Sequential sampling plans for the hairy chinch bug (Hemiptera : Lygaeidae)

Two sequential sampling plans were developed to produce tools to reduce the use of pesticides for the control of the hairy chinch bug, Blissus leucopt erus hirtus Montandon, on turfgrass lawns in the cool-humid region of Quebe c, Canada A first plan based on Wald's method was shown to be too conservat ive in a validation conducted on infested lawns. The second plan developed using Iwao's method yielded good results. The difference between the two pl ans may have occurred because no common k could be found for the negative b inomial functions describing chinch bug distribution on lawns, thereby viol ating an essential assumption of Wald's approach. Application of the Iwao p lan, which is based on visual sampling of 0.1-m(2) quadrats, requires appro ximate to 20 min when lawn evaluation is conducted by a single person. Esti mation of the occurrence of chinch Lug infestations (28% infested lawns in the regions of Montreal and Quebec cities), and results from validation of the Iwao plan on infested lawns, indicate that the error rates alpha and be ta of the plan are lower than an upper limit of 0.05 and 0.14 respectively. The adequate precision and practicality of this plan suggest that it could become an essential tool for management of turfgrass lawns in regions wher e the hairy chinch bug completes less than two generations per growing seas on.