Tag: biodiversity

Wildlife on the highway to hell: Roadkill in the largest wetland, Pantanal region, Brazil

*Adult individual of Erythrolamprus aesculapii captured in roadside habitats of BR-262. Photo by Michel Passos*

Scientists provide crucial data to prompt further conservation and safety measures at the notorious BR-262 highway

Having systematically monitored wild animals killed on the Brazilian federal highway BR-262, which passes through the Pantanal region, a research team from the Federal University of Mato Grosso do Sul, Brazil, published their data concerning birds and reptiles in the open access journal Check List.

Apart from information crucial for future conservation activities, the paper provides new and unexpected roadkill records, including the Black-and-white hawk-eagle.

Authored by Wagner Fischer and his colleagues Raquel Faria de Godoi and Antonio Conceição Paranhos Filho, the article is part of the first dataset of vertebrate mortality in the region. A separate paper of theirs is planned to present the data concerning mammals gathered during the same survey, which took place between 1996 and 2000.

*An adult individual of Xenodon matogrossensis captured in roadside habitats of BR-262. Photo by Cyntia Santos.*

Having mapped bird and reptile roadkill on the highway between the cities of Campo Grande and Corumbá in the Brazilian savannah, the team reports a total of 930 animals representing 29 reptile and 47 bird species. In addition, the data provide the first regional geographic record of the colubrid snake Hydrodynastes bicinctus.

The researchers conclude that the species richness observed in the road-killed animals clearly confirms earlier concerns about wildlife-vehicle collisions in the Pantanal region. Such accidents lead to long-term and chronic impact on both wildlife and road safety.

“Mitigation of wildlife-vehicle collisions on this road continues to claim urgency for biodiversity conservation and for human and animal safety and care,” say the authors.

“For managers, the main goal should be to determine target species of greatest concern, focusing on those vulnerable to local extinction or those which represent major risks of serious accidents.”

In the past, the team’s dataset had already been used as a guide to road fauna management. In particular, it was used by government road managers when planning animal overpassess and underpassess equipped with roadside fences as part of the long-term project Programa Estrada Viva: BR-262. So far, however, only some of the less efficient safety methods, such as road signs and lowered speed limits, have been applied at the most critical points.

Over the past several years, a few independent studies have been conducted to monitor roadkill in a similar manner. Two of them (2010 and 2017) looked into mammal-vehicle collisions, while the third recorded reptiles and birds as well. All of them serve to demonstrate that BR-262 continues to be a major cause for the regional wildlife mortality, which in turn increases the risks of serious accidents.

“BR-262 keeps its inglorious fame as a highway to hell for human and wild lives,” points out lead author Wagner Fischer.

*Roadkill on the BR-262 highway, Pantanal region, Brazil. Photos by Ricardo Fraga and Wagner Fischer.*

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Original source:

Fischer W, Godoi RF, Filho ACP (2018) Roadkill records of reptiles and birds in Cerrado and Pantanal landscapes. Check List 14(5): 845-876. https://doi.org/10.15560/14.5.845

Large-sized fossilised lacewings prove remarkable species diversity during Middle Jurassic

Middle Jurassic has always been considered as a mysterious ancient period full of ‘magical’ dinosaurs, pterosaurs and plants. However, when we think about the Jurassic landscape, we should take insects into consideration as well.

The lacewings, for example, are a graceful group famous for the lovely net-like veins on their wings, beautiful enough to stand the test of time, preserved as fossils. In addition, the wing spots on their wings form various patterns, which serve to tell us more about their adaptation to the particular environment.

Having carefully studied several pieces of compressed fossils of the large and distinct insects they found in Dohugou village, Inner Mongolia, Chinese scientists Hui Fang, Dong Ren, Jiaxi Liu and Yongjie Wang, College of Life Science, Capital Normal University, Beijing, discovered two species new to science.

Due to their complex, one-of-a-kind wing venations, all three of them were placed in the same genus (Laccosmylus) in the family Saucrosmylidae. Their descriptions, along with the redescription of another previously known species, are published in the open access journal ZooKeys.

