Tag: Hymenoptera

Bee populations expanded during global warming after the last Ice Age

The Australian small carpenter bee populations appear to have dramatically flourished in the period of global warming following the last Ice Age some 18,000 years ago.

The bee species is found in sub-tropical, coastal and desert areas from the north-east to the south of Australia. Researchers Rebecca Dew and Michael Schwarz from the Flinders University of South Australia teamed up with Sandra Rehan, the University of New Hampshire, USA, to model its past responses to climate change with the help of DNA sequences. Their findings are published in the open access Journal of Hymenoptera Research.

“You see a rapid increase in population size from about 18,000 years ago, just as the climate began warming up after the last Ice Age,” says lead author Rebecca Dew. “This matches the findings from two previous studies on bees from North America and Fiji.”

“It is really interesting that you see very similar patterns in bees around the world,” adds Rebecca. “Different climate, different environment, but the bees have responded in the same way at around the same time.”

In the face of future global warming these finding could be a good sign for some of our bees.

However, the news may not all be positive. There are other studies showing that some rare and ancient tropical bees require cool climate and, as a result, are already restricted to the highest mountain peaks of Fiji. For these species, climate warming could spell their eventual extinction.

“We now know that climate change impacts bees in major ways,” says Rebecca, “but the challenge will be to predict how those impacts play out. They are likely to be both positive and negative, and we need to know how this mix will unfold.”

Bees are major pollinators and are critical for many plants, ecosystems, and agricultural crops.

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Original source:

Dew RM, Rehan SM, Schwarz MP (2016) Biogeography and demography of an Australian native bee Ceratina australensis (Hymenoptera, Apidae) since the last glacial maximum. Journal of Hymenoptera Research 49: 25-41. doi: 10.3897/JHR.49.8066

Scientist collects 30 sawfly species not previously reported from Arkansas

Sawflies and wood wasps form a group of insects that feed mainly on plants when immature. Field work by Dr. Michael Skvarla, which was conducted during his Ph.D. research at the University of Arkansas, Fayetteville, USA, has uncovered 30 species of these plant-feeding wasps that were previously unknown in the state. The study is published it in the open access journal Biodiversity Data Journal.

After collecting sawflies in tent-like Malaise traps or hanging funnel traps, Dr. Michael Skvarla sent the specimens to retired sawfly expert Dr. David Smith for identification.

In total, 47 species were collected, 30 of which had not been found in Arkansas before. While many of the species are widespread in eastern North America, eight species were known only from areas hundreds of kilometers away.

“I knew that many insect groups had not yet been surveyed in Arkansas, but I was surprised that 66% of the sawfly species we found were new to the state,” Skvarla says.

“In addition, over a quarter of the newly recorded species represent large range extensions of hundreds of miles; Monophadnoides conspiculatus, for instance, was previously known only from the Appalachian Mountains. This work highlights how much basic natural history is left to discover about insects.”

Sawflies and wood wasps comprise the wasp suborder Symphyta and derive their common names from the serrated or saw-shaped ovipositor many species use to lay eggs into plant tissue, and because some species bore into wood.

While some sawfly and woodwasp species can be pests on crops or ornamental plants, most do not pose an economic concern, and all are harmless to people.

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Original source:

Skvarla M, Smith D, Fisher D, Dowling A (2016) Terrestrial arthropods of Steel Creek, Buffalo National River, Arkansas. II. Sawflies (Insecta: Hymenoptera: “Symphyta”). Biodiversity Data Journal 4: e8830. doi: 10.3897/BDJ.4.e8830

Hollywood star Brad Pitt shares a name with a new wasp species from South Africa

Not only did an international research team discover two new endoparasitic wasp species in South Africa and India, and significantly expanded their genera’s distributional range, but they also gave a celebrity name to a special one of them.

While thinking of a name for the new wasp, Dr Buntika A. Butcher, Chulalongkorn University, Thailand, recalled her long hours of studying in her laboratory right under the poster of her favourite film actor. This is how a parasitic wasp from South Africa was named after Hollywood star Brad Pitt. The researchers have published their findings in the open access journal ZooKeys.

The new wasp species, called Conobregma bradpitti, belongs to a large worldwide group of wasps parasitising in moth or butterfly caterpillars. These wasps lay their eggs into a host, which once parasitised starts hardening. Thus, the wasp cocoon can safely develop and later emerge from the ‘mummified’ larva. Despite their macabre behaviour, many of these wasp species are considered valuable in agriculture because of their potential as biological control.

