Month: January 2023

 

 

In a previous episode we met strange gall-forming psyllids making their homes on leaves of the sacred ʻŌhiʻa tree, Metrosideros polymorpha. Once again, we escape the chilly confines of the DMV and return to the big island of Hawai’i to visit another intriguing family of insects, picture-winged flies, Drosophilidae. The Hawaiian archipelago formed and continues to grow as tectonic plates beneath the Pacific Ocean pass over a volcanic “hot spot.” This movement of the earth’s crust spawns enormous land masses that eventually emerge from the sea, the islands of Hawaii. For millions of years, this ongoing process has created new land, pristine habitat awaiting the arrival of plants and animals in what has been called an “evolutionary laboratory.” At some point in time eons ago, ancestral picture-winged flies, voyagers by an unknown conveyance, arrived on the islands and initiated a process of evolutionary adaptation exploiting the bountiful resources and diverse climatic regimes found in this tropical paradise. This unending process has resulted in almost 700 named species of drosophilids inhabiting the Hawaiian Islands, with another 300 or more yet to be described.

At the Hawai’i Tropical Bioreserve and Garden just north of Hilo, strange cannonball trees produce fragrant flowers along the length of their trunk. After visitations by pollinators, they rain to the ground and provide a rich source of nutrients for decomposers. Picture-winged flies swarm over the rotting blossoms and rest on vegetation before depositing eggs in the organic stew. Maggots like this one slithering across a leaf are important recyclers of organic matter. Hawaii’s diversity of plants, habitats, and isolation help generate roughly a quarter of all known drosophilid species worldwide.

While visiting the spectacular Tropical Bioreserve and Garden on Hawai’i, we had the opportunity to get up close and personal with one of the many species of drosophilids on the island. Along a forested path in the garden grows a remarkable, bizarre cannonball tree, Couroupita guianensis. This native of Central and South America is often found in botanical gardens around the world by virtue of its stunning blossoms and cannonball-shaped fruit. Trunks of the cannonball tree are festooned with extremely fragrant blossoms and woody round fruits, a stunning presentation of flowers and fruit. When blossoms complete their task of attracting pollinators, they tumble to earth and create a thick slimy carpet of decaying organic matter beneath the cannonball tree, a perfect nursery for developing larvae of drosophilid flies. As I crouched in the stinky goo to photograph some maggots, drosophilid flies swarmed around the vegetation beneath the tree. My efforts were rewarded when I discovered fly larvae slithering across the surfaces of decaying blossoms. Lucky me.

Ah, but all is not rosy for the drosophilid flies in Hawai’i. It turns out that the invasive western yellow jacket we met a few weeks ago finds drosophilids delectable. This predatory rascal is responsible for population collapses of many species of picture-winged flies since the yellow jacket arrived in the Hawaiian Islands. Let’s hope its presence doesn’t seriously disrupt the course of evolution of picture-winged flies and other creatures in this unique evolutionary laboratory.    Hawaiian

Acknowledgements

We thank Dan Gruner for stimulating discussions about the ecology of Hawaiian flora and fauna and Paula Shrewsbury for images used in this episode. The great articles “Sexual Selection and Speciation in Hawaiian Drosophila” by Christine R. B. Boake and “Hawaiian Drosophila as an Evolutionary Model Clade: Days of Future Past” by Patrick O’Grady and Rob DeSalle were used as references for this episode. We also thank the wonderful staff of the Hawai’i Tropical Bioreserve and Garden for creating a great location to observe and enjoy picture-winged flies and tropical plants.

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Last week we met a handsome wasp inspecting galleries in wooden posts at the visitor center in Volcano National Park on the big island of Hawai’i. The keyhole wasp, Pachodynerus nasidens, belongs to a subfamily of cosmopolitan vespid wasps called the Eumeninae, commonly called potter and mason wasps. As we learned last week, keyhole wasps use galleries abandoned by other insects or human-made tubes and hollows as nurseries to raise their brood. Now let’s travel a few thousand miles east back to the DMV to visit another member of the Eumeninae.