“Fossil lacewing insects are much more abundant compared to living ones,” comment the authors.

“These large-sized fossil lacewing species reflect a high lacewing diversity in Middle Jurassic. Soon, they will help us reconstruct the wonderful environment of the Jurassic world.”

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Original source:

Fang H, Ren D, Liu J, Wang Y (2018) Revision of the lacewing genus Laccosmylus with two new species from the Middle Jurassic of China (Insecta, Neuroptera, Saucrosmylidae). ZooKeys 790: 115-126. https://doi.org/10.3897/zookeys.790.28286

Newly discovered moth named Icarus sports a flame-shaped mark and prefers high elevations

The paper describing the new species is part of a special issue dedicated to macro moths of the New World published in the open-access journal ZooKeys

Newly-recognized species of owlet moth recently discovered to inhabit high-elevation mountains in western North America was named after the Greek mythological character Icarus. From now on, scientists will be referring to the new insect as Admetovis icarus.

In their paper, Dr Lars Crabo, Washington State University, USA, and Dr Christian Schmidt, Agriculture and Agri-Food Canada, explain that the combination of the distinct flame-shaped mark on the moth’s forewing and its high-elevation habitat were quick to remind them of Icarus, who is said to have died after flying so close to the sun that his wings made of wax and feathers caught fire.

The study is part of the seventh volume of the “Contributions to the systematics of New World macro-moths” series, where all previous volumes have also been published as special issues in ZooKeys.

Found in the town of Nederland, Colorado, the moth was collected at an elevation of 2,896 m above sea level. The species has also been recorded all the way from central Utah and central Colorado to the Selkirk Mountains of southeastern British Columbia, including a record from northeastern Oregon. It can be spotted between June and August at night.

In fact, it turns out that the moth has been collected during surveys in the past on multiple occasions, but has been misidentified with another closely related species: Admetovis oxymorus.

While the flame mark is a characteristic feature in all three species known in the genus (Admetovis), in the newly described species it is darker. When compared, the wings of the Icarus moth are also more mottled.

Despite the biology of the larvae being currently unknown, the scientists believe they are climbing cutworms and feed on woody shrubs, similarly to the species Admetovis oxymorus.

“Finding undiscovered moths is not that unusual, even though scientists have been naming insects since the eighteenth century,” says lead author Dr Lars Crabo.

“The Contributions series, edited by Don Lafontaine and Chris Schmidt, in which this discovery is published, really encourages professional and citizen scientists alike to go through the steps necessary to properly name the species that they have discovered. This series of seven volumes also includes a new check list for the United States and Canada, which has led to a re-kindling of interest in moths during the last decade.”

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Original source:

Crabo LG, Schmidt BC (2018) A revision of Admetovis Grote, with the description of a new species from western North America (Noctuidae, Noctuinae, Hadenini). In: Schmidt BC, Lafontaine JD (Eds) Contributions to the systematics of New World macro-moths VII. ZooKeys788: 167-181. https://doi.org/10.3897/zookeys.788.26480

The first drywood termite known to use snapping stick-like mandibles to defend its colony

Tasked to defend the colony from attackers, the specialised soldier caste in some termite species has evolved various impressive mechanisms, including plug-like heads – meant to block intruding ants trying to invade their lairs, and mouthparts designed to bite and pierce.

Still, there are even more spectacular soldiers, such as a recently discovered drywood termite species, whose unique long and slender, stick-like snapping mandibles produce one of the highest acceleration speeds measured in a living organism. Rather than bite, these peculiar ‘jaws’ deliver powerful strikes at enemies bold enough to stand in the way of the soldier termite and its colony.

The scientists describe the new termite’s specialty in detail:

“Roisinitermes employs a unique strategy of snapping, achieved by long and slender mandibles pressed against each other in a defensive encounter. When this potential energy is released, the left mandible springs over the right and the resultant snap is forced onto the opponent if it is in the path of the strike.”