Brad Pitt’s flying namesake is a tiny creature measuring less than 2 mm. Its body is deep brown, nearly black in colour, while its head, antennae and legs are brown-yellow. The wings stand out with their much brighter shades.

Interestingly, the wasp with celebrity name unites two, until now, doubtful genera. Being very similar, they had already been noted to have only four diagnostic features that set them apart. However, C. bradpitti shared two of those with each. Thus, the species prompted the solution of the taxonomic problem and, as a result, the two were synonymised.

In their paper, the authors from Chulalongkorn University, Thailand and the University of Calicut, India, also describe another new species of parasitic wasp. It is the first from its subtribe spotted in the whole of India, while its closest ‘relative’ lives in Nepal.

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Original source:

Butcher BA, Quicke DLJ, Shreevihar S, Ranjith AP (2016) Major range extensions for two genera of the parasitoid subtribe Facitorina, with a new generic synonymy (Braconidae, Rogadinae, Yeliconini). ZooKeys 584: 109-120. doi: 10.3897/zookeys.584.7815

Flightless survivors: Incredible invertebrate diversity in Los Angeles metropolitan area

Urban wildlife is surprisingly understudied. We tend to know more about animals in exotic places than about those that live in our cities.

This is why researchers Emile Fiesler, president of Bioveyda Biological Inventories, Surveys, and Biodiversity Assessments, USA, and Tracy Drake, manager of the Madrona Marsh Preserve, looked into the fauna of the Madrona Marsh Preserve, California, a small nature preserve in one of the world’s largest metropolitan areas.

Consequently, they published the astonishing number of 689 species of invertebrates, which have managed to survive decades of farming and oil exploration, followed by development pressures, in the open access Biodiversity Data Journal. The study was minimally invasive as the live animals have been recorded with macro-photography.

Even though it is the insects that first developed the ability to fly, long before the dinosaurs became birds, the latter have always received the most of our attention. This major evolutionary breakthrough, which has occurred more than once in the past, is also a reason why insects are currently the most diverse animals on earth in terms of number of species.

“Insects and other invertebrates have filled all ecological niches and all corners of our planet,” explain the authors. “No surprise that these small creatures conquered our cities and invaded our homes as well.”

Most of the urban dwellers, however, have been introduced – accidentally or deliberately – by humans.

“The remainder – native ‘wild’ species – are able to survive in the city mainly due to their adaptivity,” they point out. “It is therefore surprising to find a number of flightless species in a small area surrounded by urbanization.”

The Madrona Marsh Preserve is located in Torrance, which is part of the Los Angeles metropolitan area. The greater Los Angeles Metropolitan area is one of the world’s largest, with a human population of more than 17 million.

The Madrona Marsh Preserve, boasting seasonal wetlands, is well known as a birdwatchers’ paradise. Besides birds, its other vertebrates (mammals, reptiles, amphibians, and fishes), as well as its flowering plants, are relatively well known. The invertebrate fauna of the Preserve, on the other hand, aside from butterflies and dragonflies, was virtually unknown.

Interestingly, night surveys revealed the presence of a ‘second shift’ diversity, or creatures seemingly complementary to those active during the day.

Among the long-time survivors are wingless camel crickets as well as velvet ants, which are wasps whose flightless females look like furry ants. Another curiosity that intrigued the researchers is an obscure flightless female bradynobaenid wasp.

The researchers were especially surprised by their encounter with a large Solifugid [image 3] – also known as Camel Spider or Wind Scorpion. Solifugids are little-known arachnids that are neither spiders, nor scorpions, and can grow up to 15 cm (6 in). Their order’s name Solifugae translates from Latin as “those that flee from the sun”.

All in all, the biodiversity study resulted in 689 species without a backbone, belonging to 13 classes, 39 orders, and 222 families, found on this island surrounded by urbanization.

“Not unlike the moas and dodos, these ‘island’ inhabitants stayed grounded through the ages,” acknowledge the researchers.

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Original source:

Fiesler E, Drake T (2016) Macro-invertebrate Biodiversity of a Coastal Prairie with Vernal Pool Habitat. Biodiversity Data Journal 4: e6732. doi: 10.3897/BDJ.4.e6732

About the authors:

Emile Fiesler is president of Bioveyda Biodiversity Inventories, Surveys, and Studies, and Tracy Drake is manager of the Madrona Marsh Preserve.

