Population dynamics of the whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), in Java, Indonesia, with special reference to spatio‐temporal changes in the quantity of food resources

Abstract

Six monitoring plots were established in the northern part of West Java, Indonesia, to clarify the factors that influence population fluctuations of the whitefly, Bemisia tabaci. Yellow sticky traps were used to monitor adult populations. To examine the relationship between the population fluctuations and the quantity of food resources, the quantity of food resources of B. tabaci (i.e. soybean and mung bean) was also investigated routinely in each subdistrict where the experimental plot was located. The maximum number of adults per trap in each sowing season showed a similar noticeable seasonal trend in all experimental plots. Climatic factors did not have a major role to play in population fluctuations. The number of adults per trap in each experimental plot tended to increase when the quantity of food resources in each subdistrict increased. The changes of the quantity of food resources seemed to influence the population fluctuations. It is suggested that the operation of regulatory processes in population density is influenced largely by both the distance between habitat patches and the amplitude of temporal fluctuations of the quantity of food resources. An explanation for why the time lag between fluctuations of the quantity of food resources and the number of individuals of B. tabaci occurred is discussed. Based on their flight ability and intrinsic rate of natural increase, B. tabaci is considered not to be a serious pest in the environment where the host plants are grown discontinuously in time and space.

Whitefly population dynamics in okra plantations

“…At the beginning of the first and second plantations, natural enemies were not detected, except for ladybirds in the first, indicating that these natural enemies were latent in nearby areas until okra plants infested with nymphs appeared. Hirano et al (1995) reported that one of the major factors responsible for whitefly population dynamics seems to be temporal variations in the quantity of host plants in the area.…”

Factors affecting attack rate of whitefly on the eggplant

“…(Homoptera: Aleyrodidae) (Seal, 1993). It causes severe damage to plants by feeding on sap, by secreting honeydew where black sooty mold grows, and by transmitting viral diseases (Hirano et al, 1993(Hirano et al, , 1995.…”

“…Such information could help the prediction of the attack by insects which in turn could reduce economic losses (Dent, 1995). Many factors can influence population density of whitefly in host plants such as weather, levels of N and K, age and vigor of plants, type and density of trichomes, allelochemicals and natural enemies (Horowitz et al, 1984;Horowitz, 1986;Hirano et al, 1993Hirano et al, , 1995Dent, 1995;Leite, 2000). The objective of this study was to determine the effects of weather, predators and parasitoids, canopy height and plant age, leaf chemical composition, levels of N and K and leaf trichomes on the intensity of Bemisia tabaci attack in Solanum melongena.…”

“…Horowitz (1986) has reported that in Sudan, after heavy rainfall, generally a sharp fall occurs in the population of B. tabaci in the cotton fields compared to when there is no rain. However, Hirano et al (1993Hirano et al ( , 1995, studying dynamic population of B. tabaci in soybean and mung beans in Java and Indonesia, respectively, reported that the weather was not among the principal factors to regulate the populations of this insect.…”

Fatores naturais que influenciam o ataque da mosca-branca em pimentão

“…Horowitz (1986) relatou que no Sudão, após chuvas pesadas, geralmente ocorre uma queda brusca na densidade de B. tabaci em campos da mesma cultura anterior. Entretanto, Hirano et al (1995), estudando a dinâmica populacional de B. tabaci em lavouras de feijão mungo na Indonésia, concluíram que os fatores climáticos não foram os fatores mais importantes que regulavam as populações desta praga nestas regiões, e sim, plantas hospedeiras alternativas.…”