The Life Cycle of a Spider Mite: What You NEED to Know Before Going into Battle!

Spidermite webbing and mites on heavily infested tomato plant.

As many of you, my gardening friends know big damage can come from small pests!  One of the most ubiquitous foes of indoor and outdoor gardeners alike is the Spider Mite.  This creature which is not a spider as the name may imply, is actually a member of the Acari (mite) family Tetranychidae.  Their similarity to spiders ends with their ability to spin telltale webs which can often be the first clue to their presence in your garden.  These little garden pests can multiply so quickly under the right conditions that a single female can spawn a population of over one million in under 1 month.  They reproduce quicker under warmer conditions and prefer low humidity as it helps them excrete the water they ingest as they suck the life (sap) out of your plants.  The two-spotted spider mite can hatch in as little as 3 days, and become sexually mature in as little as 3.5 days. One female can lay up to 20 eggs per day and can live for 2 to 4 weeks, thereby laying 800+ eggs. 

This capability for exponential population growth, coupled with the speed at which each individual mite itself becomes reproductively mature allows spider mites to rapidly adapt to novel pesticides.  This ability to become resistant to pesticides has caused millions and millions of dollars in damage to food and ornamental crops every year.  This is why it is imperative to rotate pesticides in your attempts to control them.  Any pest management program should be a rotation of at least three different pesticides, each having a unique mode of action; not just a different active ingredient but a unique way of killing the mites.  For example some will be mitochondrial electron transport inhibitors while others may be neuronal inhibitors or GABA (gamma-Aminobutyric Acid) blockers. 

Spider Mite Life Cycle

       
Grow-Room Temperature in °F

60

64

70

90

Number of Days from Egg to Adult

30

21

14.5

3.5

Now that you understand what you are up against read my next blog about miticides that will cure your mite problem quickly and painlessly.