Lecture 10

Question 1

what type of predators over come ground beetles? & what are some exs? (5)

Answer 1

bigger predators including:

o	Mongoose
o	Camelion
o	Crow
o	Frogs
o	Ants – see carabidae beetles as their competitors

Question 2

Usually ____ visible segments, but ___ abdominal segments in total (usually some are hidden)

Answer 2

6

7-10

Question 3

when are the abdominal segments of the ground beetles hidden?

Answer 3

when mating

Question 4

pygidium

Answer 4

abdominal segments

Question 5

pygidial glands

Answer 5

defensive glands

come in a pair on either side of the anus

located in the hindgut

Question 6

where are the pygidial glands located?

Answer 6

hindgut

Question 7

secretory lobes

Answer 7

where secretion occurs

Question 8

collecting canal

Answer 8

duct

Question 9

efferent duct

Answer 9

goes from an organ to the outside

Question 10

why is the efferent duct thick-walled?

Answer 10

Thick-walled b/c it contains muscles that force the liquid out

Question 11

opening muscle

Answer 11

controls when the muscle is open

Question 12

valve

Answer 12

muscle that controls where the liquid is directed

Question 13

how do you describe thin-walled pygidial glands

Answer 13

membranous, no muscles

Question 14

accessory gland

Answer 14

adds surfactant to the mixture

Question 15

what effects does a thin-walled reservoir have?

Answer 15

secretion oozes out for the surface of the beetle causing itself to be distasteful

Question 16

where does the liquid secrete?

Answer 16

simple pore in the abdominal surface

Question 17

what effects does a thick-walled reservoir have?

Answer 17

forcibly contract enabling spraying for several cm

contain a nozzle which can direct the spray

Question 18

the chemical composition of the liquid is: ____ irritant & ___ sufractant

Answer 18

> 90%

<10%

Question 19

surfactant

Answer 19

cause liquids to spread on surfaces, hits target & spreads (influences surface tension)

Question 20

what is the most common irritant?

Answer 20

formic acid

Question 21

what % of formic acid is the defensive secretion? & who uses this?

Answer 21

95%

Harpalus

Question 22

describe the irritant in Pterostichus

Answer 22

90% methacrylic acid

Question 23

describe the irritant in Chlaenius

Answer 23

96% 3-methylphenol

Question 24

describe the irritant in Brachinus

Answer 24

100% quinones

Question 25

describe the defensive mechanism of Anthia, the Oopister beetle

Answer 25

formic acid in a directed spray (muscular reservoir)

Synthesized spray

aposematic yellow & black colouration (other organisms mimic it)

Question 26

describe the defensive mechanism of Brachinus, the Bombardier beetle

Answer 26

aposematic

quinones - directed

has a exploison chamber complex - unique

Question 27

what enzymes are produced in Brachinus, the Bombardier beetle

Answer 27

Catalase: convert hydroquinone –> Benzoquinone (more reactive)

Peroxidase: produces the propulsion
H2O2 –> H2O + O2

Question 28

what are the final products released by Brachinus, the Bombardier beetle when making an attack?

Answer 28

o Benzoquinone
o Oxygen
o Steam at 100C

Question 29

what is the function of the inlet valve?

Answer 29

prevents back splash when there is an exploison

Question 30

what are the steps in the exploison of Brachinus, the Bombardier beetle?

Answer 30

1. Inlet valve opens, charging rxn chamber (from the reservoir)
2. Valve closes & enzymes are released
3. Heat-producing rxn brings liquids to boil
4. Pressure increase opens pressure relief valve
5. Reduced pressure causes steam explosion
6. Spray is released through aimed nozzle (directed)
7. Temp & pressure drop, relief valve closes

Question 31

duct

Answer 31

sclerotized cuticle on one side & the other side is flexible

Question 32

describe the diff in headspace volatiles during the reproductive stages?

Answer 32

male - high levels

females - low levels

Question 33

what is the primary ingredient in C.cordicollis?

Answer 33

3 methylphenol (irritant)

Question 34

describe the concentration of 3,5- dimethylphenol during the reproductive season in C. cordicollis

Answer 34

males - 2%
females - 0.5%

females have about 1/4 of what the males have

Question 35

why do females have so much less irritant in C. cordicollis during the reproductive season?

Answer 35

E expense to produce

not investing in that when wanting to mate

Question 36

C. cordicolis - there is a ____ _____ in defensive secretions during the reproductive season

Answer 36

sexual dimorphism