Several years ago, an eagle-eyed Master Gardener made an inquiry regarding black and white wasps poking around her mason bee colony. My gardener friend wondered about the identity and intent of these winged wonders. Were these wasps nefarious ruffians out to eat mason bee babies and pillage their pollen cakes? You may recall meeting hard working mason bees in a previous episode of Bug of the Week and seeing photographs of hollow cardboard tubes and holes drilled in wood used to accommodate these industrious early season pollinators. Mason bees are not the only members of the bee and wasp clan that have evolved to take advantage of vacant galleries in wood. These hollow chambers excavated by wood-boring bees like carpenter bees and round-headed beetle borers are used by several species of mason wasps as nurseries to raise their brood.

As adults, mason wasps provide two important ecosystem services, one of pollination as they seek nectar and pollen as sources of food, and another as biological control of plant-eating caterpillars. Unlike the larvae of mason bees that consume pollen cakes supplied by their mothers, mason wasps consume living but paralyzed caterpillars. Prior to the hunt for caterpillar prey, the female mason wasp deposits her egg in the chamber where caterpillars will be stored. She then hunts for prey on flowers, foliage, vegetables, and fruit. Like potter wasps we met in a previous episode of Bug of the Week, female mason wasps use a potent venom to paralyze their pray. Sometimes as many as 19 caterpillars are captured, paralyzed, and used to provision the cell where an egg awaits. Once a sufficient number of prey has been captured, the chamber is sealed with a plug of mud or sand particles. In a remarkable display of gender control, the female wasp is able to lay either a male or a female egg. Due to the shorter developmental time of the male offspring, male eggs are usually placed near the opening of the gallery. Female eggs are placed deeper within the gallery. In this way faster developing males avoid trying to climb over, around, or bore through their sisters on the way out of the nursery.

Mountain mint looks like a super food for mason wasps as they carbo-load in preparation to search for caterpillars. Watch as this female sips nectar from several blossoms before the hunt. Natural holes made in wood by other insects and human-made holes drilled in logs for mason bees make great nurseries for mason wasps. A little tickle with a wisp of wood brings a female out of her nursery. A quick look around reveals nothing amiss and back she goes into the gallery to resume her work. To my surprise, a weep-hole made in the vinyl frame of my living room window makes a great nursery for a mason wasp. After provisioning galleries with paralyzed caterpillars to feed their young, mothers gather balls of mud which will be used to seal the nursery chambers. Using jaws and patience, a female makes a beautiful mudball. With the mudball complete and cradled beneath her legs, she flies back to her nursery. It takes several loads of mud to seal the gallery completely. Here a mother puts the final touches on her handiwork. A solid coat of mud plaster helps prevent enemies from attacking and killing her developing brood. 

So, when you see these magnificent black and white wasps hovering around mason bee colonies, fear not, these are highly beneficial mason wasps looking for an empty apartment as a nursery to raise their brood. They are part of Mother Nature’s hit squad helping to reduce damage caused by caterpillars in our gardens and landscapes. You can make them part of your pest management team by providing them with critical nectar and pollen sources such as gorgeous native mountain mint and spotted horse mint.

Acknowledgements

The wonderful references “Trap nesting wasps and bees: Life histories, nests, and associates” by Karl Krombein and “The Cocooning Habit of the Wasp Monobia quadridens” by Phil Rau were consulted to prepare this episode.  

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Over the past several weeks we meet gorgeous peripatetic butterflies, monarchs and Gulf fritillaries, that somehow found their way to the Hawaiian Islands. Last week fierce western yellowjackets of the vespid clan took center stage as they murdered invasive cockroaches at Volcano National Park. This week we return to the site of erupting Kilauea for a quick stop at the visitor center to meet another member of the vespid clan, keyhole wasps that arrived in the islands by ship in the early 1900’s. Exterior wooden posts at the visitor center bear many holes made by humans and unidentified wood-boring insect. These abandoned galleries now provide a wonderful set of condominiums in paradise for fetching keyhole wasps.