Rediscovering an interesting group of ant-loving beetles

Case-bearer leaf beetles, scientifically called Cryptocephalinae, live a secretive life.

While the adults hide their heads inside their torso, like a cloaked, mysterious figure, their eggs stay hidden inside a case, carefully constructed by their mothers, using fecal pellets. Having already hatched, the larvae and, later, the pupae keep this initial case and build on forming a protective ‘fortress’ that their enemies can mistake for a plant twig or caterpillar frass.

The studied Cryptocephalines genus, like most of the 40,000 known species of leaf beetles, feed on leaves, fruits, flowers, roots and stems. Indeed, some species of leaf beetles are some of the biggest threats to our crops.

A study published in ZooKeys, led by Dr. Federico Agrain, an Argentinian researcher of CONICET, and his colleagues in the USA and Germany, has unveiled some remarkable new patterns in the secretive life of a specific group within the leaf beetle genus that live within ant nests.

Their research highlights that these myrmecophilic (literally, ‘ant-loving’) leaf beetles live mainly among species of the ant families Formicinae and Myrmecinae.

“Living with ants might offer these beetles multiple advantages, and it might have aided the colonization of xeric environments,” hypothesised Dr. Agrain.

“Ants are notoriously territorial and aggressive, sniffing out and killing enemies that try to enter the ant nests. We suspect that these beetles sneak inside the ant nests by mimicking the scent and behavioral profiles of the ants,” suggests Dr. Caroline Chaboo, a leaf beetle expert at the University of Kansas and co-author of the paper. “How else could the beetles get the ants to pick them up outside the nest and take them into the nest where they can live undetected and with an endless food supply?”

These hypotheses need to be tested in future research. In addition to these novel aspects and hypotheses. “Specialized natural enemies, especially parasitoid Hymenoptera (the insect order where ants belong), exploit cryptocephaline beetles inside the ant nests,” says Dr. Matthew Buffington, a research entomologist at the ARS-Systematic Entomology Laboratory in Washington DC, and co-author of the present study.

Key evolutionary steps, needed to be taken by these leaf beetles, so that they are able to form an association with ants, are also discussed by Dr Federico Agrain and his colleagues. How does a leaf beetle find a host ant, enter the nest, survive within the nest, and, later, exit the ant nest? How strong is the strength of the host association? What are the benefits for the host? What about the diet specialization of adult and larvae? These are the sort of questions the scientists ask themselves.

Clearly, there is a wide range of new hypotheses to be investigated and inter-disciplinary approaches will be needed to unravel the secrets to myrmecophily and the covert, enigmatic lives of case-bearer beetles.

Photo Credit:

Original source:

Agrain FA, Buffington ML, Chaboo CS, Chamorro ML, Schöller M (2015) Leaf beetles are ant-nest beetles: the curious life of the juvenile stages of case-bearers (Coleoptera, Chrysomelidae, Cryptocephalinae). In: Jolivet P, Santiago-Blay J, Schmitt M (Eds) Research on Chrysomelidae 5. ZooKeys 547: 133–164. doi: 10.3897/zookeys.547.6098

Seventy-four cuckoos in the nest: A new key to all North European cuckoo wasp species

Captivating with their bright, vivid and brilliantly metallic bodies, the cuckoo wasps are also fascinating with their curious lifestyle, which has given them this common name. However, in terms of their taxonomic grouping, they have been quite problematic due to similarities between species and a wide range of variations within them.

To shed light on the issue, an international research team, led by MSc Juho Paukkunen, Finnish Museum of Natural History, Helsinki, provides descriptions and illustrations of all 74 species found in the Nordic and Baltic countries, including one new, in their recent publication in the open-access journal ZooKeys.

Beautiful in appearance, the cuckoo wasps penetrate the nests of unrelated solitary wasps and solitary bees to lay their eggs, similar to how a cuckoo bird does in songbird nests. With their armoured bodies and the ability to curl up into a tight ball the cuckoo wasps are well-defended against the owners of the nests and their stings and jaws. At the larval stage, they take advantage of their hosts by either parasitising them or stealing their food, eventually killing the host’s offspring.

