How to get rid of mosquitoes, gnats and cockroaches

Reader and old friend Valerio wants to know how to get rid of mosquitoes, gnats and cockroaches.

    Growing up in Singapore, I'd had my share of mossies and cockroaches.

    Mossies love me in any country, any part of the world:  Singapore, Indonesia, Taiwan, Finland, Japan, France, Spain -- just to name a few.  Singapore people would console me by telling me that I had intelligent blood.

    So, my having fallen prey to mossies everywhere would say that I'm not the right person to ask about deterring them.  I can, therefore, only offer some ideas, which may or may not work.

Mosquitoes and gnats:  maybe try the wine bottle residue trick. (How to trap fruit flies: https://piccola-chinita.blogspot.com/2026/03/how-to-trap-fruit-flies.html)  

Cockroaches:  maybe have the wine bottle lying on its side (horizontally) for them to get in.  I don't know what cockroaches like, but I've heard that rotting fruit like plums have a high alcoholic content, so bees/wasps/hornets that feed on rotting fruit in the garden often get so drunk they can't fly.  Maybe throw an overripe plum into the horizontal bottle, leave it to rot in there, and see if cockroaches will go for it.

Mosquitoes:  one method that's supposed to help (deter them) is to take Vit.B7 or B12, but googling tells me "there's no scientific evidence".  For sleeping, the best is a mosquito net, which is very common out in the tropics (and other parts of China), but you'd still need a solution for when you're not able to stay in bed.

Sticky glue paper:  the French farm that I used to go to and a restaurant in S.E. China hang them from the ceiling for the huge population of flies they get, but it looks gruesome with the flies stuck to them -- you have to leave them there for a while, as you can't keep replacing them.  If you want to try them (if you have beams), make sure they're higher than the top of your head, so that you don't walk into them.

Flies and mosquitoes:  one common Chinese practice is to hang a bead curtain in the doorway.  Flies and mosquitoes are supposed to be unable to negotiate the bead "wall" which will still allow air to circulate in the hot weather (vs a solid door).

For any flying insects:  I've seen those lamps (that emit a UV light) which attract insects and electrocute them.  Googling tells me that they're called UV Light Bug Zapper.  (From googling) UV light insect traps use 365nm wavelength tubes to attract flies, mosquitoes, and moths, killing them via high-voltage grids or adhesive boards. Suitable for indoor/outdoor use, popular models include AspectEK and FanFuGuo 20W lamps. They offer a chemical-free, hygienic pest solution, often requiring UV bulb replacements every 12 months for maximum efficiency.

(From googling in Chinese; translation by google translate)

Cockroaches:

自然处理蟑螂的核心在于“物理阻隔+天然毒饵+驱赶气味”。最有效的方法包括：用硼酸+砂糖（1:1）制成毒饵；利用小苏打+砂糖诱杀；使用肥皂水直接喷杀；以及在角落放置薰衣草、薄荷、香茅或柠檬精油 以驱赶它们。同时，保持家居环境干燥和清洁是根除的关键。

The core of natural cockroach control lies in "physical barriers + natural poison bait + odor repellent". The most effective methods include: making poison bait with boric acid and sugar (1:1); using baking soda and sugar to lure and kill them; spraying directly with soapy water; and placing lavender, peppermint, lemongrass, or lemon essential oils in corners to repel them. At the same time, keeping the home environment dry and clean is key to eradication.

Mosquitoes

使用自然方法处理蚊子，核心在于“物理阻隔”、“环境清理”和“天然驱避”：安装纱窗、蚊帐以阻隔蚊子；清除花盆、水缸等处的积水以杜绝滋生；利用香茅、薄荷、迷迭香等驱蚊植物 或艾叶、柑橘皮点燃产生烟雾来驱赶；同时使用电蚊拍或捕蚊灯辅助杀灭。

The core of using natural methods to deal with mosquitoes lies in "physical barriers," "environmental cleanup," and "natural repellency": installing screens and mosquito nets to block mosquitoes; removing stagnant water from flower pots, water tanks, etc. to prevent breeding; using mosquito-repelling plants such as citronella, mint, and rosemary, or burning mugwort and citrus peels to produce smoke to repel them; and using electric mosquito swatters or mosquito lamps to assist in killing them.