By: April HarpeBy: April Harpe

Clinton LiddellClinton Liddell

JeCinda WhittkerJeCinda Whittker

Bitter BeetlesBitter Beetles

IntroductionIntroduction Did you know that certain plants have specific genes that Did you know that certain plants have specific genes that

make them less likely to be eaten by pests? Cucumbers make them less likely to be eaten by pests? Cucumbers are among these types of plants. Some cucumbers are are among these types of plants. Some cucumbers are bitter because of the cucurbitacin gene found in them. bitter because of the cucurbitacin gene found in them. Other cumbers are non-bitter, but how much of a difference Other cumbers are non-bitter, but how much of a difference does this bitter gene really make against cucumber eating does this bitter gene really make against cucumber eating pests like cucumber beetles (striped and spotted)? When pests like cucumber beetles (striped and spotted)? When cucumber beetles are placed with bitter and non-bitter cucumber beetles are placed with bitter and non-bitter cucumbers will the bitter cucumbers have a lower predation cucumbers will the bitter cucumbers have a lower predation rate than the non-bitter? This is the information the rate than the non-bitter? This is the information the research team is trying to gather through this experiment. research team is trying to gather through this experiment.

Research QuestionResearch Question Will bitter cucumbers have a greater resistance Will bitter cucumbers have a greater resistance

to cucumber beetles than non-bitter to cucumber beetles than non-bitter cucumbers.cucumbers.

Hypothesis and VariablesHypothesis and Variables

Hypothesis: Hypothesis: If bitter and non-bitter cucumbers are placed If bitter and non-bitter cucumbers are placed with cucumber beetles (spotted and striped) then the non-with cucumber beetles (spotted and striped) then the non-bitter plants will show more predation than the bitter plants bitter plants will show more predation than the bitter plants because cucurbitacin found in bitter plants is a deterrent of because cucurbitacin found in bitter plants is a deterrent of cucumber beetles.cucumber beetles.

Independent variable: Type of cucumber and type of Independent variable: Type of cucumber and type of beetles in each cage.beetles in each cage.

Dependent: Predation rate of cucumber plantsDependent: Predation rate of cucumber plants

Literature ReviewLiterature Review Cucumbers are eaten on fresh salads and Cucumbers are eaten on fresh salads and

sometimes cooked. Pickles are also made from sometimes cooked. Pickles are also made from cucumbers.cucumbers.

““The cucumber grows as a rough stemmed, The cucumber grows as a rough stemmed, climbing, or trailing plant with large and yellow climbing, or trailing plant with large and yellow flower” (Gale 1).  flower” (Gale 1).  

““The cucumber is an annual plant, probably The cucumber is an annual plant, probably originally native to southern Asia but possibly to originally native to southern Asia but possibly to India” (Gale 1). India” (Gale 1).

Literature Review Cont’dLiterature Review Cont’d Cucumber beetles are beetles that eat cucumbers and Cucumber beetles are beetles that eat cucumbers and

many other plants also. many other plants also. Most of the severe damage caused by cucumber beetles Most of the severe damage caused by cucumber beetles

is from transmission of bacterial wilt.is from transmission of bacterial wilt. This bacterial wilt can destroy many plants in a field and This bacterial wilt can destroy many plants in a field and

seriously diminish the yield. seriously diminish the yield. The striped cucumber beetle and the spotted cucumber The striped cucumber beetle and the spotted cucumber

beetle have comparable life cycles and both can transmit beetle have comparable life cycles and both can transmit the bacteria. the bacteria.

The spotted cucumber is not considered as serious a The spotted cucumber is not considered as serious a problem then the striped beetle. The striped cucumber problem then the striped beetle. The striped cucumber beetle has a more specific host range and feed almost beetle has a more specific host range and feed almost exclusively on cucurbits in the adult stage.exclusively on cucurbits in the adult stage.

MaterialsMaterials Beetles (Spotted and Striped)Beetles (Spotted and Striped) Six CagesSix Cages Cucumbers (Bitter and Non-Bitter)Cucumbers (Bitter and Non-Bitter) 10mm of water10mm of water ScreenScreen Measurement indexMeasurement index SoilSoil Planters (20oz. bottles cut in half)Planters (20oz. bottles cut in half)

Experimental ProcedureExperimental Procedure1.1. Plant ten non-bitter cucumbers and ten bitter cucumbers in a Plant ten non-bitter cucumbers and ten bitter cucumbers in a

20 oz. bottle cut in half.20 oz. bottle cut in half.

2.2. Build cages (six)Build cages (six)

3.3. Put a bitter plants in three cages and non-bitter plants in three Put a bitter plants in three cages and non-bitter plants in three cages. Use two cages as the controlcages. Use two cages as the control

4.4. Put three striped, and spotted beetles in a cage with bitter Put three striped, and spotted beetles in a cage with bitter plants, then put three striped, and spotted in a non-bitter cage.plants, then put three striped, and spotted in a non-bitter cage.

