ВУЗ:
Составители:
Рубрика:
The gnawing appetites of insects have enormous economic effects. Some
15 to 20 percent of U.S. food and fiber crops - and 40 percent around the world -
are consumed by Insect pests. Sales of farm pesticides total nearly 5 billion
dollars a year, and household insecticides and repellents add an additional 2.3
billion.
Notes:
bug клоп, жук
mosquito москит; комар
fire ant муравей Рихтера
Japanese beetle хрущик японский, жучок японский
Formosan termite термит, coptotermes formasanus (
ЛАТ.)
gypsy moth шелкопряд непарный
hardwood твердая древесина (лиственных пород)
Text 5
GYPSY MOTHS
In parts of the Northeast, where this voracious Insect has devastated 21
million acres of trees, the caterpillar has been thwarted by its own seven-year
life cycle, spraying, disease sad the introduction of natural parasites. However,
the Mid-Atlantic states as well as Michigan, California and the Pacific
Northwest have been hit with new infestations, threatening some of the country's
most productive timberland.
Mаnу U.S. experts wonder if insects are beginning to overwhelm
mankind's age-old efforts to dominate them. Among the reasons; Hundreds of
major insect species have grown resistant to some pesticides, and others have
adapted well to climatic changes and changing agricultural practices.
To stem the tide, biotechnologists are using a variety of exotic methods for
turning nature itself against the pests. Says Isao Kubo, a chemist at the
University of California at Berkeley: "Most natural pesticides work by
interfering with some specific process - the way insects reproduce, mature, find
food and even taste food.
Text 6
MEET THE MOLLUSKS
Mollusks are soft-bodied animals that have no skeletons. Many mollusks,
such as
snails and clams, form shells that protect them. But some mollusks have
no shells around their bodies. They have other ways of protecting themselves.
46
Страницы
- « первая
- ‹ предыдущая
- …
- 45
- 46
- 47
- 48
- 49
- …
- следующая ›
- последняя »
