Identification of Nymphal Instars of emMecidea/em emmajor/em Sailer and Mecidea minor Ruckes (Hemiptera: Heteroptera: Pentatomidae: Mecideini) from the Southwestern and Central United States.

The mecideine stink bug genus Mecidea is represented in America north of Mexico by three species: Mecidea major Sailor, Mecidea minor Ruckes, and Mecidea longula Stål. M. major and M. minor are widely distributed, occurring collectively from the Midwest to California. M. longula is known only from south Florida. The life histories of M. major and M. minor have been published including laboratory rearing from egg to adult and descriptions of the immature stages. However, no key has been developed for identification of the nymphs of these two species. Here, we present a key to the nymphs of these taxa to the species and instar levels.

Life history of Mecideamajor with descriptions of nymphal instars (Hemiptera, Heteroptera, Pentatomidae).

The life history of the stink bug Mecideamajor Sailer was studied in the southern half of New Mexico primarily from January 2005 through December 2007, and the nymphal instars were described. This species was active throughout the year as adults and nymphs, including the winter months. It occurred on various species of grasses during this time but primarily on Lehmann lovegrass, Eragrostislehmanniana Nees; grama grasses, Bouteloua spp.; and tobosagrass, Pleuraphismutica Buckley. The times of occurrence and abundance of the eggs, nymphs, and adults suggest this species is bivoltine with the possibility of a third generation. Instars can be distinguished by several morphological features including body size and presence and relative development of wing pads.