Potato Bugs

We hope to be able to produce enough potatoes this year to supply Darryl’s family and ourselves.  We planted some of the little potatoes Darryl had left from last years crop—13 rows about 45 feet long and 50# of seed potatoes that were purchased, another 9 rows.  I spent yesterday working through these potato plants, getting the weeds and grass out, cultivating the soil and then pulling dirt to the rows, making a ridge which gives the potatoes room to produce the tubers.  As I was working on this all-day job I found several adult potato bugs as well as several young larvae.

The potato bug, or Colorado potato beetle, is a common garden pest. (The scientific name is Leptinotarsa decemlineata.)  As far as beetles go the adult potato bug is a rather attractive dome-shaped fellow (or gal) nearly a half-inch long, yellow, with five black stripes on each wing cover.  The adults spend the winter hibernating in the soil and in the spring they emerge quite hungry.  They begin walking and/or flying about looking for potato plants or some other relative in the nightshade family, such as tomatoes, peppers, eggplants, and tobacco.

Once the potato bugs find the potato plants they begin snacking on them and also begin a family.  The female beetle lays clusters of 15-25 bright yellow-orange eggs on the undersides of the leaves.  From these eggs hatch the soft-bodied, hump-backed larvae.  They start out small but grow fast, molting four times into larger stages, or instars.  The last instars grow to be quite plump, and these are the guys that eat the most foliage.  They soon crawl into the soil and pupate.  From this resting stage a second generation will emerge by the end of the season, ready to eat again before hibernating through the winter and starting the process again come spring.

According to all reports the Colorado potato beetle was first discovered by Thomas Nuttal in 1811 and was described in 1824 by Thomas Say from specimens collected in the Rocky Mountains on buffalo-bur, a tough weed that grows along the eastern foothills.  Then, about 150 years ago the little critters discovered a new food growing in the white man’s gardens.  It quickly adopted the cultivated potato as its favorite food, spread rapidly eastward and eventually to Europe after World War One.

Numerous methods have been used to try and control these beetles but they build a resistance to most chemical sprays.  One of the most effective method of dealing with the potato bug is hand-picking.  Although this may sound a bit grotesque to some with bug phobias it is truly one of the most efficient and least harmful ways to control the little guys.  And, this is where the grandkids enter the picture.  Darryl pays the kids a nickel for each adult and a penny for each of the larvae.  They also watch for and smash any eggs that are on the underside of the leaves.  Malchiah came by this evening and showed me the potato bugs he had found and put into a plastic bottle.

For more information on this interesting little critter please check out  potatobeetle.org.  You may even wish to check out the potato museum’s section on the Colorado potato beetle.