Plants with a bug home advantage.Last summer, Anurag A. Agrawal and Richard Karban spent a morning at a California cotton farm, dabbing the leaves of 120 young cotton plants with spots of Elmer's School Glue. Half of the glue-dotted plants were also given a small tuft tuft (tuft) a small clump or cluster; a coil. tuft (toothbrush), n part of the toothbrush head, refers to the small, individual clusters of bristles that proceed from a single opening. of cotton fibers. At the end of the growing season growing season, period during which plant growth takes place. In temperate climates the growing season is limited by seasonal changes in temperature and is defined as the period between the last killing frost of spring and the first killing frost of autumn, at which , the entomologists The following is a list of entomologists, people who have studied insects. Name Born Died Country Speciality John Abbot 1751 1840 United States from the University of California, Davis The University of California, Davis, commonly known as UC Davis, is one of the ten campuses of the University of California, and was established as the University Farm in 1905. reaped their reward: The artificially tufted plants produced 30 percent more cotton. Agrawal and Karban took their cue from nature. Oaks, maples, and many other plants sport small tufts of hairs or pockets of leaf tissue on the undersides of their leaves. These so-called leaf domatia "truly are extremely common," says Agrawal. About 2,000 plant species are known to have them. Scientists have long known that domatia provide cover for insects--hence the name--presumably for the plants' advantage. The cotton experiment, reported in the June 5 Nature, demonstrates that domatia are beneficial not only to the plants but also to certain insects. The researchers found eggs and nymphs of predatory insects such as the big-eyed bug (Geocoris species) inside the glued-on domatia. These bugs were five times as abundant on domatia-bearing plants as on undecorated plants. Two other predators, the minute pirate bug (Orius tristicolor) and the western flower thrips thrips, minute, agile insects of the order Thysanoptera. Thrips have piercing-and-sucking mouthparts and cup-shaped feet from which bladderlike adhesive organs may be extended. Some species are wingless, but many have four narrow, featherlike wings fringed with hairs. (Frankliniella occidentalis The western flower thrips (Frankliniella occidentalis) is an important pest insect in agriculture. This species of thrips is native to North America but has spread to other continents including Europe, Australia, and South America via transport of infested plant material. ), were also more plentiful. The big-eyed bug preys on spider mites ((Tetranychus species), serious pests of the cotton plant. On plants with domatia, the number of spider mites was down and the number of cotton bolls was up. Use of domatia could provide an environmentally friendly form of pest control, Agrawal and Karban suggest. Since some wild cotton species sprout their own domatia, it may be possible to breed or genetically engineer the trait into cultivated cotton. The strategy may also work with avocados and other crops that have wild domatia-bearing relatives. |
|
||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion