Predation ecology and natural control of the cotton fleahopper, Pseudatomoscelis seriatus (Reuter)

A method for the identification and quantitative evaluation of predators of the cotton fleahopper (CFH), Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae) is described. The method involves mass-labeling CFH by exposing the insects to Phosphorus-32 for 1-3 h, and after determining the mean CPM (counts, or disintegrations, per minute), cohorts of CFH were field-released on host plants. After 24 and 48 h, the host and adjacent plants were sampled for labeled predators. The CPM of the radioactive predators was measured by liquid scintillation counting and an algorithm was developed to determine the number of individual prey items consumed by field captured predators.;The method described above was used to identify and find the rate of consumption by the predators of CFH on woolly croton and cotton. Estimated consumption rates of CFH by the predators was based on the presence of Phosphorus-32 transferred from the radiolabeled CFH to their predators. Ten species of spiders and one species of ant preyed upon CFH on woolly croton. On cotton, predators included 17 species of spiders belonging to 11 families and 10 species of insects representing 9 families.;The efficacy of the three important spider and single ant species of predators of immature CFH was calculated using cotton-field (spiders) and laboratory-cage confinement (ant) tests for consumption rate. The functional response of the four arthropod species to the different prey densities is illustrated and discussed.;The dynamics of CFH on cotton was predicted using the Texas Cotton Insect Model (TEXCIM) and compared with observed data from D-Vac sampling. The natural enemies and their estimated rate of CFH consumption and efficacy were used along with a rain component as mortality factors to calibrate the model. When current economic thresholds for CFH were used, TEXCIM made type I and type II errors in 7% of 71 sampling periods (x = 6.8 days). Unlike many other known biological control systems, this pest suppression strategy operates with density independent generalist predators already in place to defend the cotton crop against insect pest elements that cut yields. Cotton producers are now offered a choice between traditional chemical control and natural control of cotton pests through the use of sampling field natural enemy dynamics and using them in an integrated cotton simulation model.