New ant species found in poison frog's stomach
While new ant species are usually discovered when researchers go through leaf litter, it turns out that sifting through the stomach contents of insect-eating frogs might prove no less effective.
A new species of the rarely collected long-toothed ant was discovered in the belly of a Little Devil poison frog in Ecuador, and the finding was published in the open access journal ZooKeys.
The new species, Lenomyrmex hoelldobleri, was described based on a single female worker ant recovered from the frog. It is the seventh known species in this little-known Neotropical genus.
Similar to its relatives within the group, this ant has a slender and elongated mouthpart, but is larger than any of the other species. Its remarkable jaws suggest specialised predatory habits, but nothing is known about its feeding behaviour, according to a press release by ZooKeys.
The frog, whose diet consists mostly of ants, was collected from the Ecuadorian region of Choco. Even though the region is one of the most biologically diverse areas in the world, it is also one of earth's most threatened areas.
Humans' violent nature may be 'deeply rooted'
A team of scientists has concluded that human beings' violent nature was at least partly inherited from an ancient ancestor and shared with other primates.
Lethal violence appears to be "deeply rooted" in the lineage of monkeys, apes and Homo sapiens, the researchers wrote in the science journal Nature.
The Spanish researchers gathered data on more than four million deaths in 1,024 present-day mammal species, as well as over 600 human populations from the late Stone Age, some 50,000 to 10,000 years ago, until today.
The animals sampled represent about 80 per cent of mammal families.
The researchers looked specifically at the proportion of deaths caused by lethal violence perpetrated by a member of the same species - in humans, it included war, homicide, infanticide and execution.
They also searched for similarities between species with common ancestors, which they used to infer how violent those predecessors would have been, and to reconstruct a history of ancestral killing rates.
Overall, the researchers found, intraspecies killing was the cause of about 0.3 per cent of mammal deaths.
But for the ancestor of all primates, rodents and hares, killings caused about 1.1 per cent of deaths, rising to 2.3 per cent for the next, more recent, common ancestor of primates and tree shrews - small mammals native to the tropical forests of South-east Asia.
By the time the common human ancestor first appeared around 200,000 to 160,000 years ago, the rate was about 2 per cent - similar to that for other primates, the team found.
Study co-author Jose Maria Gomez Reyes said the new data showed there was "an evolutionary component to human violence, not that this is the only component". This evolutionary component is not only genetic, but also "most likely" influenced by environmental pressures on survival.
Invasive insects cost the world billions per year
Ecologists have estimated that invasive (non-native) insects cost humanity tens of billions of dollars a year and such imported vermin are likely to increase with climate change and growing international trade.
Researchers from the University of Adelaide in Australia, as well as France's National Centre for Scientific Research and Paris-Sud University, have compiled the first comprehensive and robust database of the global economic costs of invasive insects. But they said estimates are likely to be greatly underestimated because of the lack of research into costs in many parts of the world.
Published in the journal Nature Communications, the researchers report a minimum US$70 billion (S$96 billion) annual cost globally to goods and services, and more than US$6.9 billion a year in health costs, from invasive insects.
"Most of the damage to human industry occurs in agriculture and forestry - damage and loss of production and also costs of clean-up, eradication and prevention," said Professor Corey Bradshaw from the University of Adelaide's Environment Institute, in a press release by the college.
"Billions of dollars are spent on the treatment and prevention of infectious diseases like dengue, West Nile virus and chikungunya disease spread by insects that have invaded other countries."
An example of an invasive insect is the Formosan subterranean termite transported worldwide from eastern Asia. A colony of this termite is capable of consuming as much as 400g of wood a day. Another example is the gypsy moth, of Eurasian origin, which is one of the most destructive pests of hardwood trees.
The researchers report that these costs are probably just "the tip of the largely unseen and unmeasured iceberg" because many regions of the world, such as Africa and South America, have yet to measure and estimate many of these costs.
Correcting for minimal sampl- ing bias could bring total annual global costs of invasive insects to as high as US$270 billion.
Compiled by Samantha Boh