Three new species of braconid wasps from Costa Rica are described here: Allorhogas crinitus reared from leaf galls on Protium panamense (Burseraceae), Allorhogas lacuna reared from galls on Melastomataceae and Allorhogas triopsis reared from fruit galls on Psychotria (Rubiaceae). These new species are diagnosed and compared with other species in the genus. These are the first records of an Allorhogas species associated with the plant families Burseraceae and Rubiaceae. It is the third association of Allorhogas with the family Melastomaceae.

The purification and characterization of rhodanese, an enzyme that catalyses the detoxification of cyanide, from the gut of the variegated grasshopper (Zonocerus variegatus L.) were carried out to understand the biochemical basis of the survival of this grasshopper living on cyanogenic plants such as cassava. All experiments, including enzyme assay, were carried out at room temperature and all buffers contained 10 mm sodium thiosulphate to stabilize the enzyme. Grasshoppers were caught alive from a cassava farm within the locality and kept frozen until analysis. Each grasshopper was dissected and the gut was removed quickly. Approximately 102 g of the gut were homogenized in three volumes of 0.1 m acetate glycine buffer (pH 7.8) containing ɛ-amino-n-caproic acid. The supernatant was collected by centrifugation at 12,000 rpm, for 30 min at 40 °C. The enzyme was purified to homogeneity by a combination of procedures such as ammonium sulphate precipitation, ion-exchange chromatography (CM-Sephadex and DEAE-Sephadex), gel filtration (Sephadex G-75) and Agarose-Blue affinity chromatography. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) and non-SDS–PAGE were used to ascertain the purity of the enzyme. The native and subunit molecular weights of the enzyme were determined by gel filtration on a Bio-Gel P-200 column and SDS–PAGE, respectively. Kinetic parameters were determined by using varying concentrations of one of the substrates at a fixed concentration of the other, and vice versa. Furthermore, the effects of temperature, pH and cations on the activity of the enzyme were investigated. The purified enzyme had a specific activity of 51.7 μmol thiocyanate formed/ml/min/mg protein (U/mg protein) with a yield of about 29%. The apparent molecular weight of the enzyme estimated by Sephadex G-75 gel filtration was 35,400 ± 482 Da and its subunit molecular weight determined by SDS–PAGE was 33,000 ± 212 Da. The Km values of KCN and Na2S2O3 were found to be 29.63 ± 02.87 and 26 ± 03.04 mm, respectively. An optimum pH and temperature of 7.0 and 35 °C, respectively, were obtained for the enzyme. The results of enzyme inhibition showed that the activity of the enzyme was not affected by NH4Cl, MgCl2, CoCl2, CaCl2, MnCl2, NiCl2 and SnCl2, but inhibited by ZnCl2 and BaCl2. In conclusion, these results suggest that the survival of Z. variegatus depends on the presence of the enzyme rhodanese, which shows high activity and has suitable kinetic properties in the gut of the grasshopper that feeds mainly on cassava leaves which are cyanogenic.

The present study surveyed adult caddisflies in Ile-Ife to identify the species that contribute to the fauna of freshwater ecosystems of this area and to determine their seasonal abundance. Adult caddisflies were collected between June 2009 and November 2010 from eight sampling stations established at different locations using an improvised light trap. A total of 754 adult caddisflies that were collected represent six species in six genera and three families. The species identified are Dipseudopsis conformis Navas, 1931, Polymorphanisussimilis Ulmer, 1912, Aethaloptera dispar Brauer, 1875, Ceraclea njalaensis (Mosely, 1933), Pseudoneureclipsis mlangensis Mosely, 1939 and Cheumatopsyche digitata (Mosely, 1935). The Hydropsychidae was represented by three species belonging to three genera. The hydropsychid C. digitata was the dominant and most widely distributed species, occurring at all sampling stations with the highest frequency of occurrence (51%). On the other hand, P. mlangensis (Dipseudopsidae) was the least abundant with the lowest frequency of occurrence (0.8%).

The demographic attributes of the parthenium beetle Zygogramma bicolorata Pallister were studied using Parthenium hysterophorus L. as food under different abiotic and biotic variables. Intrinsic and finite rates of increase were highest with the shortest mean generation and doubling times when Z. bicolorata was fed on inflorescences followed by the leaves and stems of P. hysterophorus. Temperature significantly affected the demographic parameters. The net reproductive rate was highest at 27 °C and lowest at 35 °C. Different photoperiodic exposures altered the demographic attributes of the beetles with long-day exposure (14L:10D) resulting in optimal values compared with other photoperiodic exposures. Continuous darkness (0L:24D) and continuous light (24L:0D) suboptimally affected the demographic attributes of the beetles. In response to the light of different wavelengths, the net reproductive rate, and intrinsic and finite rates of increase were significantly higher when the beetles were reared under a broad spectrum of white light followed by those under ~570 nm (yellow), ~475 nm (blue) and ~650 nm (red). Information gained in this study may be helpful in the mass multiplication of Z. bicolorata, and thereby strengthening the biocontrol of parthenium weed.

