Judul: Aphids infesting bananas in Java: Identification, Morphometric, Host Range, and Population Density
Abstrak: Banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) has been known as the vector of Banana bunchy top virus (BBTV), the causal agent of banana bunchy top disease. The disease is threatening production of banana which can cause yield loss up to 100%. Understanding the basic information of the vector can help farmers and IPM practitioners to formulate better and more effective strategies in controlling the BBTV distribution. The goal of this research was to identify and to analyze morphometric characters of aphids infesting banana in Java, to determine the banana aphid host range and its population density. Sampling was done by using purposive method. Morphology and morphometry of aphid observation was conducted to identify aphids infesting banana and non banana host plants. As many as 151 specimens collected from various of banana cultivars were examined to identify the species of aphid infesting banana in Java. Moreover, as many as 101 specimens was selected from eleven banana cultivars of West Java, Central Java and East Java in order to assess the morphometric variation of P. nigronervosa. Morphological measurement was derived from image-measuring using Stereo Microscope Leica M 205C and Leica Application Suit Software Version 4.4.0. Eleven morphometric characters of apterous (wingless aphid) were measured: length of body, head width, antennal length, length of antennal segment I-II, length of antennal segment III-V, length of antennal segment VI, length of ultimate rostrum segment, length of siphunculus, length of femur, length of tibia and length of caudal. Investigation of population density of banana aphids was conducted on two different altitudes, i.e. <500 m asl and 500-1000 m asl. The observation was done on a total of 320 banana suckers from 32 villages in West Java, Central Java and East Java. Suckers with 50-150 cm height were selected for aphid observation. Aphid species identification was done based on the identification key by Blackman and Eastop (2006) and Miller et al. (2014). The morphometric data was analyzed using Principle Component Analysis (PCA). Multivariate analysis of variance (MANOVA) was done to test the morphometric differences among the colonies of P. nigronervosa. Linear discriminant analysis (LDA) was performed to test the classification of the species based on the morphometric characters. Cluster analysis with unweighted pair group method with arithmetic mean (UPGMA) using Euclidian distance was conducted to assess character similarity of P. nigronervosa collected from different banana cultivars. The identification result showed there were two aphid species infesting bananas in Java, P. nigronervosa and P. caladii. P. nigronervosa mostly infested bananas (Musa spp.), and a few on heliconia (Heliconia sp.) and the banana traveler (Ravenala madagascariensis). In contrast P. caladii was rarely found on bananas; the aphid generally infested taro (Colocasia esculenta), turmeric (Curcuma longa), costus (Costus sp.), and dumbcane (Dieffenbachia sp.). Some new host plants of banana aphids in Java were recorded in this study, P. nigronervosa was found on banana traveler (Ravenala madagascariensis) and P. caladii was found on banana (Musa sp.), turmeric (Curcuma longa), and banana traveler (Ravenala madagascariensis). The morphometric variation of P. nigronervosa inhabiting different banana cultivars in Java was clearly indicated by the PCA
Keyword: Banana bunchy top virus, banana genome, morphology character, multivariate analysis, Pentalonia spp