Degree Day Requirements for Kudzu Bug (Hemiptera: Plataspidae), a Pest of Soybeans

Understanding the phenology of a new potential pest is fundamental for the development of a management program. Megacopta cribraria Fabricius (Hemiptera: Plataspidae), kudzu bug, is a pest of soybeans first detected in the United States in 2009 and in Maryland in 2013. We observed the phenology of kudzu bug life stages in Maryland, created a Celsius degree-day (CDD) model for development, and characterized the difference between microhabitat and ambient temperatures of both kudzu, Pueraria montana (Lour.) Merr. (Fabales: Fabaceae) and soybeans, Glycine max (L.) Merrill (Fabales: Fabaceae). In 2014, low population numbers yielded limited resolution from field phenology observations. We observed kudzu bug populations persisting within Maryland; but between 2013 and 2016, populations were low compared to populations in the southeastern United States. Based on the degree-day model, kudzu bug eggs require 80 CDD at a minimum temperature of 14°C to hatch. Nymphs require 545 CDD with a minimum temperature of 16°C for development. The CDD model matches field observations when factoring a biofix date of April 1 and a minimum preoviposition period of 17 d. The model suggests two full generations per year in Maryland. Standard air temperature monitors do not affect model predictions for pest management, as microhabitat temperature differences did not show a clear trend between kudzu and soybeans. Ultimately, producers can predict the timing of kudzu bug life stages with the CDD model for the use of timing management plans in soybean fields.