In about 1990 we applied Milky Spore to our lawn, just once, in the fall, after several years of  trapping Japanese beetles  in funnel shaped plastic bags with flower-scented lures. I’ll never forget the sickly sweet smell after it rained,  and the dead beetles started decomposing! Milky Spore Disease was outstandingly  effective, already the following summer. Over the past 20 years it has been rare to spot even one beetle.

Then why do I keep hearing  reports of failures from various people? We even received a refund from the mail order company the next year, as many people had reported failure. How were their lawns different from ours? I wish a research agency would do a systematic study! In the meanwhile, perhaps internet comments can begin to solve the mystery.

Gadwa Case in Cheshire CT.

1: Our  high beetle population at the time of application must have allowed an initial build-up of high spore concentrations.

2. We live on an exposed  ridge top in central Connecticut – Hardiness Zone 5b.

3. We had used no herbicides or insecticides, but  some  chemical fertilizer (granules about once a season), and had initially added much composted cow manure & peat moss to our four year old lawn.

4. Our soil was a stony, well-drained fine sandy loam (largely subsoil, stripped of topsoil when the house was built), derived from glacial till, sunny in 1990.

If it were only clear how to make Milky Spore Disease work, I’m sure this natural one-time control would be preferred by most to repeated applications of  long-lasting broad spectrum neurotoxins, such as  imidacloprid!    Imidacloprid  is toxic to ALL insects, be they pests or  benign, and harms human health as well.  It  has a half life of up to 730 days, and migrates through the soil.  Imidacloprid is the active ingredient in  Merit, Preen and Bayer Advanced, among others. The new formulation of GrubEx has Chloratranilipole, also a systemic, broad- spectrum insect neurotoxin, toxic to aquatic life – but with less risk to mammals (like us) and birds and somewhat less persistent.

Comments on others’  experiences are very welcome!