Month: February 2020

A rainforest beauty better for observing rather than touching: Silkmoth caterpillar, Automeris spp.

  Silk moth caterpillars like this Automeris species are spectacular denizens of the rainforest.

Silk moth caterpillars like this Automeris species are spectacular denizens of the rainforest.

 

 

With the return of warm weather, leaves, and insects still weeks away here in the DMV, it’s time to travel to tropical rainforests in Costa Rica to see what’s up with some of our southern neighbors. First stop is the rainforest near the village of Santo Domingo bordering the Savegre River in Costa Rica. Scrambling across the ground near the base of a tree was a magnificent caterpillar. At first glance the identity of this beauty had me stumped, but after picking it up fiery stings to my finger and palm refreshed my memory of its true identity. This caterpillar is a member of the silk moth clan in the genus Automeris. The remarkable color pattern of this extraordinary larva leads me to believe its identity is Automeris metzli, a creature found from Mexico to Ecuador and also on the island of Trinidad, where it munches leaves of oak and less commonly Erythrinaand coconut.

Don’t let these amazing spines and beautiful colors fool you. Handling this lovely caterpillar could result in a spicy and memorable surprise.

False eyespots on the hind wing may help beautiful male (top) and female (bottom) Automeris moths gain protection from hungry predators. These two are Io moths, Automeris io.

False eyespots on the hind wing may help beautiful male (top) and female (bottom) Automeris moths gain protection from hungry predators. These two are Io moths, Automeris io.

You might think that a very large (this one was several inches long) tasty caterpillar would attract the attention of hungry predators. But Automeris caterpillars have a clever defense. Lining their sides and backs are spines loaded with venom. These spikey armaments are called urticating spines. Upon contact by a predator or overcurious human these spines release venom, causing a painful and relatively long lasting sting. For most people this sting resolves without complication but for some it may cause a serious allergic reaction. For me, well, getting up close and personal with this creature was worth some minor discomfort. Urticating spines are employed for defense by several families of moths, including flannel moths and saddleback caterpillars we met in previous episodes. While stinging shock and awe are the defensive syndrome employed by these caterpillars, adult moths use a different strategy. When resting on vegetation or on the ground, the brownish dappled forewings of the moth help it blend with background vegetation, effectively camouflaging the moth. If a predator draws too near, the moth spreads its forewings revealing large vertebrate eyespots on the hindwings. This ruse is thought to startle and frighten would-be predators, allowing the moth to escape or break-off the attack. False eyespots have evolved many times in the insect world and are found on caterpillars including swallowtail caterpillars, Promethea moths, and owl butterflies we met in previous episodes.

A cousin of Automeris metzli called the Io moth is relatively common in much of North America. including the DMV. This beautiful species of moth was once very abundant from New England to the Gulf States and west to the Great Plains. However, in New England and throughout much of its range, Io moths have declined. In addition to loss of natural habitat, the introduction of the parasitic fly Compsilura concinnata to control gypsy moth caterpillars has been implicated in local and regional declines in populations of Io moths and several other moth species attacked and killed by the fly. Habitat destruction and invasive species are but two threats to these charismatic and beautiful creatures throughout their ranges.

Acknowledgements

Bug of the Week thanks Hugh and Bridgette for discovering the gorgeous caterpillar, Costa Rica Vacations, and the intrepid guides Mono and Kenneth at Rafiki Lodge, for providing the inspiration for this episode.  “Automeris metzli Sallé (Lepidoptera: Saturniidae) in Trinidad, West Indies” by Matthew J.W. Cock, “Moth decline in the Northeastern United States” by David Wagner, and “Insect Defenses” by T. Eisner, M. Eisner, and M. Siegler, were used as references for this episode.

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Small Dragons: Dragonflies, Anisoptera

  On hot days with brilliant sunshine a dragonfly may point its abdomen upward to reduce the surface area exposed to the sun.

On hot days with brilliant sunshine a dragonfly may point its abdomen upward to reduce the surface area exposed to the sun.

 

This week we continue our adventures in the aquatic realm where we recently visited whirligig beetles and water striders. Now let’s meet some tiny dragons. Dragons are mythological beings common to many cultures. These fanciful and fearsome predators are often chimeras of several creatures with wings of a bat, head of a reptile, scales of a fish, feet of an eagle, or tail of a serpent. With enormous compound eyes, reticulate wings, long legs, and a snaky tail, dragon seems a fitting name for the insects we call dragonflies.

