Killing the Red Lily Beetle

I have the dreaded red lily beetle (aka scarlet lily beetle). Yesterday I saw several adult beetles living on the Fritillaria imperialis in my bulb bed, as well as on the Lillium ‘America’ in my long bed, but not (yet) on the shorter Lillium ‘Stargazer’ in the same bed about 15 feet away.

So I sprayed Lillium ‘America’ with Schultz House & Garden Insect Spray (0.02% Pyrethrin) yesterday. The product claims to work on beetles, and today I saw no beetles there, although they were still on the unsprayed F. imperalis. But I have seen reports of very limited effect from this organic pesticide, and it’s close to impossible to spray-cover all parts of this Lily plant, whose leaves are still quite curled up, especially if you want to avoid overspray.

I do not want to use far more toxic pesticides such as imidacloprid. Instead, I have a more radical plan, or experiment, in mind. That is to use fumigation (i.e., gas, within an enclosure). In general, fumigants are considered too dangerous for amateur use. But I would use either cigarette smoke or carbon dioxide to kill the beetles, and I can’t see fearing either gas (well, smoke is more like an aerosol), especially when used outside, and within an enclosure.

Basically, I could upend a container like a trash can – preferably clear – on the plants. This container would have two holes in it, one connected to a hose, the other with a flap or other one-way valve on it. Since smoke (and carbon dioxide) is heavier than air, I will pump smoke into the lower hose, with air to vent out the top until the container is full of smoke. The cigarette will be held within a pipe-like mechanism, surrounded by a glass cylinder, so I can watch the cigarette burn down as I pump air into the mechanism, through the hot cigarette, and into a narrower tube placed on the filter. (I may remove the filter; why reduce the toxins?)

Of course, I do not know if this will work – ideally, kill adults, eggs and larvae. I have read of a high-school science experiment / propaganda, where tobacco smoke is shown to kill flies, which are unharmed by a similar amount of paper smoke. Also, nicotine has long been used as an insecticidal powder, and is in the tobacco plant precisely as a systemic pesticide, as are most plant toxins. It’s just a question of dose and duration, relative to the particular susceptibility of the Lily Beetle.

Provided the beetle infestation survives the pyrethrin – which seems likely – I think I will have to head out to a hardware store, or maybe a head shop, if they still have those, soon.

Whether tobacco works or not, I may also try carbon dioxide. It’s easy to get 10 to 20 oz. tanks of pressurized liquid CO2 for use in “constant air” paint ball guns (they’re rather smaller than the standard propane tank used by plumbers).

I have not been able to find anything concerning horticultural use of tobacco smoke as an insecticidal fumigant. Does anyone have any experience with such methods, or know of any source concerning the same?