Spider Mite’s Reproductive Cycle Is Its Strength

October 28, 2011 by · Leave a Comment
Filed under: Spider Mites 

According to science there are approximately 1,200 species of spider mites around the world. These pests attack all sorts of vegetation in ways that are completely devastating, both economically and personally. And although all the species do have her differences they have one thing in common: their reproductive cycle is their strength.

Spider mites have an incredibly large number of natural predators. And because they have no defense mechanisms, they are wide open for any hungry predators looking for a meal. Where natural predators are in abundance spider mite populations are kept in check. But when natural predators are killed off by pesticides and insecticides, spider mites can reproduce at an alarming rate.

Two Types of Eggs

There are two types of eggs involved in the spider mite breeding cycle. The most common are the fertilized eggs which produce female spider mites; the second type is the unfertilized which produce the males. Whether by design or accident, more female eggs are produced than male eggs, helping the breeding cycle to continue. Under optimal conditions this could mean a lot of hatchlings in a very short amount of time.

The Breeding Cycle

The breeding cycle begins when an adult female makes her home on the underside of a plant leaf. As soon as she finds a spot she begins to move across the surface of the leaf, simultaneously feeding and laying eggs as she goes. She may also spin a fine web between a leaf and the plant stem in order to lay more eggs. The female spider mite is so good at laying eggs that she can potentially put down thousands in her lifetime.

Once eggs are laid they generally take only 3 to 5 days to hatch if temperature and humidity are optimal. Under less than optimal conditions it could be extended to 5 to 7 days. Usually a day or so before an egg is ready to completely hatch its outer shell begins to crack as the growing hatchling requires more space. When the egg finally does completely hatch the new spider mite emerges and reaches full maturity in about seven days.

If we assume optimal temperature and humidity levels, it becomes obvious that new female spider mites are ready to begin laying eggs only 10 days after their own eggs were laid by their mother. If we assume 50% of the eggs laid are female, and the mother puts down 750 in a week, that means 375 new mothers laying eggs just 10 days later. Multiply this by the average 30-day life cycle and you have a potential nightmare.

Spider mites only survive because of their sheer numbers. But by using an organic miticide like Liquid Ladybug you can gain the upper hand by stopping the breeding cycle. Since liquid Ladybug kills adult spider mites and hatchlings alike, three applications over the course of several days should be all you need to bring an end to your spider mite infestation.

Mite Life Cycle

Mite Life Cycle

Figure 1. Life cycle of Acarus siro, including egg, 6-legged larva, 8-legged protonymph, deutonymph (hypopus), 8-legged tritonymph, adult male and adult female (larger than male).   Image: Solomon, M.E. 1962. Ecology of the flour mite, Acarus siro L. (= Tyroglyphus farinea DeG.). Annals of Applied Biology 50: 178-184.  http://www.ontariocheese.org/images/cheese_mites.jpg

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