Arthropods Associated with Passion Fruit in Western Venezuela

Abstract

The region east and southeast of Lake Maracaibo, Venezuela, is one of the main passion fruit (Passiflora edulis f. flavicarpa Degener) production areas in the world. The area under cultivation has increased more than 8-fold in the last ten years (Dominguez 1986, Domfnguez et al. 1987). Increasing production has not been accompanied by sufficient pest management research. The arthropod fauna associated with the crop in Venezuela is not well known (Dominguez et al. 1987), with only a few reports of phytophagous insects and pollinators from central Venezuela (Haddad & Millan 1975, Brown & Fernandez 1984, Osuna 1984). There is no information on natural enemies of the pests attacking passion fruit. Without this basic knowledge, farmers may have no way of determining the pest status of any particular arthropod species, and development of an integrated pest management (IPM) program is difficult. With no IPM alternative, farmers must rely exclusively on pesticides to solve pest problems. Therefore, our objective was to initiate a faunistic survey involving identification of the most important phytophagous arthropods, natural enemies, and pollinators associated with passion fruit. Arthropods were sampled in 60 commercial passion fruit plantings east and southeast of Lake Maracaibo, Venezuela, between May, 1986, and May, 1990. These plantings varied between 1-15 ha in size and ranged from newly established to 4-5 yr old. Individual plantings were visited 1-16 times over the 4 yr period (46 plantings were visited once, 10 were visited twice, 3 were visited 3 times, and 1 planting was visited 16 times for a total of 91 visits). Visits took place throughout the entire year and at various times of day. During each visit, growers were questioned about entomological, disease, and agronomic conditions in the orchard, and their answers were recorded. First, observations of arthropods were made in any area identified as having an arthropod problem. Then, a random survey (at least 0.5 ha over a time span of 2 h) was made to assess arthropod levels in each orchard. During this random survey, feeding behavior of phytophagous species was observed directly and presence/absence or relative abundance of all arthropods was determined by visual inspection or sweep netting (40 cm in diameter, variable number of sweeps per orchard). Immature insects were collected and reared to adults in the laboratory for identification and to characterize parasitoid occurrence. Voucher specimens have been placed in the Museo Entomol6gico, Facultad de Agronomia, Universidad del Zulia, Maracaibo, Venezuela. Twenty-eight phytophagous arthropod species were found on passion fruit (Table 1). Four major groups of pests attack the fruits and foliage of passion fruit. These groups are discussed briefly in order of decreasing pest impact. Three heliconiine caterpillar species, Dione juno (Cramer), Eueides isabella Menetries, and Agraulis vanillae (L.), were the most significant pests of passion fruit. Dione