoort and van den Born (2021) did not find significant increases in measures of nature relatedness amongst citizen scientists in the Dutch National Bee Survey, although participants reported enhanced appreciation of wild bees.

On the other hand, they found, “While enjoyment was the most common emotional response reported, there were many comments expressing sadness and concern about observing declining numbers and diversity of butterflies. People referred back to their experience of taking part in previous years’ counts, or their memories of earlier decades in which there was much greater abundance of butterflies and other insects.” Increased facility in ‘noticing nature’ more broadly also was evident in the study cohort, and participating in the butterfly count increased the level of ‘hope and helping’ for conservation action and other pro-nature activities.

The impact on reduced anxiety and wellbeing, however, didn’t persist and was no longer statistically significant by the third survey, suggesting that regular involvement in citizen science activities is important for maintaining health and wellbeing gains from things like butterfly watching and counting.

“Citizen science participation prompts people to notice and enjoy nature in ways that enhance their wellbeing and connection with nature, supporting the mutual health of people and the rest of the natural world,” the authors conclude. “[Our work] highlights the potential for nature-based citizen science to benefit conservation beyond the focal species or habitat, by changing how people think, feel and act towards nature more broadly.”

The work was published in the 2024 March 04 issue of the journal Biological Conservation.

View a PDF of the article here:

butler-et-al-2024_impact-of-counting-butterflies-on-nature-connectedness-and-wellbeing-in-citizen-scientists-Download

MD DNR Seeks Rare Insect Survey Field Tech

The Maryland Department of Natural Resources is currently recruiting for a Senior Natural Resources Technician I (seasonal contractual position) to survey for rare insects in MD. Although much of this position will entail survey and identification work, duties will also include data entry, GIS mapping, and creating or revising conservation recommendations. This position will be based out of Tawes State Office Building in Annapolis, MD but will require traveling all across the state. See the full position description at https://www.jobapscloud.com/MD/sup/bulpreview.asp?R1=24&R2=002293&R3=0015

Legacies: Malcolm Barcant and the butterflies of Trinidad and Tobago

For anyone exploring the butterflies of the Caribbean, Malcolm Barcant’s 1970 “Butterflies of Trinidad and Tobago” still occupies a favored spot on the bookshelf. As Barcant was fond of saying, for its size Trinidad (not so much Tobago) is one of the most butterfly-rich places on the planet. Between the two small islands, they host some 750 butterfly species.

A chartered accountant by trade, collecting and identifying neotropical butterflies was Barcant’s real vocation. By the time he decided to emigrate to the US (Florida) in 1976, he had amassed an enviable collection of butterflies from Trinidad and Tobago, which he donated to the Angostura Company (they of bitters fame, on the occasion of their 150th anniversary celebration). The collection, numbering some 6,000 specimens, is housed in a purpose-built room on the company grounds, where it may still be viewed and accessed by lepidopterists today.

Barcant died in Florida in 1986. He is memorialized by two eponymic species, Heliconius hecale barcanti and Pachythone barcanti.

“Butterflies of Trinidad and Tobago,” now long out of print, generated considerable criticism at publication when Barcant decided to forego traditional classification schemes and instead presented his work in simple lay language and arranged by habitat, not taxonomy. 

A tribute article to Barcant begins on page 90 of the 2014 issue of the Bulletin of the Royal Entomological Society.

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Olfaction in the Anthropocene

White-lined Sphinx (Hyles lineata) pollinating a pale evening primrose [photo courtesy University of Washington News Service]

Unsurprisingly, many pollinators use chemical cues to find the flowers they visit, but few seem to be as well-equipped with olfactory senses as sphingid moths. Unlike dayflying pollinators, they appear to have few visual signals to guide them through the dark to their preferred plants.

One of those plants is evening primrose, a genus (Oenothera) of widely distributed flowers that bloom at night. Oenothera pallida, the pale evening-primrose, is widely distributed in North American desert landscapes. Its principal pollinators are hawkmoths, especially Hyles lineata (the White-lined Sphinx) and Manduca sexta (the Tobacco Hawkmoth). Both find their plants in the desert night by olfactory cues, and these strong-flying, robust moths can follow the scent trail for a kilometer or more to pollinate them. 

Various researchers, however, have noted a decline in nighttime pollination activity by these and other moths in urbanized areas. A research team led by Jeremy Chan (then at the University of Washington, now at the University of Naples) suggests that decline results from smoggy and polluted air that diminishes the ability of hawkmoths to find evening primroses.

chan-2024-olfaction-in-the-anthropocene_science.adi0858Download

In the lab, Chan et al first characterized all the likely scent compounds that might be used by the moths. These floral volatiles, they discovered, were significantly degraded by ozone and nitrogen dioxide at concentrations these pollutants are likely to be found in urbanized environments. 

Next, they tested the flower-finding capacity of hawkmoths in wind tunnels where they set up primrose scent at the far end. When ozone and nitrogen oxide were introduced into the ambient air at concentrations expected from urban pollution, the ability of Manduca to find the scent target dropped by half, and Hyles couldn’t find it all. 

Finally, they moved the experiment to the field, where they placed odor-enhanced fake flowers around the landscape and found they were as attractive to the moths as real flowers. But when they altered the scent with pollutants, they had the same results as in the lab: Pollination visits to the flowers plummeted. 

Interestingly, nitrogen dioxide was the more powerful pollutant in this case, and ozone on its own didn’t affect pollination that much. 

Based on these data, the authors plotted where the effect of urban air pollution would be expected to be the most disruptive. Western North America, much of Europe, the Middle East, Central and South Asia, and southern Africa were judged to be most likely impacted. Moreover, nighttime pollution was suspected to be more problematic, since sunlight quickly degrades nitrogen dioxide during the day.

“Pollution from human activity is altering the chemical composition of critical scent cues, and altering it to such an extent that the pollinators can no longer recognize it and respond to it,” said co-author and University of Washington (UW) biology professor Jeff Riffell to the UW news service. “The NO3 is really reducing a flower’s ‘reach’ — how far its scent can travel and attract a pollinator before it gets broken down and is undetectable.”

Lead author Jeremy Chan in the field with his chemistry set-up to monitor hawkmoth visits to night-blooming flowers whose scent has been altered to mimic urban pollution.