Monitorização da traça-dos-cachos Cryptoblabes gnidiella (Millière) na cultura da vinha em clima semi-árido tropical na região de Pernambuco, Brasil | Monitorization of Cryptoblabes gnidiella (Millière) in vineyard under semi-arid climate in the region of Pernambuco, Brasil

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia

Cryptoblables gnidiella (Millière) (Lepidoptera: Pyralidae) is a major pest of vineyards in the region of Vale São Francisco, in Brazil. This study took place in the farm of Santa Maria (ViniBrasil), Pernambuco (9º2’ S and 40°11' W), between March and August of 2009, aiming to: compare the efficiency of two types of pheromone traps (delta and funnel traps) for the monitoring of C. gnidiella and to study the biology of this insect in relation to the phenology of grapevine. The efficiency of delta traps (10 cm height x 21 cm width, 23 cm length; sticky plate 20 x 19 cm), and funnel traps (Ø 16 cm and 18cm height; green top and transparent bottom), for the monitoring of C. gnidiella, were compared in a field trial, by exposing five traps of each type in a complete randomized design, from March 9 to April 13, 2009, in a 42000 m2 plot cv. Syrah. Male captures were counted twice a week. The study of C. gnidiella biology was carried out in four 10000 – 55000 m2 plots of cv. Aragonez. Male captures were counted once a week from March 16 to August 11, 2009. The phenological stage was also registered in each sampling date. The infestation level was estimated by visual observation of two bunches per vine in 50 vines per plot. Infested bunches were collected and maintained in laboratory conditions until the emergence of adult moths, to confirm species identity based on the study of genitalia. No significant differences were observed between male catches in the two types of traps. Therefore, the choice of the trap should rely on cost and simplicity of utilization. The estimated cost of using two delta and funnel traps per plot for a monitoring period of 120 days is 64,49 euros and 58,35 euros, respectively. The utilization of funnel traps is also considered to be more convenient in practical terms. However, its application is dependent on the availability of diclorvs (or alternative insecticides) in the market. The trend of male captures and infestation level by C. gnidiella was mainly dependent on grapevine phenology. No relationship was found between the infestation level and the number of males captured in pheromone traps. In one of the plots, moth infestation was associated with the mealybug Phenacoccus solenopsis. Although mealybugs are known to influence the infestation level of C. gnidiella, the ability of this pest to originate injury on vineyards was not dependent on the presence of mealybugs.