Impact of some bio-insecticides on certain biological aspects of pulvinaria tenuivalvata [newstead] [fam.: Coccidae, order: Homoptera] infesting sugar-cane

The red-striped soft scale insect, [R.S.S.S] Pulvinaria tenuivalvata attacking sugar-cane at Attfieh region, Giza Governorate is recently considered an important economic insect pest of sugar-cane in Egypt. Laboratory evaluation of different extracts of the spicked centaury, Centaurium spicatum on the biological aspects of P. tenuivalvata was studied. Petroleum ether extract proved the most effective extract on all insect stages. The impact of the most effective extract, mineral oil, and biocide on the biological aspects of P. tenuivalvata under laboratory and field conditions was studied. The tested compounds are effective against soft scale insect, P. tenuivalvata on sugar-cane leaves and they increased sugar-cane yield significantly, at Attfieh region

Host-plant preference of the red-striped soft scale insect, Pulvinaria tenuivalvata [Newstead]

Effect of five host plants on different biological aspects of the red striped-soft scale, Pulvinaria tenuivalvata [Newstead] was studied. The percentage of nymphs that succeeded to reach the adult stage differed on the different host plants. This percentage was maximum on sugar-cane and sweet sorghum followed by cogon grass, while the minimum was on maize. The shortest pre-oviposition period of the insects was recorded on sugar-cane and elephant grass plants, while the oviposition period was about twice greater on sugar-cane than on sweet sorghum. No significant difference existed between the oviposition period on sweet sorghum and maize. The maximum number of eggs was found on sugar-cane, but the minimum number was found on maize and sweet sorghum. Adult longevity on sugar-cane was about twice greater than that on maize, while it was one and half that on elephant grass. Thus, sugar-cane plant was more preferable to the insect than all other tested host plants