Archive for the Grasshoppers & crickets Category

GRASSHOPPER LOVE

Posted in Arizona, Defense, Grasshoppers & crickets, Insects with tags , , , , , on September 15, 2010 by Dr. Art Evans

By Arthur V. Evans

Arguably the most spectacular looking and certainly among the most distinctive of all the grasshoppers in North America, painted grasshoppers, Dactylotum bicolor (24-32 mm) are a riot of color. These boldly marked orthopterans are also known as rainbow or barber-pole grasshoppers. Studies have shown that diurnal predators, especially birds, will avoid eating them presumably because of their aposematic coloration. Females tend to be significantly larger than the males.

Painted grasshoppers make their living along the western edge of the Great Plains from southern Saskatchewan south to western Texas and northern Mexico, and west to Arizona. Active from mid- to late summer, painted grasshoppers feed on a wide variety of desert plants, especially grasses and low broadleaf plants.

© 2010, A.V. Evans

BACKYARD MONSTERS? NOPE, JERUSALEM CRICKETS!

Posted in Grasshoppers & crickets, Insects with tags , , , , on March 29, 2010 by Dr. Art Evans

By Arthur V. Evans

Jerusalem crickets of the genus Stenopelmatus (Greek for “narrow foot”) are found in a variety of habitats throughout much of western North and Central America. This individual was photographed in Costa Rica. Their large, humanoid heads have inspired fear and superstition wherever they are found. However, they are not venomous and bite only when handled.

My first encounter with one of these giant, almost ant-like creatures occurred when I was about seven or eight years old and living on the fringes of the Mojave Desert in southern California. The inch-long insect had thread like antennae attached to an oversized head, a wingless narrow midsection armed with thick spiny legs and a fat abdomen distinctly banded in black and tan. I approached the animal cautiously, but closer inspection revealed that the insect was dead, frozen forever in a sprawling, lifelike pose. I carefully picked up the stiff corpse and presented it to my dad, who told me it was a Jerusalem cricket.

Resembling a cross between Jiminy Cricket and a Cootie, Jerusalem crickets – or JCs as they are fondly known by some – are impressive animals. Their large, round and naked heads are fitted with two small black eyes suggesting the head of a child. Jerusalem crickets are often the subject of fear and superstition and have been given a variety of monikers.

They have been dubbed Child of the Earth or Niña del la Tierra in Spanish. The Navajo thought them deadly poisonous and called them “wó se ts´inii,’ or the “skull insect” or “bone neck beetle.”  Their powerful jaws are used for digging and chewing roots. Jerusalem crickets can bite with considerable force if handled, but are not poisonous in any way. In California, JCs are known as potato bugs due to their predilection for nibbling on potatoes and other crops in direct contact with the soil. Extensive damage to crops and gardens by these insects is rare. They also occasionally scavenge dead animal matter and may engage in cannibalism. The name “Jerusalem cricket” is believed to have originated in the 19th century when ‘Jerusalem’ was a commonly used as an expletive. It is easy to imagine that unexpected encounters with these crickets could easily illicit such outbursts until the name eventually stuck!

Jerusalem crickets, including the genera: Ammopelmatus, Stenopelmatus and Viscainopelmatus, belong the family Stenopelmatidae and are related to crickets and katydids. They resemble the large king crickets of South Africa and the giant wetas of New Zealand, both of which are now classified in the family Anostotsmatidae.

From the "Dark Side of Entomology." California Academy of Sciences.

Jerusalem crickets are distributed throughout much of western North and Central America, where they live in almost every imaginable habitat from coastal and desert sand dunes to montane and tropical forests. Of the more than 100 species of JCs known, only about a third been formally described in the scientific literature. Most of the 60-80 species living in the western United States call California home.

The Kelso Jerusalem Cricket (Ammopelmatus kelsoensis), Point Conception Jerusalem Cricket (Ammopelmatus muwu) and Coachella Valley Jerusalem Cricket (Stenopelmatus cahuilaensis) are all restricted to coastal or desert dunes. These sandy habitats are under assault from developers, off-road vehicle use, and agricultural interests. The localized distribution and sensitivity to habitat disruption of these and other JCs require further study and may result federal or state protection.

Adult males are distinguished by a pair of small black hooks located between the cerci, a pair of short projections near the tip of the abdomen. Adult females have the short blades of their egg-laying tube or ovipositor located just beneath the cerci.

