Two New Creeping Water Bug Species Found in Belize and Peru
By Kevin Fitzgerald
Two new insect species have been added to the 900,000+ species that have previously been described: Ambrysus cayo, which was found in streams in western Belize, and Procryphocricos pilcopata, which was found in streams in southeastern Peru. Both are true bugs in the suborder Heteroptera in the family Naucoridae and the subfamily Cryphocricinae — the saucer bugs (also called the creeping water bugs), so called because of their round, flat shape.
The discoverers are Dr. Robert W. Sites of the University of Missouri’s Enns Entomology Museum, Dr. William Shepard of the University of California-Berkeley’s Essig Museum of Entomology, and Dr. Shepard’s wife, Cheryl Barr. Dr. Sites and Dr. Shepard have collaborated on many insect-collecting expeditions around the world. Dr. Sites is a specialist in aquatic hemipterans, and Shepard specializes in aquatic beetles.
Descriptions of the new species appear in an article called “Neotropical genera of Naucoridae (Hemiptera: Heteroptera: Nepomorpha): New species of Ambrysus and Procryphocricos from Belize and Peru,” which was published in the Annals of the Entomological Society of America.
The Naucoridae are found in still water and running streams, and a few are even found in waterfalls. There are about 383 species in 37 genera and five subfamilies. They resemble the giant water bugs (Belostomatidae) and are related to the water boatmen and water scorpions, and are found in tropical and temperate regions.
Ambrysus cayo was discovered by Sites and Shepard in April 2014. According to Dr. Sites, it’s “about the size of a fingernail, with dark wings, and orange marks on the wings.” An adult A. cayo is 9.76 mm long, and its maximum width is 6.2 mm. The species is aquatic, in both the nymphal and adult forms. The New World genus Ambrysus is widespread, found from northern North America to Argentina, with its greatest diversity in Mexico in running streams.
These insects, with their powerful claws that allow them to cling to rocks and gravel, are perfectly at home in their turbulent worlds. Their hard beaks are used to pierce prey — mostly other insects and small fish — and then to draw up the inner fluids through their straw-like mouthparts.
A. cayo breathes underwater by means of a bubble tucked under its wings. Dissolved oxygen in the water diffuses into the bubble and into the insect.
Like all hemipterans, A. cayo is hemimetabolous, so it doesn’t undergo an elaborate metamorphosis and there are no larval or pupal stages. Instead, the young insects (the nymphs) resemble the adults. The only major changes from nymph to adult is in size and in the growth of wings and sexual organs.
Procryphocricos pilcopata was discovered in Peru in October 2012 by Cheryl Barr and her colleague from the University of Kansas, entomologist Caroline Chaboo. It was rediscovered in Peru in September 2013 by Dr. Shepard and Cheryl Barr. The discovery of this aquatic species is the first record of Procryphocricos in Peru, although other species of the genus have been discovered in Colombia and Venezuela.
According to Dr. Shepard, “It’s small, flat, dark-brown, nondescript, and might easily be overlooked.” Its length is 5.68 mm, with a maximum width of 3.44 mm.
So how can anyone find these tiny creatures? The scientists capture the underwater insects by turning over rocks and leaves and having a net ready in the water. The insects get caught by the current and flow right into the net.
“We know how to collect in areas where fauna was never checked before for aquatic insects,” said Dr. Shepard. “Dr. Sites and I have long experience netting and turning over rocks and leaves.”
To breathe underwater, P. pilcopata uses a plastron, a network of flat-topped setae or hairs on the body, which holds a thin film of air. Dissolved oxygen in the water diffuses into the film, which is passed on to the insect’s body. Like its cousin, A. cayo, the species is carnivorous, and clings to rocks and gravel with powerful claws. Reproduction is similar to that seen in A. cayo.
Shepard and Barr searched streams for insects at descending elevations, from cloud forests right down to the Amazonian lowlands.
“Getting there was exciting,” said Shepard. “We drove from Cuzco on a one-lane dirt road, and had to watch for big trucks coming the other way. We had to stop and wait while people in buses cleared roads of landslides. We stayed in local hotels and rooms.”
However, landslides were among the least of their worries.
“Actually, the greatest danger we face [in the field] is from tiny organisms — viruses, bacteria and fungi,” Shepard said. “Both Bob and I are heavily vaccinated, and both of us carry a small pharmacy of antibiotics, disinfectants, pain killers, and antihistamines. But we still get diseases. For instance, I have picked up both dengue and blood flukes (schistosomiasis). Bob has been infected with dengue cytomegalovirus, and malaria. We also are very watchful for poisonous snakes and crocodiles. Minor problems have also involved corrupt police, army, and guerrilla folks.”
Despite all of the difficulties, the scientists believe that they need to hurry up and collect before it’s too late.
“We must collect now because of the destruction of the Amazon forests,” Shepard said. “Habitat is being destroyed by mining and clear-cutting. We have to try and get as many insects as possible so we can at least save records that these things existed. Insects get studied last, since they’re less charismatic.”
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Kevin Fitzgerald is a freelance science writer living in Connecticut. He has published in newspapers, encyclopedias, and online.