Discovered in Cameroon, this striking species is the first drywood termite found to rely on snapping mandibles as a defense strategy. Given that until now there had been a single subfamily (Termitinae) known to have developed such, the very existence of the new insect poses a whole new set of questions before scientists. Have snapping mandibles evolved independently in two evolutionary lineages? Or, is it that these groups share a distant kin relationship which has gone unnoticed for that long?

The new drywood termite, which is also assigned to a new genus, is named Roisinitermes ebogoensis, and is described in the open access journal ZooKeys by an international team of researchers, led by Dr Rudolf Scheffrahn of the Institute for Food and Agricultural Sciences at University of Florida, Davie, USA. Although this particular species is not thought to be a pest, some drywood termites cause serious damage to wooden structures around the world.

Both colonies studied by the scientists were found near the Ebogo II village, which also stands behind the name of the species. The first unusual colony to draw the attention of the scientists was collected from a forest on an island in the Nyong River, where it lived in a thin (3 cm) and long (over 3 m) broad-leaf tree branch suspended from a canopy. The second one – in a 15-mm thick dead liana branch hanging from a tree in a nearly pristine rainforest.

The team expects that future research will shed more light on the origins and evolution of the newly discovered termite.

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Original source:

Scheffrahn RH, Bourguignon T, Akama PD, Sillam-Dussès D, Šobotník J (2018) Roisinitermes ebogoensis gen. & sp. n., an outstanding drywood termite with snapping soldiers from Cameroon (Isoptera, Kalotermitidae). ZooKeys 787: 91-105. https://doi.org/10.3897/zookeys.787.28195

Scientific divers from the California Academy of Sciences discover new species of dazzling, neon-colored fish

Post originally published by the California Academy of Sciences

Named for Aphrodite, Greek goddess of love and beauty, a new species of fish enchants Academy scientists

On a recent expedition to the remote Brazilian archipelago of St. Paul’s Rocks, a new species of reef fish—striped a vivid pink and yellow—enchanted its diving discoverers from the California Academy of Sciences.

First spotted at a depth of 400 feet beneath the ocean’s surface, this cryptic fish inhabits rocky crevices of twilight zone reefs and is found nowhere else in the world. Upon discovery, the deep-diving team was so captivated by their finned find that they didn’t notice a massive sixgill shark hovering above them in an exciting moment captured on camera. The new fish description published today in Zookeys.

“This is one of the most beautiful fishes I’ve ever seen,” says Dr. Luiz Rocha, the Academy’s Curator of Fishes and co-leader of the Hope for Reefs initiative. “It was so enchanting it made us ignore everything around it.”

The sixgill shark stretched nearly ten feet long and cruised overhead as Rocha and post-doctoral fellow Dr. Hudson Pinheiro delicately collected the fish for further study back at the Academy. Behind the camera, the team’s diving officer Mauritius Bell enthusiastically announced the behemoth visitor to the duo, but to no avail. Aptly named, Tosanoides aphrodite enchanted its discoverers much like Aphrodite, Greek goddess of love and beauty, enchanted the ancient Greek gods.

“Fishes from the twilight zone tend to be pink or reddish in color,” says Pinheiro. “Red light doesn’t penetrate to these dark depths, rendering the fishes invisible unless illuminated by a light like the one we carry while diving.”

Back at the Academy, laboratory and collections manager Claudia Rocha helped the diving duo describe the new species: Males are outfitted with alternating pink and yellow stripes while females sport a solid, blood-orange color. Using a microscope, the team counted fins and measured spine length; DNA analysis revealed the new species is the first Atlantic-dwelling member of its genus.

