In the belly of the Devil: New rare ant species found in the stomach of a poison frog

While new ant species are usually discovered in surveys involving researchers searching through leaf litter, it turns out that sifting through the stomach contents of insect-eating frogs might prove no less effective, especially when it comes to rare species. Such is the case of a new species of rarely collected long-toothed ant, discovered in the belly of a Little Devil poison frog in Ecuador.

The international team of Drs Christian Rabeling and Jeffrey Sosa-Calvo, both affiliated with University of Rochester, USA, Lauren A. O’Connell, Harvard University, USA, Luis A. Coloma, Fundación Otonga and Universidad Regional Amazónica Ikiam, Ecuador, and Fernando Fernández, Universidad Nacional de Colombia, have their study published in the open access journal ZooKeys.

The new ant species, named Lenomyrmex hoelldobleri after renowned myrmecologist Bert Hölldobler on the occasion of his 80th birthday, was described based on a single individual – a female worker, recovered from a Little Devil poison frog. It is the seventh known species in this rarely collected Neotropical genus.  

Similarly to its relatives within the group, this ant amazes with its slender and elongate mouthpart, yet it is larger than all of them. The remarkable jaws speak of specialised predatory habits, however, so far, nothing is known about these ants’ feeding behavior.in-full-face

The amphibian, whose diet majorly consists of ants, was collected from the Ecuadorian region Choco, which, unfortunately, despite being one of the most biologically diverse areas in the world with exceptionally high levels of endemism, is also one of Earth’s most threatened areas.

In conclusion, the authors point out that “studying vertebrate stomach contents is not only a way of studying the trophic ecology” (meaning the feeding relationships between organisms), “but also an interesting source of cryptic and new arthropod species, including ants.”

Furthermore, the scientists note that nowadays there is no need to kill a frog, in order to study its stomach. “Stomach flushing methods have been developed and successfully applied in numerous studies, which avoids killing individuals.”

 

Original source:

Rabeling C, Sosa-Calvo J, O’Connell LA, Coloma LA, Fernández F (2016) Lenomyrmex hoelldobleri: a new ant species discovered in the stomach of the dendrobatid poison frog, Oophaga sylvatica (Funkhouser). ZooKeys 618: 79-95. doi: 10.3897/zookeys.618.9692

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).

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.