The Flowtron BK-40D is a plug-in outdoor lantern zapper with two UV black light bulbs, an electrified grid and a slot for an octenol mosquito lure. Bob Vila's Tony Carrick ran it against five other zappers over several summer nights in rural North Carolina, rated it 9/10 and called it the best of the group at thinning out biting insects. His complaints were the very short power cord, the bright blue light and utilitarian looks, and the fact that it kills beneficial insects along with the biting ones.
Full review
How Bob Vila tested it
Bob Vila's standalone review, by Tony Carrick, put the Flowtron up against five other bug zappers over several summer nights in humid, bug-ridden rural North Carolina. Carrick looked at setup, how well it attracted and killed biting insects, cleaning and maintenance, and what it did to the look of the yard. He rated it 9/10 and wrote that it outperformed and out-zapped the other models he evaluated.
Bob Vila's separate bug zapper roundup, which tested six models, also names this Flowtron its best overall pick.
Setup and the short cord
The unit comes fully assembled. Carrick hung it from a bird-feeder hook about 30 feet from his patio, following the manufacturer's advice to keep a buffer between the zapper and the seating area, and slid the octenol cartridge into the holder on the bottom.
The catch is the cord. Bob Vila reports it extends less than a foot from the unit, so Carrick needed a 40-foot extension cord to reach an outdoor outlet, which he found unsightly and a tripping hazard. The roundup adds that there is no on/off button, so its testers used a switched power strip.
What it did to the bug population
Bob Vila says the zapper began registering kills just minutes after being plugged in, and that after about 15 minutes there was a steady flow of insects heading to it. Flowtron claims a 1-acre range; the review says it appears to do just that, while the roundup calls that figure ambitious.
Carrick found mosquito activity on his back patio declined noticeably, but he still suffered a bite or two with a densely wooded area behind the house.
Looks, noise and collateral damage
Bob Vila describes the fluorescent blue light as very bright and the design as utilitarian, and warns that some people will be put off by the constant popping. A guard surrounds the bulbs and grid, but the review still advises hanging it out of reach of pets and small children.
The review also notes the Flowtron kills indiscriminately, taking out beneficial nonbiting insects along with mosquitoes, and suggests running it only on nights when people are outdoors.
Running costs
According to Bob Vila, an octenol cartridge lasts about 30 days and a replacement three-pack costs about $15. The review judges the zapper worth the money for large areas with a significant mosquito problem, and says a smaller, cheaper zapper may be enough for minor ones.
Strengths
- +Rated 9/10 by Bob Vila, which found it out-zapped five other models
- +Registered kills within minutes of being plugged in, per Bob Vila
- +Bob Vila found mosquito activity on the patio declined noticeably with it running
Watch-outs
- −Power cord is less than a foot long; Bob Vila needed a 40-foot extension cord
- −Bright fluorescent blue light, constant popping and utilitarian looks, per Bob Vila
- −Kills all flying insects, including beneficial nonbiting ones, Bob Vila notes
- −No power switch; it must be unplugged to turn off, per Bob Vila's roundup
How it compares
The Flowtron BK-40D Electronic Insect Killer is the only outdoor-only unit on this page and the only one Bob Vila scored in a standalone review. Bob Vila lists its coverage as up to 1 acre, against about 625 square feet for the Black+Decker BDPC941 Bug Zapper, and found the Flowtron far more effective in a heavily wooded yard but much louder and brighter than the near-silent Black+Decker. Its grid is listed at 5,600 volts, double the 2,800 volts of the ASPECTEK Electric Indoor Bug Zapper.
Rating sources
Counts as 4.18/5 in our score — this publisher's 42 scores on the site average 4.53, so its scores are adjusted down to compare fairly with other publishers.
“I don't see any reason to get a different brand since this one worked so well.”
“it's probably the best bug zapper I've tried lots of them I have one in the front yard one in the backyard and hands down it's the best”
Our 4.2 score is the average of the 1 scored review above, each adjusted for how strictly its publisher scores; 3 more reviewed it without printing a score and are not in the average. More about methodology.
