Category: Uncategorized

Call for arms and stings: Social wasps use alarm pheromones to coordinate their attacks

Humans might know them as vicious stingers, but yellow jacket wasps also impress with their vigorous protection over their young. To resolve the mystery around their complex defensive behavior, a Canadian research team, led by Dr. Sean McCann, Simon Fraser University, have used simple components to develop and construct a device that consequently helped them to locate the species-specific alarm pheromones in three wasp groups. The insects use the emission of these substances to mark the enemy threatening their colonies and then join forces against it. The study is published in the open-access Journal of Hymenoptera Research.

Social insects invest a lot of work and resources in their colonies, working together to raise large numbers of larvae. Because their nests contain so many protein-rich, yet helpless young, they have evolved elaborate defence mechanisms to protect them.

One way the social wasps have found to increase the efficiency of their defence is through chemical signals, called alarm pheromones, which are used to rouse the colony to action and mark intruders for attack. As a result, the coordinated attack of a large colony of yellow jackets can drive even large predators away from the nest. Several social wasp alarm pheromones have been discovered, and most of these have been detected in the venom sacs of the wasps. Nonetheless, the process of finding out which chemicals are involved requires many experiments in the field in addition to chemical analysis.

“We developed a new and standardized method to evaluate alarm pheromone activity in yellowjackets and other social wasps that is inexpensive and easy to use. The device we constructed uses off-the-shelf components, and consists of a pair of black targets enclosing a pair of microphones,” explain the authors.

“A test substance and a control can be applied to each target, and then a stereo audio file is recorded at the nest site,” they further comment. “When wasps hit the black targets, it makes a percussive sound, almost like a drum. The resulting stereo file is then split and analysed with an open-source software program to count the number of strikes received by the treatment and control targets.”

The advantage of this system is its ease of use, low cost, and the ability to use rapid automated counting, which saves a lot of time compared to other methods.

The scientist have used this new method to figure whether three species of yellow jackets (the western yellow jacket, the common yellow jacket and the German yellow jacket) have alarm pheromones, and whether each species is able to recognize each of the alarm pheromones of the rest.

“We found evidence for alarm pheromones in all three species, and that each species recognizes and responds to the other species’ alarm pheromones in similar ways,” say the researchers. “We conclude that the chemical messages produced by these three yellow jacket species must be very similar.”

“It makes sense that wasps can recognize the alarm pheromones of other species, because it would be advantageous to be able to detect a pheromone-marked predator that has attacked other wasps nearby and start stinging it to drive it away before it finds their own colony,” conclude the authors.

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Original source:

McCann S, Moeri O, Jimenez SI, Scott C, Gries G (2015) Developing a paired-target apparatus for quantitative testing of nest defense behavior by vespine wasps in response to con- or heterospecific nest defense pheromones. Journal of Hymenoptera Research 46: 151-163. doi: 10.3897/JHR.46.6585.

Guardian ants: How far does the protection of a plant-ant species to its specific host go?

Seemingly helpless against their much more lively natural enemies, plants have actually come up with a wide range of defences. In the present research, published in the open-access Journal of Hymenoptera Research, Dr. Adriana Sanchez, Universidad del Rosario, Colombia, and Edwin Bellota, Texas A&M University, USA, focus on the mutualistic relationship developed between a specific Neotropical knotweed and an ant species. During a series of ant-exclusion experiments the scientists observed and subsequently reported an aggressive and highly protective behaviour.

In order to assess the extent of protection these plant-ants provide their exclusive host with, the researchers compared the percentage of herbivory between control plants and experimental ones, which had their resident ants removed. The unambiguous results showed a 15-fold increase in the herbivory in the latter group, which kept on growing even further as the time progressed.

Normally, the studied ants patrol their hosts during both day and night at temperatures sometimes as low as 13C. Every time they found a herbivore, they were seen to attack it aggressively by biting and stinging.

