120 AGRIVITA VOLUME 36 No. 2 JUNE - 2014 ISSN : 0126-0537 DIVERSITY OF ARTHROPODS ON COCOA PLANTATION IN THREE STRATA OF SHADE TREE Moh. Hibban Toana1*), Gatot Mudjiono2), S. Karindah2) and Abdul Latief Abadi2) 1) Faculty of Agriculture, Tadulako University Kampus Bumi Kaktus Tondo Palu Indonesia 2) Faculty of Agriculture, University of Brawijaya Jl. Veteran Malang 65145 East Java Indonesia *) Corresponding author Phone: +62-82345074910 Email: [email protected] Received: May 3, 2014 /Accepted: July 12, 2014 ABSTRACT Tenggara, East Java, East Kalimantan, North Moluccas and Irian Jaya (Anonymous, 2012). The Research was aimed to identify the diversity Cocoa production ishampered by plant pests of arthropods in Cocoa plantation in three strata and the strataof shade tree. Major pest on cocoa of shade tree. Research was conducted in is Cocoa Pod Borer Conopomorpha cramerella Rahmat village, the sub-district of Palolo, District Snellen, Helopeltisspp, Zeuzera coffeae of Sigi, the Province of Central Sulawesi, Nietnand Glenea spp. (Firdausil et al., 2008). Indonesia from December 2012 to June However, in South East Sulawesi Cocoa Pod 2013.Berlese funnel, Pitfall, Malaise and Light Borer (Conopomorpha cramerella Snellen trap were used to collect arthropod samples. (Lepidoptera: Gracillariidae) was reported as the There were five indices such as species major pest (Bradley, 1986). Wiryadiputra (1993) richness (R), species evenness (E), species stated that C. cramerella resulted 75-80% yield diversity (H`and D), and species similarity (Iss) loss of cocoa production. There were 3,445 ha to analyze the diversity of arthropods in cocoa of severe attack and 4,867 ha of moderate plantations. The result showed that species attack in Sigi District, caused by C. cramerella richness (R) of arthropods under the two strata (Disbun Sulteng, 2012). As impacts of C. of shade tree, species evenness (E) and both of cramerella, production of cocoa bean decreased species diversity indices, Shannon (H`) and 615-833 kg/ha and this production was lower Simpson (D) was the highest, with value of than national production (1,000 kg/ha) 18.216, 0.839, 4.383, and 0.833 respectively. In (Sulistyowati and Wiryadiputra, 2008). addition, percentage of species similarity (Iss) In Rahmat village, cocoa was cultivated was the highest under two strata of shade tree on spaces between forest trees and fruit trees with value 72.297%. (called two strata of shade tree) (01 11‘ 55.7‘‘S, 120 03‘ 41.5‘‘E, 802-1237 m asl). In addition, Keywords: arthropods, cocoa, species diversity, they cultivated cocoa under Candlenut trees two strata of shade tree (called one stratumof shade tree) (01 11‘ 35.8‘‘S, 120 03‘ 43.3‘‘ E, 752-1237 masl) or no INTRODUCTION shade tree (closed to be monoculture) (0111‘ 33.9‘‘S, 120 03‘ 54.2‘‘ E, 742-1237 masl). Altieri Cocoa (Theobroma cocoa L.) is one of and Nicholls (2004) mentioned that monoculture agricultural commodities that contribute to the can cause agroecosystem susceptible to the Indonesian foreign exchange. Susanto (1994) pest attack. Cocoa cultivated by monoculture will reported that Cocoa as an export commodity also create susceptible agroecosystem. provides raw material for certain agroindustry. The difference of cocoa cultivation system, Availability of areas in Indonesia can be the especially strata of shade tree, can induce the important factor to support Cocoa plantation and difference of arthropod composition. Diversity of industry (Sutrisno and Winahyu, 1997).Cocoa is herbivores, parasitoids, predators, detritivores, planted as major crop in South, South East, and other functional roles of arthropods, and Central Sulawesi, North Sumatera, East of Nusa additional number of arthropod species will be Accredited SK No.: 81/DIKTI/Kep/2011 http://dx.doi.org/10.17503/Agrivita-2014-36-2-p120-127 121 Moh. Hibban Toana et al.: Diversity of Arthropods on Cocoa Plantation…………………………………………………… different related to the difference of strata types 6.00 pm and insect samples were collected at of shade tree. Knops et al. (1999) mentioned 6.00 am. Arthropod samples were collected that the vulnerability to invasions by plant every two weeks for 6 months. species, and increasing of the spread of plant Pitfall Trap. Pitfall traps, which contained fungal diseases caused by experimental water and detergent, were put into the ground reduction of plant richness in grassland will also for 24 hours. The distance of each pitfall trap influence richness and structure of insect was 20 m. Arthropod samples were collected communities. every two weeks for 6 months. Insects greatly determines the biological Malaise Trap. Malaise trap was located diversity of fragmentation of habitat in the for 24 hours in the center of each type of cocoa agricultural landscape (Kruess and Tscharntke, plantation. Plastic bottles containing water and 1994). Structure of agricultural landscape can detergent were set up at the top of Malaise trap. have strong impact on activities of natural The trap was set up once in two weeks for 6 enemies, such as parasites and