Keyhole wasps are so named for their habit of using empty galleries in wood made by other insects and human-made voids such as keyholes or electrical sockets as nesting sites. They sometimes also nest in abandoned nests of other wasps like mud daubers, or empty silken cases of caterpillars. After thoroughly inspecting, cleaning, and accepting a nest site, the female wasp captures and paralyzes several caterpillars. These living dead are stuffed into the gallery. Mother wasp lays eggs within the gallery and seals the chamber with mud. The fresh meat of paralyzed caterpillars serves as larder for her young as they hatch from eggs and develop. For the hapless caterpillars, what a way to go!

 

Keyhole wasps use holes in wood made by humans and wood-boring insects as nurseries for their young. One little lady inspects a potential nest site and decides it isn’t quite right. An industrious female nearby prepares the nursery by removing trash left behind by former occupants. Once the perfect gallery is cleaned and ready for occupation, it’s off to find and paralyze delectable caterpillars to feed her youngsters. Caterpillars returned to the nursery provide fresh nutritious food for developing wasp larvae that hatch from eggs deposited in the gallery by their fierce mother.

But you don’t have to travel to the Hawaiian Islands to observe these splendid hunters. Keyhole wasps are indigenous to Central and South America and have been found in Mexico, Texas, Virginia, and Florida. They have also made their way to several Islands in the Atlantic and Pacific as well as the continent of Australia. Their arrival in Australia caused a bit of a stir at the Brisbane airport, where keyhole wasps decided that pitots on airplanes created excellent galleries in which to build nests for raising their young. Know what a pitot is? Me neither, but I have learned that these are small hollow tubes on the nose cone of an aircraft used to measure the airspeed of the plane. Keyhole wasps nesting in these tubes plugged them with mud which resulted in “serious safety incidents” as information on airspeeds “critical for landings, takeoffs, and flight became unreliable.” Yikes! By modifying habitats near the airport to disfavor nest-building by wasps, providing alternate nest sites, covering pitots between flights, and inspecting pitots regularly, problems created by these opportunistic invaders have been quelled Down Under. Although keyhole wasps are not yet common in the DMV, a close relative called the four-toothed mason wasp makes its home in the DMV. We will learn a bit more about this interesting caterpillar hunter in next week’s episode.  

Acknowledgements

Fascinating references used to create this episode include “Inventive nesting behaviour in the keyhole wasp Pachodynerus nasidens Latreille (Hymenoptera: Vespidae) in Australia, and the risk to aviation safety” by Alan P. N. House, Jackson G. Ring, and Phillip P. Shaw, and “The Genus Pachodynerus in North America (Hymenoptera: Vespidae: Eumeninae)” by James M. Carpenter.  We thank Drs. Nancy Breisch and Al Greene for assistance in identifying the keyhole wasp, Dr. Paula Shrewsbury for discovering and photographing wasps, and Dr. Dan Gruner for interesting discussions of invasive species in the Hawaiian Islands.

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Discover Which Pests Want to Move in During the Winter and How to Protect Your Home from Infestations

Spring and summer may be buggy with mosquitoes and stinging insects, but once the temperature drops, other household pests begin infesting homes throughout the region.

Weather throughout the year also has an impact on pest pressures for the following seasons. Significant periods of rainfall during the summer allowed for pests to survive during colder weather. This news comes as a warning of ticks during the early part of the season and rodents that start moving indoors to escape frigid conditions.

As a result, many homeowners in the Northeast opt for year-round pest control services to avoid issues in the cold months. Catseye Pest Control’s Platinum Home Protection includes pest removal as well as sealing and treating gaps and cracks. It also covers perimeter treatments and bi-monthly visits for ultimate peace of mind.

Although it may be tempting to loosen pest control protocols during cool weather months, these seven winter pests are waiting to prove the need for year-round vigilance.

Mice

Mice spend their winters actively searching for warmth, food, and shelter. These tiny household pests can squeeze through a gap or crack as tiny as one-quarter-inch wide, which is why it’s essential to seal gaps and cracks.

It’s also why exclusion systems, which create a permanent barrier to keep mice and other pests out, can be so effective for prevention and ongoing control.

Once inside, these critters are attracted to food and may chew up items in the pantry or on counters. One of the most common species found in the Northeast and New England is the common house mouse.

These critters are also known to damage insulation when nesting, chew wood and drywall, and even gnaw on wires. Make your home less inviting by regularly cleaning floors and counters and keeping food stored in plastic containers.

