Whitefly

Background:

Adult whiteflies are small, flying insect pests that resemble tiny white moths
(Fig. 1). They are usually about 1 or 2 millimetres in length and can be found feeding and laying eggs on the younger leaves of many different plant species. Whitefly feed on plant sap through a long tube-like mouth piece. Excess sap and waste products are excreted as honeydew, on to the plant leaves. Honeydew contains sugars which soon become contaminated with black sooty moulds that grow over the leaves producing unhealthy and unsightly plants. The larvae of whitefly are often confused with scale insects since they look very similar. Once they hatch from the eggs they crawl across the leaves to find a suitable place to feed then shed their skins. During this skin shed, the larvae lose their legs and remain motionless, feeding on plant sap for around 4 weeks. During this time the infested plant continues to grow, resulting in the larvae being found on the older, lower leaves of a plant by the time they are ready to pupate.
The most common and perhaps the most difficult whitefly species to control around the world are the Glasshouse Whitefly Trialeurodes vaporariorum and the Tobacco Whitefly Bemisia tabaci, although the Tobacco whitefly is only found in the warmer regions of the world. Both of these whiteflies also transmit plant viruses. Other whitefly species that can be a problem include the Strawberry whitefly, the Cabbage whitefly, the Vibernum whitefly, the Citrus whitefly and the Spiralling whitefly.

Using SB Plant Invigorator to control whiteflies:

Independent research studies have shown that SBPI is highly effective at controlling whiteflies if used correctly.

Almost total control of adult whiteflies can be achieved after just one application of SBPI if the infested leaves are treated thoroughly. The treatment also needs to be applied to the point it runs off the leaves. SBPI causes adult whiteflies to stick to leaves and other surfaces that they land on, although the plants and treated surfaces do not become sticky themselves. When the treatment has dried, the affected whiteflies remain stuck and die (Fig. 2).

The larval stages of whiteflies are also controlled by SBPI. Again, a thorough application of the product to the infested areas of the plant is essential since only the larvae that are treated with SBPI will be controlled.

It is often the case that whitefly pupae and eggs are harder to control with products than the other life stages. This is also the case with SBPI. So, to ensure that effective and sustained whitefly control is achieved, re-applications of SBPI are recommended at weekly or fortnightly intervals. This will not only ensure that newly hatched adults and larvae are controlled, but also any new whiteflies that may have flown on to the plants.

SBPI does not affect whitefly pupae, so it can be used in conjunction with an IPM system using parasitic wasps.

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.

Figure 1. A strawberry plant infested with adult whitefly

Figure 2. Dead whitefly adults after treatment with SBPI . Small black eggs are also visible.