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Whiteflies and parasitoides associated with the cassava crop in South America
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Poster26: Whiteflies and parasitoides associated with the cassaava crop in South America


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Poster26: Whiteflies and parasitoides associated with the cassaava crop in South America

  1. 1. Whiteflies and parasitoides associated with the cassava crop in South America María del Pilar Hernández1 , Bernardo Arias1 and Anthony Bellotti2 1 Associates researchers and 2 Entomologist, & International Center for Tropical Agriculture 2009 Subfamily: Aleyrodicinae: INTRODUCTION Table 2. Distribution of Parasitoids associated to The whiteflies (Hemiptera: Aleyrodidae), are one of the most important pest of the cassava crop (Manihot species of whiteflies in Cassava crop. esculenta Crantz) in the Tropics. The generalized lack of knowledge on the species present in different Whitefly/ Parasitoide Brasil Colombia Ecuador Venezuela production areas and their poor management, have resulted in losses of up to 80% of root production. In Aleuroglandulus subtilis Feet with claws, lingual long with two pairs of seta, composit pores present extreme cases, farmers have abandoned the crop. Encarsia sp. x Incomplete information is available on the importance of natural enemies on whitefly population dynamics dynamics. Encarsia desantisi Viggianni x Encarsia guadeloupae Viggiani x Surveys were needed to determine the natural enemies, especially parasitoids, associated with each of the whitefly species. Aleurodicus dispersus OBJECTIVES Aleuroctonus vittatus (Dozier) Encarsia sp. x x (a) (b) Euderomphale sp. x Figure 1. Pupa of Aleuronudus sp. (a.). Ovalated with long and short waxi filamennts. . (b). Eretmocerus sp. x 6 composite pores of diferents sizes A. To identify the species of Aleyródidos associated with the cassava crop in the production zones of Brazil, Colombia, Ecuador and Venezuela. Aleurodicicus flavus Aleuronudus n. sp. B. To determine the parasitoids associated with each of the present species of Aleyródidos in the cassava crop. Aleurotrachelus socialis Amitus mcgowni Evans & Castillo x x x Amitus sp. x METHODS Encarsia americana (Debach& Rose) x x (a) (b) Encarsia bellotti Evans & Castillo x Encarsia cubensis Gahan x x Figure 2. Pupa of Aleurodicus dispersus. (a). Abundant quantiti of cottony secretions and long crystaline waxi filaments . (b). 4 compositae pores on the abdomen. For more than a decade the Cassava Entomology Program in CIAT has been working on distribution and Encarsia hispida DeSantis x x identification of whiteflies species and parasitoids associated with cassava in cooperation with institutions Encarsia luteola group x x Encarsia. sophia (Girault & Dodd) x such as INIAP in Ecuador, CENIAP in Venezuela and EMBRAPA in Brazil. Encarsia sp. E i x x Encarsia tabacivora Viggiani x x Encarsia sp. prob. variegata x x A. Aleyrodidos. Leaves of plants infested with pupas were collected, and were introduced into vials with Eretmocerus spp.(3) x x x Figure 3. Pupa of Aleurodicus flavus. Covered of a cottony waxi secretion alcohol 70%. The specimens were processed and mounted on plates with balsam of Canada for Euderomphale n. sp. x Metaphycus n. sp. x x radiating in all directions. identification. Signiphora aleyrodes Ashmead B. Parasitoids. Leaves with pupae were placed in plastic bags and taken to the laboratory and were Aleurothrixus aepim examined. So that only one predominant species remained. Encarsia aleurothrixi Evans & x Polaszek x Encarsia hispida DeSantis Whiteflies and parasitoids was sent to Dr. G.A. Evans (USDA/APHIS/PPQ) for their identification. Eretmocerus sp. x (a) (b) Figure. 4 Pupa of Paraleyrodes sp. (a). Ovalated, with long crystaline filamenta. (b). 6 pair RESULTS of composite pores on segments III-VIII. Bemisia tabaci Encarsia sp. Subfamily: Aleyrodinae: The recognition of whiteflies species and parasitoids associated with the crop, was made in 17 localities from Bemisia tuberculata Colombia, Ecuador (7), Brazil (5) and Venezuela (10). Encarsia hispida DeSantis x x Encarsia pergandiella Howard x Encarsia sophia (Girault & Dodd) p ( ) x x Encarsia sp. Whiteflies. Thirteen species of whiteflies were identified, located in the subfamilies: Aleurodicinae and Encarsia tabacivora Viggiani x x x Aleurodinae (Table 1). Euderomphale sp. x x Eretmocerus sp. x x Feet without claws, lingual Metaphycus sp. x x inserted within the vasiform orifice, composite pores absent. Aleurodicus dispersus, Aleurotrachelus socialis, Bemisia tuberculata and Trialeurodes variabilis are the predominant species in all countries sampled . Nevertheless, only the last three are considered of economic importance. Aleurothrixus aepim was found in Brazil and Venezuela. Bemisia tabaci was found in low populations Paraleyrodes sp. in two localities of Ecuador; this species is an important pest of the cassava crop in Africa and Asia. Tetraleurodes sp. Encarsia