seasonal population dynamics of sugarcane whitefly, neomaskellia andropogonis corbett (hom.: aleyrodidae) in south of khuzestan

the outbreak of sugarcane whitefly, neomaskellia andropogonis corbett has been recently recorded in sugarcane fields in khuzestan province. the seasonal population dynamics of n. andropogonis was investigated in sugarcane fields (cultivar cp69-1062) in amir kabir agro-industrial in khuzestan during 2006-2007. one hectar field in the middle of a large field (25 hectar areas) was selected randomly and divided into three equal parts. each part was a replication. in each part, ten stations were selected randomly and sampled each week. in each station, one sugarcane stalk was selected randomly and the number of eggs, nymphs, pupa, adults and percentage of parasitized pupae were recorded. in both years, the population of all developmental stages rises gradually from early august and continued until late november. the peak of egg population was in mid october (244±9.55 and 168±28.67 eggs per leaf in 2006 and 2007, respectively). egg population decreased to zero in mid november and late november in 2006 and 2007, respectively. the peak of nymphal population was observed in mid october (130±2.08 nymphs per leaf and early november (103±60.98 nymphs per leaf) in 2006 and 2007, respectively. population of nymphal stage disappeared in mid november and late november in 2006 and 2007, respectively. the peak of pupal population was observed in early december (130±21.70 pupa per leaf) and late november (103±24.91 pupa per leaf) in 2006 and 2007, respectively and that of adult population occurred in mid october (35±0.54 adults per leaf) and early november (21±8.54 adults per leaf) in 2006 and 2007, respectively. the adult population decreased to zero in late november in both years. percentage of pupal parasitism was 85%, 0% in 2006 and 2007 years, respectively.