The yellowmargined leaf beetle.
The yellowmargined leaf beetle, Microtheca ochroloma Stål, is a pest of cruciferous crops. It was first recorded in the United States from Mobile, Alabama, in March 1947, feeding on turnip, cabbage, collard, mustard, and radish (Chamberlin and Tippin 1949). It can devastate high value crops, such as mizuna and mibuna (Japanese leafy vegetables), napa cabbage, turnip and watercress (Bowers 2003).
Outside the United States, the yellowmargined leaf beetle is found in several South American countries (Argentina, Brazil, Chile, and Uruguay) where it is native (Woodruff 1974).
In the United States, Chamberlin and Tippins (1949) first reported it from Alabama in Mobile and Baldwin Counties. In 1956, it was reported for the first time in Tangipahoa Parish, Louisiana, on mustard greens. Eventually, its distribution was listed as 22 counties in four states (Woodruff 1974).
While Edwards (1949) listed the species from “Alabama and Florida,” there does not seem to be a Florida record until 4 April 1972 when it was found in Tampa. It was then found on watercress at an aquatic nursery (Woodruff 1974). The first published report in Texas was from Harris County in 1977 when the beetle was discovered on collard greens, but there are specimens in the Texas A&M University insect collection from Galveston County dated 5 June 1975 (Drees 1997).
The beetle is now distributed along the Gulf Coast from Florida to Texas (Drees 1997), and in Georgia (Guillebeau 2001) and North Carolina (Kriz 1997).