Harvard Forest Data Archive

HF114

Sarracenia Purpurea Prey Capture at Harvard Forest 2008

Related Publications

Data

Overview

  • Lead: Aaron Ellison, Katherine Bennett
  • Investigators:
  • Contact: Aaron Ellison
  • Start date: 2008-07-01
  • End date: 2008-09-05
  • Status: completed
  • Location: Tom Swamp Tract (Harvard Forest)
  • Latitude: +42.50
  • Longitude: -72.20
  • Elevation: 240 meter
  • Taxa: Dolichoderus pustulatus, Formica fusca, Formica subaenescens, Myrmica lobifrons, Sarracenia purpurea, Tapinoma sessile
  • Release date: 2009
  • Revisions:
  • EML file: knb-lter-hfr.114.12
  • DOI: digital object identifier
  • Related links:
  • Study type: short-term measurement
  • Research topic: physiological ecology, population dynamics and species interactions
  • LTER core area: populations
  • Keywords: carnivorous plants, insects, predation
  • Abstract:

    We experimentally demonstrate that nectar, not color, is the primary attractant of prey to carnivorous pitcher plants in their native habitats. Prey capture (either all taxa summed or individual common taxa considered separately) was not associated with total red area or patterning on pitchers of living pitcher plants. We separated effects of nectar availability and coloration using painted "pseudopitchers", half of which were coated with sugar solution. Unsugared pseudopitchers captured virtually no prey, whereas pseudopitchers with sugar solution captured the same amount of prey as living pitchers. In contrast to a recent study that associated red coloration with prey capture but that lacked appropriate controls for nectar availability, we conclude that nectar, not color, is the primary means by which pitcher plants attract prey.

  • Methods:

    We conducted this study during mid-summer, when insect abundance and prey capture is highest in New England (Fish and Hall 1978). In July 2008, we randomly identified 25 pitchers, each on a different Sarracenia purpurea plant, at Tom Swamp, a bog in Petersham, Massachusetts, USA. On 3 July 2008, we suctioned out all liquid and prey carcasses from pitchers, rinsed them, and then refilled them with distilled water. Three days later, pitcher contents were collected and the prey counted and identified. The experiment was repeated on 11 and 14 July 2008. On 17 July 2008, pitchers were harvested, cleaned, flattened and photographed (Canon S3-IS digital camera) to determine each pitcher’s area, proportion red color; and perimeter of red venation (using SigmaSan Pro 5.0; SPSS, Chicago, Illinois). Spectral reflectance (375 - 800 nm) of pitchers was measured at 2-cm intervals around the pitcher and across the pitcher hood using an Ocean Optics S2000 fiber-optic spectrometer, ISP-REF integrating sphere, and OOIColor/OOIIrrad 2.05.00 software (Ocean Optics, Dunedin, Florida). Reference scans were made using Kodak (Rochester, New York) black and white reference cards.

    Seventy "pseudopitchers" (painted 50-ml plastic centrifuge tubes [BD Biosciences, San Jose, California]) were used to separate effects of color and nectar on prey capture. Seven sets of ten were assigned different color treatments. One set was painted entirely green using "Fresh Foliage" acrylic paint (Plaid Enterprises, Norcross, Georgia); one set was painted entirely red (Plaid Enterprises' "Burgundy"); four sets were first painted green, then red "veins" were added to produce 6 - 62% red color, the range found on real pitchers; and one set of 10 was unpainted controls. Peak reflectances of the green and red paints were the same wavelengths as peak reflectances of green and red pitchers. To determine how availability of nectar interacted with color in attracting prey, four lines of Karo Corn Syrup (ACH Food Companies, Memphis, Tennessee), cooked until thick, were streaked at random locations on one-half of each set of pseudopitchers. Like all plant nectars, Karo Corn Syrup is a mixture of fructose and glucose. To closely resemble real pitcher plants, pseudopitchers were embedded at an angle in the bog surface with more than 50% of the tube visible above the Sphagnum. Psuedopitchers were located within 10 meters of the plants for which we assessed prey capture. Fifteen ml of 50% ethanol was put inside each tube; trapped insects were collected after 48 hrs, counted, and identified. The entire experiment was repeated twice over a three-week span of time.