It’s also helpful to minimize clutter in spaces where mice can hide and monitor the home for signs of mice (like droppings and gnaw marks).

Rats

Like mice, rats leave messy droppings, food messes, gnaw marks, and damage in their wake. These rodents can squeeze through openings as small as a quarter. Common rats in the region include Norway rats, which typically nest in debris piles, crawlspaces, and basements. They may gnaw through pipes, and like other rodents, they can carry multiple diseases, including rat-bite fever and cowpox.

Signs of rats in the house include greasy track marks left by their oily fur, droppings, and disturbed food packaging. Cleaning and sanitation, along with securing food in airtight containers, can help minimize rat infestations. Dehumidifying basements and crawlspaces can also help, as can sealing any gaps, cracks, and other openings.

Stink Bugs

What is thought of as a warm-weather pest, it actually takes numerous consecutive days of extreme, negative temperatures to eliminate stink bugs. This means the pest could be looking for a way inside homes throughout the Northeast year-round.

Looking for a warm place to spend their winter days, stink bugs see man-made structures as the ideal place to be during the colder months.

Making their way into structures through siding, soffits, window and door frames, chimneys, or any variety of opening they can find, homeowners can find hundreds or thousands of stink bugs in their homes, garages, or sheds.

Cockroaches

Any season can be cockroach season, so winter is no exception. Common cockroaches in the Northeast include the German cockroach, which is usually around 1/2 inch long and light brown or tan. The American cockroach, which is typically reddish brown, can grow to lengths of up to 2 inches.

Cockroaches crawl inside homes through tiny cracks and openings, often in search of food and water. They may also catch a ride on backpacks, luggage, and grocery bags. Sealing openings is the only way to prevent a winter infestation. Keep floors and counters clean, regularly dispose of garbage, and remain vigilant in kitchens and bathrooms.

Spiders

Spiders, including the brown recluse spider, which has a venomous bite, are also active through winter. They can enter buildings by crawling into small openings or hitching a ride on clothing. Once inside, they like to hang out in quiet spots like crawlspaces, basements, attics, closets, and cardboard boxes.

Keeping shrubs and trees trimmed away from houses helps minimize the risk of spiders coming indoors. If you suspect you have a spider bite, seek medical attention promptly.

Bed Bugs

Winter’s frigid temperatures can be a benefit for bed bugs, which crave warm humans to feed upon, because humans stay inside more frequently during winter. Also, thicker, warmer bedding provides these household pests with more spots to nestle in and hide.

Bed bugs typically catch a ride into homes on clothing, luggage, backpacks, and soft, upholstered items that come in contact with infested areas. Signs of an infestation include tiny spots of blood on bedding or pajamas, itchy bites, and live bugs near mattress tags and crevices. Professional bed bug control is essential for eliminating these pests.

Ladybugs

North America is home to approximately 475 species of ladybugs, also known as ladybird beetles or lady beetles. Although the pest holds many benefits, including consuming aphids and other crop-damaging insects, they look to man-made structures for warmth.

The red and black pest often enters buildings through eaves and other small openings, then spend their time hiding in the walls, only to crawl onto windows during the day to soak up the sun.

Ladybugs are unlikely to reproduce inside homes, sheds, garages, and other man-made structures, but can attract other pests as the population begins to die if the situation isn’t handled properly.

Call Catseye for Winter Pest Control

House bugs and other pests are still active, even when there is snow on the ground and temperatures plummet. Professional pest control can quickly and effectively eliminate the problem, locate how winter pests are getting in, and prevent them from returning.

Contact Catseye today to schedule a free inspection. From there, we can create a custom plan to efficiently address your unique property and pest control needs.

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In previous episodes we met strange plant-sucking psyllids and opportunistic ants colonizing plants growing on some of the newest real estate on earth. We also met monarch butterflies and Gulf fritillaries, gorgeous aerial voyagers that traveled thousands of miles across the ocean to reach the isolated Hawaiian archipelago. We met some beauties, but this week we meet some of the beasts. Creatures indigenous to the Hawaiian island have been slammed by the accidental or deliberate introduction of animals like rats, mongooses, fire ants, and frogs. While visiting Volcano National Park in autumn of 2022, we bumped into two clans of unwelcome colonists, cockroaches and yellowjackets that made their ways to the Hawaiian Islands in addition to other lands around the globe.

