Tag: Neotropics

Cave fights for food: voracious spiders vs assassin bugs

Killing and eating of potential competitors has rarely been documented in the zoological literature, even though this type of interaction can affect population dynamics. In a recent publication in the open-access journal Subterranean Biology, Brazilian scientists presented their notes regarding the predation of an assassin bug by a spider in Neotropical caves. Underground, where food resources are scarce, such events might be possible as a result of ecological pressures imposed by the hostile environment, hypothesise the researchers.

Killing and eating of potential competitors, also known as intraguild predation, is a rare event that occurs only in specific situations such as severe scarcity of food resources, resulting in the competition between predators.

A recent paper in the open-access journal Subterranean Biology examines the case of a wandering spider species (Enoploctenus cyclotorax) seen to prey upon assassin bugs (Zelurus diasi) in a limestone cave in Brazil.

Even though such type of ecological interaction is uncommon, it is potentially important since it may decrease the competition between apex predators and thus, affect their population dynamics. Zelurus and Enoploctenus are voracious predators with a wide distribution in caves and epigean environment. Both of them have similar diets. In normal conditions, spiders reject assassin bugs as potential prey, so intraguild predation cases occur only in very specific situations.

From the perspective of the participants, intraguild predation is a dangerous strategy because the prey is also a predator, armed and capable to kill. However, in caves, this could be a very useful behaviour since food resources are scarce and have low density.

“This may be an important factor, maintaining the species in that challenging environment”, concludes lead author of the study Dr. Leopoldo Ferreira de Oliveira Bernardi.

The scientists suggest that probably prey scarcity has left little choice for spiders, and that’s why they ended up using unconventional type of prey in their diet.

Intraguild predation between female Enoploctenus cyclotorax and adult Zelurus diasi observed during the study.
Credit: Leopoldo Ferreira de Oliveira Bernardi
License: CC-BY 4.0

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Original source:

Bernardi LFO, Sperandei VF, Audino LD, Sena CH, Alves JA (2020) Notes on the predation of an assassin bug by a spider in a Neotropical cave. Subterranean Biology 33: 17-22. https://doi.org/10.3897/subtbiol.33.48292

Total of 21 new parasitoid wasps following the first ever revision of their genus

As many as twenty-one species of parasitoid wasps are described as new to science, following the first ever revision of their genus since its establishment back in 1893.

The study simultaneously updates the count of species within the genus (Chromoteleia) to 27 in total, produces a systematic revision of the world’s representatives of this group of wasps, expands their biogeographic knowledge, and clarifies their generic concept.

The monograph is published in the open access journal ZooKeys by a team of US and Canadian scientists, led by Hua-yan Chen, graduate student at the Ohio State University.

The wasps in the genus Chromoteleia are easily distinguished thanks to their large size in combination with their vivid colouration. Compared to other species in the family of platygastrid wasps, which normally measure merely 1 – 2 mm in length, the species in the studied genus range between 3 and 9 mm. Their uncommonly large, robust and elongated bodies is why the scientists assume that these wasps likely parasitise the eggs of orthopterans, such as grasshoppers, crickets and katydids.

A focal point in the study is the intriguing distribution of the wasps. While the genus is widespread throughout continental Mesoamerica, Central America and South America, and its distribution ranges from the Mexican state of Jalisco in the north all the way to Itapúa Department in Paraguay and Paraná in southern Brazil, the species C. congoana is a lone representative of the genus in Africa.

*The ‘lone’ African representative of the genus, Chromoteleia congoana.*

While dispersal from South America to Africa has been observed in the past in another genus of parasitoid wasps (Kapala), the scientists are not willing to reject the possibility of Chromoteleia wasps having been widely distributed across the Old World during a previous geological epoch. Such phenomenon, also known as a relict population, would not mean that the wasp group has subsequently ‘conquered’ the Neotropics and current species inhabiting the New World are rather remainders of once widespread insects.

To conclude their findings, the scientists examined specimens hosted in collections at twenty natural history institutions from around the globe, including the American Entomological Institute; American Museum of Natural History; Bernice P. Bishop Museum; California Academy of Sciences; Canadian National Collection of Insects; California State Collection of Arthropods; Florida State Collection of Arthropods; Instituto Alexander von Humboldt; Illinois Natural History Survey; Kansas University’s Natural History Museum; Museo del Instituto de Museo del Instituto de Zoologia Agricola; Museum National d’Histoire Naturelle; Museu Paraense Emílio Goeldi; Lund Museum of Zoology at Lund University; Triplehorn Insect Collection at the Ohio State University; South African Museum; Texas A&M University’s Insect Collection; Bohart Museum of Entomology; University of Colorado; and Smithsonian National Museum of Natural History.

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Original source:

Chen H-y, Talamas EJ, Valerio AA, Masner L, Johnson NF (2018) Revision of the World species of the genus Chromoteleia Ashmead (Hymenoptera, Platygastridae, Scelioninae). ZooKeys 778: 1-95. https://doi.org/10.3897/zookeys.778.25775

New species of frog from the Neotropics carries its heart on its skin

In the Neotropics, there is a whole group of so-called glassfrogs that amaze with their transparent skin covering their bellies and showing their organs underneath. A recently discovered new species from Amazonian Ecuador, however, goes a step further to fully expose its heart thanks to the transparent skin stretching all over its chest as well as tummy.