Dragonflies belong to a group of flying insects called the Anisoptera. The name Anisoptera comes from the Latin roots aniso- (meaning unequal) and –ptera (referring to wing). Anisoptera is a reference to the fact that the forewings of dragonflies are not nearly as wide as the hindwings. Dragonflies are an ancient clan. Those patrolling the skies 250 million years ago had wingspans of two and a half feet. Modern dragonflies are smaller but no less magnificent. They are active predators hunting and capturing prey while on the wing. Spiny legs held beneath the body in a basket-like arrangement trap victims. Small insects such as mosquitoes or crane flies are common snacks, but larger insects including bees, butterflies, and other dragonflies or damselflies may be captured. There are reports of large dragonflies catching hummingbirds.

On a chilly day in February it’s nice to think about a warm summer day when a dragonfly might choose a dragonfly ornament to perch upon amongst zinnias in my flowerbed. But dragonflies are fierce predators. Watch as a dragonfly devours a damsel in extreme distress – damselfly that is.

An empty shed skin attached to a stem is all that remains of a dragonfly’s life underwater.

An empty shed skin attached to a stem is all that remains of a dragonfly’s life underwater.

Male dragonflies often patrol specific territories along ponds or streams on the lookout for food, potential mates, or other males. Other males entering a territory are pursued and driven away. Females are wooed and mating pairs of dragonflies are often seen flying in tandem. The male sometimes guards his mate while she deposits eggs in the water or on aquatic vegetation. Eggs hatch into fascinating submariners called nymphs. These beautiful swimmers live in ponds or streams obtaining oxygen from the water through gills found inside their anus. Muscular contractions allow the nymph to pump water in and out of its rear-end to breath. How curious!

Dragonfly nymphs capture many kinds of insects such as the larvae of aquatic beetles, midges, and mosquitoes. Yes, dragonfly nymphs are important predators that help hold mosquitoes at bay. Crustaceans, worms, tadpoles, and even small fish are fair game for these stealthy hunters. Dragonfly nymphs sit and wait for a potential meal to come near. When in range, a remarkable, hinged mouthpart snaps forward like a bullfrog’s tongue to ensnare the victim. Nymphs usually move about by crawling slowly. However, when startled or under attack, they expel a blast of water from their rear ends and are propelled forward like a jet. After molting several times and completing development, a nymph will climb out of the water and attach itself to a plant or stone. The nymphal skin splits and the adult dragonfly emerges. Once the exoskeleton has hardened, the daring aerialist will take wing to hunt, mate, and entertain lucky humans on a warm summer day.

The insect on the left with gills on its tail is a damselfly nymph. The insect more centered is a dragonfly nymph. Watch mosquito larvae disappear into the maw of the dragonfly nymph, captured by the lightning strike of the nymph’s hook-bearing mouth-parts. Clips at normal speed have been slowed by 85% to observe prey captures.

Acknowledgements  

We thank Bill Lamp for providing the gorgeous dragonfly nymphs featured in this bug of the Week. Information was gleaned from “An Introduction to the Study of Insects” by D.J. Borer, D.M. De Long, and C.A. Triplehorn, “Beginner’s Guide to Dragonflies” by B. Nikula, J. Sones, D. Stokes and L. Stokes, and “Eco-Friendly Control of Mosquito Larvae by Brachytron pratense Nymph” by S.N. Chatterjee, A. Ghosh, and G. Chandra. 

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Palm Tree Diseases, Fungus & Pests

Learn How to Defend Your Florida Landscape Against Palm Tree Damage

If there’s something homeowners in Southwest Florida love, it’s sunny skies and sculpted landscapes. But as many of us have discovered, these landscape trees and plants can be vulnerable to a host of nasty insects, fungi, bacteria, and viruses.

Fear not!

By understanding the multiple types of diseases, fungus, and pests that can damage palm trees, homeowners can create a tree care plan to protect their Florida lawns.

Top Palm Tree Diseases, Pests & Deficiencies

From the statuesque Washingtonia palm tree to the elegant Canary Island Date, over 200 species of palm trees can thrive in the sunny climate we’re accustomed to in Florida.

The Lawn Care Services team at Catseye Pest Control cares about your landscape, and we would like to help you keep an eye on your landscape investment. Here’s a few of the conditions you should look for, and if the worst should happen, we’ll be here to help.

Rugose Spiraling Whitefly ​

A relative newcomer to the area, the invasive rugose spiraling whitefly is a lawn pest that first appeared in Dade County, Florida in 2009.

Since that time, the insect has become a serious concern. While this pest is most commonly found on palm trees, especially coconut palm trees, they are not exclusive to palms.

Susceptible plants include the black olive tree, gumbo-limbo trees, avocado trees, and mango trees, as well as many other species of ornamental plants and trees.

