During the pupal stage, they are orange in color and oval. It takes an average of five days before they develop into a larva, which has a length of 1/8 to ½ inch. At such point, their color is slightly red and they develop two rows of black dots on both their sides. They also develop a soft shell and grows up to four times its size throughout their stage. This is the time wherein they are at their most destructive. For the eggs, meanwhile, they are usually in a group of 20 to 40, and the color is orange or yellow. Females can lay more than 500 eggs within a month.
Colorado Potato Beetle’s Habitat
This pest is common in Northern America, Mexico, and Canada. They also grow in Asia and Europe. You can spot the eggs of this beetle underside potato leaves. When they mature into a larva, this is the point where they grow on the other parts of the plant.
The lifecycle of this pest begins when the adults overwinter, which usually happens in spring. They are active in May, which is also the same time when potatoes grow. They mate and produce eggs within ten days. The females, on the other hand, lay their eggs on the host plant. One generation of this pest will have a full cycle of about one to two months.
Identifying Colorado Potato Beetle’s Damage
As the name implies, the most common plant where you can find this beetle is in a potato. It is also common in plants that belong to the solanaceae family, such as eggplant, pepper, tomato, tobacco, horse nettle, ground cherry, and thorn apple, among others.
Not sure if Colorado potato beetles are already causing damages in your plants? Below are some of the symptoms you should watch out for:
- The most common symptom is the presence of the holes in the leaves of their host plants, such as potato, cabbage, and eggplant. More often than not, they feed only on the blades or edges of the leaves. Only the veins and petioles will remain after serious infestation.
- The appearance of the holes is not only unsightly, but it also negatively affects the health of the plants. This makes them unable to absorb the nutrients that they need for survival, which is why they will inevitably end up wilting. Their structure will seem weaker than the normal.
- In some instances, the presence of Colorado potato beetles also leads to plant stunting. The latter is a disease that causes a plant to appear sickly and dwarfed. They do not reach full maturity because of the lack of nutrients, dehydration, and of course, the presence of pests.
Result of Infestation
The larva is the most damaging, making it result to the worst infestation in plants. In fact, 75% of damages are due to the larva. If you do not pay immediate attention once you are able to determine their presence, defoliation is most likely to happen. Aside from feasting in the leaves of a plant, it weakens its overall structure and health. For younger plants, they will die sooner. For adult plants, on the other hand, they are not as vulnerable, yet the yield can end up being significantly lesser than the usual.
How to Get Rid of Colorado Potato Beetles
Natural and Organic Solutions
Here are some of the most promising ways to control and eliminate Colorado potato beetles without worrying about toxicity:
- Physical control is one of the solutions that works best. This involves hand-picking the eggs before they fully grow into destructive larvae. Dispose these eggs in a bucket filled with soapy water and not just anywhere in the garden. This solution, however, works best only if you have a small garden since it is a tedious task.
- Biological controls are also effective elimination measures. Consider having plants that encourage the presence of lady beetles and stink bugs, which are natural predators. Beauveria bassiana, a type of soil fungus, will also help.
- Removing weeds and other debris in the garden will also help. This is one of the most common food sources of Colorado potato beetles, which will inevitably encourage their presence.
- There are also organic pesticides that can control the presence of these pests. They are effective for post treatment, yet they do not contain toxic chemicals.
There are systemic insecticides that are promising in the elimination of Colorado potato beetles, but as much as possible, stay away from their use. This is especially true for home gardeners. Many of them are toxic and they kill not only Colorado potato beetles, but other insects as well. Among others, esfenvalerate is a top pick. Pyrethrin can also work, but will only deliver effective results for small larvae.
One important thing to note is that Colorado potato beetles have insecticide resistance, especially from those with permethrin and carbaryl. With this, stay away from such active ingredients as they will most likely not yield successful outcomes.
How to Prevent Colorado Potato Beetles
One of the best ways to prevent infestation is to plant cultivars that resist the presence of these pests. By doing this, you will not have to think about how to control their presence. Before having any plant in the garden, do your research and find out if it is prone not only to Colorado potato beetles, but on other pests as well.
Companion planting also offers an easy, but effective solution. In this case, one of the best choices is buckwheat plants. They will encourage the presence of predators that will prevent serious damages that arise from the presence of Colorado potato beetles.