A truly nightmare insect
Spider mites are small – you need a magnifying lens to see them. They are also voracious and will destroy any plant they attack in very short order. Like just a few weeks!
Close up of a spider mite – they are actually the size of a speck of dust !
Spider mites are in the spider family (8 legs). They are not technically insects (six legs), and as such do not respond to the same type of insecticides made for insects.
The pesticides that use synergists (chemicals) made for insects don’t work on spider mites because their chemistry and metabolisms is different.
Look closely an you can see the even smaller round yellowish eggs on the leaf.
They can be easier to identify by their webs. These are parallel webs – not octagonal ones like other spiders, and tend to be connected in many locations on to anything close by. Sometimes they will encase a leaf or bud with their webs.
A strawberry flower encased in webbing – horrible !
Spider mites damage plants by piercing into the leaves and sucking out the cell contents. The damage left behind has a rounded spot appearance. This dead spotting is a big clue to their presence. We call it stippling.
A leaf stippled to death ! Its not even green anymore – they drained all the cells !!!!!!
Outdoor vs Indoor
Outdoors they like any soft new growth like the tips of alberta spruce. Also any flat herbaceous leaves – that is a very wide range of plants they attack. But thin leaves are preferred always, and mono cultivar hedges are a magnet for them ! Think a row of boxwood – a spider mites heaven.
They do not like windy spots, and prefer secluded areas. They love warm summer weather and reproduce faster and more prolific as the temperatures rise.
Outdoors they are not as quick to destroy a plant as in indoor spaces. Partly because of the cooler outdoor nights, but also because the adults and their eggs are predated. Carnivorous species of mites as well as lady bugs and their larvae will kill and eat both.
Parallel webbing is a tell tale sign of spider mites
Indoors they go for anything they can, but tend to avoid plants with a latex (like Ficus) or with a thick cuticle (like cactus). But I have seen them on new growth of Ficus – just less often.
Anything broad leaf, and in a warm, dry spot that has little to no air circulation is the prime target. The hotter the room the more eggs are laid ! Palms are the top host – Areca palms. phoenix, and bamboo palms are always choice. Avoid these like the plague.
They tend to be more destructive indoors because of the lack of other predators and competition. They are also a year round pest indoors as most homes are perfectly warm for them during winter.
What can you do
Whatever you do do it fast! Females lay 400 eggs per week and those hatch in a few days and themselves are ready to lay eggs in a few weeks. It can get out of hand really quickly. Don t procrastinate.
Spray !
Wash the leaves. Its that simple. In a garden you can hose the plant down, wash the leaves with a horticultural oil or soap, wait a few minutes and rinse everything off. Repeat again in a month.
Start early in Spring before they arrive, and do the wash rinse thing every month until the fall. You will not get rid of them entirely, but the population will be so low it wont be noticeable and there will be very little damage.
Important : Spray both top and bottom sides of the leaves
For indoor plants the treatment is similar, it just depends on the size of the plant. Small ones can be placed in a sink or bathtub for this same procedure.
Large ones are more complex to treat. Here, you may have to protect the floor from the soapy water, and later the rinse water. You also have to limit the amount of solution to stop from flooding your floor !
The best strategy – Call Plant Specialists !
TODAY !
We have an entire department ( Plant Health Care)
with staff that is NYS licensed, experienced, and knowledgeable
in all sorts of insect eradication !
So you can enjoy your plants and not worry about the bugs !
Don’t delay – the sooner the better !
GREENING NEW YORK FOR OVER 52 YEARS !
Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBA
All photographs used with permission from @SHUTTERSTOCK
