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FRUIT FLIES (DIPTERA: TEPHRITIDAE) INFESTING FRUITS OF THE GENUS PSIDIUM (MYRTACEAE) AND THEIR ALTITUDINAL DISTRIBUTION IN WESTERN VENEZUELA
Kamta P. Katiyar, Jesus Camacho Molina and Ricardo Matheus
Unidad Técnica Fitosanitaria (UTF), Facultad de Agronomía, La Universidad del Zulia, Apdo. 526, Maracaibo, Estado Zulia 4002, Venezuela
Museo de Artr-podos (MALUZ), Facultad de Agronomía, Apdo. 526, Maracaibo, Estado Zulia 4002, Venezuela
Abstract
A survey of fruit flies infesting Psidium fruits was conducted in western Venezuela from June 1992 through December 1995. Of 201 fruit samples collected from 139 localities at altitudes between sea level and 2,000 m, four species of Psidium plants were found in the western region of Venezuela. These were P. guajava L. (10-1930 m), P. guineense Sw. (100-1950 m), P. caudatum McVaugh (1800-1950 m) and P. friedrichsthalianum (Berg) Niedenzu (35-1700 m). Four tephritid fly species were reared: Anastrepha striata Schiner, A. fraterculus (Wiedemann), A. obliqua (Macquart), and Ceratitis capitata (Wiedemann). All four fruit fly species emerged from P. guajava. A. striata was the most common on P. guajava, P. guineense and P. friedrichsthalianum, with an infestation range of 96.1%-97.0%. P. caudatum was more frequently infested by A. fraterculus (94.5% adults emergence); the plant's distribution was restricted to highlands. Observations on the altitudinal distribution of A. striata on P. guajava showed that the highest infestation (253.9 adults/kg fruits) occurred at about 1,000 m. The infestation rate of P. guajava by A. fraterculus and A. obliqua varied with elevation. In low elevation areas (0-1,200 m), A. obliqua was found more frequently than A. fraterculus, whereas A. fraterculus was found more frequently than A. obliqua in high altitude areas (1,201-2,000 m). C. capitata was erratically encountered in this study.
Key Words: Anastrepha, Ceratitis capitata, guava, Psidium spp., altitudinal distribution
Resumen
Desde junio de 1992 a diciembre de 1995 se estudiaron las moscas de las frutas (Diptera: Tephritidae) que infestan plantas del género Psidium en el occidente de Venezuela. Se recolectaron un total de 201 muestras de frutas en 139 localidades comprendidas desde el nivel del mar hasta 2,000 m de altitud. Se encontraron cuatro especies de plantas del género Psidium: P. guajava L. (10-1930 m), P. guineense SW. (100-1950 m), P. caudatum Mc Vaugh (1800-1950) y P. friedrichsthalianum (Berg) Niedenzu (35-1700 m). Se lograron criar cuatro especies de moscas de la Familia Tephritidae: Anastrepha striata Schiner, A. fraterculus (Weidemann), A. obliqua (Macquart) y Ceratitis capitata (Weidemann)]. De P. guajava emergieron las 4 especies de moscas de las frutas encontradas en el presente estudio. A. striata result- ser la mosca más común en P. guayaba, P. guineense y P. friedrichsthalianum encontrándose infestaciones comprendidas entre 96.1%-97.0%. P. caudatum fue encontrada como la planta hospedera preferida por A. fraterculus con un 94.5%. Además, su distribuci-n está restringida a tierras altas. La distribuci-n altitudinal de A. striata muestra que la mayor infestaci-n en frutos de P. guajava ocurre alrededor de los 1,000 m de altitud (253.9 adultos/Kg de frutas). La infestaci-n relativa de A. fraterculus y A. obliqua en P. guavaja varia con la altitud. En tierras bajas (0-1,200 m), A. obliqua se encontr- como la especie predominante sobre A. fraterculus. En cambio, en tierras altas (1,201-2,000 m), A. fraterculus fue la especie predominante sobre A. obliqua. La distribuci-n geográfica y altitudinal de C. capitata fue muy errática.
The Genus Anastrepha is endemic to the Americas and is restricted to tropical and subtropical environments. Its range extends from the southernmost part of the United States (Rio Grande Valley of Texas and southern Florida) to South America, with the exception of the southern parts of Argentina and Chile. Fruit flies of the genus Anastrepha compose one of the largest and most economically important insect groups in the tropics and subtropics due to their damage to cultivated fruits. This group comprises more than 190 identified species but hosts are known for less than half (Norrbom & Kim 1988). In Venezuela there are four economically important Anastrepha species: the South American fruit fly, A. fraterculus (Wiedemann), the West Indian fruit fly, A. obliqua (Macquart), the guava fruit fly, A. striata Schiner, and the zapote fruit fly, A. serpentina (Wiedemann). In the 1980's, cultivation of guava, Psidium guajava, in the northern region of Zulia State was expanded. By 1992, in the lake Maracaibo plain, about 4,000 ha of guava orchards were in production (Araujo et al. 1997). Several species of fruit flies of the family Tephritidae, especially A. striata and C. capitata, are very important from a quarantine point of view when fruit export is the objective. P. guajava is found from sea level to 1,930 m in commercial orchards, backyards of houses, roadsides, pasture lands, and forests throughout western Venezuela. The work described in this paper was done to obtain basic information about the altitudinal distribution of different fruit flies infesting cultivated or wild fruits belonging to the family Myrtaceae, genus Psidium, which can be used in the economic management of these fruit flies. Materials and Methods From June 1992 to December 1995, 201 Psidium spp. fruit samples were collected whenever available from sea level to 2,000 m elevation in 139 localities in the western Venezuelan states of Falc-n, Mérida, Táchira, Trujillo, and Zulia comprising an area of 117,700 sq-km. The Northern and Southern borders of the study area are delimited with latitudes 11°45'N and 7°32'N respectively, while Eastern and Western borders are delimited with longitudes 68°30'W and 72°40'W respectively. Fruit samples were collected from four species of Psidium: P. guajava L. (common guava) from sea level to 1,930 m, P. guineense Sw. (mountain guava) from 100-1,950 m, P. caudatum McVaugh (jumangue) from 1,800-2,000 m, and P. friedrichsthalianum [Berg] Ndz. (cas or sour guava) from 35-1,700 m altitude. The total number of fruits collected from each Psidium spp. host plant comprised 7,015, 255, 3,816 and 59 fruits from P. guajava, P. guineense, P. caudatum and P. friedrichsthalianum respectively. Following the technique described by Katiyar et al. (1995), fruit samples were incubated and processed in the laboratory. Mature fruits were picked from sample trees as well as from the ground and were placed in open top wooden boxes (30 × 20 × 10 cm). A sheet of plastic screening (about 4 mm/mesh) had been fitted about 2 cm from the bottom of each box. The wooden boxes containing fruit samples were placed in plastic rearing containers (35 × 24 × 13 cm). The tops of the rearing containers were fitted with a fine-screened window (15 × 8 cm) for aeration. Each container had a layer of moist sawdust about 2 cm deep at the bottom as a pupation media for the larvae. The fruit samples were taken to the laboratory in this manner. In the laboratory, samples were removed from rearing containers. The fruits were counted, weighed, and put back in the containers. Every 2-3 days the sawdust was sieved, and recovered larvae and pupae were placed in 500 cc plastic cups containing a thin layer (2-3 cm) of moist saw dust. Each container with pupae was placed inside an adult emergence cage to recover fruit flies and parasitoid adults. The emerged adults were preserved in 70% ethyl alcohol. Rearing was carried out in the laboratory at 26 ± 3°C and 60 ± 10% RH. The climatic