http://www.durgan.org/URL/?PGJCQ 27 June 2012 Colorado Potato Beetle. First or second generation?
After five weeks constantly picking four times per day from 18 May to 27 June,the Colorado Potato Beetle (adults about 200, instars (larvae,etc) about 2000 plus, and egg clusters about 50),from 70 potato plants and 4 egg plants,it appears there are few left.Today all I found were two adults,of second generation. It was a hard won effort, since I did not want to use insecticides.Temptation was resisted to the bitter end. Here are pictures of the two adults picked today.On 28 June, one second generation adult was found.
http://www.durgan.org/URL/?WSBLL 12 June 2012 Larvae of Colorado Potato Beetle
Since about the 18 of April, I have picked about 200 adults, 60 egg clusters, and probably around a 1000 larvae.
A few facts about the Colorado Potato Beetle.
From egg to egg laying adult takes 22 days under ideal conditions.
One adult lays an egg cluster of about 60 eggs at one sitting. During their life span of generally about five weeks a female can lay about 300 eggs.
The second generation adults either lays eggs or go into dormant mode for next years assault.
They survive as adults in the soil during the dormant period.
The eggs turn into larvae (munchies my term), moult four times before turning into adults.
Apparently they become immune to pesticides rather quickly, so the same control should not be used year after year.
Egg plant is a host.
A hot three days and the hatching eggs can lay waste to a patch of potatoes, absolutely strip the leaves clean.
The infestations get more severe each year if no action is taken.
Crop rotation must be a field about half a mile distant.
The beetle did not originate in Colorado, but is of Mexican origin.
It is best to do a complete kill before the eggs turn into adults. This means getting all the adults in early Spring before they lay eggs, and if eggs are laid get all the clusters, while the potato plant is small.If egg plants are grown check these, since egg plant is a host. The eggs are always on the underside of the lower leaves. Hand picking is out of the question if a patch is large. It is simply too labour intensive.
http://www.durgan.org/URL/?OKJFX 18 May 2012 Colorado Potato Beetle
The potatoes are just starting to emerge from the soil, and the Colorado Potato Beetle is out in force. I collected 22 adult beetles and found one egg cluster. The plants are being powder sprayed with diatomaceous earth/boric acid powder, but this probably affects the young leaf eaters after they emerge from an egg clusters, speculation only at this juncture. For hand picking it is best to collect the adults and carefully check for egg clusters and destroy both. After the eggs hatch the plant is covered with hungry munchers, making hand destruction difficult. Diatomaceous earth/boric acid powder has absolutely no effect.
http://www.durgan.org/URL/?RVOCO 18 April 2012 Colorado Potato Beetle
While rototilling the garden row to plant radishes, I discovered two Colorado Potato Beetles in the soil in the centre of the garden. When squashed the insect was discovered to be full of eggs or at least the rich orange colour of such. Apparently they survive the Winter as adults, just awaiting my potatoes to start growing. And the battle is on.