5.5. Put spotted beetles in bitter, and non-bitter two in each. Then Put spotted beetles in bitter, and non-bitter two in each. Then striped in bitter and non-bitter cages two in each.striped in bitter and non-bitter cages two in each.

6.6. Watch beetles every other day for 5 days and water the plants.Watch beetles every other day for 5 days and water the plants.

7.7. Collect percentage of leaves eatenCollect percentage of leaves eaten

8.8. Record Data Record Data

Graphs 1Graphs 1ControlBitter

ControlNon-Bitter

Bitter Spotted

BitterStriped

Non-BitterSpotted

Non-BitterStriped

Day 1 55 units

80 units

245 units

10 units

130 units

0 units

Day 3 Totally Predated

Totally Predated

N/A N/A N/A N/A

Day 5 Totally Predated

Totally Predated

175 units

142 units

175 units

Totally Predated

Total Totally Predated

Totally Predated

420 units

152 units

305 units

Totally Predated

Predation Day 1 and 5Predation Day 1 and 5( ( 500 units= total predation)500 units= total predation)

Graph and DataGraph and Data

Type Of plant Alive and in Cage Dead Missing

Non-bitter control 2 striped 0 1 striped3 spotted

Bitter spotted 1 1 0

Bitter control 2 spotted1 striped

1 striped 1 spotted1 striped

Non-bitter spotted 0 0 2

Bitter striped 1 1 0

Non-bitter striped 2 0 0

Analysis of ControlAnalysis of Control

Our measurements were in units, because we Our measurements were in units, because we created our own measurement tool. 100 units created our own measurement tool. 100 units equals 1 leaf eaten. Both of the controls were equals 1 leaf eaten. Both of the controls were eaten by day three. Showing that the beetles eat eaten by day three. Showing that the beetles eat both types of the plants. We believe that the both types of the plants. We believe that the beetles escaped the cages when they ran out of beetles escaped the cages when they ran out of food, or they didn’t like it. Only the bitter control food, or they didn’t like it. Only the bitter control had a death and the bug was striped.had a death and the bug was striped.

Analysis of Experiment DataAnalysis of Experiment Data

We found in our experiment that the beetles as a whole ate We found in our experiment that the beetles as a whole ate more of the non-bitter plants. The non-bitter plants had a more of the non-bitter plants. The non-bitter plants had a total predation rate of 805 units and the bitter plant had a total predation rate of 805 units and the bitter plant had a total of 572 units. One of the non-bitter plants was total of 572 units. One of the non-bitter plants was completely eaten. We also found that it is a possibility that completely eaten. We also found that it is a possibility that spotted beetles may prefer bitter cucumbers but do not spotted beetles may prefer bitter cucumbers but do not have a problem with non-bitter cucumbers. The striped have a problem with non-bitter cucumbers. The striped beetles prefer the non-bitter because they have a low beetles prefer the non-bitter because they have a low predation rate on the bitter plants and they completely ate predation rate on the bitter plants and they completely ate the non-bitter plant. the non-bitter plant.

Results and ConclusionResults and Conclusion

Our hypothesis stated that non-bitter Our hypothesis stated that non-bitter cucumbers will have a higher predation rate cucumbers will have a higher predation rate than bitter cucumbers. The hypothesis was than bitter cucumbers. The hypothesis was proven correct because the bitter plants had proven correct because the bitter plants had a lower predation rate than the non-bitter a lower predation rate than the non-bitter 572 units to 805 units.572 units to 805 units.

What We Could Have ChangedWhat We Could Have Changed

The cages were not uniform and some bugs escaped out of the cages.

Test with some kind of sweet plant like corn. Find a more accurate way to measure Grow plants to a average height and number of

leaves. In a future experiment we would put a single type

of the beetles in a cage with both plant types to see which they ate first.

Works CitedWorks Cited

1. Bessin, Ric. "Cucumber Beetles." University of Kentucky College of Agriculture unknown6,November2007 1. 10 Jul 2008 <http://www.ca.uky.edu/entomology/entfacts/ef311.asp>.

2. Day, Eric. "Cucumber Beetles." unknown August 1996 1. 8 Jul 2008 <http://www.ext.vt.edu/departments/entomology/factsheets/cucbeet.html>.

3. "Gourd family." Gale Encyclopedia of Science. Thomson Gale, 2001. NA. Academic OneFile. Gale. Wichita State University Libraries. 10 July 2008 <http://find.galegroup.com/itx/start.do?prodId=AONE>.

 

ThanksThanks

Ms. Hart Mrs. Gossage Ms. Gallegos Mr. Smith Mrs. Scott Mrs. Morgan

Questions?