Colorado Potato Beetle
Description
This species is under the classifications of the phylum Arthropoda, the order Insecta, and the class of Coleoptera, more commonly known as beetles. The Colorado Potato Beetle (Leptinotarsa decemlineata), part of the genus Leptinotarsa or leaf beetles, can be distinguished by their yellow-orange and black striped shell, and spotted head. The name Colorado Potato Beetle, sometimes referred to as the "potato bug", is due to them being severe pests of the potato plant, but the insect can also damage others crops such as tomato, and pepper. Their red bodied larvae, typically with two rows of black spots on their side, also feed on crops in large groups, which can often be more damaging than the adult beetles [1]. Despite the name, they were originally discovered in central Mexico, but soon appeared in most areas of the United States (excluding Alaska, California, Hawaii, and Nevada), and also in southern Canada, parts of Asia, and Europe.
Habitat and Life Cycle
Generally, the Colorado Potato Beetle prefers warmer climates, and reveal themselves between the months of April to September in the United States [2]. Adult potato bugs will hibernate over the winter, digging themselves about a foot into the ground. In the spring, they will emerge to feed and begin to mate and lay eggs on their host plants [2]. The number of eggs each female produces can be in the upward range of 500, and can be found in large clusters [3]. While the beetle can live in a variety of climates, eggs will take between four to ten days to hatch depending on the temperature. A lower temperature will cause a longer egg stage, while a hotter temperature will make the process move along quicker. The climate will also affect the amount of potato bugs present throughout the year, as warmer climates can support about one to three generations per year, while cooler areas may result in less than two generations per season [3]. This stage of their life lasts only about three weeks, and then the pupa stage beings, which occurs in the soil and lasts anywhere from five to ten days [3]. The cycle continues once the beetles form into adults. Adult females can begin laying eggs in only a few days after leaving the pupa stage [1].
Impact on the Environment
As mentioned, the Colorado Potato Beetles feed on crops, mainly the potato plant, from the beginning of their larvae stage up to their adult hood. The first discovery of this detriment was in 1859, when many crops were destroyed near Nebraska, and quickly spread to other areas in the United States [3]. The larvae feed on these plants for most of their cycle before entering the pupa stage, generally in groups, leading to a significant amount of damage on these plants, which can cause reduced yield and plant death [1]. The main reason why the Colorado Potato Beetle remains an issue is their extreme resistance to insecticides, making them harder to get rid of. To aid in their removal, it is recommended to use differing insecticides with each treatment rather than the exact same treatment to limit resistant beetles [1]. These insects can also be managed by their diversity of predators, including lady bug (or lady beetles), stink bugs, and parasitic wasps.
References
[1] Bessin, R. 2019, November. Colorado potato beetle management. https://entomology.ca.uky.edu/ef312.
[2] Colorado potato beetle. 2019, July 22. . https://cropwatch.unl.edu/potato/colo_potato_beetle.
[3] Jacques, R. L. 2020, May. Colorado Potato Beetle. https://entnemdept.ufl.edu/creatures/veg/leaf/potato_beetles.htm.