INSECT MOUTHPART LAB

Insect Classification• Kingdom – Animalia

• Phylum – Arthropoda

• Class – Hexapoda (Insects)

Characteristics of Arthropods• They have an

exoskeleton.

• The hard outer covering supports the muscles.

• The appendages are jointed.

• The body is formed of a number of segments.

Characteristics of Insects

Three Main Body Parts

Head

• One pair of antennae.

–tactile organs• sense of touch

–olfactory organs •sense of smell

Thorax• Three pairs of legs.

– The thorax has three segments.

– Each segment has one pair of legs.

Note: Some larvae have leg-like appendages on the abdomen.

• Often one or two pairs of wings. – The wings are borne by

the second and/or third of the thoracic segments.

Note: Some insects are wingless.

Abdomen• The gonopore (genital

opening) is at the posterior end of the abdomen.

• No appendages used for moving on the abdomen of adults (except in a few primitive insects).

• Sometimes there are some appendages at the end of the abdomen.

Insect Mouthparts

Sponging/Lapping

Ex. housefly

Siphoning/Proboscis

Ex. butterfly

Piercing/Sucking

Ex. Mosquito

Chewing

Ex. caterpillars

None

Ex. mayfly

http://www.cals.ncsu.edu/course/ent425/library/labs/external_anatomy/anatomy_mouthparts.html

Mouthparts Animation

The Scientific Method

1. Problem/Question

2. Research

3. Hypothesis

4. Experiment

5. Conclusion

6. Report Results

Problem / Question

• Which insect mouthpart absorbs the largest volume of liquid in a given period of time; siphoning, piercing/sucking, or lapping?

Hypothesis

Which mouthpart do you think will absorb the most liquid in 30 seconds?

• Sample: The Siphoning mouthpart will absorb the most liquid in 30 seconds. Siphoning is a lot like using a straw and liquid can be obtained quickly using this method.

• DO NOT START A HYPOTHESIS WITH . . . “I think”, “I predict” or “My hypothesis

is”!

The Experiment

• Independent Variable: Type of mouthpart

• Dependent Variable: Volume of liquid

• Constants: What was kept consistent/same?– List at least 5 factors.

• Control Group: N/A

• Experimental Group: Mouthpart types (3)

Other Experimental Factors• Materials

– How much? Use metric units.

• Procedure – List numerically. Be detailed.

• Results: Data Table – Used to organize data.

• Results: Graph – Used to visualize and analyze data.– Bar/column graph, line graph or pie chart

Data Table: Volume of liquid absorbed in 30 seconds.

Data Collection

Lab Group Siphoning (ml) Piercing (ml) Sponging (ml)

1      

2      

3      

4      

5      

6      

Data Analysis(Sample Data Table)

 Siphoning

(mL)Piercing (mL) Sponging (mL)

Individual Average 12 8 28

Period Average 14 11 31

Team Average 9 10 27

Data Analysis(Sample Graph)

Volume of Liquid Absorbed by Various Insect Mouthparts in 30 Seconds

0

5

10

15

20

25

30

35

Siphoning Piercing Sponging

Mouthpart

Vo

lum

e o

f L

iqu

id (

mL

)

Individual Avg.

Period Avg.

Team Avg.

Analysis & Conclusion

• Make a statement revealing whether the data collected provided support for or against the hypothesis.

• Explain the data collected including specific numerical or observational data from the experiment.

• Provide a reasonable explanation for the data and attempt to make connections based on the data collected.

• What future experiments could be done based on the data collected or how could the experiment be extended to collect more data?