The microbial peptide BT, derived from the bacterium Bacillus thuringiensis, is widely used to protect crops from insect pests. Schellenberger et al. identified another insecticidal peptide from a different soil-dwelling bacterium, Pseudomonas chlororaphis (see the Perspective by Tabashnik). Corn plants expressing the Pseudomonas peptide were protected from attack by western corn rootworm. Rootworms that were resistant to BT were susceptible to the Pseudomonas peptide. Addition of another insecticidal peptide diversifies the arsenal against insect pests, which may slow down the development of resistance.
Fall armyworms genetically modified to wipe out wild populations of the pests have been released in corn fields in São Paulo State in Brazil in the first farm trial of the new technology. The test was a success and is now being expanded, says Oxitec, the UK-based company that created the modified armyworms. Fall armyworms (Spodoptera frugiperda) are in fact moth caterpillars. They get their name from the fact that they multiply very fast and feed on many plants. They are native to the Americas, but in recent years have spread across Africa, Asia and Australia, reducing harvests of some crops by up to half.
Of all the fungi out there, Botrytis cinerea is the one that keeps farmers up at night. The scuzzy fungus has a voracious appetite. It'll happily munch through hundreds of plant species--although soft fruits like grapes are its favorite--covering everything it feasts on with a velvety layer of mold. If you've ever left a tub of strawberries in the refrigerator a little too long and returned to find them looking a sort of gray-green, there's a good chance that one of the ever-present spores of Botrytis floating through the air decided to make its forever home in your dessert. A spoiled dessert is a pain, sure, but for the food industry Botrytis poses a major problem.
Deer and rabbits can make quick work of plants such as hostas and petunias. Physical barriers like fences are best to keep the browsers out of your garden. But most are also deterred by pest-repellent sprays based on animal blood or raw eggs, for which DIY recipes can be found online. Aphids generally won't harm healthy, mature plants, and they're food for beneficial insects--but they can weaken young plants. Many gardeners swear by planting the brightly colored flowers as protective companions for tomato vines.
FOR the first time, a crop that produces an RNAi-based pesticide has got the green light. The US Environmental Protection Agency has approved a genetically modified corn known as SmartStax Pro. In addition to producing two Bt toxins to kill any western corn rootworm larvae that try to eat it, the plant produces a piece of RNA that shuts down a specific gene inside the larvae, killing them. On paper at least, such RNA interference (RNAi) is the perfect pesticide: it kills the target species while leaving others untouched. But it only works in some insects.