condition of the study area is characterized by a rainy season from April to November, followed by a dry period from December to March. The rainfall in Western Venezuela varies widely from one place to another. This variation can be observed in lowland areas (0-1,000 m) as well as in highland areas (1,001-2,000 m). During rainy season the temperature is slightly higher compared with the dry season. Table 1 presents climatic data (temperature, rainfall and RH) from 17 meteorological stations located between 5 and 2,200 m elevation in the study area. Samples of fruit fly adults were identified by A. L. Norrbom, Systematic Entomology Laboratory, USDA, PSI, ARS, Washington, D.C. Results and Discussion A total of 11,145 fruits (261.5 kg) were collected from four Psidium species. A total of 30,530 pupae and 20,970 adults of both sexes belonging to four species of tephritids were reared from these fruits. Table 2 summarizes the relative abundance of each tephritid species infesting the four Psidium host plants (based on adult emergence/kg fruits). P. guajava was infested by all four tephritid species found, P. guineense by three species (A. striata, A. fraterculus and A. obliqua), P. caudatum by two species (A. fraterculus and A. striata) and P. friedrichsthalianum by two species (A. striata and A. obliqua). The results show that A. striata was the most common fruit fly pest of Psidium species in the western region of Venezuela. Based on total adult emergence from all four Psidium spp., the proportion of each species consisted of A. striata (73.9%), A. fraterculus (24.2%) and A. obliqua (1.9%). Table 2. Rate of fruit infestation of Psidium species by Anastrepha spp. in the western region of Venezuela, 1992-1995. Host fruit Adult emergence/kg A. striata A. fraterculus A. obliqua Totals P. guayaba1 110.6 2.4 1.3 114.3 P. guineense2 91.2 0.4 2.4 94.0 P. caudatum3 0.8 13.7 0.0 14.5 P. friedrichsthalianum4 29.8 0.0 1.2 31.0 1Indicates (n = 185 samples and 249,2 Kg). 2Indicates (n = 5 samples and 3.1 Kg). 3Indicates (n = 7 samples and 6.9 Kg). 4Indicates (n = 4 samples and 2.3 Kg). The results also show that A. striata was the most common fruit fly in three Psidium spp. (guajava, guineense, and friedrichsthalianum) with an infestation range of 96.1%-97.0% (based on number of adults emerged/kg fruit). Whereas A. fraterculus was the predominant species in P. caudatum (the emerged adults were 94.5% A. fraterculus and 5.5% A. striata). P. caudatum is a native wild Psidium species found at relatively high elevation (1,500-2,000 m) and has a small fruit, mean weight of 1.8 g. In general A. striata was the dominant fruit fly in Psidium species except P. caudatum in the western part of Venezuela. A. striata is also reported as the major pest of P. guajava in several other Latin American countries. In Costa Rica, 97.8% of fruit samples were reported infested by A. striata (Jiron & Hedström 1988), and in Ecuador A. striata emerged from 70.8% of fruit samples examined (Hedström 1987). Figure 1A shows the relative intensity of infestation by A. striata in P. guajava at different altitudes (8 strata). Results demonstrate that the most prevalent distribution for A. striata infestations occur between 500 to 1,500 m and the highest infestations occur at about 1,000 m. Figure 1B shows the altitudinal distribution of A. fraterculus and A. obliqua. The results show that at low altitudes (0-1,200 m), A. obliqua was more prevalent than A. fraterculus, whereas at higher altitudes (1,201-2,000 m), A. fraterculus was more prevalent than A. obliqua. Similar results, which indicate that A. obliqua prefers lowland zones and A. fraterculus prefers higher elevation areas, have been found in other studies (Celedonio-Hurtado et al. 1995, Eskafi & Cunningham 1987, Hedström 1987). C. capitata was reared only from seven fruit samples of P. guajava collected between 50-1650 m. The distribution of these fruit samples were four (Zulia state) at 0-250 m and one each from 