The new amphibian is described by a team of scientists led by Dr. Juan M. Guayasamin, Universidad San Francisco de Quito, Ecuador, in the open access journal ZooKeys.

It can also be distinguished by the relatively large dark green spots at the back of its head and the foremost part of the body. Additionally, the species has a characteristic long call.

The new frog is named Hyalinobatrachium yaku, where the species name (yaku) translates to ‘water’ in the local language Kichwa. Water and, more specifically, slow-flowing streams are crucial for the reproduction of all known glassfrogs.

The reproductive behaviour is also quite unusual in this species. Males are often reported to call from the underside of leaves and look after the egg clutches.

Having identified individuals of the new species at three localities, the researchers note some behavioural differences between the populations. Two of them, spotted in the riverine vegetation of an intact forest in Kallana, have been calling from the underside of leaves a few metres above slow-flowing, relatively narrow and shallow streams. Another frog of the species has been observed in an area covered by secondary forests in the Ecuadorian village of Ahuano. Similarly, the amphibian was found on the underside of a leaf one metre above a slow-flowing, narrow and shallow stream.

However, at the third locality – a disturbed secondary forest in San José de Payamino – the studied frogs have been perching on leaves of small shrubs, ferns, and grasses some 30 to 150 cm above the ground. Surprisingly, each of them has been at a distance greater than 30 metres from the nearest stream.

The researchers note that, given the geographic distance of approximately 110 km between the localities where the new species has been found, it is likely that the new species has a broader distribution, including areas in neighbouring Peru.

The uncertainty about its distributional range comes from a number of reasons. Firstly, the species’ tiny size of about 2 cm makes it tough to spot from underneath the leaves. Then, even if specimens of the species have been previously collected, they would be almost impossible to identify from museum collection, as many of the characteristic traits, such as the dark green marks, are getting lost after preservation. This is why the conservation status of the species has been listed as Data Deficient, according to the IUCN Red List criteria.

Nevertheless, the scientists identify the major threats to the species, including oil extraction in the region and the related water pollution, road development, habitat degradation and isolation.

“Glassfrogs presumably require continuous tracts of forest to interact with nearby populations, and roads potentially act as barriers to dispersal for transient individuals,” explain the authors.

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Original source:

Guayasamin JM, Cisneros-Heredia DF, Maynard RJ, Lynch RL, Culebras J, Hamilton PS (2017) A marvelous new glassfrog (Centrolenidae, Hyalinobatrachium) from Amazonian Ecuador. ZooKeys 673: 1-20. https://doi.org/10.3897/zookeys.673.12108

Of Star Trek, Mark Twain and helmets: 15 new species of wasps with curious names

A total of fifteen new species of parasitic wasps have been described from across the Neotropical region. Apart from belonging to a peculiar group of wasps distinct with large and elongated bodies, the new insects also draw attention with the curious names they have been formally assigned with.

Among them, there are species named after characters from the television series Star Trek and Mark Twain’s The Prince and the Pauper, and five wasps bearing species names all translating to ‘helmet’. The study, conducted by graduate student Katherine C. Nesheim and Dr. Norman F. Johnson, both affiliated with the Ohio State University, USA, and Dr. Lubomír Masner, Agriculture and Agri-Food Canada, is published in the open access journal ZooKeys.

The larvae of the studied wasps parasitise the eggs of lanternflies and planthoppers. These species inhabit exclusively the Neotropical region, with their range stretching from the Isthmus of Tehuantepec in the north to Misiones in southern Paraguay. Despite being quite abundant in the region, these insects have remained under-researched until recently.

One of the newly discovered wasp is named Phanuromyia odo, where the species name odo refers to the Star Trek: Deep Space Nine fictional character of the same name. In the popular sci-fi television series, Odo belongs to a species of shapeshifters called Changelings. The reason for the scientists to associate the parasitoid with the character is the spectacular variability observed within the insect species. In fact, it was this peculiarity that, at some point, led the entomologists believe they were dealing with two separate species.

The authors do not make a clear statement that the new species P. pauper has a name inspired by the famous novel The Prince and the Pauper by Mark Twain. Instead, they justify their choice with the fact that the species lacks a specific morphological feature – thus making it ‘poor’. On the other hand, the authors confirm that the new species called P. princeps is of ‘blue blood’ indeed, having its name derive from the other main character of the same book. Furthermore, both species are reported to look a lot like each other.

Among the curious names in the list of new species, there are also five wasps whose scientific names all translate to ‘helmet’ in three different languages – Greek, Latin and Old Norse. The reason behind is that they have unusually large heads, which reminded the scientists of a “knight wearing a helmet”. Likewise, a related species received a name that in Latin means ‘wearing a hood’.

There is also a species, whose name means ‘having long hair’, and another called ‘constellation’ in Latin.