*Male specimen of the new species (Tosanoides aphrodite). Photo by LA Rocha.*

The new denizen of the deep is a remarkable testament to the vast ocean habitats that still remain unexplored. Rocha and Pinheiro are part of a deep-diving research team that ventures to twilight zone reefs—mysterious coral habitats stretching across a narrow band of ocean 200 – 500 feet beneath the surface. In these deep reefs, animals live in partial darkness—beyond recreational diving limits, yet above the deep trenches patrolled by submarines and ROVs. As part of its Hope for Reefs initiative, the Academy team and their collaborators are exploring this unknown frontier with the help of high-tech equipment like closed-circuit rebreathers that allow scientists to extend their research time underwater.

Nearly 600 miles offshore the coast of Brazil, St. Paul’s Rocks is so remote that it required the team to utilize the research vessel M/V Alucia as their homebase to explore the archipelago. The rocky outcroppings are extensions of the Mid-Atlantic Ridge—an active, tectonic plate boundary—puncturing the ocean’s surface. Given the region’s unique geology and isolated location, many of the species that live there are found nowhere else on Earth. Through their research, the Hope for Reefs team is finding that twilight zone habitats also host many location-specific species.

In a recent landmark paper, the team found that twilight zone reefs are unique ecosystems bursting with life and are just as vulnerable to climate change threats as their shallow counterparts. Their findings upended the long-standing assumption that species might migrate between habitats to avoid human-related stressors. As documented in the footage from this new fish’s discovery, a piece of fishing line can be seen streaming behind the sixgill shark—evidence that human impacts extend to depth too.

“In a time of global crisis for coral reefs, learning more about unexplored reef habitats and their colorful residents is critical to our understanding of how to protect them,” says Rocha. “We aim to highlight the ocean’s vast and unexplored wonders and inspire a new generation of sustainability champions.”

Research article:

Pinheiro HT, Rocha C, Rocha LA (2018) Tosanoides aphrodite, a new species from mesophotic coral ecosystems of St. Paul’s Rocks, Mid Atlantic Ridge (Perciformes, Serranidae, Anthiadinae). ZooKeys 786: 105-115. https://doi.org/10.3897/zookeys.786.27382

Two fish a day keep the mantid coming back to prey: The 1st fishing praying mantis

Commonly known to predate on insects, praying mantises have occasionally been observed to feed on vertebrates, including small birds, lizards, frogs, newts, mice, snakes and turtles. Mostly, such records have either not been scientifically validated or have occurred under induced and human-manipulated circumstances.

Nevertheless, no scientific data of mantises preying on fish existed until the recent study of Roberto Battiston, Musei del Canal di Brenta, Rajesh Puttaswamaiah, Bat Conservation India Trust, and Nayak Manjunath, published in the open access Journal of Orthoptera Research.

Last year, the team observed an adult male hunting and devouring guppies in a pond located in a private roof garden in Karnataka, India. Curiously enough, the predator came back five days in a row and caught a total of nine fish (a minimum of two a day). To reach its prey, the insect would walk on the leaves of water lilies and water cabbage growing on the surface of the pond.

*The artificial pond with the praying mantis sitting on a leaf visible to the right.*

Apart from being a curious first-of-its-kind, the observation raises three new discussion points worthy of further study, point out the researchers.

Firstly, the fact that praying mantises hunt on vertebrates outside cages in labs confirms that a single invertebrate species is indeed capable of having an impact on a whole ecosystem. In this case, a mantis preys on guppies which, in their turn, feed on aquatic insects.

*The mantis eating a guppy starting from the tail, while the fish is still alive and breathing in the water.*

Secondly, the discovery questions previous knowledge about the visual abilities of mantises. While the structure of their eyes clearly indicates that they have evolved to prey in daylight, the studied male specimen proved to be an excellent hunter in the dark. The insect managed to catch all nine fish either at sunset or late at night.

Besides visual, mantises might have evolved impressive learning abilities too. The researchers speculate that the observed repetitive behaviour might have been the result of personal experience, utilised to navigate the specimen. Sophisticated cognitive skills, on the other hand, might have allowed the mantis to develop its hunting strategies.

“Remembering the prey’s abundance in a particular site, in relation to their ease of capture and their nutritional content, could be one important factor of this choice and indirectly influence the individual predator’s fitness,” comment the scientists. “This should be investigated in further studies.”

