The species richness and relative abundance of faunas in defined areas are the raw materials in biodiversity science. The research methodology to acquire these data is inventory, and inventory quality depends on a number of parameters, for example collecting methods, season, and collector experience. To assess the ability of rapid inventory techniques to estimate local richness seven collectors sampled the fauna of true bugs in the Iberá watershed (Corrientes, Argentina) with seven methods during early spring, summer, and late summer (December, May, September) of 1 year. Twenty-three families, 225 spp. and 4,678 adults were found. We also applied various statistical techniques to correct the observed data for undersampling bias, which suggested the lower bound of annual heteropteran species richness at Pellegrini was about 250-300 species. Among heteropteran families, the particular inventory methodology was especially efficient in sampling Miridae.

The life history of the shield-backed bug, Pachycoris stallii Uhler (Heteroptera: Scutelleridae), immatures was studied on its host plant, Croton californicus Muell.-Arg. (Euphorbiaceae), in Baja California Sur, Mexico. Immature stages are described and illustrated. Pachycoris stallii is bi- or multivoltine and occurs in xeric areas with sandy soil where it is rarely encountered away from C. californicus. Nymphs and adults feed on seeds within C. californicus fruit. Bugs oviposit on the underside of leaves, and females guard their eggs and first-instar nymphs from natural enemies. Embryonic orientation of prolarvae is nonrandom; each embryo is oriented with its venter directed toward the ground. This orientation may facilitate aggregation of first instars. The longitudinal axes of eggs are always oriented upward at about a 16° angle of deviation from a line perpendicular to the leaf surface. This is the first recorded observation of this phenomenon in Pentatomoidea. Experimental removal of females guarding first instars results in 100% loss of nymphs, and this is attributed to disruption of the aggregative behavior of nymphs. Maternal guarding appears to be a net benefit to P. stallii, despite possible costs to the brooding female.

Instars I–V and eggs of Liorhyssus hyalinus (Fabricius) (Heteroptera: Rhopalidae) are described and illustrated based on specimens from La Pampa, Argentina. Host plant and parasite data are given for this species.

Material from Southern Chile and Patagonia was revised, and information on distribution and adult morphology of Atherimorpha imitans Malloch, A. nemoralis (Philippi), A. scutellaris Malloch and A. triangularis Malloch is given.

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