Atração de adultos de Sphenophorus levis Vaurie (Coleoptera: Curculionidae) a fragmentos vegetais em diferentes estados de conservação

Abstract

-The occurrence of the sugarcane weevil Sphenophorus levis Vaurie is important in sugarcane in some regions in Brazil. Damage is caused by the larvae as they bore into the nodes and can reach 30 ton/ha/year. Many control alternatives have been attempted, but none were satisfactory, except for the use of toxic baits. Therefore, it is necessary to optimize their effi ciency or to propose new techniques. The objective of the current study was to evaluate the attractiveness of adults of S. levis to sugarcane nodes and pineapple peelings in an "Y" tube olfactometer. The sugarcane internodes were treated with 10% molasses, and tested after different periods of fermentation (24, 48 e 72h), at different times of the day (diurnal and nocturnal) and with both sexes. These tests were carried out in order to correlate the response of S. levis to ethyl acetate and ethanol release as a result of the fermentation process. The release of both compounds was monitored by gas chromatography-mass spectrometry (GC-MS). Our data indicated that sugarcane internodes mixed with 10% molasses fermented for 24h and 48h were the most attractive to S. levis (up to 90%). Pineapple peelings attracted 62.5% of the tested insects. The olfactory response was higher during the day, and no differences were found between the sexes. The production of ethanol in all plant substrates was higher than ethyl acetate, but we could not establish a clear correlation with the insect response to baits. KEY WORDS: Sugarcane, sugarcane weevil, soil pest, volatile RESUMO -A ocorrência do besouro da cana-de-açúcar, Sphenophorus levis Vaurie, é importante em algumas regiões do Brasil. O dano é causado pelas larvas que perfuram os colmos, ocasionando perdas de até 30 ton /ha/ano. Várias alternativas de controle têm sido utilizadas, embora nenhuma delas com resultados satisfatórios, à exceção do uso de iscas tóxicas. Sendo assim, há necessidade de otimizar sua efi ciência ou propor novas técnicas. O objetivo do presente estudo foi avaliar a atratividade dos adultos de S. levis a toletes de cana e casca de abacaxi por meio de olfatômetro em "Y". Os entrenós foram tratados com melaço a 10% e foram testados depois de diferentes tempos de fermentação (24, 48 e 72h), em diferentes horários (diurno e noturno) para ambos os sexos. Os testes foram conduzidos na tentativa de relacionar a resposta de S. levis ao acetato de etila e etanol produzidos pela fermentação. A produção de ambos compostos foi determinada por cromatografi a gasosa de massa (GC-MS). Os dados obtidos indicaram que os entrenós da cana-de-açúcar misturados com melaço a 10% e fermentados por 24h e 48h foram os mais atrativos a S. levis (acima de 90%). A casca de abacaxi só atraiu 62,5% dos insetos testados. A resposta olfativa foi maior durante o dia e não houve diferenças entre os sexos. A produção de etanol em todos os substratos foi maior do que a do acetato de etila, embora não tenha sido possível estabelecer uma relação clara com a resposta dos insetos às iscas.PALAVRAS-CHAVE: Cana-de-açúcar, be...

Response of Hypothenemus hampei (Coleoptera: Curculionidae) to semiochemicals and blends using baited traps in coffee fields

“…Although EA exerts an interchangeable effect with ET and other alcohols on the olfactory response of other coleopteran species (Lin and Phelan, 1991), the use of EA at the same ratio in all the combinations, evaluated in this study, was probably unable to increase H. hampei attractiveness compared to ET:MT. Also, Girón-Pérez et al (2009) revealed that the production of ET in plant substrates is higher than EA over time, suggesting that the ratio of the ester EA in the mixture should probably be lower in relation to the alcohols ET and MT. Perhaps other compounds should be added to potentiate the synergistic effect among the volatiles found in greatest proportions in the mature fruits, i.e., aldehydes (Sulaeha et al, 2017).…”

Moths of Economic Importance in the Maize and Sugar Beet Production

“…Later in vegetation, sugar beets are increasingly attacked by a variety of pests as a result of favorable weather conditions. In this "unprotected" sugar beet period pheromone traps comprise one of the most effective methods for monitoring the seasonal flight dynamics of adult male moths [29][30][31]. These traps are often used to detect the presence of pests by season and location within a facility and to monitor apparent changes in the size of pest population over time [32].…”

Harvest load transfer sites influence sugarcane billbug (Coleoptera: Curculionidae) spatiotemporal injury in sugarcane

“…However, during transfer, harvested material may fall on the ground, which may be infested with the pest or be attractive to sugarcane billbug due to the release of volatiles during the fermentation process of the fallen material. 17,18 We hypothesize that areas near the transfer sites are more prone to be infested by the sugarcane billbug compared to more distant ones, as individuals are attracted by emitted volatiles in crop residues. The main objective of this work was therefore to determine how the spatiotemporal distribution of S. levis injury is affected by load transfer sites in commercial sugarcane fields.…”