“When an ant encountered a caterpillar, a worker approached and detected it with its antennae, and then recruited more workers. Typically more than 10 workers were recruited around the intruder in less than five minutes,” shared their observations the researchers. “Several workers harassed the herbivore by stinging or biting, until it dropped off the plant. The caterpillars usually hung by a silk thread and attempted to move back onto the plant. However, individuals of Pseudomyrmex continued to chase them until they dropped again. This cycle was repeated several times.”

While patrolling, they were noticed to remove any found debris from the top of the leaves. When they failed to find any signs of mosses, fungi or lichens on the sampled saplings, the scientists suggested that the ants not only protect their host from herbivores, but also from various disease-causing agents.

Plant vitality, growth and reproduction are seriously threatened by herbivores such as, in the case of the hereby studied knotweed, Triplaris americana, caterpillars and grasshoppers. Fighting for their life, plants use structural defenses, toxins, digestibility-reducing compounds, or mutualistic relationship with the enemies of their herbivores.

The herein researched Neotropical plant have found its way of survival through becoming the only host to the ant species Pseudomyrmex dendroicus, characterised with remarkable eyes, light brown body and potent venom, injected through a well-developed sting. In its turn, the knotweed shelters their entire colony in its hollow stems while another symbiont, scale insects, feeds them with the sugary sticky liquid it secrets on digesting plant sap.

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Original source:

Sanchez A, Bellota E (2015) Protection against herbivory in the mutualism betweenPseudomyrmex dendroicus (Formicidae) and Triplaris americana(Polygonaceae). Journal of Hymenoptera Research 46: 71-83. doi: 10.3897/JHR.46.5518.

Rare Amazonian butterfly named after British national treasure Sir David Attenborough

A beautiful new Black-eyed Satyr species has become the first butterfly named in honour of the popular naturalist and TV presenter Sir David Attenborough. Although not the first animal to be named after the British national treasure, the butterfly is so rare that it is known only from lowland tropical forests of the upper Amazon basin in Venezuela, Colombia, and Brazil. The study, conducted by an international team of researchers, led by Andrew F. E. Neild, Natural History Museum, London, and Shinichi Nakahara, McGuire Center for Lepidoptera and Biodiversity and Entomology & Nematology Department, University of Florida, is published in the open-access journal ZooKeys.

The presently described Attenborough’s Black-eyed Satyr, scientifically called Euptychia attenboroughi, has such a restricted distribution that all of its known sites lie within 500 kilometres from each other in the north-west of the upper Amazon basin.

Best known for scripting and presenting the BBC Natural History’s ‘Life’ series, Sir David Attenborough is also a multiple winner of the BAFTA award and a president of Butterfly Conservation.

“Other animals and plants have previously been dedicated to Sir David, but it makes us happy and proud to be the first to dedicate a butterfly species in his name,” says Andrew Neild. “Although we are a large team from several countries from across four continents and speaking different languages, we have all been deeply influenced and inspired by Sir David’s fascinating and informative documentaries.”

The butterfly’s atypical wings in comparison to its relatives, have been the reason the scientists took to plenty of diagnostic characters to define its taxonomic placement. The peculiar patterns and morphology initially led the researchers to think the species could be even a new genus.

“It was a surprise for us that DNA data supported inclusion of this new species in the existing genus Euptychia, since this species lacked a distinctive structural character which was considered to be shared by all members of the genus” explains Shinichi Nakahara.

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Original Source:

Neild AFE, Nakahara S, Zacca T, Fratello S, Lamas G, Le Crom J-F, Dolibaina DR, Dias FMS, Casagrande MM, Mielke OHH, Espeland M (2015) Two new species of Euptychia Hübner, 1818 from the upper Amazon basin (Lepidoptera, Nymphalidae, Satyrinae). ZooKeys 541: 87-108. doi: 10.3897/zookeys.541.6297

To kill a wolf spider: Further observation of a spider wasp larva growing on its host

Having been attacked, paralysed and implanted with a wasp egg to its belly, a wolf spider carries on with its life fully mobile and active. At least, until it is time for the larva to reach out for its first solid meal at a certain development stage. The present study, conducted by a Brazilian team of scientists, led by PhD student Hebert da Silva Souza, Universidade Estadual de Campinas, Sao Paulo, and published in the open-access Journal of Hymenoptera Research, follows the entire cycle of larval development from the egg laying through the formation of a full-grown wasp.