The present study aimed to determine the selectivity of the pyrethroid lambdacyhalothrin on arthropod natural enemy populations in irrigated rice fields in Rio Grande do Sul, Brazil. The study was conducted at three sites: districts of Cachoeira do Sul, Eldorado do Sul and Capivari do Sul during the crop years of 2007/2008 and 2008/2009. Each site consisted of two subareas divided into four plots. One of the subareas received a spray application of 150 ml/ha of lambdacyhalothrin CS 50, while the other subarea was untreated. Arthropods were collected at 2, 15, 30 and 45 days after the application of the insecticide to assess its impact on natural enemy populations. The results indicated consistent differences in natural enemy populations between the treated and untreated areas, especially within the first 2 weeks after the application of the insecticide. Principal components analysis together with χ2 analysis revealed differences in the populations of Tetragnathidae, Anyphaenidae, Araneidae, Coccinellidae, Phytoseiidae and Coenagrionidae between the treated and untreated areas. This study indicated the existence of a great diversity of arthropod natural enemies in irrigated rice fields in a subtropical environment similar to that reported previously from rice fields in tropical environments. In addition, lambdacyhalothrin was shown to be a rapid acting insecticide, with a significant initial decrease in natural enemy populations followed by a rapid recovery beginning at 2 weeks after the application of the insecticide. Especially disconcerting is the severe impact of the insecticide on Phytoseiidae and Araneidae, which are considered key natural enemies for the management of rice pests in southern Brazil.

Maize (Zea mays L.) is Kenya's most important staple crop with annual production fluctuating between 2.6 and 3.1 million tons in 2012 and 2011, respectively. However, frequent food shortages are still experienced in the country. These have been attributed to pests and diseases and post-harvest constraints. The dominant post-harvest pest of maize is Sitophilus zeamais (Motsch.), which causes losses between 10 and 20% of harvested grain. The objective of this study was to establish the repellent activity of essential oils extracted from selected eucalyptus species against S. zeamais. Essential oils were extracted from the fresh leaves of Eucalyptus saligna Sm., Eucalyptus globulus Labill., Eucalyptus camaldulensis Schlecht and Eucalyptus citriodora Hook by steam distillation using a Clevenger-type apparatus. A repellency bioassay, with varying concentrations (0.002, 0.02, 0.2 and 2 μl/μl) of the oils, was carried out against the maize weevils using a Y-shaped olfactometer. Repeated measures of analysis of variance were applied to test the different doses and repellents, and their interactions against S. zeamais. The essential oils of E. camaldulensis and E. citriodora presented better repellent activity at the 2 μl/μl concentration (74.35 and 69.15%, respectively) followed by those of E. globulus (53.68%) and E. saligna (40.5%). Gas chromatography (GC)–mass spectrometry and GC co-injections with authentic samples showed the presence of the following major constituents in: (i) E. camaldulensis oil: 1,8-cineole (18.9%), α-cardinol (6.4%) and β-phellandrene (2.6%); (ii) E. citriodora oil: 1,8-cineole (11.2%), β-pinene (3.2%) and 4-terpineol (3.1%); and (iii) E. globulus oil: 1,8-cineol (17.2%), α-pinene (7.1%) and spathulenol (6.5%). The results provide a scientific rationale for the use of eucalyptus oils in the protection of maize against weevils.

The storability of five new different formulations of Metarhizium acridum (two oil, one paste, one semi-solid and one powder) was investigated under ambient and low temperatures. Fourth-instar nymphs of the desert locust Schistocerca gregaria (Forskål) were used to evaluate their virulence. Under ambient conditions (23–38°C), all the formulations maintained acceptable viability (66.1 ± 2.30 to 71.8 ± 0.88% germination) after 6 months of storage. After 10 months, only conidia from the powder formulation remained viable. In contrast, samples of the formulations kept under low temperatures ( − 1.2 to 15°C) did not show significant loss of viability after 30 months of storage despite repeated power cuts, lasting sometimes several days. During this period, M. acridum conidia remained virulent to nymphs with 100% mortality 5 to 7 days after the treatment. These results show that all the formulations have greater stability when stored under low and even fluctuant temperature changes. Under ambient conditions, the formulations could remain effective for at least 6 months of storage.

Trapping of adult red palm weevil (RPW) Rhynchophorus ferrugineus Olivier using food-baited pheromone traps is a major component of the integrated pest management strategy currently adopted against the RPW in the United Arab Emirates (UAE). Field trials were carried out in RPW-infested date plantations of Al-Rahba, Abu Dhabi, UAE from January to December 2010 to ascertain the combined influence of ethyl acetate (EA) and trap colours on weevil captures in RPW pheromone traps. Weevil captures were recorded throughout the experimental period with a sex ratio (male:female) of 1:2.2 and capture rates of 25.13 and 15.14 weevils/trap/month in traps with and without EA, respectively. Furthermore, treatments with black-coloured traps recorded significantly higher weevil captures.