To Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG).

Apresentação em tema: "To Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)."— Transcrição da apresentação:

1 To Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG).
Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) feeding behavior on native Myrtaceae and Eucalyptus urophylla in Brazil MOIO, Simone Graziele¹; CORAL, Dorival José²; ZANUNCIO, José Cola³; SERRÃO, José Eduardo³, WILCKEN, Carlos Frederico¹ ¹ Faculdade de Ciências Agronômicas, Departamento de Proteção Vegetal, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, São Paulo.² Centro de Ciências da Saúde, Universidade Sagrado Coração (USC), Bauru, São Paulo.³ Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais. INTRODUÇÃO RESULTS Thaumastocoris peregrinus Carpintero Dellapé (Hemiptera: Thaumastocoridae), an exotic pest of Eucalyptus spp., has been reported in 2008 in Brazil and it is distributed in several Brazilian States. The damage by this insect in eucalyptus plants are the silvering of leaves that eventually evolves into tanning. High infestations of this insect can cause defoliation, what reduces photosynthetic area and, even, tree death. The eucalyptus is grown in regions with native Myrtaceae in Brazil, what can allow the migration of T. peregrinus to new hosts. This study assessed the damage by T. peregrinus on leaves of Eugenia uniflora, Eugenia pyriformis, Psidium guajava and Eucalyptus urophylla variety platyphylla. Thaumastocoris peregrinus fed preferentially on the abaxial leaf surface where it introduced the stiletts in the regions near the bundle vessels. The spongy parenchyma was the most damaged area in all plants. The hypodermis and the esclerenquima of P. guajava can inhibit feeding of this insect. The longevity and viability of adult T. peregrinus were higher on the abaxial leaf surface. The survival of T. peregrinus was higher on E. urophylla var. platyphylla and E. uniflora. Fotos: EVERTON SOLIMAN Figure 1. Cross-section of the Eucalyptus urophylla var. platyphylla (Myrtaceae) leaves (A). Detail of the epidermis (Ep), palisade parenchyma (Pp), conducting vessels (Cv), spongy parenchyma (Sp), and secretory cavity (Sc). Bar 200 µm; (B) Detail of idioblasts containing drusen bodies (Id). Bar 100 µm; (C) Injured areas in the palisade parenchyma. Bar 100 µ. Figure 2. Cross-section of the Eugenia uniflora (Myrtaceae) leaves. (A) Idioblasts (Id) containing drusen bodies, secretory cell (Sc). Bar 100 µm. (B) Cells of the spongy parenchyma injured (circle). Bar 100 µ. (C) Damaged epidermis (arrow). Bar 100 µm. A- Adult T. peregrinus. B- Silvered leaf. C- Bronzed leaf MATERIAL AND METODS Damage by T. peregrinus were evaluated on leaves of Eugenia uniflora, Eugenia pyriformis, Psidium guajava and Eucalyptus urophylla variety platyphylla. This study was developed with adults T. peregrinus obtained from rearing facility, where newly emerged pairs of this insect are kept in Petri dishes (6 cm diameter) with a fragment of plant leaf on agricultural gel in the proportion of 1 g of gel per 400 mL of water. The experiment was conducted in two stages. In the first, a couple of this insect was placed on the abaxial leaf and in the second on the adaxial one, without choice at both stages. The means of the treatments were compared with Student's t-test (LSD) with 5% significance. The areas of healthy leaves and those injured by this pest were histologically examined. Figure 4. Cross-section of the Psidium guajava (Myrtaceae) leaves. (A) Intact leave showing. Epidermis (Ep), Hypodermis (Hp), Palisade parenchyma (Pp), conducting vessels (Cv); idioblasts with drusen bodies (Id), spongy parenchyma (Sp), and stomata (St). Bar 100 µm; (B) abaxial surface with lesions closely stomata (circle). Bar 50 µm. (C) Detail of the damage near the one secretory cell and above the stomata (circle). Bar 50 µm. Figure 3. Cross-section of the Eugenia pyriformis (Myrtaceae) leaves. (A) Intact leaves showing. Epidermis on the adaxial surface (Ep); palisade parenchyma (Pp); conducting vessels (Cv); spongy parenchyma (Sp). Bar 100 µm. (B) Lesions in the mesophyll of the abaxial and adaxial surfaces (circles), damaged epidermis (arrow). Bar 100 µm. (C) Detail of the lesions in the mesophyll (circle). Bar 50 µm. CONCLUSIONS The bioecology studies of T. peregrinus related to leaf anatomy is important to understand the feeding behavior and to develop methods to control this insect. AGRADECIMENTOS To Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG).