BEBERAPA ASPEK DINAMIKA POPULASI Toxoptera citricidus Kirk. (HOMOPTERA: APHIDIDAE) PADA TANAMAN Citrus nobilis Lour.

• Main Author: Helmiyetti
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/1118
• Institution: Institut Teknologi Bandung

<b>Abstract: </b><br>A study on several aspects of the population dynamics of the black <u>Citrus aphid</u>, <u>Toxoptera citricidus</u> infesting <u>Citrus nobilis</u> plants in the green house and in the field at Pakar-Dago, Bandung was conducted in September 1989 until April 1990. The fluctuat on of abundance, population structure of the aphids, the presence of the predators of the aphid, <u>Coccinella transversalis</u> and <u>C. arcuata</u> were observed and the micro climatic factors were measured weekly. The largest proportion (> 68.7%) of the aphid population consisted of nymphs, followed successively by the aptera adults and the alate adults. Multiple regression analysis show that the abundance of aphids in the field, depends on the presence of <u>Coccinella</u> beetles, whereas in the green house, on the relative humidity of air. <u>T. citricidus</u> showed a life cycle of 8.9±0.3 days, an average fecundity of 45.2±1.4 nymphs/apteran adult and a longevity of 23.3±0.2 days. Predation experiments of <u>T. citricidus</u> by the beetle <u>C. transversalis</u> indicated the relatively high potential and effectivity of the third stage of the beetle as aphid predator. Some aspects of the interaction between ant species, <u>M. brunnea</u> and the aphid were also discussed.