Within the framework of interest to biological control of field crop insect pests, the aim was to look for new parasitoids of the sugar beet moth scrobipalpa ocellatella in the Egyptian environment. As well as evaluating its effectiveness in reducing the population of the pest. This study was carried out at the experimental farm of Sakha Agricultural Research Station, Kafr El-Sheikh and laboratory of Economic Entomology Department, Faculty of Agriculture, Kafr El-Sheikh University during three successive seasons. In 2016/2017, 2017/2018 seasons, new parasitoid was recorded from the beet moth pupae. It was defined as Diadegma oranginator Aubert (Hymenoptera: Ichneumonidae). By estimating the mean of parasitism under field conditions, 55.17, 60.46 and 68.91% were recorded at the three cultivations in 2016/2017 season, respectively. It was 57.57, 44.44 and 62.71% at the three cultivations in 2017/2018 season, respectively. Statistical analysis proved that a highly positive significant correlation coefficient values between S. ocellatella and its parasitoid populations in the three cultivations during 2016/2017 and 2017/2018 seasons. In 2018/2019 season, three IGRs and three conventional insecticides were applied against the beet moth. The general mean reduction of parasitoid population generating by the tested insect growth regulators (IGRs) application was ranged between 37.33 to 53.13%. However these values ranged between 86.81 to 95.04% in the case of the tested insecticides application. There were significant differences among the tested IGRs and the tested conventional insecticides in D. oranginator reduction. This demonstrated that the role of the insect growth regulators in maintaining the presence of parasitoid.
Key words: Scrobipalpa ocellatella, Diadegma oranginator, Parasitoids, Biological Control, Insect Growth Regulators.
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