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In the cultivation of loquat (Eriobotrya japonica (Thunb.) Lindl.) in Japan, injury to fruit by fruit bugs, such as the brown-winged green bug, Plautia stali Scott (Heteroptera: Pentatomidae), is a serious problem. Bagging developing fruits with a double-layer fruit protection bag ("double bag") prevents damage better than a single-layer bag. In 19 field trials using both types of bags from 2005 to 2015 under varying conditions of fruit bug pressure, we compared the effects of bag types on the harvest rate of saleable fruits and the suppression of injury. Meta-analysis of the relative effect of double bags gave an odds ratio of 5.57 for the harvest rate of saleable fruits, indicating the high effect of protection by double bag. Explicit solution of the odds ratio showed the effect as a function of fruit bug pressure. This method makes it possible to cost-effectively choose which bag to use according to the predicted emergence of fruit bugs each year. [ABSTRACT FROM AUTHOR]

The abundance of the adult brown-winged green bug, Plautia stali Scott, varies annually. During outbreaks, P. stali causes severe damage to various fruit crops. Therefore, predicting its abundance beforehand is important. In this study, we constructed multiple regression models to predict the abundance of overwintered adult P. stali in Chiba Prefecture, Japan, by using the accumulated aggregation-pheromone-trap captures of P. stali and the male flower production of sugi Cryptomeria japonica (Thunb. ex L.f.) D. Don, which relates to cone production, from 1998 to 2016. The abundance of overwintered adults in the present year can be predicted by male C. japonica flower production and the abundance of P. stali adults in the previous year. The models are highly precise and can calculate estimates in August for the abundance in the next year, which is far enough in advance for the application of control measures. These models also indicate intraspecific competition for food resources in P. stali. [ABSTRACT FROM AUTHOR]