Desenvolvimento e reprodução da mariposa-oriental em macieira e pessegueiro

Abstract

Resumo -O objetivo deste trabalho foi avaliar o desenvolvimento de estágios imaturos e parâmetros reprodutivos de adultos de Grapholita molesta em dietas naturais, constituídas de ramos e frutos de pessegueiro 'Vanguarda', frutos de macieira 'Gala' e 'Fuji', e em dieta artificial à base de milho. O delineamento experimental foi inteiramente casualizado. Considerou-se cada inseto uma repetição e, no estudo dos parâmetros biológicos dos adultos, cada casal foi considerado uma repetição. Foi calculada a tabela de vida de fertilidade. O tempo para o desenvolvimento das lagartas foi menor em ramos e frutos do pessegueiro, em comparação a frutos de macieira e dieta à base de farinha de milho. Quanto à sobrevivência das larvas, não houve diferença entre as dietas. Com base na tabela de vida de fertilidade, os frutos da cultivar Fuji foram mais adequados ao desenvolvimento de G. molesta do que os da Gala. Os ramos de pessegueiro foram mais adequados ao desenvolvimento do inseto do que os frutos. A dieta à base de farinha de milho foi adequada para a criação dos insetos em laboratório. As dietas avaliadas afetam a taxa de sobrevivência, o desenvolvimento e o potencial de crescimento populacional de G. molesta. Termos para indexação: Grapholita molesta, Malus domestica, Prunus persica, criação em laboratório, tabela de vida. Development and reproduction of the oriental fruit moth in apple and peachesAbstract -The objective of this work was to evaluate the immature stages development and the reproductive parameters of Grapholita molesta adults reared on shoots and fruit of 'Vanguarda' peach, on fruit of 'Gala' and 'Fuji' apples, and on a diet formulated with corn meal. The experimental design was completely randomized. Each insect was considered one replicate; and for the biological parameters of adults study, each couple was considered a replicate. The fertility life table was calculated. The time for larvae development was shorter in peach shoots and fruits, in comparison with apple fruit and corn meal diets. There were no differences for larvae survival, in the comparison between diets. Based on fertility life table, 'Fuji' apple fruit are more appropriated to the G. molesta development than Gala ones. Peach shoots were more suited for insect development than fruit. The corn meal-based diet is suitable to rear G. molesta in laboratory. The evaluated diets affect survival rate, development and growth potential of G. molesta population.

Burrknots as Food Source for Larval Development ofGrapholita molesta(Lepidoptera: Tortricidae) on Apple Trees

“…The observed values (211.1 Ϯ 5.90, 290.0 Ϯ 9.70, and 313.0 Ϯ 6.65 eggs for insects reared on the artiÞcial diet, Fuji apples, and burrknots, respectively) are higher than those reported by Silva et al (2010), who reared this insect on branches and fruits of peaches and apples, and obtained a mean fertility ranging from 110 to 202 eggs.…”

“…These periods are similar to the 3.07 d reported by Grellmann et al (1991), who studied the embryonic development at 26ЊC. For the larval stage, the longest duration observed for insects fed on burrknots (19.1 d) in relation to apples (15.9 d) and artiÞcial diet (14.8 d), is greater than the values reported for preferred hosts, such as branches (13.0 d) and fruits (14.0 d) of peach trees (Silva et al 2010). However, Rosenthal et al (1994), using the same artiÞcial diet and temperature, found a duration of 20.5 d for larval development of G. molesta.…”

“…These values are higher than those reported by Rosenthal et al (1994), who reared the insects on artiÞcial and natural diets and obtained eggs with viabilities ranging from 26.6 to 53.5%. However, higher viabilities were reported by Marin et al (2006), who tested an artiÞcial diet based on beans and obtained a viability of 78%; and by Silva et al (2010), who obtained eggs from insects fed on stems and fruits of peach and apple, with viabilities higher than 76%. In addition, viability rates over 95% were reported by IvaldiÐSender (1974) and Arioli et al (2010), for larvae fed on an artiÞcial diet and green apples, respectively.…”

“…Two recently eclosed larvae (Ͻ12 h old) were placed on each fruit. Netting material was placed over the container, and Þxed on the sides with a rubber band to prevent the larvae from escaping before they pupated and to exclude other insects, in accordance with the method of Silva et al (2010).…”

“…However, in recent harvests, signiÞcant damage was also reported in São Joaquim, SC, and in Vacaria, state of Rio Grande do Sul (RS), important fruitgrowing centers in Brazil Botton 2003, Arioli et al 2007). The increase in damage caused by G. molesta in apple trees could be explained by three hypotheses: 1) reduction in the number of applications of insecticides against key pests of the crop, mainly the South American fruit ßy Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) and the apple leafroller Bonagota cranaodes (Meyrick) (Lepidoptera: Tortricidae), after the implementation of the program Integrated Production of Fruits (PIF); 2) the utilization mainly of organophosphate insecticides to control pests in apple orchards could have led to selection of resistant populations; and 3) low efÞ-ciency of these insecticides against the pest and inadequate use of sex-pheromone traps Botton 2003, Arioli et al 2005) and the high capacity for population growth of G. molesta feeding on apples (Silva et al 2010). In addition to these factors, the potential for population growth of G. molesta is higher in apple than in peach fruit, even though the latter is traditionally recognized as the host of this pest (Silva et al 2010).…”