Silent Spring By Rachel Carson Chapters 16&17 in comparison to Biology: 7 th edition By: Vanie Mangal, Lisa Lee & Jordan Monfort

Insects Fight Back Organismal ecology is concerned with morphological physiology behavioral ways in which individual organisms meet the challenges posed by their biotic and abiotic environments.

In 1945 there were 12 known insect species that had grown resistant. By 1960 the number reached a peek of 137 species. The Blue Tick in South Africa killed 600 cattle. They had gained resistance to arsenical dipst Benzene hexaechloride (1949). By 1950, houseflies and the Culex mosquitoe became resistant to chlorodane. Body lice caused typhus. By 1957, 15 cuntries had confirmed that the lice had grown resistant to DDT.

Insect Resistance, Public Health & the Role We Play Stability is the tendency of community to reach and maintain anequilibium or relatively constant composition of species, in the face of dissturbances.

Throughout much of the Midwest, thousands of acres were destroyed by insects now impervious to spraying. Another insect to learn the profitable way of resistance was the codling moth or appleworm, in the 1920s, although lead arsenate had been used successfully against it for some 40 years.

Before 1945, only about a dozen species were know to have developed resistance to any of the pre-DDT insecticides with the new methods for their intensive application, resistance began a meteoric rise that reached the alarming level of 137 species in The oriental rat flea, the principal vector of the plague, has recently demonstrated resistance to DDT, a most serious development.

Both houseflies and mosquitoes of the genus Culex began to show resistance to the sprays. In 1948 a new chemical, chlordane, was tried as a supplement to DDT. This time good control was obtained for two years, but by August of 1950 chlordane-resistant flies appeared, and by the end of that year all of the houseflies as well as the Culex mosquitoes seemed to be resistant to chlordane. As rapidly as new chemicals were brought into use, resistance developed.

In an army camp in southern Taiwan samples of resistant bedbugs were found actually carrying a deposit of DDT power on their bodies. Resistant houseflies may have the stable fly habit of sitting still in one place, thus greatly reducing the frequency of their contact with residues of poison.

Cultural Eutrophication is human intrusion that disrupts freshwater ecosystem. Relationship between insect and disease  Mosquito = malaria, yelow fever, encephalitis.  Bodylice = typhus  Ratfleas = plague  Housefly = contamination of food to transmit eye diseases. A biological attempt using sound as an agent of direct destruction of insect. Ultrasonic sound will kill all mosquito larvae, but it also kills other aquatic organisms.

Because of human actions of spraying and dusting to annihilate insect species, the insects have actually grown stronger: the population number has actually increased resulting in more potential harm for humans.

The interactions between organisms and their environments determine the distribution and abundance of organisms. By the end of 1951, DDT, mexthoxychlor, chlordane, heptachlor, and benzene Hexachoride had joined the list of chemicals no longer effective. The flies, meanwhile, had become “fantastically abundant.” When the Taiwanese bedbugs were experimentally placed in cloth impregnated with DDT, the live as long as a month; they proceeded to lay their eggs; and the resuling young grew and thrived.

Flies in Canada have been slower to develop resistance than those in southern United States, where long hot summers favor a rapid rate of reproduction.

Predator vs Prey Predation: an interaction between species in which one species, the predation, eats the other, the prey. Erasmus Darwin was the 1 st to practice the method of Biological control- insect vs insect. In 1988, Albert Koebele found natural enemies of the cottony cushion that was detrimental to the California citrus industry. It was highly successful. Insects vs Insects

A wasp imported from Japan gained complete control of an insect attacking eastern apple orchards. Japanese beetle was controlled by Tiphia wasp.

“It is more than clear we are traveling a dangerous road.” - Dr. Briejér