Print version ISSN 1519-566X
Neotrop. entomol. vol.37 no.1 Londrina Jan./Feb. 2008
Outbreaks of Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae) under field conditions in the State of São Paulo, Brazil
Surtos de Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae) no campo, no Estado de São Paulo
André L. LourençãoI; André C. AlvesI; Cristina G.Q. FugiI; Evandro S. MatosII
IInstituto Agronômico - IAC, C. postal 28, 13001-970, Campinas, SP
IISyngenta Seeds Ltda. - Rogers, C. postal 1578, 13256-000, Itatiba, SP
Trialeurodes vaporariorum (West.) is a pest of greenhouse vegetables and ornamentals and infests crops in Europe and in the American continent. In Brazil, just a few cases are known on economic crops, being all restricted to greenhouse crops. In 2003, in Itatiba and neighboring localities of State of São Paulo, Brazil, field infestations of T. vaporariorum were observed, mainly on tomato and green bean. So far, whitefly infestation in this area expanded to squash and kale also. Field studies are needed for determining interactions of T. vaporariorum with plants and natural enemies, injury levels, and methods of control.
Key words: Insecta, greenhouse whitefly, occurrence
Trialeurodes vaporariorum (West.) é praga de hortaliças e ornamentais em cultivo protegido e infesta diversas culturas na Europa e nas Américas. No Brasil, as informações sobre sua ocorrência restringem-se a estudos em casa de vegetação. Em 2003, em Itatiba e cidades adjacentes (SP), observaram-se infestações de T. vaporariorum em hortaliças e ornamentais em campo, com maiores níveis populacionais em tomateiro e feijão-vagem. Nos anos seguintes, as infestações se mantiveram, atingindo cultivos de couve e de aboboreiras. São necessários estudos em campo para conhecer as interações dessa mosca-branca com plantas e inimigos naturais, níveis de dano e avaliação de métodos de controle.
Palavras-chave: Insecta, mosca-branca, casa de vegetação, ocorrência
The greenhouse whitefly or glasshouse whitefly, Trialeurodes vaporariorum, was described by Westwood in 1856 as Aleyrodes vaporariorum (Mound & Halsey 1978). According to these authors, it is a cosmopolitan species, with records in every zoogeographic region of the world. In South America, it has been noted in Argentina, Chile, Colombia, Ecuador, Guiana, Peru, and Brazil (Russell 1963). Within Brazils national boundaries, references about its presence exist for São Paulo, Minas Gerais, and Brasília (Silva et al. 1968, Oliveira 1995), although its distribution is likely much broader than that. It is a polyphagous insect, and plants belonging to 82 plant families serve as hosts (Mound & Halsey 1978). In Brazil, 162 plant species in 40 families have been identified as hosts in the greenhouse (Oliveira et al. 2003).
Considered a key pest in ornamentals and vegetable crops under protected cultivation (Lenteren & Noldus 1990), T. vaporariorum also occurs under field conditions, infesting several crops in countries of the American Continent and in Europe. There is limited information in Brazil on its occurrence and damages in crops of economic expression, and the few available studies have mostly dealt with greenhouse cultivations (Oliveira 1995, Campos et al. 2003, Oliveira et al. 2003). The objective of this work was to report the occurrence of this whitefly species at high populations in the field, infesting vegetable and ornamental crops in the State of São Paulo.
In September 2003, at Syngenta Seeds Ltda. - Rogers experiment station, located in the city of Itatiba, SP, a high infestation of T. vaporariorum was detected in a field used for the selection of tomato lines (Lycopersicon esculentum Mill.). Adults, eggs, and nymphs covered the lower surface of the leaves throughout the entire experiment area of approximately 1800 m2. After this observation, infestations of the pest remained steady in that field and in adjacent areas, damaging the subsequent crops of collard greens (Brassica oleracea L. acephala DC) and especially green beans (Phaseolus vulgaris L.).
In September of the following year, in the same experiment area, a field of tomato plants measuring approximately 2000 m2 was infested by the insect, and the leaves had their abaxial surfaces heavily colonized. There were green pepper (Capsicum annuum L.) and collard greens plantations next to that field; adults and eggs were observed on collard greens, but none of the insects stages were detected on green pepper, which is an indication that green pepper is not a suitable plant for the development of this insect, although it was listed as a host (Mound & Halsey 1978). Pumpkin plants (Cucurbita spp.) transplanted later in an adjacent area were also infested by the whitefly, and more than 100 adults were observed per leaf in some hybrids, indicating differences in attractiveness, as demonstrated by Alves et al. (2006). Among the invasive plants in that area, sow thistle (Sonchus oleraceus L.) was the most infested, with eggs, nymphs, and adults covering the lower surface of the leaves.
