Researchers have found nearly four times more specimens of a rare insect on Maunakea this year than in the last two years combined.
This year, live traps set out by researchers at the University of Hawaii at Hilo’s Center for Maunakea Stewardship collected nearly 3,000 wekiu bugs, a rare insect endemic to the Maunakea summit area.
By comparison, traps laid at the same spots the prior two years only collected about 400 specimens a year.
“It’s normal for insect populations to fluctuate like this,” said CMS natural resource specialist Jessica Kirkpatrick, before adding that the wekiu bug was a candidate for the U.S. Fish and Wildlife Service’s endangered species list as recently as 2011.
Each year, CMS places live traps at more than 100 sites on UH-managed lands on Maunakea, some on top of cinder cones more than 200 feet high.
The traps sit out for three days, baited with tuna fish — “the bugs are attracted to stinky things,” Kirkpatrick said — until a researcher stops by, notes the number, gender and life stage of the specimens collected before releasing them.
Kirkpatrick said this year’s wekiu increase could be because of an increase in precipitation at the summit area.
“These insects need moisture to survive, especially because the summit area is so dry,” Kirkpatrick said. “We’ve seen some correlation between periods of high precipitation and an increase in wekiu bugs.”
Even during the more recent lean years for the bug, Kirkpatrick said the traps were able to collect specimens at all stages of life, indicating that the population has continued to reproduce.
However, because the species is confined to the fragile ecosystem of the summit, a few bad years could lead to the species’ extinction.
In particular, Kirkpatrick said, ants pose the primary threat for wekiu bugs.
There are no ant species native to Hawaii, and one of the invasive species, the Argentine ant, is capable of surviving the cold temperatures at Haleakala summit on Maui — if introduced on Maunakea, it could reduce the area’s native pollinators by 70%.
And because wekiu bugs are scavengers — feeding on dead and dying insects blown to the summit by the wind and killed by the low temperatures — they have no means of actually defending themselves from ants or other threats.
For now, however, the bugs appear to have a healthy population.
“Our commitment to monitoring native species on Maunakea goes beyond overseeing their condition and status,” Greg Chun, CMS’ executive director, said in a statement. “We are deeply devoted to the protection and safeguarding of these precious species that live and breathe within this wahi pana.”
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.