International Carnivorous Plant Society

Mealybugs

Mealybugs can be a problem on Sarracenia as well as Nepenthes and epiphytic Utricularia . They especially like living in the crevices where the leaves attach to the crown or stem. They can also get into the roots of plants. Mealybugs suck the sap out of plants using long mosquito-like mouthparts. They may not significantly hurt a healthy Sarracenia but are quite capable of giving the coup de grâce to a plant that is doing poorly.

Unlike most things we call "bugs", mealybugs actually are bugs. That is they are insects in the order Hemiptera. Hemiptera are noted for having larvae and adults that look similar. What you see on your plants are mostly females and nymphs of both sexes. Adult males have wings, look like white fluffy gnats, and live only to mate--they don't eat and they die when the deed is done--if they are lucky.

The usual way to get a mealy bug infestation is to get one from your friends. Even if you get plants from a well-known nursery, it is best to quarantine any new plants you get to make sure they don't have nasties on them. Carefully check where the leaves attach to the stem or rhizome. Wait a few weeks and check again. If the plants have eggs it will take a few weeks to see the nymphs and adults.

You usually first notice a mealy bug infestation from the white fluff they produce on the plants and it is usually not at the crown of the plant. That is, you usually first notice them when there are so many mealybugs on the plant they have ventured away from the crowded crown. Yes, usually by the time you notice them you HAVE them. Badly.

The first thing to do, after you have stopped screaming, is to trim or pull off all brown leaves. You want to eliminate as many places as possible for the bugs to hide out. Clean any litter or weeds out of the pots. AND most importantly, make sure no ants can get anywhere near your plants. Ants will care for and protect mealybugs in exchange for honeydew they can excrete.

Controlling mealybugs is not easy. There are no spray and forget solutions. You can knock them down with applications of Imidacloprid, Diazinon, or Malathion at two week intervals, possibly for the rest of your life. There are some pesticides not listed for home use that may work better, if you can get them and want to pay what they cost. The reason for the repeated spraying at two week intervals is because the pesticides don't kill the eggs and you may not have gotten all the creatures the first, or second, or ... time. Keep in mind some of these pesticides will kill aquatic carnivorous plants such as Aldrovanda and Utricularia, will kill many tuberous Drosera and damage other Drosera and Pinguicula, and can cause deformed leaves on Venus flytraps. Use pesticides with caution.

Another, much safer approach, is swabbing your plants weekly with a solution of isopropanol and detergent. Use straight 70% "rubbing alcohol" with a few drops of dish detergent and apply with cotton swabs. The alcohol and detergent dissolve the wax the mealybugs use to protect themselves from desiccation.

--John Brittnacher

 

mealybugs

Mealybugs in the crown of a Sarracenia plant.

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