americana (Debachj & Rose) x x Tetraleurodes and Al T t l d d Aleuroglandulus appeared i l l d l d in low populations i C l bi E l ti in Colombia, Ecuador and V d d Venezuela. T l T. Encarsia hispida DeSantis x x vaporariorum was found in great numbers in mountainous regions of Ecuador. Aleuronudus and Paraleyrodes Encarsia sp. x x Eretmocerus sp. x x are sporadic in occurance. Possibly due to the number of sites sampled, Colombia and Ecuador have the Signiphora aleyroidis Ashmead * x (a) (b) largest number of species, followed by Venezuela and Brazil. Figure 5. Pupa of Aleuroglandulus subtilis (a). A pair of crystaline waxi tubes on the Tetraleurodes ursorum dorsal surface. (b). Glandular pores on the protorax III abdominal segment Trialeurodes. vaporariorum Table 1. Distribution of species of white flies in South America Encarsia tabacivora Viggiani x Trialeurodes variabilis SPECIES Amitus macgowni Evans & Castillo BRASIL COLOMBIA ECUADOR VENEZUELA x Encarsia bellotti Evans & Castillo x Aleuroglandulus subtilis Bondar X Encarsia hispida DeSantis x Encarsia luteola group x (a) (b) Aleurodicus dispersus Russell X X X X Encarsia pergandiella Howard x x Figure 6. Pupa of Aleurotrachelus socialis. (a). Capsule black and sorrounded of waxi Aleurodicus flavus Hampel X Encarsia nigricephala Dozier x Encarsia sophia (Girault & Dodd) x secretions. (b). Process in form of trachea on abdominal segments . Aleuronudus sp X X x Encarsia strenua group x Encarsia sp. x Aleurotrachelus socialis Bondar X X X X Encarsia tabacivora Viggiani x Eretmocerus spp. x Aleurothrixus aepim (Goldi) X X Signiphora aleyroidis Ashmead* x x Bemisia tabaci (Gennadius) X X * Hyperparasite Bemisia tuberculata Bondar X X X X Paraleyrodes sp X X (a) (b) Tetraleurodes ursorum Cockerell X Figure 7 Pupa of Aleurothrixus aepim. (a). Pupal capsule sorrownded by long waxi filaments (Foto: V. Pietrowski). (b). Submarginal sutura truncated, small vasiform orifice. Tetraleurodes sp X X Trialeurodes vaporariorum (Westwood) X Trialeurodes variabilis (Quaintance) X X X X Parasitoids. 22 species of parasitoids have been identified belonging to the Aphelinidae Families: (Encarsia and Eretmocerus), Eulophidae (Aleuroctonus and Euderomphale), Platygasteridae (Amitus), (a) (b) Encyrtidae (Metaphycus) and a Signiphoridae (hyperparasite), (Table 2). Figure 8. Pupa of Bemisia. tabaci. (a). Pupal capsule ovoid. (b).orifice vasiform triangular and longer than the caudal groove. Encarsia genus (Figure 13 – 15), shows a greater richness of species displayed (15). Eretmocerus (Figure 16) with 5 nondescribed species; 2 new Euderomphale species (Figure 17), 2 Amitus spp (fig 18), 1 new Metaphycus specie. E. hispida was the most colleted specie. Non parasites were collected from A. flavus, Aleuronudus sp., (a) (b) Paraleyrodes sp. and T. ursorum. Figure 9. Pupa of Bemisia tuberculata. (a.) Ovoid. (b). Dorsal surfase with granulations Figure 13. Encarsia hispida Figure 14. Encarsia nigricephala and vasiform orifice and the same length as the caudal groove. CONCLUSIONS Thirteen species of whiteflies were associated with the cassava crop in Brazil, Colombia, Ecuador and Venezuela. A. subtilis, A. socialis, B. tuberculata and T.variabilis are the most widely distributed species (a) (b) A. socialis and T. variabilis are the species of greatest occurance in the cassava in Colombia, Ecuador Figure 10. Pupa of Tetraleurodes spp. (a.) Bright black. (b) Margin dentate and submargen and Venezuela. with rows of small glands. A. aepim and B. tuberculata are important economically in the Northeast and Southeast of Brazil, respectively. There is a complex of parasitoids associated to whiteflies in cassava. Figure 15. Encarsia sp. Figure 16. Eretmocerus sp. The greatest diversity of parasitoids were found on A. socialis and T. variabilis. (a) (b) REFERENCIAS Figure 11. Pupa of Trialeurodes vaporariorum.(a.) Ovalated, with seta.(b).Papilla in sub- marginal region, lobulated lingual and coxa without seta. Bellotti, A., J. Peña, B. Arias, J.M. Guerrero, H. Trujillo, C.M. Holguin and A. Ortega. 2005. Biological control of whiteflies by indigenous natural enemiesfor major food crops in the neotropics. In. Whitefly and whitefly-borne viruses in the tropics: Building and Knowledge base for global action Edited by: P K Anderson and F J Morales 313-323 pp action. P.K.Anderson F.J. Morales. Polazek, A., G.A. Evans and F.D. Bennett. 1992. Encarsia parasitoids of Bemisia tabaci (Hymenoptera: Aphelinidae, Homoptera: Aleyrodidae): a preliminary guide to identification. Bull. Entomol. Res. 82: 375-392. Trujillo, H.E., B. Arias, J. M. Guerrero, J.M., M.P. Hernandez, A. C. Bellotti and J. E. Peña . 2004. Survey of parasitoids of Figure 17. Aleuroctonus vittatus Figure 18. Amitus macgowni (a) (b) whiteflies (Homoptera: Aleyrodidae in cassava growing regions of Colombia and Ecuador. Florida Entomologist 87 (3). 268-273 pp Figure 12. Pupa of T. variabilis. (a.) Ovalated, with long seta. (b). Papilla in submarginal region, lobulated lingual and coxa with seta.