While conducting studies in hemp at the University of Kentucky’s Spindletop Farm in Lexington, the twice stabbed sting bug (Cosmopepla lintneriana, formerly C. bimaculata) (Hemiptera: Pentatomidae) was observed in hemp grown for grain (Figure 1) during the first week of October 2021. This is a first report of this stink bug species associated with hemp and the potential to cause economically important damage is not yet known. This species has been observed on different plant species from Mexico to Canada.
Description & Life Story
This stink bug is a small stink bug, no larger than 8 mm long and 5 mm wide. The twice stabbed sting bugs observed in hemp were black or bluish black with orange or yellow markings (Figure 2). However, other specimens are brownish or speckled brown or brown-red in color.
There is scarce information on this stink bug species. In southern Illinois, it was reported as bivoltine (two generations per year) with adults observed from early May to late October. Egg clusters were found from late May to early June on common mullein and geranium, and from mid-to late August on figwort. Fifth instar nymphs from the first generation were collected in late June-early July. Nymphs of the second generation were found approximately from early August to late September, primarily on the same host plants with a peak of fifth instars in early September.
The twice stabbed sting bug is a polyphagous stink bug and previous reports indicate that they were also common in milkweed. Their presence in maturing hemp indicates a potential for feeding on the hemp seeds or foliage. In studies conducted in western Kentucky for hemp grown for CBD, this species was not noticed. In field crops, this is not a common species. In a study conducted about the community composition, abundance, and phenology of stink bugs in soybeans in 9 states of the north mid-central USA in 2016 and 2017 only 8 (~0.004%) twice stabbed sting bugs were found out of 1,968 individuals captured.
While this is an interesting find on hemp, and currently there is no reason for alarm, we would be interested in grower reports of this insect potentially feeding on floral or grain hemp.
- Notes on the life histories of Acrosternum hilare and Cosmopepla bimaculata in Southern Illinois (link)
By Raul T. Villanueva, Entomology Extension Specialist; Magdalena Ricciardi, Visiting Scientist, and Bob Pearce, Plant and Soil Science Extension Professor