These oothecae may be mantis egg cases.
Post Update: Several members of the BugGuide Facebook group confirmed that these are in fact mantis egg cases. Group member Beatriz Moisset identified the species as Chinese Mantis (Tenodera sinensis), as indicated by the distinctive roundish shape of the oothecae. Chinese Mantis is a non-native species.
Introduced from China in 1896 to combat pests. It outcompetes many of the native preying mantises, which are in decline. Source Credit: Species Tenodera sinensis – Chinese Mantis, BugGuide.
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