Sexually receptive males and virgin females drum their abdomens on the soil to attract species of their own kind. The drumming is audible nearly 60 feet away and is “heard” by special organs located near the bottom of each leg of the JC.

Courtship involves a bit of a tussle and sometimes resembles an energetic wrestling match as the male grapples for position. Eventually the male deposits a sperm packet, after which the female may kill and eat her mate. The function of the sperm packet in JCs is not understood. In other crickets and katydids the packet not only provides the female with reproductive materials and a nutritious snack, it also serves to block the amorous advances of other males.

Eggs are probably laid in small clutches in the soil soon after mating. They are oval and white with a roughened surface. In California, JCs reach adulthood during the summer. Small nymphs appear either by fall or early the following spring. Hatchlings resemble miniature adults and may take nearly two years to develop, while individuals experiencing nutritional deficiencies or parasitic infections may take up to five years. Nymphs may molt up to eleven times before reaching maturity. Like stick insects, JCs can regenerate legs lost during molting. In time, the new leg may approximate a normal leg in size, increasing in size with each successive molt.

Plump and juicy, JCs are an excellent potential food source for many animals. Bats, coyotes, foxes and owls prey them upon. It is not uncommon to find their droppings and pellets studded with the tough and distinctive remains of JCs mixed with the bones and fur of other animals.

Tachinid flies and horsehair worms attack and parasitize Jerusalem crickets. Dead JCs found in or near pools and streams are often infested with horsehair worms that must emerge from the body of the host and complete their life cycle in the water.

When threatened, JCs may suddenly kick out to brandish their thick spiny hind legs, menacingly raising them up over their body. Others will somersault on their backs, flailing their spiny legs forcefully in the air. Their mandibles are opened wide, capable of delivering a painful nip. Some species produce a scraping sound when agitated by scraping their legs against rough plates on the side of the abdomen. A few Mexican and Central American species are even capable of jumping when disturbed.

Jerusalem crickets are usually found under objects on the ground during the cooler, wetter months of the year. Trails of oatmeal left along paths will attract foraging crickets that will follow the food-laden path as they feed. Pitfall traps (cans or jars sunk in the ground so the opening is flush with the surface) baited with oatmeal will also attract hungry JCs.

Jerusalem crickets do well in captivity. Because of their cannibalistic tendencies they must kept in separate containers. Fill an eight-ounce margarine tub with damp, sterilized, fine-grained sand and cover with a lid punched with a few small holes. The containers must be kept cool since temperatures exceeding 70 ºF may not only be harmful to JCs, but also encourages the development of mites.  Humidity is critical. The substrate must be kept moist, but not wet, at all times.

Fresh slices of apple or potato offered every 7-10 days will not only provide your animals with nutrition, but also help maintain humidity. Add washed romaine lettuce and “old-fashioned” oatmeal. Jerusalem crickets will also eat bread, grass roots and a variety of vegetables. Supplement their weekly feedings with bits of raw meat or soft-bodied insects such as greater wax moth larvae (Galleria melonella). Remove uneaten food items after a few days to prevent the growth of potentially harmful molds.

Both immature and adult JCs have been kept successfully in captivity, but reports on egg-laying have never been published. In the wild, eggs are probably laid well below the surface so they are not subjected to freezing temperatures.

Nymphs molt on their backs with the old exoskeleton positioned behind them. After molting is complete, the JC will right itself and eat the caste, recycling vital minerals needed for the development of the new exoskeleton.

Throughout the western United States JCs are familiar, yet exotic, insects. In spite of their secretive nature, they still make unusual and interesting pets, even if kept only for a short period. Much remains to be learned about these incredible animals. Carefully recorded observations of your captive JCs may help to reveal their mysterious lives.

References

Field, L.H. (editor). 2001. The biology of wetas, king crickets, and their allies. CABI Publishing. Wellingford, UK.

Poinar, G. and D.B. Weissman. 2004. Horsehair worms and nematode infections of North America Jerusalem crickets, field crickets, and katydids (Orthoptera: Stenopelmatidae, Gryllidae, and Tettigoniidae). Journal of Orthoptera Research 13(1): 143-147.

