Tag Archives: new species

The Scaly Crickets

by Joseph DeSisto

Among many new species named today, some of the most unusual were three new crickets from Southeast Asia (Tan et al. 2015). These crickets belong to the obscure and poorly-known family Mogoplistidae, cousins to the more recognizable (and audible) field crickets (Gryllidae). They look like field crickets too, except that their bodies are covered in scales.

A scaly cricket (Arachnocephalus vestitus). © Entomart.

A scaly cricket (Arachnocephalus vestitus). © Entomart.

When you touch a butterfly’s wings, you might notice a fine, powdery substance rubbing off on your fingers. The powder is made up of microscopic scales, which cover the wings of butterflies and moths. Scales give the wings their color, but they also provide insulation and protect the wings during flight. Perhaps most importantly, scales can fall off and make the wings slippery. This allows butterflies and moths to evade a careless hand as easily as a wet bar of soap.

The scientific name for butterflies and moths is Lepidoptera, which translates to “scaly wing” — scales are one of the most important features defining the group. However, many other groups of insects also have scales. Mosquitoes and silverfish have them, and so do scaly crickets.

The scales of a scaly cricket (Ornebius formosanus). Figure from Yang and Yen (2001), licensed under CC BY 2.0.

The scales of a scaly cricket (Ornebius formosanus). Figure from Yang and Yen (2001), licensed under CC BY 2.0.

Cricket scales, like those of butterflies and mosquitoes, are microscopic, powder-like, and easily shed. To really appreciate their beauty, a scanning electron microscope is needed. The first look came in 2001, when Yang and Yen published the first high-resolution images of cricket scales.

Aside from being scaly, scaly crickets aren’t all that unusual. They are adaptable, able to eat decaying plants as well as other insects, and they tend to live in moist sandy habitats. No scaly crickets are capable of flight, and females lack wings entirely, but the males do have small wings which they rub together to make chirping sounds (Love and Walker 1979). Click on the audio file below to listen to an amorous male scaly cricket (recorded by Thomas J. Walker).

Of the three new species, two were found in the Sakaerat Biosphere Reserve, in Thailand. This reserve consists mainly of high-altitude dry forest, with a few grasslands, and is home to many endangered species including tigers and giant black squirrels.

The third cricket is native to Pulau Ubin, an island off the coast of Singapore. Pulau Ubin is one of the last remaining wild areas in the already tiny country. Singapore’s government has been eager to develop portions of the island, but in recent years tourism has become more profitable. Fear of losing foreign visitors has encouraged officials to protect, rather than level, valuable habitat. For now, the status of the new scaly crickets appears secure, but in rapidly urbanizing Southeast Asia, nothing is certain.

A scaly cricket (Mogoplistes brunneus). © Entomart.

A scaly cricket (Mogoplistes brunneus). © Entomart.

Cited:

Love R.E. and T.J. Walker. 1979. Systematics and acoustic behavior of scaly crickets (Orthoptera: Gryllidae: Mogoplistinae) of eastern United States. Transactions of the American Entomological Society 105:

Tan M.K., P. Dawwrueng, and T. Artchawakom. 2015. Contribution to the taxonomy of scaly crickets (Orthoptera: Mogoplistidae: Mogoplistinae). Zootaxa 4032(4): 381-394.

Yang J. and F. Yen. 2001. Morphology and character evaluation of scales in scaly crickets (Orthoptera: Grylloidea: Mogoplistidae). Zoological Studies 40(3): 247-253.

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Saving the Easter Island Springtails

by Joseph DeSisto

By the time European settlers reached tiny Easter Island (Rapa Nui), far off the Pacific coast of Chile, it was already in ecological turmoil. The island had first been colonized by Polynesians as late as 1200 B.C.E. — their descendents comprise the Rapa Nui people, now the island’s indigenous population. They had at least 500 years before European colonization, and in that time the Rapa Nui people did great things — they constructed the world-renowned moai statues, for example:

Fifteen maoi -- on average, each of these is 13 feet tall and weighs 14 tons, but many are much larger. Photo by Ian Sewell, licensed under CC BY-SA 3.0.

Fifteen maoi — on average, each of these is 13 feet tall and weighs 14 tons, but many are much larger. Photo by Ian Sewell, licensed under CC BY-SA 3.0.

Despite the grandeur of the sometimes 30-foot-high moai, Easter Island already had its own wonders — the island was dominated by a species of palm tree, with trunks easily large enough to make a sea-faring canoe. That palm tree (Paschalococos disperta) existed only on Easter Island. I wish the picture below showed one of these trees, but that would be impossible — the Easter Island palm has been extinct for centuries. When European settlers arrived in 1722, the island was already almost completely deforested, with just a few pockets of forest left. Over the next few centuries, intensive sheep-grazing sealed the palm’s fate.