250-500 m (Trujillo state), 1250-1500 m (Táchira state), and 1500-1750 m (Mérida state) elevation ranges. The altitudinal distribution and presence of this fruit fly was erratic and the infestation rate was very low (1.4 adults/Kg). Acknowledgments We thank Alan L. Norrbom (Systematic Entomology Laboratory, USDA, PSI, ARS, Washington, D.C.), Daniel S. Moreno (Subtropical Agricultural Research Laboratory, Crop Quality and Fruit Insects Research, USDA, ARS, Weslaco, TX), and Andrew F. Neild, 116 Crosslet Wale Greenwich, London SE10 8DL for their comments and suggestions in the review of earlier draft of the manuscript. We also thank 3 anonymous reviewers for critically reviewing and improving this manuscript. This study was funded by Consejo de Desarrollo Científico y Humanístico de La Universidad del Zulia (CONDES), through project 1912-96 "Programa Museo de Artr-podos". References Cited Araujo, F., S. Quintero, J. Salas, J. Villalobos, and A. Casanova. 1997. Crecimiento y acumulaci-n de nutrientes del fruto de Guayaba (Psidium guajava L.) del tipo "Criolla Roja" en la planicie de Maracaibo. Rev. Fac. Agron. (LUZ) 14: 315-328. Celedonio-Hurtado, H., M. Aluja, and P. Liedo. 1995. Adult population fluctuation of Anastrepha species (Diptera: Tephritidae) in tropical orchard habitats of Chiapas, Mexico. Environ. Entomol. 24: 861-869. Eskafi, F. M., and R. T. Cunningham. 1987. Host plants of fruit flies (Diptera: Tephritidae) of economic importance in Guatemala. Florida Entomol. 70: 116-123. Hedström, I. 1987. Fruit flies (Diptera: Tephritidae) infesting common guava (Psidium guajava L.) (Myrtaceae) in Ecuador. Rev. Biol. Trop. 35: 373-374. Jir-n, L. F., and I. Hedström. 1988. Occurrence of fruit flies of the genera Anastrepha and Ceratitis (Diptera: Tephritidae), and their host plant availability in Costa Rica. Florida Entomol. 71: 62-73. Katiyar, K. P., J. Camacho, F. Geraud, and R. Matheus. 1995. Parasitoides hymen-pteros de moscas de las frutas (Diptera: Tephritidae) en la regi-n occidental de Venezuela. Rev. Fac. Agro. (LUZ) 12: 303-312. Norrbom, A. L., and K. C. Kim. 1988. A list of the reported host plants of the species of Anastrepha (Diptera: Tephritidae). USDA-APHIS-PPQ Bull. 81-52, 114 pp. Fig. 1. Infestation of Psidium guajava by three tephritid species in western Venezuela, 1992-1995. (A) by A. striata. (B) by A. obliqua and A. fraterculus. Table 1. Annual climatic data1 (temperature, rainfall and relative humidity) in western Venezuela. Weather station State Data period (years) Latitude (N) Longitude (W) Altitude (m) Annual temperature (1/4C) Annual rainfall (mm) RH (%) Mean Mean Min Max Mean Min Max Sta. Barbara Zulia 67-98 08°58' 71°53' 5 28.4 23.9 33.2 1297 768 1813 83 Coro Falc-n 82-92 11°25' 69°41' 16 27.8 25.0 32.7 362 189 613 75 Maracaibo Zulia 81-98 10°41' 71°38' 45 29.2 24.9 33.4 484 234 688 75 El Isiro Falc-n 82-92 11°18' 69°37' 72 29.0 24.7 34.5 570 258 926 68 Machiques Zulia 50-98 10°03' 72°33' 99 28.2 22.7 33.6 1500 1011 2196 66 Sto. Domingo Táchira 82-92 07°35' 72°04' 327 23.7 20.4 29.2 2854 2496 3572 84 San Antonio Táchira 85-95 07°51' 72°27' 377 25.9 21.9 31.4 712 312 1168 72 Valera Trujillo 86-96 09°21' 70°37' 582 24.4 20.1 29.7 1071 743 1380 81 Col-n Táchira 85-95 08°02' 72°15' 760 22.3 19.3 25.7 1513 996 1937 79 Churuguara Falc-n 74-84 10°48' 69°30' 920 22.7 16.8 27.1 729 466 1328 NA Tovar Mérida 69-90 08°20' 71°44' 952 21.9 17.7 26.7 1069 550 1622 73 La Grita Táchira 74-84 08°08' 71°59' 1270 21.4 15.6 26.5 795 467 1911 82 Mérida Mérida 51-98 08°36' 71°11' 1479 19.1 15.3 24.7 1732 1159 2302 80 San Giusto Trujillo 80-90 09°17' 70°12' 1499 18.0 13.0 24.4 1848 1335 2574 81 Bocon- Trujillo 91-91 09°16' 70°13' 1560 18.0 11.6 23.9 1570 1437 1742 75 Sto. Domingo Mérida 78-83 08°52' 70°40' 2155 15.6 10.5 20.4 1233 700 1780 NA Betania Táchira 84-94 07°28' 72°26' 2210 15.1 9.6 20.5 1035 763 1368 NA 1Provided by Ministerio del Ambiente y de los Recursos Naturales Renovables de Venezuela (MARNR). NA, not available.