Maximum Yield USA 2016 June | Page 104

PESTS When they emerge as adult insects, they seek out other aphids to continue the cycle. The remaining hollow aphid carcass that these wasps leave in their wake is known as an aphid mummy. If using beneficial insects makes you a bit queasy or sounds too much like science fiction, you can use a variety of liquid applications that are naturally derived from plants to effectively kill aphids by suffocating them or interfering with their body functions. Pyrethrins, not to be confused with the man-made pyrethroids, is an extract from the Chrysanthemum plant. It is a common ingredient in many organic insecticides. It works by confusing the nervous system of the aphids, leading to paralysis and death. Azadirachta indica or the neem tree of India is the source of another bio-pesticide, neem oil. Neem-based products can be applied to infested plants as either a foliar spray or as a soil drench. Regardless of the method you have selected to control your aphid problem, multiple applications will be required. If you are using bio-controls such as lady beetles or parasitic wasps, it is important to release them on a regular basis to keep their populations sufficient for pest control. If you opt for a spray treatment, plan on applying the product two or three times every seven to 10 days, making sure to get thorough leaf coverage, both on the undersides as well as the tops and stems. Whiteflies Whiteflies, as their name implies, are white, flying insects. There are several species of whiteflies out there, all of which are closely related to aphids. Like aphids, whiteflies are visible without magnification. They damage plants by sucking the sap from them, but their damage appears differently than damage from aphids. Leaves damaged during whitefly feeding will turn yellow or brown and drop off prematurely. They may get a speckled appearance before turning color. Like aphids, whiteflies also secrete honeydew with the same potential " results of attracting ants and fostering the development of black, sooty mold on leaves that may be below where the whiteflies are feeding. These pests are also prolific reproducers and each female whitefly can lay up to 400 eggs in her lifetime. Her nymphs will immediately begin sucking on leaves once they have hatched and can stay fixed in one spot, feeding for up to four weeks as they pupate into adult whiteflies. A heavy infestation of whiteflies will appear as a burst of smoke when disturbed. Care should be taken to not wear light-colored clothing when working around plants with whiteflies as they can easily be transported to other plants unknowingly. Whiteflies can be controlled with beetles and parasitic wasps, like their aphid cousins, but different beneficial species are better at controlling them. A small, black beetle, known as Delphastus pusillus, which is about the same size as the whiteflies themselves, will feed on all stages of whiteflies, but they prefer the eggs and nymphs. They are especially useful in high-infestation areas, as they If using beneficial insects makes you a bit queasy or sounds too much like science fiction, you can use a variety of liquid applications that are naturally derived from plants to effectively kill aphids by suffocating them or interfering with their body functions." 102 Maximum Yield USA  |  June 2016