The herein observed wasp species, called Paracyphononyx scapulatus, belongs to a well-known group of spider parasites, which after laying their eggs on a paralysed spider, let it recover and continue living fully mobile until the larvae are mature. However, little has been known about this curious behaviour of this wasp species in particular, since previous studies have already showed differences between the separate members of the genus.

To observe the whole cycle of the wasp larval development, the researchers caught a recently parasitised wolf spider and placed it in a plastic container.

While the larva grew and fed on the abdominal hemolymph, which is the analog to the blood in backboned creatures, its host did not show any peculiarities in its behaviour and even kept its routine being active at night and resting during the day. This is suggested to be attributed to the need of the larva to keep its host safe from predators, such as ants, which could otherwise eat the dead body.

However, ahead of its fifth and last development stage, the larva was seen to double its size and, in the morning, twenty days after the hatching of the egg, it killed its host and fully consumed it within the next forty-eight hours. Having left its host, the larva began to search for a place within the container to construct a cocoon, which took it sixteen hours. Thirty-two days later, a fully grown female wasp emerged.

In comparison, a relative of the observed spider wasp is known to manipulate its host’s behaviour, making it to enwrap itself and the larva in a cocoon-like silken structure so that it is protected while feeding. Yet, it is not certain whether the observed larva’s growth in captivity is not the reason why it had not induced similar behaviour.

In conclusion, the authors suggest that further investigation of the interaction between the two species could provide more information about the evolution of this kind of parasitism, which is likely to have developed independently among the wasp groups.

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Original source:

Souza HS, Messas YF, Masago F, dos Santos ED, Vasconcellos-Neto J (2015) Paracyphononyx scapulatus (Hymenoptera, Pompilidae), a koinobiont ectoparasitoid of Trochosa sp. (Araneae, Lycosidae). Journal of Hymenoptera Research 46: 165-172. doi: 10.3897/JHR.46.5833

Cage the fly: Walk-in field cages to assess mating compatibility in pest fruit flies

Fruit flies mating compatibility studies have been examined by an international team of researchers to assess the usefulness of walk-in field cages in studying the sexual behavior within fruit fly species complexes and recognition of taxonomically misplaced flies. In addition, they have also evaluated the relevant chemical signals during pheromone emission for species discrimination. The experimental part was conducted with the support of Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture in Seibersdorf, Austria. Their findings are published in the open-access journal ZooKeys.

Evolution has led to divergence in some groups, which sometimes results in new, yet very similar species. Hence, they might successfully confuse taxonomists, making them coin terms like ‘cryptic’ species, or in other words, distinct species misplaced under the same name.

However, these species are kept isolated from each other via reproductive barriers. Preventing interbreeding and hybridization, they can be ecological and mechanical, but also behavioral (i.e. sexual). The latter are behaviors or signals that affect recognition within a species, as well as attractiveness and mate choice. They affect their evolution and therefore, are key elements in species differentiation.

The authors of the present paper have found that the walk-in field cages methodology provides an appropriate ground to study these issues. By applying it, researchers around the world are able to detect pest species among others when occurring in the same populations.

Apart from taxonomic value, the scientists also point out the significance of these findings to pest management. As the studied pest fruit fly species are agricultural pests of major economic importance, assessing their mating behaviour, including the pheromones the males emit when attracting partners, can be utilised in the development of highly specific control methods. For instance, there is the sterile insect technique that involves releasing males reproductively sterilised via ionizing radiation into a wild population, where they inseminate the pest females with sterile sperm so that they end up with unviable offspring.

The main advantage of using walk-in field cages, rather than small laboratory-based ones, is that they provide semi-natural conditions under which they are “reliable and powerful tools to measure the level of mating compatibility among different species and populations of a putative single species.”

However, the present paper highlights that such an approach is only to be applied as a part of integrative taxonomic analyses, together with molecular, physiological and morphological approaches when assessing to which species a particular pest population belongs.

