Spider mites are tiny arachnids belonging to a group known as the Acarina. Although they belong to the same order as common spiders, there are distinct morphological differences. Their bodies, for example are small and bloated and are not divided into sections like true spiders. Also, their juvenile stages only have 3 pairs of legs whilst the adults have four.
The most common spider mite pest, affecting a wide range of glasshouse, indoor and garden plants, is the Two Spotted Red Spider Mite or Glasshouse Red Spider Mite Tetranychus urticae. Despite its name, it is only red in colour during its inactive stage through the autumn and winter seasons. During the spring and summer seasons, it is usually a pale green colour with two distinct darker spots on its back.
The first signs of a spider mite infestation are usually the appearance of small pale spots on the leaf surface. This gradually becomes more intense leading to a pale mottling effect across the whole leaf surface as the mite numbers increase and they suck dry the contents of the leaf cells. If left untreated, a spider mite infestation continues to increase and infested plants become covered in a fine silk webbing, particularly around the new growth regions. Within this webbing the spider mites are protected from many types of topical insecticides and the leaves become covered with their tiny spherical eggs. At this level of infestation (see Fig. 1), the plant will soon lose its green colour and begin losing leaves. It may eventually die.
Using SB Plant Invigorator to control spider mites:
Controlling spider mites is not always as easy as controlling other plant pests, especially when infestations have become established and protected by heavy webbing. However, independent research studies have shown that SBPI can be highly effective at controlling spider mites if used correctly.
If a spider mite infestation is found during the early stages, before webbing has become intense, then a thorough application (to upper and lower leaf surfaces) of SBPI applied to the point it runs off the plants will control the problem. However, a few re-applications at weekly intervals will be required since spider mite eggs are not affected and the product does not have residual activity.
An established spider mite infestation (see Fig. 1), can also be controlled by SBPI although 2 or 3 applications will be required at 2 or 3 day intervals. This will overcome the protective webbing and access the mites within (see Fig. 2). Weekly applications will then ensure newly hatched juveniles and adults that may have crawled on to the plant from elsewhere continue to be controlled.
Although the leaves from a heavily infested plant will not recover from the spider mite damage, any new leaf growth will be healthy and hopefully the plant will recover (see Fig 3).
Spraying as often as weekly may seem excessive but please remember SBPI provides foliar nutrients, comprehensive pesticide and mildewcide all at the same time.
Most growers using SBPI weekly rarely use other products. Resistance to SBPI will not occur due to its physical mode of action.