  • Use:

    This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

  • Citation:

    Ellison A, Bennett K. 2009. Sarracenia Purpurea Prey Capture at Harvard Forest 2008. Harvard Forest Data Archive: HF114.

Detailed Metadata

hf114-01: real prey

  1. plant: plant number (1-25)
  2. height: height of pitcher in cm (unit: centimeter / missing value: NA)
  3. diameter1: diameter across the pitcher mouth in cm (unit: centimeter / missing value: NA)
  4. diameter2: diameter perpendicular to diameter 1 in cm (unit: centimeter / missing value: NA)
  5. totalarea: surface area of the plant in cm2 (unit: squareCentimeters / missing value: NA)
  6. redarea: total surface area that is red in cm2 (unit: squareCentimeters / missing value: NA)
  7. redperimeter: total perimeter of red veins in cm (unit: squareCentimeters / missing value: NA)
  8. ants20080703: number of ants captured from July 1 - July 3, 2008 (unit: number / missing value: NA)
  9. ants20080711: number of ants captured from July 8 - July 11, 2008 (unit: number / missing value: NA)
  10. ants20080714: number of ants captured from July 11 - July 14, 2008 (unit: number / missing value: NA)
  11. collembola20080703: number of springtails captured from July 1 - July 3, 200 (unit: number / missing value: NA)
  12. collembola20080711: number of springtails captured from July 8 - July 11, 2008 (unit: number / missing value: NA)
  13. collembola20080714: number of springtails captured from July 11 - July 14, 2008 (unit: number / missing value: NA)
  14. spiders20080703: number of spiders captured from July 1 - July 3, 2008 (unit: number / missing value: NA)
  15. spiders20080711: number of spiders captured from July 8 - July 11, 2008 (unit: number / missing value: NA)
  16. spiders20080714: number of spiders captured from July 11 - July 14, 2008 (unit: number / missing value: NA)
  17. flies20080703: number of flies captured from July 1 - July 3, 2008 (unit: number / missing value: NA)
  18. flies20080711: number of flies captured from July 8 - July 11, 2008 (unit: number / missing value: NA)
  19. flies20080714: number of flies captured from July 11 - July 14, 2008 (unit: number / missing value: NA)

hf114-02: pseudo prey

  1. tubenumber: pseudopitcher number
  2. paint: painted (yes or no)
    • yes: painted
    • no: not painted
  3. nectar: nectar added (yes or no)
    • yes: nectar added
    • no: nectar not added
  4. tubearea: surface area of the pseudopitcher. Always = 64.28 cm2 (unit: squareCentimeters / missing value: NA)
  5. redarea: total surface area of pseudopitcher painted red in cm2 (unit: squareCentimeters / missing value: NA)
  6. redperimeter: total perimeter of pseudopitcher painted red in cm (unit: centimeter / missing value: NA)
  7. ants20080819: number of ants captured from August 17 - August 19, 2008 (unit: number / missing value: NA)
  8. ants20080905: number of ants captured from September 3 - September 5, 2008 (unit: number / missing value: NA)
  9. collembola20080819: number of springtails captured from August 17 - August 19, 2008 (unit: number / missing value: NA)
  10. collembola20080905: number of springtails captured from September 3 - September 5, 2008 (unit: number / missing value: NA)
  11. spiders20080819: number of spiders captured from August 17 - August 19, 2008 (unit: number / missing value: NA)
  12. spiders20080905: number of spiders captured from September 3 - September 5, 2008 (unit: number / missing value: NA)
  13. flies20080819: number of flies captured from August 17 - August 19, 2008 (unit: number / missing value: NA)
  14. files20080905: number of flies captured from September 3 - September 5, 2008 (unit: number / missing value: NA)