Weissman, D. 2005. Jerusalem? Cricket! (Orthoptera: Stenopelmatidae: Stenopelmatus); origins of a common name. American Entomologist 51(3): 138-139)

Weissman, D. The dark side of entomology. http://www.calacademy.org/science_now/archive/where_in_the_world/jerusalem_crickets.php (accessed 16 March 2011)

© 2010, A.V. Evans

INSECTS BRING OUT THE INNER CHILD

Posted in Beetles, Education, Grasshoppers & crickets, Insects, Musings, Virginia with tags , on March 18, 2010 by Dr. Art Evans

By Arthur V. Evans

Two wars, recession, earthquakes, and the seemingly endless wrangling of politicians—the news has not been very good lately. These combined with the usual everyday stuff makes it all too easy to get bogged down wondering where the world is headed. But occasionally, I am afforded a welcome change of perspective—that of seeing the world once again through the eyes of a child.

The author at the tender age of 14, or thereabouts, enjoying a summer day on a family camping trip somewhere in California's Sierra Nevada.

I was given this fresh viewpoint awhile back at the grand opening at the new Children’s Garden at the Lewis Ginter Botanical Garden in Richmond, Virginia. The garden is a microcosm of landscapes, plant adaptations, and human-plant interactions. A boardwalk accessible to all winds through various mini environments on its way to the Leafy Overlook and Tree House, introducing visitors to coniferous forests, deciduous woodlands, grasslands, and a butterfly meadow.

Also included is an International Village with Lilliputian playhouses depicting different cultures to demonstrate how people around the world use plants for food, materials, and medicine. As the garden matures, it will continue to be a haven for young naturalists and their families to explore plant diversity with its creeping vines, prickly plants, and inviting blooms, both sweet-smelling and otherwise.

It is also a great place for bug watching. That’s where I came in. I was invited to participate in the grand opening of the Children’s Garden as entomologist Dr. Art Evans, “the bug guy.” My task was to engage garden visitors in a series of bug talks and walks. My display was simple, consisting of a collection of local insects and a variety of popular identification guides for the region, as well as copies of my own magazine and newspaper writings on insects and spiders.

Families flocked around the display, amazed at the local insect diversity. Soon I was peppered with all kinds of questions. “Are they real?” “What is this?” “Does it bite?” “What does it do?” “What do they eat?” “Are they really found around here?”

Within just minutes, my world-weariness melted away. I was once again caught up in the excitement of my audience’s infectious enthusiasm for insects. After meeting with dozens of parents and their children, it dawned on me that there are two types people in this world: those that love insects and those that don’t yet know they love insects.

After answering some questions, I briefly introduced myself to the audience, and talked about some of the things that entomologists do in the world. Then we covered some bug basics, like their number of legs (6), body regions (3), and metamorphosis. Also discussed was how insects differ from other kinds of common garden animals such as spiders (8 legs, 2 body regions), worms (no segmented appendages), and slugs (no external skeleton or appendages).

The best part of the day was the bug walk. It was like going on safari. As we searched for tiny game, our goal was not to collect or kill, but to observe and marvel. The weather was overcast and decidedly cooler from the previous day when I had done my reconnoitering for bug hot spots at the garden. Still, there was plenty of insect hubbub about the flowering plants.

Bumblebees, soldier beetles, thread-wasted wasps, and various kinds of butterflies, skippers and moths clambered over the spikes of small yellow flowers as if they knew that fall had arrived and that warm and sunny days were now numbered. Both adults and youngsters peered into the blooms to admire the diversity and activity of this energetic, winged, and multi-legged assemblage. It was a great demonstration of how both plants and insects depend on one another for their very existence.

Nearby, black swallowtail caterpillars nibbled away on a lone fennel plant beneath the dining room window of the Bloemendaal house. We were all being treated to the fact that eating is job one for growing caterpillars of all stripes. Soon, they would all disappear as quickly as they appeared and transform twice more into entirely different creatures with no resemblance whatsoever to their current state.

The shrubs and low hedges were filled with the songs of amorous male crickets and meadow katydids, all scraping their wings together to produce characteristic chirps, clicks, and rasps to attract a mate.  In just a matter of yards we found more species of insects and spiders than could be found of mammals, birds, or reptiles in the entire garden!

This fabulous hands-on experience reminded me once again of why I got into this field in the first place. Sure, insects, spiders and their relatives are everywhere and are endlessly fascinating in their ways, fueling lifetimes of scientific research and popular writing projects. But I have come to understand that my attraction to all things insect is really about my desire to learn as much as possible of the world around me. I truly believe that the desire to learn is a very basic human need; the day we stop learning is the day we start dying.