Ornamental crops were inspected in the field, in a shade house, and in greenhouses at Syngentas experiment station. Gerbera daisy (Gerbera jamesonii Bolus ex J.D. Hook) was a preferred host, with infestation levels similar to those observed in tomato plants. German primrose (Primula obconica Hance) and zinnia plants (Zinnia elegans Jacq.) were colonized at lower levels than gerbera daisy, while other ornamentals present in the area, like begonia (Begonia sp.), garden geranium [Pelargonium zonale (L.)], English ivy (Hedera helix L.), cyclamen (Cyclamen sp.), chrysanthemum (Chrysanthemum morifolium Ramat), garden balsam (Impatiens balsamina L.), and Alyssum sp. were not colonized and did not contain adults.
In October 2004, again in the city of Itatiba (two properties), tomato and green bean crops were heavily infested by T. vaporariorum. In crops at the end of the cycle, the leaves in the lower third of the plants had their lower surfaces completely colonized by nymphs and particularly by puparia, while the upper leaves had great numbers of adults, in a typical distribution of this species of whitefly (Lenteren & Noldus 1990).
Among the invasive plants present in this area, tropical soda apple (Solanum viarum Dun.) and Siberian motherwort (Leonurus sibiricus L.) were colonized, thus being characterized as hosts. Neither adults nor young forms were observed in leaves of the American nightshade (Solanum americanum Mill.), which was present in large numbers over the area; this is an indication that the plant is not a host, according to Mound & Halsey (1978).
It must be pointed out that no plants with virus symptoms were observed in the whitefly-infested areas where inspections were conducted.
In the years 2005 and 2006, T. vaporariorum infestations at the same locality remained constant in the field, also reaching neighboring localities, such as Jarinu and Atibaia, especially in tomato and green bean crops. Records of this whitefly species at high infestations in the field are unknown for Brazil, although there are reports under these conditions for countries of Central America (Hilje & Arboleda 1992, Smith et al. 2001) and for USA (Johnson et al. 1992, Omer et al. 1992, Bi et al. 2002a). In the USA, the pest is mentioned as an increasingly important problem in the field, in crops such as strawberry, raspberry, green pepper, cucumber, tomato, lettuce, citrus, bean, and cotton, and is also an important pest of vegetables under protected cultivation (Bi et al. 2002b). In Europe, infestations of T. vaporariorum in the field were also reported in recent years, in crops such as pumpkin and tomato, the pest being considered a threat to agriculture (Anonymous 2004). In this communication, we formulate hypotheses of the occurrence of environmental conditions favorable to the insect or of the appearance of a new biotype to explain this new situation. So far, no information was obtained that could either confirm or rule out any of the hypotheses. It is known that in Central America T. vaporariorum tends to be more common in regions with elevations above 1000 m, while Bemisia tabaci (Genn.) is predominant in areas below 1000 m (Caballero 1994). In the localities of the State of São Paulo where infestations of T. vaporariorum were observed, the mean elevation values ranged between 750 m (Itatiba) and 800 m (Jarinu and Atibaia), being therefore lower than the value presented by Caballero (1994). However, considering the latitude of this tropical region of the State of São Paulo, elevations from 750 m to 800 m determine lower mean temperatures than in other regions where B. tabaci biotype B is prevalent, with the annual mean in the three localities ranging from 19.9ºC to 20.3ºC. Therefore, it is suggested that in tropical regions, differently from equatorial regions, T. vaporariorum may occur and even be predominant in the field at elevations lower than 1000 m, whose mean temperatures are lower than those observed in other agrosystems.
As an insect vector T. vaporariorum is not as important as B. tabaci, which is an effective vector for more than 100 different viruses (Brown 1994, Morales 2001). However, it transmits closteroviruses (Duffus 1996). T. vaporariorum is known to transmit Beet pseudo yellow virus (BPYV), Tomato infectious chlorosis virus (TICV), and Tomato chlorosis virus (ToCV) (Wisler et al. 1997). At high infestations, the most important damage is caused when the insect sucks sap from the plant, extracting water, carbohydrates, and amino acids (Hendrix et al. 1996), consequently reducing yield (Johnson et al. 1992). In addition, large amounts of honeydew produced and deposited on the leaves provide conditions for fungal colonizations (sooty mold), affects photosynthesis and respiration, and commercially depreciates plant products (Liu et al. 1993).
Under this new condition, i.e., at high infestations in the field, basic studies involving T. vaporariorum are required to generate knowledge about its interactions with plants and natural enemies, damage levels, and to evaluate different control methods in order to devise a rational management program against the pest.
To Dr. Jon H. Martin, Department of Entomology, British Museum (Natural History), for confirming the insects identity, and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), for granting a scientific productivity scholarship to the first author.
