Seasonal abundance of some sap-sucking pests on Cape gooseberry, Physalis peruviana L.

Afsah , A. F. E.

Abstract

The effect of some weather factors and plant age after transplantation on population of some sapsucking pests on cape gooseberry plants were studied during two successive seasons of 2012 and 2013 at Qaha district, Qalubia Governorate. The cotton whitefly, Bemisia tabaci (Genn.) recorded 6 and 5 peaks at both egg and nymphal stages during two seasons, respectively. The correlation between plant age after transplantation, maximum& minimum temperature and mean numbers of B. tabaci eggs were negative and highly significant effect, but relative humidity (RH%) recorded negatively significant and wind speed had positive and highly significant effect in first season. In the second season, plant age after transplantation had negative and significant effect, but Max.& Min. Tempe. had negative and highly significant, while Max.& Min. RH% recorded negative and significant and wind speed showed positive and insignificant . B. tabaci nymph had negative and non significantly correlation with all the tested factors in both seasons, except of wind speed had positive non significant in the first season and positive significant in the second season. B. tabaci pupae had 6 and 3 peaks at the two seasons respectively, and all the tested factors had insignificant effect. The cotton thrips, Thrips tabaci lind. nymphs recorded 4 and 6 peaks in the first and second seasons, respectively, all the tested factors recorded negative and highly significant correlation except of Max. RH % was non significant, Min. RH % was significant and wind speed was positive in the first season. In the second season all the tested factors recorded negative and significant correlation except of Max. and Min. RH% had insignificant and wind speed recorded positive and non significant. Thrips adult recorded three and four peaks in the two seasons , respectively. Statistical analysis in the first season showed that the effect of the tested factors on the mean numbers of adult stage had approximately the same trend with thrips nymphs. But in the second season, plant age after transplanting, Max. & Min. temperature and wind speed had negatively correlation and insignificant effect except of Max. Temperature had significant effect. While Max. & Min. relative humidity was positively correlation and insignificant. Tomato rust mite, Aceria lycopersici (Wolffenstein) recorded four and one peaks in the two seasons , respectively. All the tested factors had non significant effect and positive correlation in the two seasons, except of wind speed recorded negative correlation in the first season. The red spider mite, Tetranychus spp. had three and five peaks in the two seasons, respectively. Statistical analysis recorded highly significant and positive relationship between mean numbers of Tetranychus spp. and the tested factors except of wind speed had negatively correlation in the first season . in the second season had positively and high significantly correlated with plant age after transplanting date , but temperature and wind speed showed positively correlation and significant effect.

Key words

Tomato rust mite, Aceria lycopersici, Tetranychus spp , temperature, relative humidity , Bemici tabaci, Thrips tabaci