Original source:

Battiston R, Puttaswamaiah R, Manjunath N (2018) The fishing mantid: predation on fish as a new adaptive strategy for praying mantids (Insecta: Mantodea). Journal of Orthoptera Research27(2): 155-158. https://doi.org/10.3897/jor.27.28067

New light on the controversial question of species abundance and population density

Inspired by the negative results in the recently published largest-scale analysis of the relation between population density and positions in geographic ranges and environmental niches, Drs Jorge Soberon and Andrew Townsend Peterson of the University of Kansas, USA, teamed up with Luis Osorio-Olvera, National University of Mexico (UNAM), and identified several issues in the methodology used, able to turn the tables in the ongoing debate. Their findings are published in the innovative open access journal Rethinking Ecology.

Both empirical work and theoretical arguments published and cited over the last several years suggest that if someone was to take the distributional range of a species – be it animal or plant – and draw lines starting at the edges of the space inwards, they would find the species’ populations densest at the intersection of those lines. However, when the team of Tad Dallas, University of Helsinki, Finland, analysed a large dataset of 118,000 populations, equating to over 1,400 species of birds, mammals, and trees, they found no such relationship.

Having analysed the analysis, the American-Mexican team concluded that despite being based on an unprecedented volume of data, the earlier study was missing out some important points.

Firstly, the largest dataset used by Tad and his team comprises observational data which had not required a certain sampling protocol or a plan. Without any standard in use, it is easy to imagine that the observations would be predominantly coming from people around and near cities, hence strongly biased.

Additionally, the scientists note that the analysis largely disregards parts of species’ geographic distributions for which there were no abundant data. As a result, the range of a species could be narrowed down significantly and its centroid – misplaced. Meanwhile, the population would appear denser on what appears to be the periphery of the area.

Similar issue is identified in the localisation of populations in the environmental space, where once again their range turned out to have been represented as significantly smaller, when compared to data available from the International Union for Conservation of Nature (IUCN) and the Global Biodiversity Information Facility (GBIF).

Further, a closer look into the supplementary materials provided revealed that the precision of the population-density data was not scalable with the climate data. As a result, it is likely that multiple abundance data falls within a single climate pixel.

In conclusion, the authors note that in order to comprehensively study the abundance of a species’ populations, one needs to take into consideration a number of factors lying beyond the scope of either of the papers, including human impact.

“We suggest that this important question remains far from settled,” they say.

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Original source:

Soberón J, Peterson TA, Osorio-Olvera L (2018) A comment on “Species are not most abundant in the centre of their geographic range or climatic niche”. Rethinking Ecology 3: 13-18. https://doi.org/10.3897/rethinkingecology.3.24827

Tiny moth from Asia spreading fast on Siberian elms in eastern North America

In 2010, moth collector James Vargo began finding numerous specimens of a hitherto unknown pygmy moth in his light traps on his property in Indiana, USA. When handed to Erik van Nieukerken, researcher at Naturalis Biodiversity Center (Leiden, the Netherlands) and specialist in pygmy moths (family Nepticulidae), the scientist failed to identify it as a previously known species.

*These are male specimens of the studied leaf mining moth Stigmella multispicata collected from Iowa, USA.*

Then, Erik found a striking similarity of the DNA barcodes with those of a larva he had recently collected on Siberian elm in Beijing’s botanical garden. At the time, the Chinese specimen could not be identified either.

In October 2015, Daniel Owen Gilrein, entomologist at Cornell Cooperative Extension of Suffolk County (New York, USA), received samples of green caterpillars seen to descend en masse from Siberian elm trees in Sagaponack, New York. He also received leafmines from the same trees.

Once they joined forces, the researchers did not take long to find out that the specimens from James Vargo and the caterpillars from New York belonged to one and the same species. The only thing left was its name.

