Sequential sampling plans with fixed levels of precision for Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera:Psyllidae) adults in citrus orchards of south of Iran

Asian citrus psyllid, Diaphoina citri, is one of the most important pests of citrus in South of Iran, mainly because it is the vector of causal bacterium of Greening disease. In this study, adults of D. citri were sampled using yellow sticky traps (10×25 cm) at 52 citrus orchard of Kerman and Hormozgan provinces in south of Iran. Taylor’s power law and Iwao’s regression methods were used to study spatial distribution of the pest adults. Taylor’s power law and Iwao’s parameters then were used to create Green’s and Kuno’s sequential sampling models at 10 and 25 percent fixed precision levels, respectively. Results revealed that adults caught by traps had an aggregated distribution pattern based on both Taylor’s power law and Iwao methods. Green’s sequential sampling plans developed by Taylor’s parameters were more appropriate than Kuno’s ones. In obtained sequential sampling models, sample sizes were reduced and performance of plans for rapid estimation of population was increased by increasing density of Asian citrus psyllid adults. Increasing fixed precision level from 25% to 10% resulted in up to 6-7 times increasing in number of traps required to estimate population density of adults. So, sampling at 10 percent precision level is time wasting because of large sample size estimations and green’s sequential sampling model at integrated pest management precision level (25%) is recommended because of less time needed for monitoring D. citri adults.