An overview of arginussa species group of Memphis Hbner, [1819], with the description of a new species from Panama (Lepidoptera: Nymphalidae: Charaxinae).

Memphis Hbner, [1819] is a nymphalid butterfly genus exclusive to the Neotropics. It includes species with iridescent bluish or greenish coloration on the upper side of the wings while the underside is cryptic, resembling dead leaves. This paper aims to describe a remarkable new species, M. smalli Riley Dias sp. nov., from the remote Atlantic slopes of Panama based on molecular and morphological analyses. We also review the taxonomy of species herein included in the arginussa species group based on distances analyses of DNA sequence data. The arginussa species group, as defined here, includes M. arginussa (Geyer, 1832), M. eubaena (Boisduval, 1870) stat. rest., M. onophis (Felder Felder, 1861) stat. rest., M. lemons (Druce, 1877), M. neidhoeferi (Rotger, Escalante Coronado, 1965), M. perenna (Godman Salvin, [1884]), M. lankesteri (Hall, 1935) stat. rest., M. paulus Costa Orellana, 2014, M. pithyusa (Felder, 1869), M. herbacea (Butler Druce, 1872) and M. smalli sp. nov. Anaea pithyusa morena Hall, 1935 syn. nov. is recognized as a synonym of Nymphalis pithyusa Felder, 1869. The new species and its closest ally, M. herbacea, are illustrated, including characters of the head, labial palpus, wings, legs, male and female genitalia and their distribution map.

Management of feeding damage and survival of southwestern corn borer and sugarcane borer (Lepidoptera: Crambidae) with Bacillus thuringiensis transgenic field corn.

The efficacy of transgenic corn hybrids expressing an insecticidal Bacillus thuringiensis (Bt) delta-endotoxin from different transformation events was evaluated in field corn, Zea mays L., against the southwestern corn borer, Diatraea grandiosella Dyar, and sugarcane borer, Diatraea saccharalis (F.). Susceptibilities of neonates and third instars were determined on Bt and non-Bt corn plants (V6 and R1 stages) in field plots and corn leaf tissue feeding exposure in laboratory bioassays. Bt corn hybrids associated with MON810 and CBH351 transformation events sustained significantly less injury by southwestern corn borer and sugarcane borer during mid-whorl stage infestations compared with their respective non-Bt hybrid equivalents. Southwestern corn borer and sugarcane borer feeding injury to ear leaf-sheath and husk tissues during the silking stage of corn was significantly reduced in MON810 and CBH351 Bt corn compared with their respective non-Bt hybrids. However, resistance levels to feeding injury in Bt hybrids associated with the MON810 event were significantly higher than that in the hybrid associated with the CBH351 event. Southwestern corn borer and sugarcane borer caused more feeding injury to husk tissue than to ear leaf-sheath tissue in both Bt and non-Bt hybrids infested during the silking stage. Laboratory performance of the MON810 event against southwestern corn borer and sugarcane borer varied among hybrids associated with the same event. Third instars of southwestern corn borer were highly susceptible to MON810 Bt corn hybrids in leaf tissue experiments. However, sugarcane borer larvae were susceptible to the MON810 event only in one of the Bt hybrids evaluated. Sugarcane borer mortality was significantly lower after 96 h of feeding exposure on CBH351 Bt corn leaf tissue than on MON810 Bt corn leaf tissue. Plant resistance to southwestern corn borer and sugarcane borer increased as plants matured, independent of the presence of a Bt construct. These results are essential to estimate the importance of Bt transgenic corn in areas of southern United States and other areas where mixed populations of southwestern corn borer and sugarcane borer are predominant and cause severe damage to corn production.