To see the natural world through the eyes of children, or adults who have not lost their childlike sense of wonder and awe, is truly a gift. For me, it is a clear reminder of my own wonder and excitement that sparked my lifelong interest in insects nearly 50 years ago. I am confident in my knowledge that there are still plenty of insects and spiders out there to see, learn, and do for at least another 50 years.

The author, down and dirty on his knees at Virginia Beach in 2007, searching for false soldier beetles (Oedemeridae) under driftwood.

One of the great things about being a biologist is that we always get to keep a part of our childhood with us while we conduct fieldwork. It is part and parcel of our various job descriptions to wonder how things work as we get down and dirty on our hands and knees to rake through the soil, muck about in the mud, or slosh around in creeks and ponds. Now I ask you, what could be better than that?

© 2010, A.V. Evans

WHAT’S IN YOUR BASEMENT?

Posted in Environment, Grasshoppers & crickets, Insects with tags , , on March 9, 2010 by Dr. Art Evans

By Arthur V. Evans

While moving some bags of potting soil on the front porch a few years back, I discovered a gathering of variously sized leggy and very nervous creatures. Their pale bodies, not quite reaching an inch in length, appeared to be brown banded, supported by long legs mottled with patches of gray and rust. Their long, hair-like antennae waved nervously about as I knelt down for a closer look. At first glance, they looked decidedly spidery in appearance. They scampered easily up, over, and around vertical surfaces of concrete, brick, and paneling and quickly disappeared into the nearby shrubbery. I had stumbled upon a congregation of camel crickets popularly known as greenhouse stone crickets, Diestrammena asynamora.

This handsome greenhouse stone cricket, Diestrammena asynamora, was photographed in my basement last fall. Our cats seem to thoroughly enjoy them and frequently leave maimed cricket bodies in conspicuous places around the house.

Greenhouse stone crickets are distinguished from other camel crickets in eastern North America by their decided preference for urban surroundings and a pair of small, closely set horns located between the bases of the antennae. Their long antennae—which may exceed three-times the body length—combined with long legs, may fool some people into thinking that they are spiders. In fact, some people call them “spider crickets.”

Their powerful jumping legs can launch them up to four feet in the air. Mature females have a long, swordlike egg-laying tube, or ovipositor that they use to deposit several hundred eggs in the soil in spring. The eggs take about two or three months to hatch. The young, wingless crickets strongly resemble the adults but are smaller in size. Once mature, the adults live for about a year. Greenhouse stone crickets overwinter as either nymphs or adults.

Greenhouse stone crickets belong to the family Rhaphidophoridae. Raphidophorids are commonly known as camel crickets because of their hump-backed appearance. They are also called cave crickets because they are often found living in and around the entrances of caves. However, they are equally at home in crevices, hollow trees, and basements, or under logs and stones. Strictly nocturnal, greenhouse stone crickets venture out during the day only when disturbed. Without wings or other sound-producing structures, these crickets never contribute to the evening chorus. However, some camel crickets are thought to drum their abdomens on the substrate in an effort to attract mates.

Some of the 200 or so species of camel and cave crickets known to occur in North America originally hail from other parts of the world. An immigrant from China, the greenhouse stone cricket first became established in the warm, moist greenhouses throughout much of Europe and North America, and is now cosmopolitan.

During heavy rains, or hot, dry days, greenhouse stone crickets will invade garages, sheds, and basements, often assembling by the dozens or hundreds. Indoors, the crickets are attracted to dark, humid spaces, such as those afforded by bathrooms and laundry rooms. Clothing and linens stored in these areas may be damaged if persistent populations of these crickets cannot find suitable plant food nearby.

Outdoors, they are commonly found on the ground, beneath stones and logs, or in piles of firewood. Areas overgrown with ivy and other ground covers provide excellent hiding places for them. Greenhouse stone crickets feed on living plants and small insects. In greenhouses, these crickets will eagerly consume seedling, flowers, seeds, or young leaves, but they seldom cause serious damage to plants. They will also scavenge other plant and animal materials.

As you read this, you can take comfort in the fact that right now, somewhere in the bowels of  your basement or elsewhere on your property, these sociable creatures are quietly taking refuge. Whether we like it or not, our steady supplies of food and water, served up in artificially warmed environments, have made it possible for these curious creatures to become a regular part of our lives.

©2010, A.V. Evans

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