In the early stages of the infestation, spirals of eggs can be seen on the underside of the leaves. As the population grows it will drain nutrients from the host producing honeydew. This insect byproduct falls on the leaves and ground around the plant and fosters the growth of a black mold. The mold is commonly known as black sooty mold, which quickly becomes visually apparent.

Lethal Bronzing Disease

Lethal bronzing was first discovered in South Florida in 2006. While this disease is similar to the Lethal Yellowing bacteria, it is not identical.

Early stages are only detectable by a sudden death of any fruit or flowers currently on the tree. A pruned palm tree without the flower or fruit pods will not show this symptom.

As the disease advances, the lower limbs will suddenly brown and die. In the final stage, the “spike” or newest frond at the crown of the tree will collapse.

Unfortunately, these are the symptoms of multiple ornamental grasses and palm tree diseases. So, diagnosis should be performed by a trained professional and confirmed via laboratory testing.

Once the presence of the bacteria has been confirmed the tree must be removed immediately and destroyed before the infection can spread. The only means of management of this disease is through preventative antibacterial injection. There are 16 palm trees currently known to be affected, a few of which include: 

  • Bismarck Palm
  • Buccaneer Palm
  • Cabbage Palm
  • Canary Island Date Palm
  • Carpentaria Palm

Palm Weevil ​Damage

The largest weevil in North America, the palm weevil is native to Florida. The insect was once known to only affect damaged or dying trees. In recent years, however, it has​ ​become a danger to mature and healthy palm trees.

This palm tree bug was once primarily associated with the native Floridian cabbage palm. Now Bismarck palms, Canary Island date palms, and latania palms are all at risk. In addition, several other species of palm trees are susceptible to palm weevil damage, but only while immature or recently transplanted.

palm weevil damaged brown palm tree in a group of green palm trees

Early detection of activity is essential. The early stages of infestation will show as an odd drooping of the older fronds. Once the palm weevil progresses past this stage, death of the tree is almost certain.

In the final stage of palm weevil damage, the head of the palm tree will collapse. This is known as popping the head.

Nutrient Deficiencies ​in Soil

The Florida climate is ideal for palm tree species from around the world, unfortunately we have one disadvantage that can be overlooked and misunderstood by those unfamiliar with our environment.

Sand!

Sand might feel great under your feet, but it is terrible as a soil for non-native plant life.

Making matters worse, foundations for new homes have been using what is commonly referred to as fill dirt for the past few decades.

Not only is this soil terrible in terms of nutritional value for plants and trees, it is almost always high in alkalinity which can drain nutrients from trees and prevent them from receiving certain vital nutrients necessary for their continued health and growth.

Nutrient deficiencies can build up over time and lead to stunted leaves and fronds, discoloration and yellowing, palm tree trunk damage, narrow trunk caliber, and can even lead to infection caused by palm tree fungus.

Severe deficiencies can cause extreme deformation of the crown, crownshaft collapse, trunk and frond necrosis, in addition to possibly losing the palm tree.

Stressed trees lacking nutrition are more susceptible to insect infestations as well.

Whether you are moving into a new home or have a well-established landscape, proper fertilization and lawn irrigation for your palm trees is essential to the landscape’s continued success.

Tree Care Program in Southwest Florida

Without a plan in place, an otherwise healthy and bug-free tree can quickly collapse and die. Often, the beginning signs of nutrient-deficient palms can go unnoticed. By the time the warning signs become obvious it’s too late for the tree.

At Catseye Pest Control, we have a team of trained horticulture professionals with years of experience ready to properly care for your trees.

Using state-of-the-art materials combined with tried and true methods and specially formulated nutrients, Catseye offers lawncare services that can give your Southwest Florida landscape and trees the longevity and beauty desired.

For more information about palm tree fungus, how we can protect your landscape, and for a free inspection, contact us today.

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Protecting Your Home & Surrounding Property from Shrews

Learn About Shrew Habitats & How to Protect Your Home from an Infestation

Shrews are small mammals with cylindrical bodies, short limbs, and are amongst the hundreds of species of insectivores. This classification also includes hedgehogs and golden moles.

Their bodies are covered in grayish brown fur, except for their tail, which is hairless. Shrews bear a similar resemblance to mice, with the exception of their long, pointed snout.

closeup of a gray and brown greater shrew with long brown whiskers and a pinkish-colored snout and rounded ears standing on broken twigs

Like other animals, their appearance can vary depending on the species.

Shrews range in size depending on their species, but even at their largest, shrews are quite small. The Northern short-tailed shrew, for example, averages 4 inches in length, including the tail.

