Red-shouldered Bug

Jadera haematoloma are typically 9.5–13.5 millimetres (0.37–0.53 in) long and 3–4 millimetres (0.12–0.16 in) wide, though the short-winged form (brachyptera) usually is 7–8 millimetres (0.28–0.31 in) long. Color is mostly blackish (sometimes, bluish grey, or purplish, or bright red immediately after molting) except for red eyes, "shoulders" (lateral margins of pronotum), and costal margins and dorsal part of abdomen. Nymphs are mostly red with a black pronotum and wingpads. All appendages are blackish.

For most of the twentieth century, little was known about the range of J. haematoloma. Reports showed breeding populations to be present in Florida, Kansas, Colorado, Texas, Arizona, California, Alabama, Illinois, North Carolina, Missouri, Iowa, as well as Georgia, South Carolina, Tennessee, Virginia, Pennsylvania, Maryland, and Royal Oak, Michigan. A study published in 1987 showed the distribution of J. haematoloma and "revealed the close correspondence of records for the bug with the ranges of the soapberry plants that serve as the insects native hosts." In addition, isolated examples have been reported as far north as Minnesota. Outside of the United States, J. haematoloma is found south through Central America and the West Indies to Colombia and Venezuela. Although native to the New World, the discovery of J. haematoloma populations in Taiwan in 2012 marked the first finding of the species and genus in Asia.

It is extremely common to see pairs of the bugs joined tail to tail. Males outnumber females by about two to one, so that as an evolutionary strategy, the males prolong copulation for about two days, thereby preventing sperm competition.