1Good afternoon, and welcome to Insect Biology 101.
2I'd like to begin this course with a few remarks about good insects and bad ones.
3Bugs are all around us and that's both a benefit and an annoyance,
4sometimes maybe even serious harm.
5First, let's talk about the good things that insects do for us.
6Probably the most important insect for humans, and maybe for all other life, is the bee.
7Bees help plants in the process of pollination,
8and thus are necessary to most flowers and fruit-producing trees.
9That is, they carry pollen from "male" flowers to "female".
10If it weren't for bees, we'd have very few food plants and no fruit either.
11In fact, there would be no "we".
12No less a thinker than Albert Einstein pointed out that,
13without bees, humanity would be dead within a year or less.
14We'd starve. It's that simple.
15That should maybe make us just a little humble.
16A little less dramatic is the fact that bees also make the honey we eat.
17Moreover, they produce beeswax, which is useful in candles
18and it's also used as a first-rate furniture polish.
19Sure, these may not be vital to our lives,
20but they can serve as reminders of how important bees are.
21That's a point I keep coming back to in this course.
22Though, in all fairness, I should point out that butterflies aid in pollination as well as bees.
23Now, here in Michigan, what's the worst part of summer?
24Yep, that's right - mosquitoes.
25But I'm talking about helpful insects, right?
26So let's look at the dragonfly first.
27If there were no dragonflies, there would be even more mosquitoes!
28Dragonflies mainly eat mosquitoes and also a few other insects.
29Yes, that's right.
30They don't just fly around, and they also help to eliminate harmful insects.
31So, the next time you see a dragonfly, don't you dare kill it!
32Now let's talk a little about those harmful insects.
33Take the mosquitoes I just mentioned as an example.
34Not so many years ago, mosquitoes here in America weren't just annoying.
35Some were even deadly.
36They carried malaria and yellow fever.
37My own ancestor, the Confederate General John Bell Hood,
38lived through the worst battles of Civil War only to die at age 38 from yellow fever.
39A pest, not a bullet!
40Well, besides the mosquitoes, in summer there is also a kind of insect that never seems tired.
41Right, that is the fly.
42Before I go on talking, I must mention an African fly called the Tsetse fly,
43which feeds on blood and can cause serious diseases in the people and animals that it bites.
44Besides, it is still a bearer of sleeping sickness,
45which affects around 300,000 people every year in Africa
46and can be treated only with toxic drugs that are hard to administer.
47Worse still, the drugs sometimes don't work.
48Other insects, of course, destroy food crops.
49In China, for instance, locusts continue to be a danger to the harvest in some areas.
50Less important, but still annoying, moths eat people's clothes and dust mites slowly destroy carpets.
51Worse, but still in the home, termites or "white ants" eat wood - the wood of your house.
52If they are not stopped, they can eventually destroy the whole building.
53Usually they seriously damage a building before anyone even notices them.
54So, as we all know, insects can be a real trouble.
55So, what to do?
56You can go ahead and start killing harmful insects.
57In the early decades after the communist revolution in China,
58Chairman Mao encouraged the people to swat every fly they could see.
59Slogans on the walls of buildings called them "Little Capitalists".
60But flies reproduced too quickly for this to be a long-term solution.
61For some decades in the West, to kill insects with chemicals seemed a good remedy.
62Unfortunately, chemicals can only be used in a limited area for a limited time.
63It's a small-scale solution.
64The insects come back.
65Worse still, some of the poisons used like DDT were found harmful to the environment.
66Many kinds of wildlife, like hawks, were harmed.
67And people in chemical-using rural areas have one of the highest rates of liver cancer in the world.
68It's no secret that chemicals remain harmful to humans.
69Like all species, insects adapt to their changing environments at an amazing rate.
70When a new chemical is introduced to their habitat,
71the insects that survive are generally the ones with some way of resisting the harmful effects.
72They then breed with the other survivors,
73and just like that insects become resistant to most poison in a few generations.
74An insect generation, remember, is a couple of months at most!
75So, again we have to ask: what to do?
76Well, there are biological solutions.
77Some of these are pretty simple.
78One is destroying the insects' habitat.
79You take away their home or food.
80Cleaning your kitchen is the best way to prevent roaches.
81No garbage: no food.
82Getting rid of marshes and swamps eliminates mosquitoes.
83Other solutions might include bringing in dragonflies or bats in areas where mosquitoes are many.
84This is a cheaper alternative to chemicals.
85Biological methods like this also bring no extra pollution to the environment.
86But you have to be careful.
87If you change the environment too much, you might be hurting other forms of life accidentally.
88One recent method of controlling insect populations involves interrupting their breeding cycle.
89What does that mean?
90It means "birth control for bugs".
91Insects are provided with food that makes them unable to reproduce.
92Since they can't have babies, the population disappears, or nearly so.
93And since no young are born,
94resistance is not a problem with no young insects developing increased resistance.
95Interrupt the life cycle, eliminate the bug!
96It's clear that we must have an understanding of the life cycle of the insect.
97At least, that's the plan.
98We'll go into more detail as the course goes along.
99Now I will stop here to see whether you have any questions or not.