My 'less than complete information' on eggshell use:Anianna wrote:I haven't tried it myself, but I have been told that ground eggshell powder will kill insects over time if you pour it on them.
-Specific to the Cabbage White Butterfly and their caterpillars, the efficacy will almost probably in all cases be nil.
**They are never on the ground to pour the eggshells on them or as something they can crawl through. Their entire existence from birth to death is in the air and on a leaf.
**Pouring the eggshells on the underside of the leaf will not hold it.
**If I actually see the buggers to be able to pour it on them I would do better to just smash it where it sits since the eggshells are not immediate death anyway (d#%$ it) and the buggers will continue to eat until their demise.
There are other caterpillars that do go from ground to leaf and back again so I would think eggshells could have at least some effect on them.
One of these is the Leaf Eater caterpillar that I've found feeds mostly at night (ten times more voraciously than the Cabbage White caterpillar) then burrows in the soil around the plant in the day.
If you walk out one day to see some or a bunch of your leaves mere skeletons, and find no caterpillars on the leaves, take a small stick and disturb the soil allllll around the plant to abt five inches from it, and down to about a quarter inch or a little more deep to look for these caterpillars.
But snails & slugs are a different story with the eggshell I'm led to believe because they are on and off the soil for the entire life of the crops they eat. So ringing the plant with crushed eggshells 'seem' to be an effective deterrent (as reported by some gardeners) and possibly a long term exterminator for them.
I don't remember where I read it (but it was multiple places) but ringing a plant with coffee grounds has a similar effect for slugs and snails. But I do not remember if used coffee grounds are as effective and out of the can because I sort of remember something about a neuro toxic effect. Possibly like speed from the caffeine?
Am fuzzy on particulars about the coffee ground deterrent/extermination thing. Google will know, if I find time.