German cockroaches and American cockroaches share much in common beyond being something you don’t want to find in your kitchen. First, their distribution is cosmopolitan, meaning that they are found around the world having traveled with humans since antiquity. Second, their common names are misnomers as scholars believe that German roaches likely originated in Asia and American roaches likely spread from their aboriginal home in Africa. Another unwelcome immigrant to the islands is the western yellowjacket from North America. This rascal creates havoc on several islands in the archipelago where it feeds on more than 40 families of arthropods, including many native and introduced insects and spiders, but it also has been documented to dine on vertebrates such as birds. In addition to disrupting ecological communities, western wasps have become an important and dangerous nuisance to residents and visitors to the islands. In 2022 in what has been called one of the worst seasons for yellowjackets, signs posted near observation points overlooking the Kilauea volcano warned visitors to beware of stinging wasps.

Why the concern? Invasive western yellowjackets behave quite differently in Hawai’i compared to their relatives back on the mainland. In their native range in the Pacific North West, yellowjackets form annual colonies, ones that last only one year. Queens spend the winter in protected locations outdoors and initiate new colonies in spring. Their colonies are usually ruled by a single queen and her daughters, the worker wasps that gather food and tend brood in the subterranean nest. The colony grows over the course of the summer but with the approach of winter, and the impending decline of prey to feed developing wasp larvae, brood production switches from producing workers to producing drones (male wasps) and new queens. By the end of the growing season the colony has grown to its final size of a few thousand wasps. With the production of new queens, colony growth ends, and new queens find overwintering sites and await spring, when new colonies are founded. But on the tropical islands of Hawai’i, harsh winters do not punctuate the warm climate of the islands. Bountiful sources of protein and carbohydrates from animals and plants are available all months of the years. Many colonies of western yellowjackets are no longer annual but continue to grow and expand year-round, becoming perennial colonies with not one, but multiple queens. These power houses grow to enormous size. One colony on Maui was estimated to house 600,000 individuals. And with this many hungry mouths to feed, it is not surprising that native and non-native prey items are consumed in huge numbers, upsetting the balance of ecosystems on several islands and forcing tourists to duck and run when workers are on the hunt.

Small German cockroaches like this one are unwelcome visitors in any home, including ones in Hawai’i. Another invasive cockroach, the American cockroach, gets a come-uppance from an invasive yellowjacket. This voracious female predator stung and paralyzed the cockroach. She will dismember it and return with meaty morsels to the nest to feed developing larvae. Yellowjacket colonies can be populated by hundreds of thousands of workers, disrupting local ecosystems and posing health hazards to humans and pets.

But is there any bright side in these otherwise grim and scary invasions? I found some small solace as I watched a ferocious yellowjacket attack, sting, paralyze, and then begin to devour a large American cockroach on a path near a visitor center. Like a scene from Jurassic World Dominion, these travelers -not in time but in space to a land where they don’t belong – do just what Mother Nature intended: eat and be eaten.

Acknowledgements

Two very cool references, “Reproductive plasticity of Vespula pensylvanica (Hymenoptera: Vespidae) on Maui and Hawaii Islands, U.S.A.” by Parker Gambino, and “Life history plasticity magnifies the ecological effects of a social wasp invasion” by Erin E. Wilson, Lynne M. Mullen, and David A. Holway, were used to prepare this episode. We thank Dr. Dan Gruner for stimulating discussions about the ecology of Hawaiian flora and fauna and Dr. Paula Shrewsbury for images used in this episode. To learn more about yellowjackets on the Hawaiian Islands, threats they impose, and how they arrived, please click on this link: https://www.usgs.gov/news/volcano-watch-tis-season-say-goodbye-yellowjacket-wasps

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Discover How to Handle a Maggot Situation in the Home and How to Prevent It from Happening in the Future

Maggots happen, unfortunately. These pests aren’t the most common invaders in homes and businesses, but they happen more often than you may think. No pest infestation is pleasant, but finding maggots in a house, garden, or workplace can leave you with a serious case of the creepy crawlies. It’s gross — plain and simple.

