Relationship Between Sphagneticola Trilobata Stem Height and Butterfly Landing Frequency
Abstract
Most insects searching for pollen and nectar demonstrate flower fidelity, an acquired commitment to a certain, single species of a plant. This experiment was carried out to find out if this constancy is further reflected in a preference for flower heights within the species of a plant. The incidence of Zizina otis lampa and Junonia almana javana butterflies landings on the Sphagneticola trilobata plant of different flower heights is studied with the aim of establishing a relationship between flower heights of the plant and frequency of butterfly landings. Results were obtained through visual measurement over eight hours, which suggested an existence of a general as well as species-specific preference of heights, with the Zizina otis lampa preferring a height of 21-25 cm while the Junonia almana javana is more inclined towards a height of 31-35 cm.
Introduction
The S.trilobata is an invasive species belonging to the Asteraceae (sunflower) family native to the tropics of Central America. It can, however, be found in humid tropical areas all around the world due to its high tolerance to even large ecological variations in habitats (PIER, 2003). The three butterflies observed include the two species to be compared, J. almana (Peacock Pansy), and Z. otis (Lesser Grass Blue) as well as Papilio polytes (Common Mormon), which is not discussed in this experiment. Z. otis is a butterfly with a pastel blue-violet coloration with a silvery sheen (Evans, 1932) while the J. almana is purple patterned with characteristic orange eyespots (Bingham, 1905). The P. polytes can be identified by a group of large ashen spots along its hind wing and forewing on a black body (Tan, 2011).
In this experiment, we explore the competitive exclusion principle using the butterflies (Z. otis and J. almana) as the model animals and the Singapore Daisy (S.trilobata) as the common resource shared. According to the competitive exclusion principle, two species with identical
Most insects searching for pollen and nectar demonstrate flower fidelity, an acquired commitment to a certain, single species of a plant. This experiment was carried out to find out if this constancy is further reflected in a preference for flower heights within the species of a plant. The incidence of Zizina otis lampa and Junonia almana javana butterflies landings on the Sphagneticola trilobata plant of different flower heights is studied with the aim of establishing a relationship between flower heights of the plant and frequency of butterfly landings. Results were obtained through visual measurement over eight hours, which suggested an existence of a general as well as species-specific preference of heights, with the Zizina otis lampa preferring a height of 21-25 cm while the Junonia almana javana is more inclined towards a height of 31-35 cm.
Introduction
The S.trilobata is an invasive species belonging to the Asteraceae (sunflower) family native to the tropics of Central America. It can, however, be found in humid tropical areas all around the world due to its high tolerance to even large ecological variations in habitats (PIER, 2003). The three butterflies observed include the two species to be compared, J. almana (Peacock Pansy), and Z. otis (Lesser Grass Blue) as well as Papilio polytes (Common Mormon), which is not discussed in this experiment. Z. otis is a butterfly with a pastel blue-violet coloration with a silvery sheen (Evans, 1932) while the J. almana is purple patterned with characteristic orange eyespots (Bingham, 1905). The P. polytes can be identified by a group of large ashen spots along its hind wing and forewing on a black body (Tan, 2011).
In this experiment, we explore the competitive exclusion principle using the butterflies (Z. otis and J. almana) as the model animals and the Singapore Daisy (S.trilobata) as the common resource shared. According to the competitive exclusion principle, two species with identical
References: Bingham, C.T. 1905. 375, Junonia almanac. Butterflies, Volume 1. The Fauna of British India, Including Ceylon and Burma. Pp. 361-362. Evans, W.H. 1932. The Identification of Indian Butterflies. (2nd Ed), Bombay Natural History Society, Mumbai, India PIER (Pacific Island Ecosystems at Risk), 2003. Wedelia trilobata Retrieved on 5th Nov, from http://www.hear.org/pier/species/wedelia_trilobata.htm Smith, T.M. & Smith, R.L. (2012). Elements of Ecology. Pearson Education, United States of America, pg 246 – 247. Tan, Horace. 2011. Featuring Nature’s Flying Jewels in Singapore!. Butterflies of Singapore. Retrieved on 20th Oct, from http://butterflycircle.blogspot.sg/2011/10/life-history-ofcommon-mormon.html.