Soft scale insect Pulvinaria tenuivalvata infesting sugar-cane

Soft scale insect Pulvinaria tenuivalvata attacking sugar-cane at Attfieh region, Giza Governorate is considered an economic important insect pest on sugar-cane in Egypt from mid-1990s. The main topics of this present study can be summarized as follows: Population dynamics of P. tenuivalvata, its rate of growth and survey of predators and parasitoids associated were conducted through careful inspection of sugar-cane fields. Nymphal infestation started from apical part of plant in the two studying seasons. Also, adult infestation started on apical part of sugar-cane plant in first and second seasons. In both seasons infestation disappear from January to the end of season. Negative Correlation was found between the population density of P. tenuivalvata and temperature. Effect of five host plants on different biological aspects of P. tenuivalvata was studied and sugar-cane plant was more preferable to the insect than all other tested host plants. Laboratory evaluation of different extracts of spicked centaury Centaurium spicatum on the biological aspects of P. tenuivalvata was studied and Petroleum ether extract was the most effective extract on all insect stages.