Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), a potential biological control agent for the submerged aquatic weed, Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae)

The leaf-mining fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), was investigated in its native range in South Africa, to determine its potential as a biological control agent for Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae), an invasive submerged macrophyte that is weedy in many parts of the world. The fly was found throughout the indigenous range of the plant in South Africa. High larval abundance was recorded at field sites with nearly all L. major shoots sampled ontaining larvae, with densities of up to 10 larvae per shoot. Adults laid batches of up to 15 eggs, usually on the abaxial sides of L. major leaves. The larvae mined internally, leaving the epidermal tissues of the upper and lower leaves intact. The larvae underwent three instars which took an average of 24 days and pupated within the leaf tissue, from which the adults emerged. Impact studies in the laboratory showed that H. lagarosiphon larval feeding significantly restricted the formation of L. major side branches. Based on its biology and damage caused to the plant, Hydrellia lagarosiphon could be considered as a useful biological control candidate for L. major in countries where the plant is invasive

Resposta de cultivares de trigo à infestação do pulgão Rhopalosiphum padi Wheat cultivars response to Rhopalosiphum padi infestation

O objetivo deste trabalho foi avaliar a resposta de oito cultivares comerciais de trigo (BRS 194, BRS 208, BRS Camboatá, BRS Guabiju, BRS Guamirim, BRS Louro, BRS Timbaúva e BRS Umbu) à infestação do pulgão Rhopalosiphum padi (Hemiptera: Aphididae). O experimento foi realizado na Embrapa Trigo, em telado, em blocos ao acaso, com oito tratamentos e seis repetições, dispostos em parcelas subdivididas. As parcelas principais receberam os tratamentos com e sem infestação de pulgões, e as subparcelas foram compostas pelas cultivares. A infestação com os pulgões (20 adultos ápteros por planta) foi realizada aos 12 dias após a emergência das plantas, quando se encontravam no início do afilhamento, e foi mantida durante 15 dias. As cultivares avaliadas responderam diferentemente à infestação do pulgão R. padi. A cultivar BRS Timbaúva é a mais resistente, e as cultivares BRS Umbu e BRS Guabiju são as mais suscetíveis ao pulgão, quanto ao crescimento e a capacidade produtiva de plantas.<br>The objective of this work was to evaluate the response of eight commercial wheat cultivars (BRS 194, BRS 208, BRS Camboatá, BRS Guabiju, BRS Guamirim, BRS Louro, BRS Timbaúva e BRS Umbu) to the infestation of Rhopalosiphum padi (Hemiptera: Aphididae). The experiment was carried out at Embrapa Trigo, in greenhouse conditions. It was used the randomized block design, in a split-plot array, with eight treatments and six replicates. The plots received treatments with or without infestation with aphids, and the split-plots were composed by the cultivars. The infestation with aphids (20 wingless adults per plant) was done 12 days after plant emergency, in the beginning of tillering, and was kept for 15 days. The cultivars responded differently to the infestation with aphids. BRS Timbaúva cultivar is more resistant, and BRS Umbu and BRS Guabiju cultivars are more susceptible to R. padi, concerning plant growth and plant yield

Intraguild predation of the aphid pathogenic fungus Pandora neoaphidis by the invasive coccinellid Harmonia axyridis