Alves, A.C., A.L. Lourenção, A.M.T. Melo & E.S. Matos. 2006. Atratividade e preferência para oviposição de Trialeurodes vaporariorum em genótipos de aboboreira. Hortic. Bras. 24: 446-449. [ Links ]
Anonymous. 2004. The glasshouse whitefly: An increasing threat? International Whitefly Studies Network Newsletter 18: 1. [ Links ]
Bi, J.L., N.C. Toscano & G.R. Ballmer. 2002a. Field evaluations of novel chloronicotinyls and insect growth regulators against the greenhouse whitefly on strawberry. HortSci. 37: 914-918. [ Links ]
Bi, J.L., N.C. Toscano & G.R. Ballmer. 2002b. Greenhouse and field evaluation of six novel insecticides against the greenhouse whitefly Trialeurodes vaporariorum on strawberries. Crop Prot. 21: 49-55. [ Links ]
Brown, J.K. 1994. Current status of Bemisia tabaci as a plant pest and virus vector in agroecosystems worldwide. FAO Plant Prot. Bull. 42: 3-32. [ Links ]
Caballero, R. 1994. Clave de campo para inmaduros de moscas blancas de Centroamérica. Escuela Agrícola Panamericana, Zamorano, Honduras. Publicación DVP-EAP # 585, 4p. [ Links ]
Campos, O.R., W.B. Crocomo & A.M. Labinas. 2003. Comparative biology of the whitefly Trialeurodes vaporariorum (West.) (Hemiptera - Homoptera: Aleyrodidae) on soybean and bean cultivars. Neotrop. Entomol. 32: 133-138. [ Links ]
Duffus, J.E. 1996. Whitefly-borne viruses, p.255-263. In D. Gerling & R. Mayer (eds.), Bemisia 1995: Taxonomy, biology, damage, control, and management. Intercept, Andover, Hants, 702p. [ Links ]
Hendrix, D.L., T.L. Steele & H.H. Perkins Jr. 1996. Bemisia honeydew and sticky cotton, p.189-190. In D. Gerling & R. Mayer (eds.), Bemisia 1995: Taxonomy, biology, damage, control, and management. Intercept, Andover, Hants, 702p. [ Links ]
Hilje, L. & O. Arboleda. 1992. (eds.) Las moscas blancas (Homoptera: Aleyrodidae) em America Central y el Caribe. CATIE, Turrialba, 66p. [ Links ]
Johnson, M.W., L.C. Caprio, J.A. Coughlin, J.A. Rosenheim & S.C. Welter. 1992. Effect of Trialeurodes vaporariorum (Homoptera: Aleyrodidae) on yield of French market tomatoes. J. Econ. Entomol. 85: 2370-2376. [ Links ]
Lenteren, J.C. & L.P.J.J. Noldus. 1990. Whitefly-plant relationships: Behavioural and ecological aspects, p.47-89. In D. Gerling (ed.), Whiteflies: Their bionomics, pest status and management. Intercept, Andover, Hants, 348p. [ Links ]
Liu, T.X., R.D. Oetting & G.D. Bunting. 1993. Population dynamics and distribution of Trialeurodes vaporariorum and Bemisia tabaci (Homoptera: Aleyrodidae) on poinsettia following applications of three chemical insecticides. J. Econ. Entomol. 28: 126-135. [ Links ]
Morales, F.J. 2001. Conventional breeding for resistance to Bemisia tabaci-transmitted geminiviruses. Crop Prot. 20: 825-834. [ Links ]
Mound, L.A. & S.H. Halsey. 1978. Whitefly of the world: A systematic catalogue of the Aleyrodidae (Homoptera) with host plant and natural enemy data. Chichester, British Museum (Natural History), John Wiley & Sons, 340p. [ Links ]
Oliveira, M.R.V. 1995. Controle biológico de pragas em casas de vegetação com especial referência a Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae). Tese de doutorado, São Carlos, UFSCar, 273p. [ Links ]
Oliveira, M.R.V., E. Amâncio, R.A. Laumann & L.O. Gomes. 2003. Natural enemies of Bemisia tabaci (Gennadius) B biotype and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) in Brasília, Brazil. Neotrop. Entomol. 32: 151-154. [ Links ]
Omer, A.D., T.F. Leigh & J.Granett. 1992. Insecticide resistance in field populations of greenhouse whitefly (Homoptera: Aleyrodidae) in the San Joaquin valley (California) cotton system. J. Econ. Entomol. 85: 21-27. [ Links ]
Russell, L.M. 1963. Hosts and distribution of five species of Trialeurodes. Ann. Entomol. Soc. Am. 56: 149-153. [ Links ]
Silva, A.G.A., C.R. Gonçalves, D.M. Galvão, A.J.L. Gonçalves, J. Gomes, M.N. Silva & L. Simoni. 1968. Quarto catálogo dos insetos que vivem nas plantas do Brasil. Seus parasitos e predadores. Parte 2, Tomo 1º, insetos, hospedeiros e inimigos naturais. Rio de Janeiro, Ministério da Agricultura, 622p. [ Links ]
Smith, H.A., R. McSorley & J.A.S. Izaguirre. 2001. Effect of intercropping common bean with poor hosts and nonhosts on number of immature whiteflies (Homoptera: Aleyrodidae) in the Salamá Valley, Guatemala. Environ. Entomol. 30: 89-100. [ Links ]
Wisler, G.C., J.E. Duffus, H.Y. Liu, R. Li & B.W. Falk. 1997. New whitefly-transmitted closterovirus identified in tomatoes. Calif. Agric. 51: 24-26. [ Links ]
Received 03/V/06. Accepted 27/VIII/07.