Contributions to the study of gall-wasp occurrence in Eucalyptus woodlots in South Brazil

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1 Contributions to the study of gall-wasp occurrence in Eucalyptus woodlots in South Brazil ROESCH, F. 1 ; FEUERBORN, M. 1 ; KOEHLER, A. 2 ; RAUBER, M. 2 FARIAS, J. 3 ; WELTER, C. A. 3 ; TEIXEIRA, D. S. 3 (1) Japan Tobacco International (JTI) (2) Universidade de Santa Cruz do Sul (UNISC) (3) Universidade Federal de Santa Maria (UFSM)

2 Tobacco production in South Brazil Source: Sinditabaco 2017 Green represents cities that grow tobacco 2

3 Firewood from Eucalyptus trees is the main source of energy for FCV tobacco curing in South Brazil Compliance with Environmental regulation in Brazil Industry efforts for a sustainable supply of firewood from renewable sources Main species are E. dunni, E. saligna and E. grandis Forestry technical assistance to improve woodlot productivity and efficient consumption 3

4 Occurrence of gall-wasp in Eucalyptus woodlots in South Brazil Share information of the gall-wasp in the Eucalyptus woodlots Distribution Biological and life cycle Symptoms and damage Bring attention to the potential risks of this insect-pest to woodlot yield and to the medium and long term supply of wood from Eucalyptus 4

5 The gall-wasp Leptocybe invasa What is it? A gall inducing wasp species currently spreading in many countries and causing damage to Eucalyptus plantations and nurseries Adult size is 1.0 to 1.4mm The body is brownish in color with a blue to green metallic shine. Fore coxae are yellow; mid and hind coxae are brown. The scape of the antennae is yellow, with the rest of the segments brown. Taxonomy: Phylum: Arthropoda Class: Insecta Order: Hymenoptera Family: Eulophidae Genus: Leptocybe Species: L. invasa 5

6 The gall-wasp Leptocybe invasa Biology and life cycle From egg to adult, it takes around 50 to 140 days, depending on the region Females can lay 80 to 100 eggs, with 2 to 3 generations per year The longevity of the adult is 3 to 7 days 1. The adult wasp lays eggs inside tender leaves, petiole and in the parenchyma of twigs 2. After hatching, the larvae remain in a cavity formed within the plant tissues and feed on the plant sap, resulting in the formation of galls 3. Following larvae development, adults then emerge leaving round exit holes Oviposition signs on leaf petiole Young gall on eucalypt leaf petiole Emergence holes 6

7 The gall-wasp Leptocybe invasa Symptoms and damage L. invasa causes bump-shaped galls on the midrib, petioles and stems of young eucalypt trees, young coppice and seedlings. The leaves of intensively growing trees may carry over 50 galls per leaf. Severely affected trees show leaf fall, gnarled appearance, loss of vigor, stunted growth, dieback and eventually tree death. 7

8 The gall-wasp Leptocybe invasa Distribution In the world In Brazil Areas of occurrence of gall-wasp 8

9 Gall-wasp (Leptocybe invasa) occurrence in ADETs Eucalyptus woodlots Since then, January 2014 insect pest observed in a trial with 11 different species of Eucalyptus March 2014 presence of the wasp observed in all eucalyptus woodlots in ADET, with symptoms either at initial and or advanced stages Partnerships with specialists and University of Santa Cruz (UNISC) and University of Santa Maria (UFSM) were established to study gall-wasp development and impact on Eucalyptus wood production Symptoms of the damage of the insect are observed in eucalyptus woodlots in the neighboring farms/areas to ADET, in young Eucalyptus trees and/or older than 5 years, which might contribute to the spread of the wasp. 9

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11 Studies conducted by UNISC and UFSM Evaluation of the gall-wasp development Behavioral aspects and development of the pest need to be understood to develop management strategies Potential measures to prevent and control Cicle length relates to climate and temperature Gall development on petiole or leaf depends on the species Observation of potential natural enemies Systemic products are not effective in field Evaluation of the effect of gall-wasp on Eucalyptus growth Species susceptibility/tolerance Severity of damage and impact on productivity Variation between species Quantified impact on productivity can only be confirmed by the end of Eucalyptus cycle (7 years) 11

12 Reduced woodlot yield potential, compromised supply of firewood Plants attacked are more susceptible to other pest and disease Source of Eucalyptus seedlings quality New pest, fast spreading No effective control measures in field Hinder potential use of alternative Eucalyptus species with high calorific power for tobacco curing National research efforts focused on large, commercial Eucalyptus production Collaborative and pioneering research focused on small scale Eucalyptus production Sharing of applicable knowledge to small scale tobacco farming worldwide, wherever Eucalyptus wood is used as a source of energy IPM development Biological control opportunities Identification and selection of less susceptible Eucalyptus species 12

13 Thank you 13