Broad Mites

Broad and Cyclamen mites can move quickly, and are exceedingly small: about 200 micrometers in length, or about the thickness of a human hair or sheet of paper. Not only can these mites be hard to find, their plant damage can be difficult to diagnose. Broad and cyclamen mites only feed on young, developing leaf tissue. The saliva they inject into the plant is a growth regulator that causes deformities that oftentimes mimic nutrient deficiencies. For this reason, accurate identification and diagnosis of these mites is critical.

What to look for: New plant growth that looks distorted, twisted, or 'spindly' in appearance.

Life Cycle of Broad Mites

Broad and cyclamen mites have only 3 life stages; their life cycle is relatively short.

Egg - Broad mite eggs are covered in large tubercles, giving them the appearance of being covered in ‘jewels’. In contrast, the eggs of cyclamen mites are smooth in appearance.
Larvae - The larvae have 6 legs, and actively feed.
Adults - Males are smaller than females, with their body being more tapered. Adults can live up to 15 days, depending on sex and environment.

Biology of Broad Mites

• Broad mites are native to the tropics and are not subject to diapause in temperate climates.
• They thrive in warm climates, with development times accelerating as temperatures rise.
• Development time of broad mites from egg to adult at 86˚F is less than 4 days, with green bean plants as a host.
• Development time drops to 15 days at 59˚F.
• Females lay single eggs, rather than in clusters, making detection difficult, especially when viewed under magnification next to trichomes.
• Adult male broad mites can sometimes be found carrying female larvae, still in their larval cuticle. This is known as ‘pre-copulation’. Copulation then occurs once the female has finally emerged.
• Broad mites are blind, and depend on their sense of smell to maneuver and locate food sources.

I see broad mites, now what?... 

There are many forms of bio-controls for broad and cyclamen mites. If you currently have a pest issues, the most effective predators that we have seen are Amblyseius swirskii, and Amblyseius californicus, and Amblyseius Cucumeris. In many cases, 2-3 successive applications of the liter containers, packaged with active adults, will be necessary to gain control.

I don't see any broad mites, but I'd like to act preventatively....

Some of the most effective delivery methods for preventative use are sachets (breeding bags). These usually allow for predators to emerge from the sachets and on to the plants for 3-5 weeks. Californicus and swirskii all come in sachets.

However, factors such as the presence of other pests and the ambient temperature and humidity will help determine the best species of predator to use. Please read the brief descriptions below to determine the best option for you operation. 

Additional Notes About Broad Mites

• Broad mites only feed on new growth.
• While damaged leaves and shoots can be inspected for the mites, nearby growth that is not currently showing signs should also be inspected.