Charges A and B in FIGURE Q22.14 are equal. Each charge exerts a force on the other of magnitude F. Suppose the charge of B is increased by a factor of 4, but everything else is unchanged. In terms of F, (a) what is the magnitude of the force on A, and (b) what is the magnitude of the force on B?
Ento 2010 Week 12 Notes April 4, 2016 o Mantids can “hear” the sonar of bats Mantids dive to avoid the bats o Importance of “behavior” in mimicry: Caterpillars avoid birds Birds see leaf damage and find caterpillars Cryptic caterpillars look like leaf or twig Caterpillar eats leaf symmetrically= “no damage” o Hides behind leaf while eating o Eats part of leaf; then clips leaf= “no damage” o Order: Mantodea Mantis=prophet Common name: Mantis or mantid Species: 1,800 o Mantids Incomplete metamorphosis Chewing mouthparts 0.5-6 in. long raptorial forelegs carnivorous long thorax eggs laid in ootheca cryptic coloration o Mantis: Sways back and forth prior to attack Has spines on front legs to hold prey Has elaborate chewing mouthparts WHEN THEY CATCH IT THEY DON’T LET GO! o Why do female mantids eat their mates Theories: It releases male “inhibitions” and his sperm He provides mated female with nutrients o But male is smaller-hard to eat him while mating o Preying mantis Eggs are laid in an egg case=ootheca o Order: Phasmida Phasma=apparition Common name: walking sticks Species: 2,500 o Walking sticks Incomplete metamorphosis Chewing mouthparts Long and slender body Cryptic coloration Feed on plants Feign death when threatened Autotomy: loss of a leg to escape o Mantis: Is a generalist predator Uses antennae to recognize prey Exerts selective pressure: prey with best mimicry survive April 6, 2016 o Ethnoentomology : cultural importance of insects o African Desert Dig toxic beetle pupae from soil Squish insects onto arrows o Darrel Posey P.h.D.-UGA 1979 Ethnoentomology of the Kayapo of Central Brazil o Kayapo Agricultural-but few insect pests Main pest=mosquito (body paint) Eat: ants, bee larvae, wasp larvae o Kayapo use of insects Place ant colony near crop Cultivate ant plants Wasp colony in banana tree o Kayapo Ceremony to acquire power of wasps Young men hit large wasp nest Wasp nest=the Universe o Vincent Holt Why Not Eat Insects 1885 o Insects are nutritious Protein Fat Vitamins (A and D) o Australian Aborigines eat: Beetle larvae: Witchetty Grubs (taste like chicken) o New Guinea Sago Palm provides: Starch=80% calories Larvae of Capricorn beetle=protein snack o Insects are rich in in protein! Botswana-charcoal grilled caterpillars Thailand-steamed bamboo worms Waterbugs Steamed hornet grubs o Scott O’Grady Shot down over Bosnia Survived by eating bugs o 1995 Chinese female runners broke many track records Were they using illegal drugs o No-they ate a caterpillar infected with a fungus o South American Indians eat: Tarantulas: Capture tarantulas-avoid venom and toxic hairs Barbecue tarantulas-taste like shrimp April 8, 2016 o Insects in the Arts Butterflies are favorable subject o Bubonic Plague Ring around the rosies A pocket full of posies Ashes ashes We all fall down o Ogden Nash: Fleas Adam had ‘em o Poetry: Robert Frost Fireflies in the Garden Design (Spider & Moth) Departmental (Ants) The Road Not Taken (Silent Spring) o Insects in language: Busy as a bee Grubby Roach Social butterfly Waspish o Insects in music “Flight of the Bumble Bee” Rimsky-Karsakov o Mariah Carey- ‘Butterfly” o Maria Merian Combined art and entomology Born in Germany Went to South America at age 52 Painted: larvae, pupae, and adult insects with hostplant o Humor Gary Larson Ento 2010 at Washington State University Far Side Insects appear in cartoons more often in winter o Insects in movies Friendly “insects” humanized People use no common sense Frequent biological errors: very large insects can’t breathe o Greatest insect movie: THEM (1954) Giant ants mutated by H-bomb invade Los Angeles sewers