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Original source:

Juarez ML, Devescovi F, Brizova R, Bachmann G, Segura DF, Kalinova B, Fernandez P, Ruiz MJ, Yang J, Teal PEA, Caceres C,, Vreysen MJB, Hendrichs J, Vera MT (2015) Evaluating mating compatibility within fruit fly cryptic species complexes and the potential role of sex pheromones in pre-mating isolation. In: De Meyer M, Clarke AR, Vera MT, Hendrichs J (Eds) Resolution of Cryptic Species Complexes of Tephritid Pests to Enhance SIT Application and Facilitate International Trade. ZooKeys 540: 125-155. doi: 10.3897/zookeys.540.6133

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

How to catch a small squid? First records for the Gulf of California and southwest Mexico

Often avoiding sampling gear with their capability to detect movements and swim their way out of the nets fast enough, the small squids living in the open-ocean zone have so long gone under-researched. The present study, conducted by Dr. Michel Hendrickx, Universidad Nacional Autonoma de Mexico, and his team, seems to provide new and first distributional records of five such species for the Gulf of California and in southwestern Mexico. It also significantly expands the currently known southernmost limit of localities of some of these squids in the eastern Pacific. The research is available in the open-access journal ZooKeys.

The researched five squid species belong to two genera, Abraliopsis and Pterygioteuthis, which although abundant and diverse, have long been shrouded by taxonomic and distributional controversies. To solve them, the researchers used specimens, collected over the span of thirteen years, comprising eight cruises across 113 locations in the Gulf of California and off the southwestern coast of Mexico.

As a result, the scientists concluded a significantly wider distributional range of the species they found. For instance, squids of the Abraliopsis genus were surprisingly found in water deeper than 600 m during the day.

The studied small squids are of high ecological value due to their vital position in the food web. Members of Abraliopsis are important preys for many fishes and mammals, such as the peruvian hake, the Indo-Pacific sailfish, the common dolphinfish and the local sharks. Meanwhile, the representatives of the other researched genus, Pterygioteuthis, are often consumed by larger cephalopods, sea-birds and fur seals. However, their abundance is strongly dependent on temperature, especially when there are fast and significant changes.

The scientists suggest that additional samplings with more adequate equipment, like faster large-sized mid-water trawls, could further bridge the knowledge gaps about these elusive marine inhabitants.

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Original source:

Hendrickx ME, Urbano B, Zamorano P (2015) Distribution of pelagic squids Abraliopsis Joubin, 1896 (Enoploteuthidae) and Pterygioteuthis P. Fischer, 1896 (Pyroteuthidae) (Cephalopoda, Decapodiformes, Oegopsida) in the Mexican Pacific. ZooKeys 537: 51-64. doi: 10.3897/zookeys.537.6023.

Smeagol found underground in Brazil: New eyeless and highly modified harvestman species

Called after Tolkien’s character from the “Lord of the Rings” series, a new eyeless harvestman species was found to crawl in a humid cave in southeastern Brazil. Never getting out of its subterranean home, the new daddy longlegs species is the most highly modified representative among its close relatives and only the second one with no eyes living in Brazil. Its introduction to science, made by the Brazilian research team of Dr. Ricardo Pinto-da-Rocha, Instituto de Biociências da Universidade de São Paulo together with Dr. Maria Elina Bichuette and MSc. Rafael Fonseca-ferreira from Universidade Federal de São Carlos (UFSCar), is published in the open-access journal ZooKeys.

While there are cave dwellers that can easily survive above the ground and even regularly go out in order to feed or mate, there are some, such as the new harvestman species, Iandumoema smeagol, that never leave their subterranean habitats. As an adaptation, the new harvestman species is eyeless and has a reduced amount of melanistic pigmentation, which shows through its pale yellowish colours.

The fourteen adult and juvenile individuals, observed by the researchers, were noticed to always stay close to the stream, most often preferring the wet cave walls. While the juveniles appeared quite active, the adults showed a more sedentary behaviour.