1. The ladybird Harmonia axyridis is an invasive alien species in many countries and is predicted to have a negative impact on native biodiversity. However, little is known on the status of this aphidophage as an intraguild predator of natural enemies of aphids such as insect-pathogenic fungi. 2. The study assessed the predation of the aphid-specific pathogenic fungus Pandora neoaphidis by adult and larval H. axyridis collected from the U.K. (an invasive population) and Japan (a native population) relative to that of the ladybird Coccinella septempunctata (native to the U.K.) and the non-U.K. C. septempunctata subspecies brucki that were either starved or unstarved. 3. Overall, predation of uninfected aphids was greater than infected aphids and, when given a choice, a preference for aphids was shown. However, the extent of this preference was dependent on the species and origin of the coccinellid. Harmonia axyridis (U.K.) consumed the greatest quantity of fungal cadavers and showed little preference for uninfected aphids over infected aphids. In contrast, C. septempunctata rarely consumed infected aphids. Life stage had no direct effects on predation but starved coccinellids consumed more uninfected aphids than infected aphids. 4. Harmonia axyridis (U.K.) is a stronger intraguild predator of P. neoaphidis cadavers than the native species C. septempunctata and, therefore, may have an impact on the occurrence and persistence of P. neoaphidis . The differences in intraguild predation by H. axyridis collected in the U.K. and those from Japan suggests that individuals that invaded the U.K. could have a different genetic profile to those in its native range

Capture of hypothenemus hampei ferrari (coleoptera, scolytidae) in response to trap characteristics Captura da broca-do-café, hypothenemus hampei (coleoptera, scolytidae), em resposta a características de armadilhas

Traps lured with semiochemical have been proposed to manage the coffee berry borer, coffee planting is however made under several environmental conditions that may affect the efficacy of traps. Several trap designs and variations were proposed and, therefore, a series of field experiments was carried out to capture coffee berry bores in traps disposed in a low density coffee plantations in the Northern part of the State of Paraná, Brazil. Traps were composed of plastic bottles (2 L) with a window (13 &times; 18 cm). Ethanol (E), Methanol (M) and coffee oil alone did not improve the capture when transparent traps with a 2 mm hole in the vial dispenser were used; traps lured with E : M mixtures (1:1, 1:2, 1:3) caught similar and higher number of insects than the control. There was synergism with the mixing of E and M; the addition of coffee oil to the mixtures did not improve the capture. Trap lured with E : M (1:1) mixtures at 342, 400, 428 and 710 mg caught similar numbers of insects. Transparent green trap, transparent trap and red trap lured with 642 mg day-1 of the E + M (1:1) mixture caught similar numbers of insects. Interaction between colors (transparent green, transparent and red) and semiochemical release rates (540, 720 and 1100 mg day-1) was observed. Transparent green trap, when lured with 720 mg day-1 of the 1 : 1 E : M mixture caught 2.3 and 4.4 times more insects than 540 and 1100 mg day-1; and caught 3.2 times more insects than transparent and red trap at the same release rates.<br>Armadilhas iscadas com semioquímicos têm sido propostas para manejo da broca-do-café. O cafeeiro é cultivado em condições ambientais diversas que podem afetar a eficiência das armadilhas. Vários modelos de armadilha e variações nos modelos são utilizados. Uma série de experimentos de campo objetivou avaliar capturas da broca-do-café em armadilhas numa lavoura de café semi-adensado no Norte do Paraná. Uma garrafa plástica (2 L) com uma abertura (13 &times; 18 cm) constituiu a armadilha. O etanol (E), metanol (M) e óleo de café, sozinhos, não incrementaram as capturas quando se utilizaram armadilhas transparentes com um frasco difusor com furo de 2 mm; armadilhas iscadas com as misturas 1 : 1, 1 : 2 e 1 : 3 de etanol (E) + metanol (M) capturaram quantidades similares e superiores à testemunha; sinergismo ocorreu pela mistura de etanol e metanol; a adição do óleo de café às misturas não incrementou as capturas. Armadilhas com taxas de liberação da mistura E:M (1:1) de 342, 400, 428 e 710 mg dia-1 capturaram quantidades similares. Armadilhas verdes transparentes, transparentes e vermelhas, iscadas com E:M (1:1) (642 mg dia-1) capturaram quantidades similares. Foi observada interação entre as cores (verde transparente, transparente, vermelha) e taxas de liberação dos semioquímicos (540, 720 e 1100 mg dia-1). Armadilhas verdes transparentes, quando iscadas com doses de 720 mg dia-1 da mistura 1:1 de E:M, capturaram 2,3 e 4,4 mais insetos do que 540 e 1100 mg dia-1; e capturaram 3,2 mais insetos do que armadilhas transparentes e vermelhas