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Original source:

Nesheim KC, Masner L, Johnson NF (2017) The Phanuromyia galeata species group (Hymenoptera, Platygastridae, Telenominae): shining a lantern into an unexplored corner of Neotropical diversity. ZooKeys 663: 71-105. https://doi.org/10.3897/zookeys.663.11554

Get to know them faster: Alternative time-efficient way to describe new moth species

Having collected thousands of moth and butterfly species from across Costa Rica, famous ecologist Daniel Janzen, University of Pennsylvania, and his team were yet to find out many of their names. When they sought help from Dr. Gunnar Brehm, the taxonomist realised he needed too much time to describe species in the framework of an extensive revision of the genus, especially as there are still only a few biologists skilled to do this.

In the end, he found a way to revise the Neotropical looper moth genus Hagnagorafast and efficiently through avoiding wordy descriptions, but focusing on diagnostic characters, illustrated external characters, genitalia structures and DNA barcoding instead. His study is available in the open-access journal ZooKeys.

Having been put together back in the 19th century, most of the species within the Neotropical moth genus Hagnagora had been described by 1913. In modern days, it seemed necessary for the taxon to be revised. As a result, Dr. Gunnar Brehm herein publishes a “concise revision” comprising twenty species. It includes two species that have been revived from synonymy, two subspecies reinstated to a species level, four species excluded from the genus and the description of three new to science. In honour of the people who had funded the research, the new species have been named after them.

Following the revision, the research concludes not only the DNA molecules divergence between the separate species, but some subtle differences such as size, form of the wing blotches or the shape of the male genitalia.

Curious characteristic behaviour traits have also been noted within the genus. The representatives of the discussed genus fold their wings vertically while resting just like most butterflies and unlike the majority of related geometrid moths. Similarly, three of the revised species were noticed to be active during the day when they would often perch on moist substances like rotting plants, mud or dung, from whose fluids they would find vital nutrients.

The author stresses on the fact that taxonomists can hardly keep up with the pace inventories are being compiled, nor with the accelerating destruction of tropical rainforests. “Taxonomists therefore need to accelerate their workflows and try to make their papers useful not only to other taxonomists but for ecologists who need their support”, Dr. Gunnar Brehm says.

“What used to be one species ten years ago, known as Hagnagora anicata, is now regarded as a complex of six species, and more might be discovered in South American rain forests”, Brehm says. “Integrating information of molecules and morphology, as concisely as possible, appears to be one promising way to cope with the problem of slow taxonomy”, he explains in conclusion.

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Original source:

Brehm G (2015) Three new species of Hagnagora Druce, 1885 (Lepidoptera, Geometridae, Larentiinae) from Ecuador and Costa Rica and a concise revision of the genus. ZooKeys 537: 131-156. doi: 10.3897/zookeys.537.6090

Black mouse-eared bat goes green: First case of a fruit-eating bat in the largest genus

Out of more than 110 allegedly well-studied mouse-eared bat species, there turns out to be one that has been keeping its diet a mystery. Belonging to the largest group of bats, known to be feeding on insects exclusively, the widely common Black mouse-eared bat (Myotis nigricans) is found to also seek fruits. The Brazilian team of researchers, led by biologist Roberto Leonan Morim Novaes, Fiocruz, conducted their work in the Rio de Janeiro’s reserve Reserva Ecologica de Guapiacu (REGUA), a 5,500 ha remnant of Atlantic Forest, and have their findings and discussion published in the open-access Biodiversity Data Journal.

The unexpected first documentation of fruit consumption in this group of bats happened when the researchers captured a number of bats with mist-nets and kept them alone in cotton bags for about thirty minutes before handling for identification and biometry. Thus, they managed to retrieve feces of the specimens, which showed to contain small seeds. Later, in an experiment, part of the seeds even grew into seedlings. As a result, the scientists report the first fruit consumption within the mouse-eared bat genus, called Myotis, as well as the whole subfamily Myotinae. Their finding might also mean that the examined species plays the ecological role of a seed disperser.

Although the finding is based on a single specimen of Black mouse-eared bat, the researchers reject the possibility of the cotton bags having been previously contaminated with feces of other animals. Dismissed is also the chance of the seeds having been consumed on accident while predation, since the Black mouse-eared bat hunts insects during flight.

Overall, bats are remarkable because of their varied eating habits. Commonly eating insects, there are predatory groups specialised in feeding on other invertebrates, terrestrial vertebrates, fishes or blood. Among the plant-eating, there are those specialised in fruits, flowers or leaves. A few are classified as omnivores and yet few, which are known to be using one category of food exclusively, on rare occasions include an untypical food item to compliment their diet. For example, a carnivorous bat may sporadically consume a plant and vice versa.

“The discovery of a well-studied species, previously considered strictly insectivorous, foraging on fruits shows how little we know about the biology and natural history of Neotropical bats,” conclude the authors.

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Original source:

Novaes R, Souza R, Ribeiro E, Siqueira A, Greco A, Moratelli R (2015) First evidence of frugivory in Myotis(Chiroptera, Vespertilionidae, Myotinae). Biodiversity Data Journal 3: e6841. doi:10.3897/BDJ.3.e6841