Learn more about what these pests are, how to identify them, and what causes maggot infestations. Ultimately, controlling flies helps control maggots, and Catseye Pest Control has more than three decades of experience performing fly control services.

What Are Maggots?

Maggots are fly larvae. Although more than 100,000 species of flies live around the world, most maggots found in homes and businesses come from the common house fly or the blowfly.

These pests are usually approximately the size of a thumbnail, with a cream or light brown color. Because they like to burrow into the materials to feed on or live in, their heads are more pointed than their rears. As they eat their way through materials, circular holes are left behind.

Facts About Maggots

• Flies lay their eggs in warm spots near or on food sources.
• Female flies can lay as many as 2,400 eggs in their lifetime.
• After a fly lays eggs, they hatch within seven to 20 hours and emerge as maggots.
• These critters can be problematic year-round but are more active in spring and summer.
• Maggots live in their larval state for approximately six days before transitioning into pupae and then adult flies.
• The number of maggots present on a dead body and the specific species helps determine the time of a person’s death.
• Maggots have hook-like mouthparts called mandibles that allow them to grab food.
• Maggots are attracted to rotting, decomposing items, including garbage and flesh.

Where Maggots Live

Maggots are often found outdoors in vegetable gardens, garbage, and the bodies of dead animals. Indoors, you might find them in or near garbage, in pantries and refrigerators on spoiled food, or around other rotting materials.

Kitchens and garbage cans are frequent spots where homeowners and business owners find maggots. In extreme cases, some people may see them crawling on the walls. Maggots in walls typically come from garbage, fecal matter, or decomposing animals or other pests.

Where to Look for Signs of a Maggot Infestation

Any location with flies and a food source can breed maggots. Leftover food and decomposing perishables commonly attract flies. Look in garbage cans and around food sources for signs of infestation. Pets and people may even have maggots in wounds or under their skin.

How to Get Rid of Maggots

The most efficient, lasting way to control maggots in homes, businesses, and other areas is through professional pest control.

Catseye Pest Control can help you remove pesky flies while preserving their ecological role. Our skilled technicians identify breeding sites and eliminate eggs, larvae, and adults. Our fly control program also includes sanitizing breeding sites and removing infestations.

There are also steps you can take on your own to prevent maggots from ever taking up residence. Eliminating food sources can help get rid of these pests and prevent future problems. A few tips to get you started include:

• Removing rotting plant materials and practicing crop rotation to avoid maggots in the garden.
• Promptly getting rid of any dead animals from in or around the home or other structures or calling animal control for help.
• Bagging up pet feces for proper disposal.
• Cleaning affected areas thoroughly and maintaining a regular sanitation schedule.

It’s essential to break the fly life cycle to prevent problems. Find whatever is attracting flies and eliminate it. Without flies, you won’t have maggots.

Call Catseye for Professional Maggot Control

For thorough, total control of maggots and other pests, learn about our Platinum Home Protection, a service that provides year-round protection and ongoing monitoring. Keep your home, business, and the people you care about healthy and safe with professional fly control and removal from Catseye.

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This week Bug of the Week returns to some of the newest land on our planet, the Big Island of Hawai’i, to meet another beautiful immigrant to this tropical paradise. Over the holidays we learned that Monarch butterflies arrived on the Hawaiian Islands sometime after the introduction in the 1800’s of milkweeds, the key food source for their young. Like the Monarch, the Gulf Fritillary is also a super specialist that evolved to utilize members of the passion vine clan, Passiflora spp., as food for its young. When the edible passion fruit yellow granadilla, P. laurifolia, arrived in Hawai’i sometime before 1871, a door was opened for Gulf Fritillaries to colonize the big island and call it home. Records of Hawaiian butterflies prior to 1958 don’t list the Gulf Fritillary, but by 2002 these beauties were recorded on six islands of the Hawaiian archipelago. This broad ranging species takes up permanent residence from Argentina to the southern United States. During summer, peregrinations take it as far north as San Francisco on the west coast and New Jersey on the east coast, but in autumn this vagabond travels south to the warm climes of the Floridian peninsula to spend the winter. 