Trap attributes influencing capture of Diabrotica speciosa (Coleoptera: Chrysomelidae) on common bean fields Atributos da armadilha influenciam captura de Diabrotica speciosa (Coleoptera: Chrysomelidae) em feijoeiro

Refinements in trap characteristics may improve ability to monitor and mass-trap beetles. Field assays were conducted in common bean fields to assess responses of Diabrotica speciosa (Germar) to some trap characteristics. Golden yellow plastic cups (750 mL) traps caught more D. speciosa females and males than did clear traps. Carrot slices in Petri dishes baited with Lagenaria vulagaris L. powder (cucurbitacin source - 0.28%) caught more beetles than did dishes with carrot alone. Dispensers for the floral volatile attractant 1,4-dimethoxybenze were also compared. Rubber septa dispenser attracted more beetles than did control (dental wicks saturated with acetone). Captures on dental wick, starch matrix and feminine pad dispensers were intermediate and did not differ from those on rubber septa and unbaited controls. Perforated bottle traps (2000 mL), when baited with the floral attractant, caught more beetles than did window bottle traps (both traps contained L. vulgaris powder) in most assessments done from two to ten days after trap placement in the field. Traps with the insecticide carbaryl captured more beetles than did traps without it, 2-4 and 8-10 days after trap placement in the field, but not in the remaining periods (0-2, 4-6 and 6-8 days). Traps baited with 1,4-dimethoxybenzene captured more beetles than did the unbaited ones in all assessments (each other day from two to ten days after trap placement in the field). Finally, similar amounts of beetles were captured using plastic bottle traps (2000 mL): perforated, window (both with cucurbitacin) and sticky (without cucurbitacin) traps, when were baited with the floral attractant.<br>Refinamentos em caraterísticas de armadilhas podem incrementar sua habilidade para monitorar e capturar em massa os insetos. Experimentos foram conduzidos em lavoura de feijoeiro para verificar as respostas de Diabrotica speciosa (Germar) a algumas características de armadilhas. Armadilhas de copos plástico (750 mL) amarelo ouro capturaram mais fêmeas e machos de D. speciosa do que transparentes. Placas de Petri com pedaços de cenoura, com pó seco de purungo, Lagenaria vulgaris L. (fonte de cucurbitacina - 0,28%) capturaram mais insetos do que placas com somente cenoura. Liberadores para o atraente floral 1,4-dimetoxibenzeno foram também comparados. Liberador de septo de borracha atraiu mais insetos do que o controle (flocos dentais saturados com acetona). Capturas nos tratamentos com liberadores de floco dental, matriz borato e absorvente higiênico foram intermediárias mas não diferiram da testemunha e septo. Modelo de armadilha de garrafa (2000 mL) furada capturou mais insetos do que armadilha vazada ("janelas") (ambas contendo pó seco de purungo) na maioria das avaliações, dos dois até os dez dias após a instalação das armadilhas no campo. Armadilhas com inseticida carbaryl capturaram mais insetos do que armadilhas sem, nos intervalos de 2-4 e 9-10 dias após a instalação das armadilhas no campo. Nos períodos restantes (0-2, 4-6- e 6-8 dias), diferenças não foram detectadas. Armadilhas com 1,4-dimetoxibenzeno capturaram mais insetos do que armadilhas sem o volátil (avaliações a cada dois dias dos dois aos dez dias após a instalação no campo). Finalmente, quantidades similares de insetos foram capturadas usando armadilhas de garrafa pet (2000 mL): vazadas ("janelas"), furadas (ambas com cucurbitacina) e adesivas quando estas foram iscadas com o atraente floral