Typically for the harvestmen, the new species was found in a cave with organic matter deposits or spots. On one occasion the team observed one of the individuals in such litter, where it was scavenging carcasses of invertebrates.

In conclusion, the authors point out that additional studies on the population biology of the new species are urgent so that an adequate conservation strategy can be assumed. It is probable that its highly restricted distribution along with the deforestation taking place in the cave’s immediate surroundings call for the creation of protected areas.

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Original source:

Pinto-da-Rocha R, Fonseca-Ferreira R, Bichuette ME (2015) A new highly specialized cave harvestman from Brazil and the first blind species of the genus: Iandumoema smeagol sp. n. (Arachnida, Opiliones, Gonyleptidae). ZooKeys 537: 79-95. doi: 10.3897/zookeys.537.6073

Long-snouted Amazonian catfishes including three new species to form a new genus

Being close relatives within the same genus, eight catfishes showed enough external differences, such as characteristic elongated mouths, hinting to their separate origin. Following a thorough morphological as well as molecular analysis, a team of researchers suggested that five previously known species along with three new ones, which they have found during their survey, need a new genus to accommodate for their specificity. The study, conducted by a Brazilian research team from Universidade Estadual Paulista and led by Dr. Fabio F. Roxo, is available in the open-access journal ZooKeys.

Among other physical peculiarities, the longer snout-like mouths of the herein discussed catfishes is a characteristic that sets them apart. This is also why the authors have chosen the name of Curculionichthys for the proposed genus, formed by the Latin word for “elongated snout” and the suffix “ichthys” meaning “fishes” in Greek.

Furthermore, one of the new species the researchers describe in the present paper surprises with its several dark-brown spots spread across its body. This colouration is unlike any other in its relatives that have various pigment patterns, yet never dark brown spots.

However, other overlapping morphological features as well as the closeness in the species’ researched habitats suggest they have a common ancestor, once lived in the Amazonian drainages.

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Original source:

Roxo FF, Silva GSC, Ochoa LA, Oliveira C (2015) Description of a new genus and three new species of Otothyrinae (Siluriformes, Loricariidae). ZooKeys 534: 103-134. doi: 10.3897/zookeys.534.6169

The owls beyond the Andes: Divergence between distant populations suggests new species

They might be looking quite identical, while perched above humanised farmlands and grasslands across several continents, but each of the populations of two owl species, living in the opposite hemispheres, might actually turn out to be yet another kind. This suggestion has been made by Dr. Nelson Colihueque and his team from Universidad de Los Lagos, Chile, based on new genetic divergence analyses of the Common Barn and the Short-eared Owl populations from southern Chile and comparing them with those from other geographic areas. The study is published in the open-access journal ZooKeys.

Although much has been known about the two widespread owl species, the knowledge about them has so far been restricted mainly to aspects such as their diet, conservation status and habitats. On the other hand, their genetic divergence in comparison with populations in distant areas has received little attention. Moreover, their taxonomical status is still based on traditional identification rather than modern methods such as the herein utilised mitochondrial COI sequencing.

Thus, the Chilean research team concluded a significant genetic divergence among the populations of both species from a few distinctive groups. In the case of the Common Barn Owl they compared the new analysis of its South American representatives with already available such data about populations from North America, Northern Europe and Australasia. For the Short-eared Owl, they compared Chilean and Argentinean birds with North American and North Asian.

One of the reasons behind such an evolutionary divergence might be the geographic isolation, experienced by the peripheral South American populations of both owl species. It is a consequence of the Andean Mountains acting as a natural barrier.

“In the case of the Common Barn Owl, the existence of geographic barriers to gene flow among populations on different continents is to be expected, and this in combination with its non-migratory or short-distance migratory behaviour, should contribute to promote the genetic divergence,” further explain the authors.

In conclusion, the researchers call for additional studies to clarify the taxonomic identification of these owl populations.

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Original source:

Colihueque N, Gantz A, Rau JR, Parraguez M (2015) Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence. ZooKeys 534: 135-146. doi: 10.3897/zookeys.534.5953