Equations (Lecture 9)

Question 1

RGR

Definition + Equation

Answer 1

Relative Growth Rate

Weight (mg) gained per day / Average larval weight (mg)

Question 2

RCR

Definition + Equation

Answer 2

Relative Consumption rate

mg ingested per day / Average Larval weight (mg)

Question 3

ECI

Definition + Equation

Answer 3

Efficiency of Conversion of Ingested food

[Weight (mg) gained / mg food ingested ] x 100

Question 4

ECD (Alternate name)

Definition + Equation

Answer 4

Efficiency of conversion of digested food
(aka net dietary utilization)

[ weight (mg) gained / (mg ingested - mg frass) ] x 100

Question 5

AD (Alternative name)

Definition + Equation

Answer 5

Approximate digestibility
(AKA assimiliation efficiency)

mg ingested - mg frass / (mg ingested) x 100

Question 6

Shortcut Nutritional Parameters (3)

Answer 6

RGR = RCR x ECI

ECI = AD x ECD

1 - ECD = metabolic cost

Question 7

Highest RGR (2)

Answer 7

Forb feeding (leaves / herbs feeders) Hemiptera and Lepidoptera

Question 8

Lowest RGR

Answer 8

Aquatic Detritivores (eg. Stonefly, mayfly naiads)

Question 9

Highest RCR

(2)

Why do these insect have High RCR ?

Answer 9

Tree feeding, Hymenoptera, Forb feeding Lepidoptera

b/c they eat twice their body weight

Question 10

Lowest RCR

(2)

Answer 10

Predatory insects (these insect would not be able to get food all the time, limited prey)

Wood feeding insect (may not contain the enzyme cellulose)

Question 11

Highest ECI (2)

Answer 11

Eg. Seed- feeding Hemiptera (these insects feed on protein rich seeds)

Eg. Blood feeders (Diptera)

Question 12

Lowest ECI (2)

Answer 12

Eg: Aquatic Detritivores (Mayflies naiads, Stoneflies naiads, Dragonflies naiads)

Eg. Tree feeding Hymenoptera

Question 13

Highest ECD (2)

Answer 13

Eg. Seed-feeding Hemiptera

Eg. Blood feeders (Diptera)

Question 14

Lowest ECD (2)

Answer 14

Eg. Ants - perform a number of activities, are very active and always moving

Eg. Stored grain feeders

Question 15

Highest AD (2)

Answer 15

Eg. Forb feeding Coleoptera

Eg. Predatory Insects

Question 16

Lowest AD (%)

Answer 16

Eg. Dung feeding insects (do not obtain much nutrient because there are low nutrient in feces)

Question 17

Positive Relationship in Water

Answer 17

There exists to be a positive correlation b/t water content and ECD and ECI

Question 18

Positive relationship in N

Answer 18

There exists to be a positive correlation b/t dietary Nitrogen and RGR and ECI

Question 19

Physiological Efficiency Model

Answer 19

As nitrogen increase and water increase, this leads to an increase in the growth rate (RGR) and AD

Question 20

Bernays demonstrated that Phenylalanine added at a rate of 1mg/day in the diet of the locust caused

(2)

Answer 20

69% weight gain in the integument of the locust

79% of the phenyl alanine was incorporated into the integument

Question 21

RCR on nutrient deficient diet

Answer 21

Consumption rate (RCR) of the insect increase on a nutrient deficient diet

Question 22

Holometabolous (eg. armyworm) insects are more efficiency in conversion of digested food to their biomass than a hemimetabolous insect (grasshopper)

Why

Answer 22

This is because the hemimetabolous insects contribute more towards their integument since they develop external wings