QUESTION: We have lived in Kailua for 40 years, but now have a major fly problem that’s been escalating for well over two years. At any given time, I can stand in my front yard and count 15 flies on one leg alone, if not more. We do have pets, but have always had pets; also, we pick up after them daily. Pest control companies cannot help without a known source. We have tried bait traps, but they do not make a dent in the number of flies. We have tried hanging zip-close bags with water and pennies in them, growing basil, spraying soap sprays. We even had our sewer pipes checked to make sure the flies were not attracted to underground leaks. Because we have pets and children, harsh chemicals and pesticides are not an option. I have spoken to close neighbors and other families in Kailua, and they all have a fly problem. Our tree trimmer says that he encounters flies at just about every home he works at in Kailua. I have even heard our town referred to as "Flylua." I contacted the University of Hawaii last May and sent samples but never heard back; I contacted the Department of Health and was told that they only deal with rats. Is there an entity/agency that might be able to help?
ANSWER: The state Department of Health was hit hard by budget cuts and layoffs in 2009, so much so that there now is only one person available to do fieldwork on vector complaints for the entire island of Oahu.
That person concentrates only on complaints from state-owned properties, on identifying new species or on communitywide complaints, said Peter Oshiro, manager of the department’s Environmental Health Program.
"At this time, flies are not a very high priority, but we will look into it as the complaint alleges it to be communitywide," Oshiro said.
You were asked to provide a sample of either a dead or live fly or have an inspection done of your property.
"The sample will help our entomologist determine the origin of the fly," Oshiro said.
THE FOLLOW-UP
Department of Health entomologist Pingjun Yang and a colleague did visit your property to assess the problem and, despite your conscientiousness in picking up after your dogs, has concluded the flies are the result of pet wastes.
As he noted in an email to you, Yang collected five species of flies from your yard: the dog dung fly, the bronze bottle fly, Tricharaea occidua, Milichiella lacteipennis and a pepper fruit fly.
He said Tricharaea occidua is a small fly breeding on dog dung and cat feces; Milichiella lacteipennis is a tiny fly breeding in organic materials; the pepper fruit fly is a small fly breeding on rotten fruits; and the bronze bottle fly is the most prevalent home-invading species in residential areas, breeding and feeding on carrion and garbage.
The common fly species is the dog dung fly, Yang said.
"This species is very annoying because of its persistent attraction to (the) human body."
The breeding sources for this species are dog dung and cat feces.
Yang noted you and your neighbors have large dogs, and many dog dung flies were found in your yard.
A few dog dung flies were also found on nearby trash cans.
Because the dog dung fly’s life cycle, egg to adult, is only about 11 days, and adult flies can live about five weeks, Yang said it is easy to build up a large fly population in the community.
Also, "The flight range of this species is 3.5 miles — quite far," Yang said. "Since we only checked a small area of the community, we cannot say there is no community problem with flies."
However, he said the Health Department had not received any other fly complaint from Kailua in the past two months.
To deal with fly infestations, Yang said pet feces should be removed daily, by first placing it in a plastic bag, then placing the bags in a trash container with a tight lid.
"Do not bury dog dung," he said, because if it contains fly eggs, burial will not prevent the development of larvae and more flies.
Write to “Kokua Line” at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email kokualine@staradvertiser.com.