Greens

The Red legged winter mite, Penthaleus dorsalis has been found in more high tunnels (HTs) growing leafy greens this past winter for the 3rd year in a row. Most of the reports I have gotten from HTs are from the Eastern seaboard, but now I am receiving reports from locations further inland, such as Baltimore and Howard counties. Red legged winter mites have dark purple/black bodies and bright red legs (fig. 1). They thrive in what we would normally consider conditions too cold for an arthropod to cause problems.

Normally at this time of year when I talk about any insect problems in crucifers I talk about harlequin bugs that feed by sucking out plant juices and inject toxins into the plant. But I have seen several fields and even some high tunnels with blister beetles feeding and defoliating several different vegetables such as tomato (including the fruit), leafy greens, crucifers, spinach and especially swiss chard (fig. 1). Blister beetles begin feeding on the edges of leaves eventually leaving only stems (fig. 1). The presence of blister beetles now is not unusual as they are often found in large clusters in late summer-early fall. They can arrive in large groups, seemingly overnight and can do a great deal of damage in a short period of time.