Species Stiretrus anchorago - Anchor Stink Bug

Anchor Bug

Stiretrus anchorago (Fabricius, 1775)

Species name anchorago is Latin, and the word was also spelled ancorago, being perhaps an alteration of ancoratus (Adams, 2007, The Regional Diversification of Latin, p. 296--via Googlebooks). Though related, the word does not come directly from Latin ancora, meaning anchor. (English anchor, originally ancor, is an early borrowing from Latin--On-line Etymology Dictionary.) Latin ancorago referred to a fish of Northern Europe, most likely a salmon, especially the breeding form with hooked jaws (Adams, 2007 and LATCict). Adams suggests it is based on a compound of Gaulish anco (bent, crooked) plus rago (before, in front), meaning "fish with a hooked snout". (To make things more confusing, Gaulish anco is, perhaps, an Indo-European cognate of Latin ancora.)

So it seems that Fabricius's use of anchorago for this insect refers to the fish, and not an anchor. A reference to the triangular marks on the hemelytra, that resemble a salmon's jaws? It also seems possible that the reference is to the salmon color of the insect. See such images as:

  

Note that there is a fish with the same specific epithet, also described in the 18th century: Choerodon anchorago (Bloch, 1791), the Orange-dotted tuskfish (Encyclopedia of Life). This would seem to lend credence to the origin of the stinkbug name from the fish name anchorago.

In North America, this is the only species in the genus.

8-11 mm

Both markings and color are variable, but generally includes a variably-shaped dark central band running from the head toward the rear of the insect. The pale area on the right and left sides of the pronotum contain one to three dark spots (usually two). The dark color is dark blue to black. The light color may be white, pink, yellow, orange, or red.

  

  

Nymph is all black or black with a red spot.

  

Boris Buche offers this tip to distinguish this genus from genus Zicrona: Profemora with strong tooth (without tooth in Zicrona).

Eastern United States and Great Plains.

Found on a wide variety of herbaceous plants.

Adults may be found throughout the late Spring, Summer, and early Fall. April-September (North Carolina).

Adults feed on the larvae of beetles, butterflies, and moths. Stiretrus anchorago is considered an economically beneficial insect, feeding on the larvae of the Mexican Bean Beetle, among other pest species.

Eggs typically take seven days to hatch. The progression through the five instars takes another 25-35 days.

A handsome species that comes in a variety of color forms. There is only one North American species recognized in this genus. In 1971 two entomologists proposed a new species, Stiretrus fimbriatus, but others believed the proposed species was simply a color variant of S. anchorago.