The Colorado potato beetle (Leptinotarsa decemlineata) has for centuries been the blight of many a gardener. Eradicating the beetle has proven to be very difficult. Once you have an infestation it is almost impossible without pesticides.
What does the Colorado potato beetle look like?
This beetle is quite distinctive and easy to spot.
- 10 brown stripes along the length of the body
- 10mm (⅜) long
- Orange to Yellow body
- Orange blood
The Colorado potato beetle was first seen in 1824 in the Rocky mountains. Where they fed on Buffalo bur, Solanum. The beetle began destroying crops near Omaha Nebraska. It then moved eastwards arriving on the Atlantic coast in about 1874. The beetle spread to Native America and then Europe from about 1859 hidden amongst potato shipments.
Life cycle Colorado beetle
Understanding the potato beetle life cycle is the first step to clearing your crops from this pest.
The beetle emerges from it’s over winter stay in a safe position usually at the bottom of a tree or shrub. Mating starts almost immediately and the fertilised eggs are ready for laying.
The female is capable of laying over 500 eggs per gestation every 4 – 5 weeks.
The eggs are yellow or orange and about 1 millimetre which is laid in easy to recognise batches of about 30 on the underside of a leaf.
The eggs hatch into larvae in about 4 to 15 days depending on temperature. The humped backed larvae have two rows of brown spots.
They grow through four stages in 2-3 weeks. Then they enter the soil, form a cell, then it pupates. Adults emerge in 5-10 days and the life cycle is repeated through the next generation.
- Pupate in soil
- Emerges from the soil as an adult
- And the circle continues
Controlling Colorado Beetle
This pest can be devastating to your potato crop if left unchecked. Within days all the succulent green growth is consumed leaving the plant unable to photosynthesise. This damage will stop potato tubers swelling to their full size.
The Colorado beetle destroys the potato plant, it can also destroy the eggplant, peppers and tomato plants too.
Known ways to control Spearmen
- Neem oil, it is an organic oil used by gardeners as a go-to insecticide.
- Handpick eggs, larvae or beetles and put them into a bucket of soapy water to kill them.
- You can use a bug vac or a handheld house vac, will also work.
- Pesticides suitable for Colorado but we don’t endorse the use of pesticides
Detering Colorado with Companion planting
There are several plants that deter the colorado potato beetle.
Straw mulch helps creates a habitat for predators of the Colorado potato beetle.
Predators of Colorado (Spearmen)
The use of natural predators is an ideal control method. Numerous natural predators can assist in the struggle to manage Colorado potato beetles.
Known predators of Colorado
- Lady beetles
- Predatory stink bugs
- Ground beetles
- Parasitic Wasps
- Foraging chickens and ducks
My conclusion in regard to this food crop pest
What approach you take to control this persistent little critter will depend on your own ethos. We have taken bio gardening approach on our land so we are not going to use any chemicals. This does impose some complications in our approach to Colorado pest control.
I won’t kid you but organic gardening is not a picnic without work! If you don’t wish to perform the daily check on your crop you may have to succumb to a pesticide such as Calypso J by the devil Bayer!
I hope you enjoyed our experience with the Colorado Potato Beetle and how we control them. I and my wife Caroline put this article together to share our findings on how to best deal with them in an environmental way. While you are here, please comment and share with your friends.