CPB

The Colorado Potato Beetle was an insignificant insect barely surviving on small solinaceous weeds (related to eggplant) until people started growing potatoes in the midwest. It hopped onto the potato bandwagon and is now a major pest of potatoes and other solinaceous crops.

 

These examples are sitting on a stake in the tomato patch. They attack tomatoes, but the tomatoes grow so fast the beetle doesn't do much damage. Eggplant and potatoes are more susceptible.

 

One of the problems with the beetle is that it adapts very rapidly. Many insecticides that were used on the CPB became ineffective within a few years as the beetle adapted to the new environment. Current pesticides are characterized by "mode of action", which describes how they are supposed to work on the target insect. This allows farmers to attack the insect with different methods to slow the development of resistance to any one pesticide.

 

In addition to pesticides, some farmers use other insects to attack the eggs or larvae, or even some types of fungi that kill the beetle. Growth regulators can be used to interrupt the natural development of the larvae. Bacteria, in particular Bacterium Thuringensis San Diego develops a protein that, when ingested by the beetle, paralyzes the gut, thereby starving the beetle. BT San Diego is genetically modified, so it is not allowed in organic production, but BT tenebrionis is similar and not GM, so it is allowed.

 

The beetle overwinters in the weeds and debris on the edges of the fields. In the spring it walks out into the field (it's not a strong flier, although it can fly). Farmers have tried flaming the early potatoes. This burns off the antennae on the beetles so they can't find food. The potatoes are set back a bit, but they recover. Also, since the beetles walk, farmers have tried installing a trench around the field, lining it with plastic and filling it with water. A little detergent will break the surface tension so the beetles will sink and drown. That wouldn't work on my fields, which are not flat. I'm sure there are other strategies that have been tried.

 

The beetle is very adaptable, and control is an ongoing battle.