Sinea diadema is a species of assassin bug family (Reduviidae), in the subfamily Harpactorinae. Sinea diadema is bivoltine, preys on small bugs and beetles, and overwinters in the egg stage.
In English the species goes by the common name spined assassin bug. Its scientific name comes from Hebrew, where sinea means thorn bush or burning bush while diadema means crown.
It is native to North America and found in the Midwest in fields, often associated with goldenrod Solidago missouriensis Nuttall. They are typically found in grasslands, gardens, as well as fields.
They wait for prey to come by, usually on blossoms which are often visited. They also will slowly approach prey before attempting capture.
Cannibalism is not common in this species. However, when it occurs it usually involves a larger female eating a smaller male.: 551
Females can lay up to 412 eggs in laboratory conditions.: 514 Eggs are laid in clusters.: 94
