Expert: Sarracenia Northwest - 5/8/2011

Question
Hi there,

One of my Nepenthes (a DeRoose Alata) has had spider mites since last autumn. Luckily they seem to have naturally decreased a little whilst the plant has been indoors over winter. There are however a few lurking in places and they seem to have also moved to my second nepenthes (also a DeRoose Alata) so I have decided to source an insecticide to hopefully solve the issue. I think I have found a suitable spray with spider mites listed as one of the pests it treats, but what I wanted to check is whether the chemical is suitable to use on the plants.

It is something called 'acetamiprid' and it is in liquid form. It apparently works both on contact and systemically.

Furthermore, the pant which has had the mites over winter is not pitchering at all. I pruned one of the growing vines a few months ago, and the plant has become more bushy which was what I wanted and it has produced new firm leaves at the base but none have pitchered. Do you think the pests have prevented the plant from pitchering?

Many thanks for your help, Chris.

Answer
I'm not familiar with the specific compound that you mentioned, but it seems to be in the same class of insecticides as imidacloprid, a derivative of nicotine found in the United States.  As long as you follow the instructions provided by the manufacturer, your plant will be fine.  (Due to regulatory issues, I can't advise you on the use of products that are not available in the United States.  The most I can say is that if the manufacture says it's safe to use on houseplants, it would be safe to use on your Nepenthes.  Just make sure to follow the manufacturer's instructions.)

Another technique to get rid of spider mites is to drench your plant with water.  Take it into your shower and douse all parts of the plant.  Get the water in every nook and cranny, between the leaves and under the leaves.  You may need to repeat this again in a few days, but usually after several treatments of this, the mites abate.

It's doubtful that the lack of pitchers is because of mites.  The lack of pitchers is usually because of low light, which is quite common in winter.  Even at our nursery, many Nepenthes stop producing pitchers in winter.  Now that we are in spring, many are finally perking up and showing signs of pitcher development.

For more information about growing Nepenthes, watch Volume 3 of the Grow Carnivorous Plants DVD series.  I also recommend watching our monthly video podcasts for information about how plants look like at various times of the year.
http://www.cobraplant.com/videos

Good growing!
Jacob Farin