Shrew Behavior

Some shrews are nocturnal, while other species of shrews are active during the day. With this in mind, it is not unlikely to encounter one during the day.

Those living in colder climates could enter a state of lethargy and decreased physical activity known as torpor. This is not quite the same as hibernation.

Shrews do not enter a full state of hibernation. Torpor refers to the shrew’s ability to reduce their body temperature. This strategy allows them to conserve energy during the colder months.

Shrews can reproduce approximately three times each year, though they tend to mate during the warmer months. The average gestation period lasts roughly 21 days and can result in a litter of five to 10 young.

With the exception of mating, shrews are solitary animals that tend to live and forage on their own. The rodent can be extremely territorial and aggressive towards other shrews, animals, or even people.

If a shrew has made a home for themselves in your home, garden, or shed, you should leave control and removal to wildlife professionals.

Where Do Shrews Live?

With more than 300 species of shrews, the rodent is found throughout the world — including parts of Florida, New York, Connecticut and other states.

Shrews commonly found in the United States include the least shrew, southern short-tailed shrew, and the northern short-tailed shrew.

Shrews can live in a variety of environments, depending on the species. But the rodent mostly prefers environments that offer plenty of ground coverage, so they are protected against predators.

Some shrews live underground in abandoned burrows, while others live in gardens, tree cavities, and even manmade structures like homes, sheds, or businesses.

Can Shrews Get in Your House?

As we’ve learned, shrews are quite small. Gaps in foundations, spaces between windows or doors and siding, openings around pipes or conduits can all act as points of entry for shrews.

Relatively speaking, shrews are not destructive. Most of the damage caused by shrews happens outside. Digging tunnels throughout your property and eating any vegetation they can get their paws on.

However, they can cause damage while in your home or business. This includes contaminating food with urine or dark-colored and corkscrew-shaped droppings. They can also leave a putrid smell throughout the building as they mark their territory.

And much like other rodents, shrews carry and spread diseases like hantavirus and babesiosis. This makes proper handling and removal from Catseye Pest Control’s rodent and wildlife control technicians essential.

How to Keep Shrews Out Permanently

Trapping and removing unwanted animal intruders is just one part of the process.

Once the critter is removed from your home or business, it’s important to put a long-term wildlife exclusion solution in place to prevent them from getting back inside.

Cat-Guard Exclusion Systems is an environmentally friendly permanent wildlife barrier that protects homes, businesses, and other structures from rodents and wildlife getting inside.

Catseye technicians have the knowledge and experience to safely remove wildlife and effectively protect your home or business from future shrew infestations.

To learn more about Cat-Guard and for a free inspection, contact us today.

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Walkin’ on water: Water striders, Gerridae

  What forces and clever adaptations enable water striders to literally walk on water?

What forces and clever adaptations enable water striders to literally walk on water?

 

Last week we visited whirligig beetles and learned their secrets of living at the intersection of water and air. This week we return to the water to visit another member of the neuston, the interesting community of organisms that spend their lives on or near the surface of water. Gerrids go by a number of colorful common names including water striders, pond skaters, and Jesus bugs owing to their remarkable ability to walk just a few millimeters above the water’s surface. One fine autumn afternoon along a gentle stream in the Blue Ridge Mountains I happened upon a nice collection of water striders scooting across the surface of a small pool. Water striders are predatory members of the true bug clan that includes terrestrial predators such as wheel bugs and spined soldier bugs we met in previous episodes. These aquatic predators dine on small insects and other arthropods, either living or dead, whose fortunes deposit them on the water’s surface. Powerful jaws are used to penetrate the exoskeleton of a victim while needle-like stylets inject proteolytic enzymes to
liquefy internal structures of the prey. A pump in the head of the water strider sucks the nutrient-rich liquid into the predator’s digestive tract. Yum.

The majority of water striders are denizens of fresh water but a few live in brackish waters or truly saline waters of the ocean. As a group, they have evolved remarkably clever strategies for dealing with the uncertainties of aquatic life. Those utilizing large permanent water sources like lakes may lack wings entirely and forgo the ability to fly, putting their bodily resources into reproduction rather than mobility. Others found in temporary water sources often have winged individuals capable of escaping vanishing pools and colonizing new water-filled ones.

Small dimples in the water caused by cohesion of water molecules beneath each of six widely spread
legs distribute the strider’s weight, enabling it to stand and zoom across the surface without sinking.

