There are several pests and diseases that are commonly encountered when growing Venus flytraps in cultivation. Below we will detail the most common pests and problems growers usually experience when growing Venus flytraps.
This list is not intended to be comprehensive but rather will only detail the most common pests and diseases. For a more comprehensive list of pests, including those commonly found on other carnivorous plants, be sure to check the Pest Identification and Control thread on the FlytrapCare forum.
Red Spider Mites
By far the most common pest encountered when growing Venus flytraps is the red spider mite (Tetranychus evansi). Due to the fact that they are very small, with adult females being about 0.5 mm in size, red spider mites are very hard to find before they cause damage.
We typically see these nuisance pests two times a year in our collection. It is normal to see them in spring, just as the days start to warm and new growth begins, and also in fall as the days start to get dry but are still warm. However, they can appear seemingly at any time of the year in a greenhouse. It is unclear how red spider mites make their way onto Venus flytraps, but anyone who grows these wonderful plants long enough is sure to encounter them.
It is most common to discover red spider mites by noticing the tell-tale yellow or brown mottled pattern that is the result of the damage caused by them. This damage is most commonly found near the edge of traps and leaves where the mites are biting into the flesh of the Venus flytrap to suck the sap from the plant. If not caught early enough, these pests can do significant damage to Venus flytraps!
The below image shows up close damage of red spider mites along with a few insects actively feeding on Venus flytrap leaves and traps.
Treating Red Spider Mites
For an organic approach, some growers report success using neem oil. We haven’t tried this method and it will likely take multiple treatments to eliminate red spider mites with neem oil.
We prefer using a dedicated miticide such as Avid, Floramite, or TetraSan. Any of these three miticides is very effective at eliminating red spider mites. Buying a miticide can be expensive and for a grower with a modest collection the smallest size offered for sale at most places would last many lifetimes, so we offer miticides for sale at FlytrapStore.com in hobbyist quantities:
We typically recommend doing two treatments with a miticide, 3 to 4 days apart. Simply mix the miticide into water at the recommended dosage and spray the leaves and traps, completely covering the plant with the mixture. Normally mites will stop causing damage within 24 hours and be completely gone within a few days to a week. The damage they caused will not heal but any newly forming traps will be damage free.
Aphids on Venus flytraps
While not terribly common to see on Venus flytraps, aphids do occasionally munch on Venus flytrap leaves and traps. Over the many years we’ve been growing, we’ve only seen aphids on Venus flytraps very few times. They are fairly easy to spot and also very easy to treat and eliminate. Any sort of insecticide used at the recommended dosage, including neem oil, will typically eliminate them after just one treatment.
Large pests – squirrels and cats
It is quite common to have larger pests uproot plants when growing outside. By far the most frequent offender is the common tree squirrel. These nuisances will often dig up plants and leave them nearby the pot to dry out and die. We encountered this when growing outdoors in Boulder, Colorado, and in Ashland, Oregon. And sometimes curious house cats will nibble on leaves and traps.
If you encounter consistent problems with larger pests, the best solution is to use some sort of cage over the top of the pots to enclose the plants and prevent access for larger animals. Building a “box” out of scrap lumber and covering it with chicken wire works great. The chicken wire has holes large enough to allow insects through so Venus flytraps can still hunt but keeps out the larger pests like squirrels and cats.
There are a few diseases that can inflict Venus flytraps. Crown rot is extremely common. Gray mold, also known as Botrytis cinerea, is also encountered when Venus flytraps are kept too wet and in an area without good airflow, such as in a terrarium (side note: terrariums are NOT good containers for growing Venus flytraps!).
The most common disease encountered when growing Venus flytraps, particularly for indoor growers, is crown rot. Similar to gray mold, crown rot is usually caused by inappropriate growing conditions where there isn’t sufficient air movement, UV light, or rain to wash away the “nasties” that accumulate on the crown of a Venus flytrap.
When Venus flytraps are grown outdoors and not kept too wet, crown rot is a fairly rare occurrence, though it can still happen even with the best of care. Some varieties (cultivars) of Venus flytraps are particularly prone to getting crown rot. It is important to catch it early and treat the plant in order to avoid losing it entirely.
The tell-tale sign of crown rot disease on a Venus flytrap is that no new traps are emerging and newly forming traps are turning yellow or black. See the below photo for an example of crown rot symptoms exhibited on a Venus flytrap.
Oftentimes, crown rot disease is noticed well after it has caused significant damage. In our experience, once crown rot has set in, the best course of action is to uproot the plant and try to remove any part of the center of the rhizome (bulb) that is brown or turning brown.
Usually, in order to access the center of the rhizome where the crown rot has taken hold, it requires the removal of one or more of the outer leaves. Once access is gained and the brown center of the rhizome is found, use a sharp tool such as precision pruning shears to snip and/or gouge out the brown parts.
After removal of all brown parts of the rhizome, repot the healthy part of the rhizome and treat it with a fungicide such as Ortho MAX Garden Disease Control.
<<< Video of this process coming soon >>>
The typical prognosis for a recovery of a Venus flytrap after crown rot isn’t good. If caught early enough and the damage to the crown isn’t too bad, a plant can make a full recovery. But more commonly, the main growth point will be lost and the plant will turn into several smaller plants. The good news is that those smaller Venus flytraps will have healthy crowns, but the bad news is that you’ve likely lost a very large Venus flytrap in the process.
Gray mold – Botrytis cinerea
Gray mold, or Botrytis cinerea, is usually not a problem when growing Venus flytraps. If you do happen to encounter it, it is likely indicative that the growing conditions are not good. Mold is usually only an issue when growing in enclosed spaces without strong lighting and good air movement.
When growing outdoors with sufficient air movement, direct sunlight, and rain, mold is usually either blown away, burned away by UV rays, or washed away by rain before it can become an issue.
If you do happen to encounter gray mold on your Venus flytraps, treat it with a fungicide such as Ortho MAX Garden Disease Control and alter your growing conditions to prevent it from recurring.
There really are only a very few pests and diseases that are commonly encountered when growing Venus flytraps in cultivation. If good growing conditions are provided and a little protection is offered to your Venus flytrap collection, most of these can be avoided. The one pest that seems to be unavoidable is the red spider mite. Thankfully red spider mites are treatable and, if caught early enough, they cause minimal damage.
We hope you’ve found this article helpful. Good growing, Venus flytrap enthusiasts!!