Size
Adult males 16 - 21 mm, adult females 18 - 25 mm.
Identification
Large, flat, speckled brown, with a short stabbing beak like all predatory stinkbugs. Very similar to Podisus maculiventris, from which it is distinguished by its larger size (over 15 mm - Podisus adults reach only 11 mm) and by the double rather than single-pointed spines on the shoulders (humeral spines).
For identification of earlier instars, see
UF Featured Creatures. First instar is hard to distinguish from that of
Euthyrhynchus floridanus. According to UF, "both have a blue-black head and thorax and red abdomen with dark central and lateral "stripes" composed of dorsal and lateral dark colored plates. Nymphs of this age do not stray far from the egg mass and may be distinguished by the form of the mass and numbers of eggs; E. floridanus masses are loosely oval and contain 20 to 90 eggs." A. grandis egg masses contain 100-200 eggs in multiple rows.
Later instars (third through fifth) are blue-black with red "shoulders" (red keels on the pronotum).
Fifth instar also has reddish bars.
Range
Reported from Florida and Texas, according to UF Featured Creatures (below).
See Also
Euthyrhynchus floridanus (resemblance is of newborn nymphs only)
