By: April Harpe Clinton Liddell JeCinda Whittker Bitter Beetles

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

Research Question  Will bitter cucumbers have a greater resistance to cucumber beetles than non-bitter cucumbers.

Hypothesis and Variables  Hypothesis: If bitter and non-bitter cucumbers are placed with cucumber beetles (spotted and striped) then the non- bitter plants will show more predation than the bitter plants because cucurbitacin found in bitter plants is a deterrent of cucumber beetles.  Independent variable: Type of cucumber and type of beetles in each cage.  Dependent: Predation rate of cucumber plants

Literature Review  Cucumbers are eaten on fresh salads and sometimes cooked. Pickles are also made from cucumbers.  “The cucumber grows as a rough stemmed, climbing, or trailing plant with large and yellow flower” (Gale 1).  “The cucumber grows as a rough stemmed, climbing, or trailing plant with large and yellow flower” (Gale 1).  “The cucumber is an annual plant, probably originally native to southern Asia but possibly to India” (Gale 1).

Literature Review Cont’d  Cucumber beetles are beetles that eat cucumbers and many other plants also.  Most of the severe damage caused by cucumber beetles is from transmission of bacterial wilt.  This bacterial wilt can destroy many plants in a field and seriously diminish the yield.  The striped cucumber beetle and the spotted cucumber beetle have comparable life cycles and both can transmit the bacteria.  The spotted cucumber is not considered as serious a problem then the striped beetle. The striped cucumber beetle has a more specific host range and feed almost exclusively on cucurbits in the adult stage.

Materials  Beetles (Spotted and Striped)  Six Cages  Cucumbers (Bitter and Non-Bitter)  10mm of water  Screen  Measurement index  Soil  Planters (20oz. bottles cut in half)

Experimental Procedure 1.Plant ten non-bitter cucumbers and ten bitter cucumbers in a 20 oz. bottle cut in half. 2.Build cages (six) 3.Put a bitter plants in three cages and non-bitter plants in three cages. Use two cages as the control 4.Put three striped, and spotted beetles in a cage with bitter plants, then put three striped, and spotted in a non-bitter cage. 5.Put spotted beetles in bitter, and non-bitter two in each. Then striped in bitter and non-bitter cages two in each. 6.Watch beetles every other day for 5 days and water the plants. 7.Collect percentage of leaves eaten 8.Record Data

Graphs 1 Contro l Bitter Control Non- Bitter Bitter Spotte d Bitter Stripe d Non- Bitter Spotte d Non- Bitter Striped Day 1 55 units 80 units 245 units 10 units 130 units 0 units Day 3Totally Predate d N/A Day 5 Totally Predat ed 175 units 142 units 175 units Totally Predated TotalTotally Predat ed 420 units 152 units 305 units Totally Predated

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

Graph and Data Type Of plant Alive and in CageDeadMissing Non-bitter control2 striped01 striped 3 spotted Bitter spotted110 Bitter control2 spotted 1 striped 1 spotted 1 striped Non-bitter spotted002 Bitter striped110 Non-bitter striped200

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

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

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

What 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 Cited 1. 1.Bessin, Ric. "Cucumber Beetles." University of Kentucky College of Agriculture unknown6,November Jul Day, Eric. "Cucumber Beetles." unknown August Jul "Gourd family." Gale Encyclopedia of Science. Thomson Gale, NA. Academic OneFile. Gale. Wichita State University Libraries. 10 July  

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

Questions?