Like other members of the longwing butterfly clan, larvae of this beauty consume leaves of passion fruit vine. The blossom of the passion fruit vine is one of the most gorgeous in the angiosperm world. Exotic flavors of the passion fruit are used around the world, adding zest to ice cream, cheesecake, and mixed drinks. Passion fruit is rich in vitamin C and lycopene and consuming this delicacy is said to sooth a queasy stomach, according to Andean lore. As a group, passion fruit plants are protected from most leaf-munching caterpillars and other vegan insects by a veritable witch’s brew of highly toxic chemicals including alkaloids, a family of toxins that includes strychnine and nicotine, and cyanogenic glycosides, chemicals that release cyanide upon entering the digestive tract of a caterpillar or human. However, the Gulf Fritillary and other members of its clan, including the zebra longwing we met in a previous episode, turned the tables on passion fruit plants, bypassing the noxious defenses and feasting with impunity on their leaves. Some species of longwings sequester cyanogenic glycosides from their food and others manufacture these compounds on their own, presumably for defense. The striking orange and black coloration of the Gulf fritillary warns vertebrate predators not to mess with this beauty. In addition to any plant derived defenses, the gorgeous Gulf Fritillary has one more bit of chemical trickery to help keep predators at bay. Glands on the abdomen produce and release a concoction of complex esters when the adult butterfly is disturbed. This stinky defensive fluid dissuades predators such as birds from making a meal of these dazzling butterflies. 

The introduction of passion vines to Hawaii in the 1800’s opened the door for pretty Gulf Fritillaries to colonize. In their new home butterflies sip nectar from a wide variety of flowering plants. Females deposit eggs on leaves of passion vines and caterpillars consume leaves to obtain nutrients for growth and defensive compounds for protection from predators. Caterpillars often move from vines to pupate and their chrysalises can be found on human-made objects. While some species of passion vines are considered invasive on the Hawaiian Islands, Gulf Fritillaries are gorgeous colonists enjoyed by islanders. 

But the beautiful Gulf Fritillary is not all about noxious chemicals and defense. Oh no, observations of mating rituals of these beauties in the Norfolk Botanical Garden some years ago revealed romance afoot where a mating pair of butterflies engaged in a quixotic duet along a footpath. Many male butterflies, including Gulf Fritillaries, have a clever trick for winning the affections of would be mates. At the tip of his abdomen, the Gulf Fritillary has small bristles called hair pencils. The male uses his hair pencils to distribute aphrodisiac pheromones on the antennae of a potential mate. Courtship pheromones are released by the male over the female while both are in flight. These pheromones calm the female’s innate escape response and upon landing the male may hover over the female dusting her with more pheromones. The resulting romantic swoon induced by the pheromone allows the male to approach his mate and, well, shall we say, fulfill the biological imperative of procreation. Beauty, danger, and romance brought to a tropical paradise by airborne voyagers, who could ask for anything more of a butterfly? 

Bug of the Week wishes you a joyous New Year! 

Acknowledgements 

References used in the preparation of this Bug of the Week include ‘Caterpillars of Eastern North America” by David L. Wagner; “Coevolution of Animals and Plants” by Lawrence Gilbert and Peter Raven; “Gulf Fritillary Butterfly, Agraulis vanillae (Linnaeus) (Insecta: Lepidoptera: Nymphalidae)” by Jaret C. Daniels; “Novel chemistry of abdominal defensive glands of nymphalid butterfly Agraulis vanilla” by Gary N. Ross,  Henry M. Fales, Helen A. Lloyd, Tappey Jones, Edward A. Sokoloski, Kimberly Marshall-Batty, and Murray S. Blum; “Insects of Hawaii: A Manual of the Insects of the Hawaiian Islands, including an Enumeration of the Species and Notes on their Origin” by Elwood Zimmerman; and “Hawaiian Terrestrial Arthropod Checklist, Fourth Edition” by Gordon M. Nishida. We thank Dr. Dan Gruner for stimulating discussions about the ecology of Hawaiian flora and fauna and Dr. Paula Shrewsbury for images used in this episode.

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