Studies on population dynamics of insect pest of safflower,carthamus tinctorius L.

Various factors such as habitat loss,pollution,environmental changes and chemical manipulation can change the biodiversity level of different insects. insects have a variety of functions ranges from destructive to beneficial aspects. the insect population community was monitored in the safflower (carthamus tinctorius l.) field located in research farm of national agriculture research centre,islamabad. the data were recorded weekly by visual count method on randomly selected whole plant basis at seedling,vegetative stage,and maturity of five varieties of safflower including saf-31,saf-32,saf-35,saf-38 and thori-78. population dynamics of four insect genera including jassid (amrasca bigutella bigutella),aphid (uroleucon carthami),lygus bug (lygus hesperus k.) and pod borer (helicoverpa armigera hub.); and two beneficial insect genera named green lacewing (chrysoperla chornea) and ladybird beetle (coccinella septempunctata linn.) were monitored. the data revealed that among the safflower varieties saf-38,thori-78,saf-31 and saf-38 carried maximum population of jassid,aphids,bug and pod borer,respectively. highly significant differences in population build up was evident at monitoring dates. population percentage of aphid (85%) was highest followed by bug (4.2%),jassid (2.79%),pod borer (2.56%),green lacewing (1.01%) and ladybird beetle (0.60%). the aphid populations on all five varieties showed significantly positive correlation with temperature but negative correlation with relative humidity. our results provide important information that the insurgence of insect population is influenced by crop cultivar,phenology of plant,time,temperature and humidity. these findings are useful for designing the effective integrated pest management of safflower insect pest. copyright 2013 zoological society of pakistan.