predators. months. Positive relationship between parasitoid Berlese Funnel. Berlese funnel was used abundance and diversity and landscape to extract arthropod samples from the soil vegetation complexity was clearly described in samples. Soil samples were collected from 5 the simple and complex landscape, where in sample points (20 x 20 cm) diagonally within 1 complex landscape, percentage of parasitism m2 area of sampling. Five soil samples were was significantly higher than that of the simple mixed and putinto the Berlese funnel. landscape (Marino and Landis, 1996). In Erlenmeyer contained water and detergent was addition, landscape factors are the key drivers of placed under the Berlese funnel to collect predator abundance in case of aphids arthropod from the soil samples. Arthropod suppression on Soybean (Woltz et al., 2012). sampling was takenonce in two weeks for 6 The closed relationship between agri- months. cultural landscape and insect diversity, the All collected arthropod samples were diversity of arthropods on cocoa plantation identified based on their morphological under the three types of shading was observed. characters and functions in the laboratory of It was assumed that there were differences in plant pest, Faculty of Agriculture, Tadulako and arthropod diversity among three intensities of Brawijaya University. Physical factors were shade tree on cocoa plantation. recorded to describe the arthropod dynamic such as rainfall, temperature and relative MATERIALS AND METHODS humidity. Variables were observed in this The diversity of arthropods was surveyed research i.e. number of species and their in three types of cocoa plantation at Rahmat population. Based on the data of each variable, village,sub-district of Palolo, District of Sigi, some ecological indices, such as Species Province of Central Sulawesi, Indonesia from Richness, Species Evenness Indices, Shannon- December 2012 to June 2013. These cocoa Wiener Indices (H`), Simpson index (D), and plantations have different types of shade tree. Sorensen Similarity index were calculated: There were three sorts of shadetree, i.e.cocoa 1. Species Richness, Margalef Index (Ludwig with two strataof shadetree, cocoa with one and Reynolds,1988) S -1 stratum of shade tree, and cocoa without shade R tree. Sampling arthropods were conducted from ln(n) December 2012 to June 2013. R, S, n, and ln are species richness index, Arthropods samples were collected by number of species, population of each light trap, pitfall trap, malaise trap and Berlese species, and logarithmic number respectively. funnel. Light trap. Thirteen light traps were 2. Species Evenness Indices, Pielou Indices located ineach type of cocoa plantation. One formulated as light trap was put on the centre of four quadrants H` of cocoa trees. Light traps were turned on at E ln(S) 122 Moh. Hibban Toana et al.: Diversity of Arthropods on Cocoa Plantation…………………………………………………… E, H` and S are species evenness indices, (Krebs, 2002) and Estimate S 910 Windows Shannon diversity indices, and number of (Colwell, 2013) were used to analyze the species respectively. data. 3. Species diversity indices, Shannon-Wiener RESULTS AND DISCUSSION Indices (H`): Combining results from several traps, number of arthropod species and the same species found in all strata of shade tree were the highest in the cocoa plantationin two strata of H`, ni and N are Shannon-Wiener index, shadetree, 186, and 34 species respectively. population of i species and population total of Based on Table 2, the diversity of all species respectively. arthropods in three strata of shade tree of cocoa plantation showed the difference in the number Table 1. 9alue and description of H‘ (Anony- of species and population of total arthropods. mous, 2014) Number of arthropod species and the same species found in all strata types of shade tree were the highest in the cocoa plantation under two strata of shade tree, 186 and 34 species, respectively. The lowest value was shown by cocoa plantation no shading, 57 species of 4. Simpson index (D) is described as below: arthropod species number and 20 species of the same species found in all strata types. The population of arthropod was the highest in the cocoa plantation with no shading (30,464 arthropods), and it was followed by one and two ni and N are population of each species and types of shading such as 28,270 and 25,736 population of all species, respectively. arthropods, respectively. Diversity will be lower if the value of D (Simpson index) is higher. Table 2. Species number, population of arthropod, and the same species were found in all 5. Sorensen Similarity index types of shade tree of cocoa plantation 2C The same Iss x100% Types of A + B Population species were shade tree No. of of found in all of cocoa species arthropods types of Iss, A, and B are Similarity index, number of plantation shade tree arthropod species in A and B types of Two strata shadetree and the number of the same One 186 25,736 34 arthropod species in both types of shade stratum 110 28,270 22 treeof cocoa plantation, respectively.