Daily Sitka Sentinel

‘Love Bugs’ Compete With Local Berry Pickers

By SHANNON HAUGLAND

Sentinel Staff Writer

There’s not much to love about the bugs that have been bothering berry pickers in the woods around Sitka.

March flies crawl on Indian celery flowers today. (Sentinel Photo)

March flies, called “love bugs” because they swarm and mate in flight, make an annual appearance, but they have been a particular nuisance this year.

Michael Shephard found that out when he went berry picking last week.

“You had to pick them off the berries,” said Shepherd, a former Sitkan visiting from Anchorage. “They were swarming on the salmon berries to the point that you couldn’t see the berries.”

“It was extraordinary,” said Linda Behnken, a Sitka friend who also noticed the bugs. “They were inside the berries, all over the berries – I’ve never seen anything like it.”

It’s not clear why so many of the bugs, in the family Bibionidae, showed up.

“We’re seeing them here too. It sounds like you’re seeing more of them,” said Elizabeth Graham, a Ph.D. entomologist with the U.S. Forest Service’s Division of State and Private Forestry in Juneau. 

Graham said the name “March fly” is a bit of a misnomer since they tend to come out later than that. They are described as “medium-sized flies with a body length from 4.0 to 10.0 mm,” with a black, brown, or rusty and thickset body, and thick legs.

Other facts about the March fly, provided by Graham:

– the adults are important pollinators, often found on flowers feeding on nectar. “However they do also seem to have a taste for salmonberries here!” Graham wrote in an email.

– the adults are an important food source for insectivorous birds; the mass emergence often coincides with the return of these birds to their nesting sites.

– the adult males emerge first then hover over female emergence sites. Once the females emerge the males compete for mating.

– the adults live three to five days. However, the cycle of emerging bugs is repeated in early summer “so it seems like they’re around longer,” Graham said.

– they spend most of their lives as larvae, feeding on organic litter on the forest floor and play an important role in nutrient recycling, Graham said. 

Graham said she doesn’t know the reason why the flies are having such a good year, but notes that populations are sporadic.

“In some agricultural settings (scientists) connected large swarms with the thickness of litter for them to decompose,” she said. She said studies in Florida suggest that March flies do better in warmer areas, so it is possible that milder temperatures in Southeast have contributed. But Graham added that this is only a hypotheses, and there is not enough research on the subject to support it.

Shephard said he doesn’t remember such bug swarms while picking berries during the 10 years he lived here before moving away.

“They were kind of annoying,” he said.

Behnken agreed, and said she’s glad that it appears the peak of the swarming appears to have ended about a week ago.