Lecture 12

Question 1

What are the two way to reproduce?

Answer 1

Asexual (known as parthenogenesis)

Sexual (mating)

Question 2

Sexual Dimorphism

Answer 2

Typically the male is smaller than the female (female needs to be big enough to carry eggs)

Question 3

Advantages/Disadvantages of parthenogenesis

Answer 3

Greater reproductive potential and reduced risk of finding mates are the types of advantages.
However, there is reduced genetic mixing (longrun=weaker species)

Question 4

Advantage/Disadvantage of Mating

Answer 4

There is a ton of genetic mixing with mating, however there is the risk of finding a mate

Question 5

Reproductive Behavior (steps to sex)

Answer 5

A. Locating a mate (time and place)
   1) Olfactory (smell)
       Pheromones
   2) Auditory (sound)(cicadas)
   3) Visual

Question 6

4 ways insects can produce sound

Answer 6

1) Stridulation(rubbing file and scraper together)
2) Vibration of substrate
3) Tymbal (drum-like)
4) Wing beating/buzzing

Question 7

Visual (locating mate)

Answer 7

• Water strider and damsel flies are examples b/c good eyesight
• Fireflies the perfect example, flashes of light in both sexes are unique
• They use luciferin and luciferase
• Huge mating swarms; females come into the swarm (mayflys & termites are perfect example)

Question 8

Reproductive Behavior (steps to sex)

Answer 8

A. Locating mate
B. Courtship
1) visual displays (most in males)
a. territories in dragonflies
2) Acoustic courtship
a. 4 types of sound insects can produce
3) Pheromones (long-range attraction, short-range courting)
C. Sexual Selection
1) hybrid matings avoided by specific mate recognition system- female choice)
a. ornaments, horns of males, promote combat between males
b. Whitefly has tending behavior (grooming?)
c. size matters in +/- way
2) Gamete transfer
a. SP put on substrate
b. SP put on genitalia
c. Copulation- Two types, either SP is inserted in female or there is direct sperm transfer with the
penis

Question 9

Predators take advantage of mating strategies

Answer 9

1) Cricket parasites are attracted to males stridulating
2) Stink bug males call attract egg parasitoids. Rides male and jumps on female during mating and waits for eggs
3) Predators attracted to pheromones produced by bark beetles
4) Predatory female fireflies mimic flashes of prey (Photinus females). Male photinus will come and will be eaten

Question 10

Spermatophores

Answer 10

• Spermatophores(SP) are sperm packets
• Evolutionary trend has gone simple—->complex
• SP is put on substrate or on female genitalia
• Males deposit a stalked SP and females come and pick it up with genitalia
• THIS IS SEXUAL REPRODUCTION WITHOUT COPULATION
• There are 4 types: love gardens, sperm rings, roping, and male guiding
• Love gardens are SP that are placed in specific area and females come wandering through the “garden”
• Sperm rings are when the male surrounds the female with SP
• Roping is where the SP is layed down and the male herds a female down the only route (a thread) to SP
• Male guiding is where male lays SP on silk and guides female to it later on
• Bristletails are perfect example of roping

Question 11

Aedeagus

Answer 11

• This is made up from the phallobase and endopallus

- Endopallus is smaller than the phallobase