Potencial inseticida de óleos de origem vegetal sobre Grapholita molesta (Busck) (Lepidoptera: Tortricidae) / Insecticidal potential of vegetable oil extracts on Grapholita molesta (Busck) (Lepidoptera: Tortricidae)

Em decorrência do estudo das interações químicas entre insetos e herbívoros, e do avanço da pesquisa fitoquímica, é conhecida ampla variedade de produtos naturais com potencial inseticida. Grapholita molesta (Busck) (Lepidoptera: Tortricidae), mariposa-oriental, é uma das principais pragas do pessegueiro, danificando brotações e frutos. O objetivo do presente estudo foi verificar a mortalidade, atratividade e deterrência de óleos vegetais em G. molesta. Ovos e pupas de insetos provindos de criação artificial foram imersos nos óleos essenciais de Elionurus muticus (Spreng.) Kuntze e Cymbopogon winterianus Jowitt ex Bor nas concentrações de 0,25%, 0,5%, 1% e 0,5%, 1%, 5%. Os testes de atratividade foram realizados em olfatômetro do tipo "Y". A deterrência à oviposição foi testada em gaiolas sem escolha e de dupla escolha. O óleo de E. muticus aplicado em ovos de G. molesta nas três concentrações causou mortalidades maiores que 30%, diferindo significativamente dos controles (p<0,05). A mortalidade causada pelo óleo de citronela foi em torno de 70%, significativamente superior ao controle (p<0,01). O óleo de citronela aplicado a 1% em pupas causou mortalidade de 99,8%. No teste com o olfatômetro, não houve atratividade dos adultos para nenhum dos óleos. A média de ovos no substrato com o tratamento (0,33±0,33), foi significativamente menor que no controle (7,3±0,88) (p<0,01), indicando deterrência à oviposição.

As a result of the study on the chemical interactions between insects and herbivores and the advancement of phytochemical research studies, a variety of natural products with great insecticidal potential are described in the literature. The Grapholita molesta (Busck) (Lepidoptera: Tortricidae), commonly known as Oriental Fruit Moth, is a major peach pest damaging shoots and fruits. The purpose of this study was to assess the mortality, attractiveness and deterrence of vegetable oils in G. molesta. Insect eggs and pupae artificially created were immersed in the essential oils of Elionurus muticus (Spreng.) Kuntze and/or Cymbopogon winterianus Jowitt ex Bor at the concentrations of 0.25%, 0.5%, 1% and 0.5%, 1%, 5%, respectively. The attractiveness tests were performed in a Y-Tube olfactometer. Oviposition deterrence was tested in no-choice and dual-choice cages. Oil of E. muticus applied in eggs of G. molesta at three concentrations caused mortality above 30%, which differs significantly from controls (p<0.05). Mortality caused by citronella oil was approximately 70%, significantly higher than control (p<0.01). The application of citronella oil at 1% in pupae caused mortality of 99.8%. There was no attractiveness of adults in the olfactometer test for any of the oils. Citronella oil presented oviposition deterrence, as the mean number of eggs in the substrate with the treatment (0.33 ± 0.33) is significantly lower than in the control (7.3 ± 0.88) (p<0.01).

Using genomics to improve fruit quality

New fruit varieties are needed to satisfy consumers, and the industry is facing new challenges in order to respond to these demands. The emergence of genomic tools is releasing information on polymorphisms that can be utilized to expedite breeding processes in species that are difficult to breed, given the long periods of time required to get new varieties. The present review describes the current stages of the ongoing efforts that are being taken to apply these technologies to obtain varieties with improved fruit quality in species of the family Rosaceae.