Following further investigation, the scientists identified the moth as Stigmella multispicata – a pygmy moth described in 2014 from Primorye, Russia, by the Lithuanian specialists Agne Rociene and Jonas Stonis.

“Apparently, this meant that we were dealing with a recent invasion from East Asia into North America,” explains Erik.

Once the researchers had figured out how to identify the leafminer, they were quick to spot its existence in plenty of collections and occurrence reports from websites, such as BugGuide and iNaturalist.

With the help of Charley Eiseman, a naturalist from Massachusetts specializing in North American leafminers, the authors managed to conclude the moth’s existence in ten US states and two Canadian provinces. In most cases, the species was found on or near Siberian elm – another species transferred from Asia to North America.

Their study is published in the open access journal ZooKeys.

Despite the oldest records dating from 2010, it turned out that the species had already been well established at the time. The authors suspect that the spread has been assisted by transport of plants across nurseries.

“Even though Stigmella multispicata does not seem to be a real problem, it would be a good idea to follow its invasion over North America, and to monitor whether the species may also attack native elm species,” the researchers point out.

Interestingly, in addition to the newly identified moth, the Siberian elms in North America have been struggling with another, even more common, invasive leafminer from Asia: the weevil species Orchestes steppensis. The beetle had been previously misnamed as the European elm flea weevil.

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Original source:

van Nieukerken EJ, Gilrein DO, Eiseman CS (2018) Stigmella multispicata Rociene & Stonis, an Asian leafminer on Siberian elm, now widespread in eastern North America (Lepidoptera, Nepticulidae). ZooKeys 784: 95-125. https://doi.org/10.3897/zookeys.784.27296

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

Towards untangling the ‘antennal grabbing’ phenomenon in mating cuckoo bees

Scientists report this behavior for the first time in the genus Nomada, following both lab and field observations in Germany

One can seldom spot a cuckoo bee, whose peculiar kleptoparasitic behaviour includes laying eggs in the nests of a certain host bee species, let alone a couple mating.

Nevertheless, German scientists – Dr. Matthias Schindler, University of Bonn, Michaela Hofmann and Dr. Susanne S. Renner of the University of Munich, and Dr. Dieter Wittmann, recently managed to record copulation in three different cuckoo bee species in the genus Nomada.

Intriguingly, in field and lab settings alike, the observed couples demonstrated the phenomenon the researchers called “antennal grabbing” where the male cuckoo bee winds his antennae around

*Insertion phase of copulation in a couple of the species Nomada flavoguttata. Note the male’s antennae spirally entangling the female’s.*

the female’s during copulation, thus transferring pheromones. Even though such behaviour is relatively common in Hymenoptera, this is the first known record for the genus Nomada.

While the particular biological reason for the “antennal grabbing” in different species remains unsettled, the scientists discuss the phenomenon in view of both previous hypotheses and their own observations in a new paper published in the open access Journal of Hymenoptera Research.

The courtship in Nomada cuckoo bee starts with the ‘swarming’ of males at willow shrubs and gooseberry or their patrolling in groups with males of the Andrena or Melitta species that will “foster” their offspring.

*Two males of the species Nomada flavoguttata patrolling at a blossom of a common dandelion.*

There is no aggression among the males. They were observed to rub their bellies and heads against the grass, in order to leave sexual pheromones, thus marking the “dating spot” for potential mates.

Earlier chemical studies of Nomada bees noted that the mandibular glands of males produce chemical compounds identical with those of their Andrena or Melitta hosts, leading to the suggestion that the males transfer pheromones that help the females mimic the odor of the host bee, and later enter its nest unnoticed to lay its eggs. An alternative explanation for the “antennal grabbing” is that males are spraying a substance onto the females to make them unattractive to other potential mates.

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Original source:

Schindler M, Hofmann MM, Wittmann D, Renner SS (2018) Courtship behaviour in the genus Nomada – antennal grabbing and possible transfer of male secretions. Journal of Hymenoptera Research 65: 47-59. https://doi.org/10.3897/jhr.65.24947