The Chilean wine palm (Jubaea chilensis) is the Easter Island palm's closest living relative. Photo by Scott Zona, licensed under CC BY 2.0.

The Chilean wine palm (Jubaea chilensis) is the extinct Easter Island palm’s closest living relative. Photo by Scott Zona, licensed under CC BY 2.0.

Today, the only evidence that palms ever existed on Easter Island come from petrified pollen grains and nut fragments (Flenley et al. 2006). The microscopic pollen grains are virtually indestructible and, in a cruel irony, have long outlasted the shepherds and, indeed, many of the moai themselves.

After such an environmental tragedy, it would be surprising to find any new species on Easter Island. And yet, even though every native vertebrate and many native plants have been driven to extinction, invertebrates that live exclusively on Easter Island continue to be discovered.

Just last week, biologists Taiti and Wynne (2015) published a survey of the woodlice (i.e., roly-polies) of the island, documenting two new species, one of which is only known from Easter Island. And that’s not all — a few months ago, five new springtails were introduced to science, unique to Easter Island (Bernard et al. 2015). Springtails are tiny, near-microscopic insect relatives that move by leaping extraordinary distances — if woodlice are the bumper-cars, then springtails are the bunnies of the micro-scape.

In profile: two new woodlouse species from Easter Island. Photo from Taiti and Wynne (2015), licensed under CC BY 3.0.

Two new cave-dwelling woodlouse species from Easter Island: Styloniscus manuvaka (left) and Hawaiioscia rapui (right). Photo from Taiti and Wynne (2015), licensed under CC BY 3.0.

So where are all these new species coming from? It turns out that even in such a desolate place as Easter Island, where almost all native wildlife and flora are gone, caves continue to provide a haven for undiscovered species (Wynne et al. 2014). All eight of these new species were found deep in caves, where humans have had less impact.

This is good news for those woodlice and springtails — now that we know they exist, perhaps we can keep them from following so many of their surface-dwelling brethren into extinction. After all, caves may be isolated, but they are not immune to our footprints. Keeping human traffic away from caves, and making sure the surrounding fern-moss habitat stays healthy, are both steps in the right direction (Wynne et al. 2014).

As a species, we have all but destroyed Easter Island’s fragile and unique ecosystems. Even so, in spite of our best efforts, a few native species, deep in the unexplored reaches of caves, persist. There is hope for them — and us — yet.

Cited:

Bernard E.C., F.N. Soto-Adames, and J.J. Wynne. 2015. Collembola of Rapa Nui (Easter Island) with descriptions of five endemic cave-restricted species. Zootaxa 3949(2): 239-267.

Flenley J.R., A.S.M. King, J. Jackson, C. Chew, J.T. Teller, and M.E. Prentice. 2006. The Late Quaternary vegetational and climatic history of Easter Island. Journal of Quaternary Science 6(2): 85-115.

Taiti S. and J. Wynne. 2015. The terrestrial Isopoda (Crustacea, Oniscidea) of Rapa Nui (Easter Island), with descriptions of two new species. ZooKeys 515: 27-49.

Wynne J.J., E.C. Bernard, F.G. Howarth, S. Sommer, F.N. Soto-Adames, S. Taiti, E.L. Mockford, M. Horrocks, L. Pakarati, and C. Pakarati-Hotus. 2014. Disturbance relicts in a rapidly changing world: The Rapa Nui (Easter Island) factor. BioScience 64: 711-718.

Easter Island’s Miniature Wonders of the World

by Joseph DeSisto

Easter Island, a tiny Pacific island more than 2,000 miles off the coast of Chile, is best known for its tremendous stone figures (moai). Hundreds of giant statues, erected by indigenous peoples before European settlers arrived, are scattered all over the island and serve as a major tourist attractions. However, Easter Island is unique not only for its enormous statues, but for its very tiny springtails: specifically, five newly described cave-dwelling species found nowhere else on earth (Bernard et al. 2015).

Fifteen maoi -- on average, each of these is 13 feet tall and weighs 14 tons, but many are much larger. Photo by Ian Sewell, licensed under CC BY 2.5.

Fifteen maoi — on average, each of these is 13 feet tall and weighs 14 tons, but many are much larger. Photo by Ian Sewell, licensed under CC BY 2.5.

Springtails (Collembola) are an ancient group of arthropods, distantly related to insects. They are all tiny, most no larger than a millimeter or so, but they are the most abundant organisms on the planet. This is especially so in soil, with estimates of more than 100,000 individuals per square meter (Ponge et al. 1997). Most springtails are detritivores, feeding on decaying plant matter, although with more than 3,600 described species there is plenty of room for diversity in lifestyle – a few species, for example, are predatory.

