Resistance categories (antibiosis and tolerance) of four sorghum (Sorghum bicolor (L.) Moench) hybrids to biotype I greenbug, Schizaphis graminum (Rondani), were determined in environmental growth chamber and field studies. Greenbug weight and fecundity were lower on ‘Cargill 607E’ compared with ‘Cargill 797’. Percentage of leaf damage area was significantly less on two resistant hybrids (Cargill 607E and Cargill 797) after a 14-d greenbug feeding period compared to two susceptible hybrids (‘Golden Harvest 510B’ and Garst 5715). In growth chamber studies on sorghum seedlings, ‘Cargill 607E’ and ‘Cargill 797’ reduced greenbug weight significantly compared with ‘Golden Harvest 510B’ and ‘Garst 5715’. Greenbug weight was 2.9 mg/25 greenbugs on ‘Cargill 607E’, 3.1 mg/25 greenbugs on ‘Cargill 797’, 3.9 mg/25 greenbugs on ‘Golden Harvest 510B’, and 4.8 mg/25 greenbugs on ‘Garst 5715’. On field grown sorghum plants, ‘Cargill 797’ did not reduce greenbug growth compared with ‘Golden Harvest 510B’. ‘Cargill 607E’ had a negative impact on weight of greenbugs. Greenbug weight was 7.9 mg/25 greenbugs on ‘Cargill 607E’, 9.2 mg/25 greenbugs on ‘Cargill 797’, and 10.0 mg/25 greenbugs on ‘Golden Harvest 510B’. ‘Cargill 607E’ and ‘Cargill 797’ were resistant to biotype I greenbugs compared with susceptible ‘Golden Harvest 510B’ and ‘Garst 5715’. Antibiosis was confirmed as the primary category of resistance in ‘Cargill 607E.’ ‘Cargill 797’ was primarily tolerant but may have some level of antibiosis, because smaller greenbugs developed in some of the studies.

Two new species of perlid stoneflies, Acroneuria bachma n. sp. and A. magnifica n. sp., are described from tropical Vietnam. Descriptions of these species are given based on male and female adults, nymphs, and eggs. The adult of A. bachma is distinguished by the presence of a large dark brown marking in the interocellar area and by the absence of patches of sensilla basiconica on the 9th abdominal tergum; the nymph is distinguished by the presence of a narrow and complete M-line marking on head and by the absence of gills on paraprocts. The adult of A. magnifica is distinguished by presence of a distinct light-yellow M-line marking on head and patches of sensilla basiconica which are sparsely distributed on the 9th abdominal tergum; the nymph is distinguished by the presence of an incomplete M-line marking on head and gills on paraprocts. Line-drawings and macro-photographs of the diagnostic characters are provided. Adult and nymphal keys to Southeast Asian species of Acroneuria are also provided.

This study provides a morphometric analysis of a new morphotype belonging to the subgenus Trigona s. str. collected in Colombia. This morphotype is similar in external morphology as to the T. fulviventris complex. We use a non-parametric multivariate approach to compare 40 characteristics from five species of bees from the subgenus Trigona s. str. Our results suggest that this morphotype is morphologically distinct from the other species used in this study, but in order to asses the real validity of this finding further data from molecular genetics and ecology are needed.

The nests of Lithurgus collaris were found in dead branches of Hibiscus tiliaceus (L.) (Malvaceae). Mean entrance diameter of the nests was 8.5±1.2 mm (n = 9). The mean tube length and diameter were 65.7±39.6 mm (n = 41, range 7–141) and 7.4±0.7 mm (n = 41), respectively. The main entrance was larger than the gallery entrance. Mean number of galleries per nest was 4.6±3.1 (n = 9). A completed nest was always sealed with wood dust, which was not seen in a new nest. The mean pollen lump length was 21±5.5 mm (n = 9). Larval fecal pellets were thread-like and often extended (5–9 mm) from the abdominal tip. The mean length and width of cocoons were 12.7±0.8 mm and 6.5±0.4 mm, respectively (n = 7). Adults appeared to forage pollen in the first half of the day and nectar during the latter half of the day.

A new host association is made for the Neotropical spider wasp Priochilus gloriosum gloriosum Cresson, which also represents the first host association for this genus. A new host association also is made for Aporinellus fasciatus Smith and additional host associations are provided for Ageniella conflicta Banks, Ageniella (Ameragenia) nr. fabricii Banks, Ageniella (Alasagenia) sp. A, Cryptochilus attenuatum Banks, Priocnemella sp. A, Agenioideus birkmanni Banks, Ammosphex silvivagus Evans, Anoplius imbellis Banks, and Tachypompilus ferrugineus ferrugineus Say. Host transportation behaviors are reported where observations were made.

Chironomidae is a cosmopolitan family of dipteran insects occurring in all zoogeographical regions of the world. The family is quite diverse and the objective of this study was to examine diversity of chironomid larvae in 115 wetlands in an extensive area of Neotropical region (∼220,000 km², southern Brazil) by analysis of richness and composition in different wetland subsystems, types and classes. Also examined were effects of wetland area, altitude, water conductivity and nutrients on these community descriptors. A total of 36 genera was found, with Chironominae showing the greatest richness, followed by Tanypodinae and Orthocladiinae. The richness and composition changed between wetland subsystems, types and classes. However, no single parameter strongly influenced the chironomid richness and composition in this broad spatial scale survey. The broad spatial scale and details of this study make it an important contribution to knowledge of chironomid diversity in the Neotropical region.

The flesh fly community was surveyed on the shoreline of Río de la Plata at an ecological reserve whose western border directly abuts downtown eastern Buenos Aires. Samples were taken at monthly intervals from September 2004 to August 2005. To attract the flies, dog faeces and rotten cow liver were used as bait. Overall number, species composition and sex ratio were referred to each chosen bait. Of the thirteen species captured during the sampling period, Helicobia aurescens (Townsend), Oxysarcodexia culmiforceps Dodge, Oxysarcodexia marina (Hall), Oxysarcodexia thornax (Walker), Sarcophaga (Lipoptilocnema) koehleri (Blanchard), S. (L.) lanei (Townsend) and Tricharaea (Sarcophagula) occidua (Fabricius) were recorded for the first time in Buenos Aires city. Regardless of species composition, higher number of flies were obtained on faeces. Tricharaea (S.) occidua, was highly dominant (78,35%) followed in abundance by Oxysarcodexia varia (7,82%), both species showing a strong preference for dog faeces. Microcerella muehni and Oxysarcodexia paulistanensis did not show any preference on either bait. Sex ratio was male biased for O. varia, while females were dominant for O. paulistanensis and T. (S.) occidua, and no differences were found for M. muehni. Bait's preference and sex ratio could not be estimated for the remaining species due to their low abundance.