Impacts of sampling effort on estimating abundance of the aphid Sipha flava (Forbes) in sugarcane in Mazabuka, Zambia.
The exotic aphid Sipha flava (Forbes) (Homoptera: Aphididae) has recently become a pest of concern for sugarcane farmers in the Mazabuka region of Zambia. The steady decline in sugarcane yields has led to the need for investigation into the spatial-temporal dynamics of S. flava outbreaks, its population dynamics and invasion potential. Field survey data of S. flava, its abundance and distribution (every 20 m by 10 lines in±6 ha blocks), were intensely collected over a period of 6 weeks on a weekly basis in 7 separate fields. Using randomisation across subsets of these data, the authors illustrate how sampling effort might impact on estimates of abundance. These data provide much greater spatial resolution than current coarse-scale monitoring techniques are able to do. The levels of uncertainty with lower sampling effort are presented, highlighting the need for improving the current inconsistent scouting procedures. These results are discussed in the context of further development of an integrated pest management programme for aphids on sugarcane in Zambia.