Perhaps the most interesting aspect of water strider life is the unique ability to walk on the water’s surface. Here’s how they do it. The body of the water strider is covered with thousands upon thousands of fine hairs. The larger of these dense hairs covering the body repel water, keeping the strider from becoming water-logged and sinking when splashed or submerged by a tiny wave or pelted by raindrops in a downpour. The real magic comes by way of tiny microhairs found at the tips of the water striders legs. These can number more than a thousand hairs per square millimeter. By distributing its weight across six legs, each with water repellent hairs, the water strider takes advantage of the cohesive force of water molecules. Water molecules
simply stick together due to the attraction of one charged molecule to another. This cohesion causes the water to form small depressions beneath each leg as it bears the weight of the insect. To move forward, the water strider shifts minute amounts of weight to one of the middle legs and then pushes against the back wall of the depression thereby propelling itself forward. By alternating movements of the middle legs, steering with the hind legs, and carefully distributing its weight among all legs, the strider walks on water. One can only imagine what fun could be had if we had skates or shoes to exploit the cohesive force of water molecules.   

Acknowledgements

Two wonderful references “Aquatic InsectEcology” by J.V. Ward and “Insect Ecology” by P.W. Price, R.F. Denno, M.D.Eubanks, D.L. Finke, and I. Kaplan were used to prepare this episode.  

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Why four eyes? Whirligig beetles, Gyrinidae

  Viewed from the side you can see compound eyes of the whirligig beetle, one looking up, another looking down. Two on the right and two on the left make four. But the question is why?

Viewed from the side you can see compound eyes of the whirligig beetle, one looking up, another looking down. Two on the right and two on the left make four. But the question is why?

 

Having crossed the optical threshold of unaided vision many years ago, I find having four eyes – that is, wearing glasses – to be incredibly useful, especially when trying to observe the antics of very small creatures like insects. In this week’s episode we meet a fascinating beetle with four eyes. No, it doesn’t wear glasses, although that would be pretty funny, but it really does have four eyes. Beetles in the family Gyrinidae, commonly known as whirligig beetles, live the life aquatic at the interface between the world of air and sunlight and the world of swirling water. The name whirligig stems from their habit of swimming rapidly and changing direction frequently, often in circular patterns.  Some observers comment that these beetles seem to gyrate on the water’s surface.

Life at the interface of two worlds, one of air and the other of water, presents interesting challenges. One challenge of course is the very different way light passes through water compared to its passage through air, and how this difference affects vision. Many of us have had the interesting experience of observing aquatic creatures underwater at an aquarium or through the lens of a dive mask. You’ve seen that objects appear significantly larger underwater than when viewed in air. This phenomenon results from water refracting or bending light as it moves through water, making objects appear about one third larger than they actually are. Imagine the dilemma of a surface dwelling insect faced with the prospects of attempting to keep an eye open for predatory fish lurking below while simultaneously monitoring for hungry birds ready to pounce from above. Whirligig beetle have a unique solution to this visual dilemma. They have evolved two unique sets of eyes, one pair gazing upward above the water’s surface, one downward-looking pair immersed in the water below.  

Sneaking up on a raft of whirligigs plying the gentle currents of the Gunpowder River, the beetles appear orderly and intent on holding their place in the current. But with a quick wave of my hand, whirligigs quickly shift into the swirling, dizzying, pandemonium from which they gain their name and possibly avoid the jaws of predators.

Upward-looking eyes are covered with a maze of incredibly tiny features called nanostructures that enhance their ability to sense wavelengths of light in the visual range. Downward-facing eyes that peer into the relative gloom below the surface lack these nanostructures. Separate nerve centers in the beetle’s tiny brain receive visual information from both pairs of eyes, integrate this information, and use it to hunt prey, find mates, and avoid predators. It is difficult for a binocular animal like me to even imagine what all of this must look like. Amazing!

The rapid, swirling movements of whirligigs are thought to help confound visually hunting predators. Whirligigs have yet another defense against their aquatic enemies, this one a nasty tasting chemical called gyrinidal produced by glands in their abdomen. When offered whirligig beetles as a snack, largemouth bass rejected them. Crazy swirly swimming, noxious chemical defenses, and four compound eyes, these are the special powers needed for whirligig beetles to survive at the interface of air and water.

Acknowledgements

Bug of the Week enjoyed “Secret Weapons” by Thomas Eisner, Maria Eisner, and Melody Siegler, and “Under- and over-water halves of Gyrinidae beetle eyes harbor different corneal nanocoatings providing adaptation to the water and air environments” by Artem Blagodatski, Michail Kryuchkov, Anton Sergeev, Andrey A. Klimov, Maxim R. Shcherbakov, Gennadiy A. Enin and Vladimir L. Katanaev, that provided the fascinating information for this episode.

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