Within the Nordic representatives of the family there are an exceptionally large number of red-listed and endangered species. This is one of the reasons why the authors intend to trigger more interest among their fellow entomologists about these curious wasps. They have compiled all relevant information concerning their distribution, abundance, habitats, flight season and host species. The authors have tried to keep their identification key as comprehensive and concise as possible, by singling out the essential information on diagnostic characters.

In the present study, the researchers describe a new species, called Chrysis borealis, which can be translated as ‘Northern’ cuckoo wasp. Although the male and female individuals are very similar, there is a significant variation in the colouration within the species. It is especially noticeable between the specimens collected from the northern localities and those from the southern ones. For instance, while the middle section of the body in southern specimens is either bright blue or violet with a greenish shimmer, in northern individuals it is nearly black, turning to greenish or golden green at the periphery.

The varying shades within a certain species are quite common among the cuckoo wasps. While it is often that distinctive colouration among other wasps and insects indicates their separate origin and therefore, taxonomic placement, within the emerald family it can be a mere case of habitat location with the northern populations typically darker.

Such tendencies often lead to doubts such as the one the authors have faced regarding their new species. It has been suggested that the Northern cuckoo wasp is in fact yet another variation of the very similar C. impressa, which is generally slightly brighter in colour, but at the same time distributed in warmer localities. However, using DNA sequence information and morphometric analysis, the team shows that there are enough consistent differences to separate them as distinct species, although they are defined as evolutionarily young siblings.

With their research the authors intend to provide a basis for further and more detailed studies on the distribution, biology and morphology of the North European representatives of these intriguing wasps.

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Original source:

Paukkunen J, Berg A, Soon V, Odegaard F, Rosa P (2015) An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species. ZooKeys 548: 1-116. doi: 10.3897/zookeys.548.6164

Tramp ant caught globetrotting under false name

A century-old mystery surrounding the origin of an invasive ant species was recently solved by an international team of scientists. Since 1893, when it was first discovered as an invasive species in the Canary Islands, entomologists have been debating where this mystery species came from. While some insisted on the Mediterranean, some proposed Arabia and others argued for Africa. The correct answer? Asia.

The authors of the study, published in the open-access journal ZooKeys, solved the taxonomic puzzle by fitting together disparate pieces of evidence. “I was having a terrible time trying to distinguish this one Asian species from the mysterious ant that was coming in on shipments from the Caribbean, Europe and Africa,” says Dr. Eli Sarnat, University of Illinois, about his research at the Smithsonian on tramp ants that were intercepted at US ports.

Tramp ants, many of which are pest species, are spread across the globe by stowing away in the cargo of ships and planes, thus posing rising environmental, food security and public health concerns.

The same day Sarnat was working on the mysterious ant in the Smithsonian, he received an email from Dr. Evan Economo, Okinawa Institute of Science and Technology (OIST). Economo and Dr. Georg Fischer, also affiliated with OIST, had included Madagascar samples of the species in a genetic analysis, and the results unexpectedly placed it within a group of Asian species. The closest genetic match to the enigmatic ant turned out to be the very same Asian species that Sarnat had found in the Smithsonian collection.

The last piece of the riddle was discovered thanks to the painstaking work of Dr. Benoit Guénard. Guénard, a professor at the University of Hong Kong, had spent years mapping the global distributions of every ant species known to science. When he compared the ranges of the mysterious ant with the common Asian species, the two fit together like a jigsaw puzzle.

Evidence gathered from classic taxonomy, modern genetic analysis, and exhaustively researched distribution maps all pointed to the same conclusion.

“What had long been considered two different species — one found across a wide swath of Asia and the other a tramp species spread by humans across Europe, Africa, the Americas and Australia — are actually one single supertramp species,” Economo explained. “It is striking that we had these two continental super-common invaders with almost entirely complementary ranges right under our noses, yet until now no one noticed they were actually the same species,”

Original source:

Sarnat EM, Fischer G, Guénard B, Economo EP (2015) Introduced Pheidole of the world: taxonomy, biology and distribution. ZooKeys 543: 1-109.doi: 10.3897/zookeys.543.6050

Additional information:

This work was supported by USDA APHIS Identification Technology Program (13-8130-1439-CA), subsidy funding to OIST, and NSF (DEB-1145989). This work was supported by USDA APHIS Identification Technology Program (13-8130-1439-CA), subsidy funding to OIST, and NSF (DEB-1145989).

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.

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