Prior to this study, the springtails of Easter Island had never been studied. In an attempt to target new, endemic, and possibly threatened species, Bernard and colleagues explored the caves of the island. They found eight cave-dwelling species of springtails in total. Of these, one was cosmopolitan, and another was known from Hawaii. The remaining six were all endemic to Easter Island, and five of those were new species.

A springtail, Orchesella cincta, from Belgium. Photo by Michel Vuijlsteke, licensed under CC BY-SA 3.0.

A springtail, Orchesella cincta, from Belgium. Photo by Michel Vuijlsteke, licensed under CC BY-SA 3.0.

The ecological history of Easter Island is a sad one. The island was never rich in natural resources to begin with, but when Polynesian settlers arrived and began cutting down forests, the result was ecological (and societal) collapse. When Europeans arrived in the 1800s, the indigenous population had gone through a major decline, and most of the forest was gone. For more than a century Europeans raised sheep on the island, whose grazing kept the forest from returning. Meanwhile, accidentally introduced rats took their toll on native biodiversity.

Today Easter Island is almost entirely grassland, and it is likely that many arthropods, once found nowhere else on earth, are now extinct due to habitat loss (Wynne et al. 2014). Caves are one of the last remaining strongholds for endemic biodiversity, but eventually they too may succumb to habitat destruction and invasive species. Bernard et al. publish descriptions of these five unique springtails not only to add to our understanding of springtail diversity, but also to call attention to the protection needed to preserve Easter Island’s smaller wonders.

Cited:

Bernard, E.C., Soto-Adames, F.N., and Wynne, J. 2015. Collembola of Rapa Nui (Easter Island) with descriptions of five endemic cave-restricted species. Zootaxa 3949(2): 239-267.

Ponge, J., Arpin, P., Sondag, F., and Delecour, F. 1997. Soil fauna and site assessment in beech stands of the Belgian Ardennes. Canadian Journal of Forestry Research 27(12): 2053-2064.

Wynne, J.J., Bernard, E.C., Howarth, F.G., Sommer, S., Soto-Adames, F.N., Taiti, S., Mockford, E.L., Horrocks, M., Pakarati, L. & Pakarati-Hotus, V. 2014. Disturbance relicts in a rapidly changing world: The Rapa Nui (Easter Island) factor. Bioscience 64: 711‒718.

Tiny Dragons in Bromeliad Pools

by Joseph DeSisto

In the last week, three amazing new Central American invertebrates were described, in two publications. These species, one dragonfly and two oligochaete worms, are interesting primarily because of where they were found: in the water-holding urn of bromeliad plants.

Bromeliads are flowering plants in the family Bromeliaceae, and include more than 3,000 mostly tropical species. The family includes such disparate species as the ground-dwelling pineapple (Ananas comosus) and the epiphytic Spanish “moss” (Tillandsia usneoides). Many epiphytic bromeliads, those species that live on the surfaces of trees, are shaped so as to hold pools of water between their leaves.

A water-holding bromeliad plant in the genus Werauhia. Photo by Dick Culbert, licensed under CC BY 2.0.

A water-holding bromeliad plant in the genus Werauhia. Photo by Dick Culbert, licensed under CC BY 2.0.

This makes them important components of the rainforest canopy community: although the rainforest floor may be perpetually moist, higher up the air dries, and permanent sources of standing water may be rare. As a result, many species dwell in the bromeliads’ urns, ranging from microscopic ostracods to salamanders, tree frogs, and even a species of Jamaican crab.

To this list Haber et al. (2015) add a new species of dragonfly, a member of the widespread family Libellulidae. Although adult dragonflies are aerial predators, their larvae are aquatic, and so their parents lay eggs in bromeliad pools. Of course, the larvae are themselves predatory, so what are they eating? Apparently, lots of other species live in bromeliad pools, including mosquito larvae, which provide the dragons with plenty to eat.

A second paper, Schmelz et al. (2015) includes a review of the microdrile oligochaete (tiny annelid) worms found in bromeliad pools in a Honduran cloud forest. It turns out that in this forest, at least six microscopic annelid worms are found in bromeliads, among them two new species in the family Enchytraeidae. This family also includes a variety of soil-dwelling species, which behave essentially like tiny earthworms, but in bromeliad pools they make their living by feeding on decaying plant matter that somehow makes its way into the water.

From worms and crabs to dragonflies and frogs, the miniature ecosystem is diverse and vibrant, and clearly there is much still to be discovered.

Cited:

Haber, W.A., D.L. Wagner, and C. de la Rosa. 2015. A new species of Erythrodiplax breeding in bromeliads in Costa Rica (Odonata: Libellulidae). Zootaxa 3947(3): 386-396.

Schmelz, R.M., M. Jocque, and R. Collado. 2015. Microdrile Oligochaeta in bromeliad pools of a Honduran cloud forest. Zootaxa 3947(4): 508-526.