Michele Potrich

Selectivity of Beauveria bassiana and Metarhizium anisopliae to Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae)

Trichogramma pretiosum Riley and the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae are efficient biological control agents and are thought to be used jointly. In here, we investigated if these entomopathogens could have any side-effects on T. pretiosum. Therefore, 1 x 8 cards containing sterilized eggs of Anagasta kuehniella (Zeller) that were sprayed with 0.2 ml of B. bassiana or M. anisopliae (1.0 x 10(9) conidia/ml) were offered to a T. pretiosum female for 24h (30 cards/fungus = 30 replicates). Afterwards, females were isolated in glass tubes. The control group was sprayed with sterile distillated water + Tween 80 (0.01%). In addition, 60 cards with sterilized eggs of A. kuehniella were submitted to parasitism by females of T. pretiosum for 24h. Of these cards, 30 were sprayed with B. bassiana or M. anisopliae and 30 with distillated water + Tween 80 (0.01%), and observed daily until parasitoid emergence. Metarhizium anisopliae decreased parasitoid emergence and caused confirmed mortality. Therefore, field and semi-field experiments should be conducted for a final assessment of the side-effects of these entomopathogens on Trichogramma as a ways to develop a control strategy in which both can be used.

Eficiência de Beauveria bassiana Vuill. e Isaria sp. para o controle de Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae).

The search for information to control Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in Eucalyptus , focus on the use of biological control techniques, including the use of entomopathogenic fungi. The objective of this study was evaluated the pathogenicity of Beauveria bassiana and Isaria sp. on Thaumastocoris peregrinus, under laboratory conditions. To do so, we tested four isolates of Beauveria bassiana and one isolate of Isaria sp. concentration of 1.0 × 10 8 conidia mL -1 . The solution was applied on leaves of Eucalyptus camaldulensis , provided as food for the insect substrates, and maintained in glass bottles sealed with plastic film in a climatic chamber (26 ± 2 ° C, 14 h photoperiod and U.R. 70 ± 10%). Four replicates were performed (bottles) for isolated with 13 adult insects per bottle. Each bottle received 13 adult insects. Evaluations were performed until the fifth day after application. The dead insects were placed in humid chamber for confirmation of death by pathogen. All isolates were pathogenic to Thaumastocoris peregrinus . The confirmed mortality ranged between 37% and 80.1% for Beauveria bassiana , and was 87% for Isaria sp. after 10 days of application. The highest mean percentage of daily mortality (39.9%) occurred on the fourth day after contact with the substrate insect spray. The isolates of Beauveria bassiana and Isaria sp. evaluated presented potential to control Thaumastocoris peregrinus under laboratory conditions.

Bacillus thuringiensis Berliner e Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae) sob ação de extratos vegetais

O objetivo deste trabalho foi avaliar o efeito de extratos vegetais aquosos de jambolao, Syzygium cumini (L.) Skeels (Myrtaceae), mamona, Ricinus communis (L.) (Euphorbiaceae), uva-do-japao, Hovenia dulcis (Thumberg) (Rhamnaceae) e urucum (Bixa orellana (L.) (Bixaceae), na concentracao de 10%, sobre Bacillus thuringiensis subesp. kurstaki(Btk) e sobre Anticarsia gemmatalis (Lepidoptera: Erebidae) e a associacao destes sobre A. gemmatalis, em condicoes de laboratorio. Os tratamentos constaram dos extratos aquosos e Btk isoladamente e a mistura de cada extrato com Btk. Estes foram incubados em agitador horizontal (30 ± 2°C, 150 rpm por 2 h) e, em seguida, aplicados sobre cubos de dieta artificial para A. gemmatalis, em placas de Petri. Como testemunha utilizou-se agua destilada esterilizada. Cada tratamento constou de 4 placas de Petri (repeticao), com 25 lagartas de segundo instar cada. Estas foram acondicionadas em câmara climatizada (27 ± 2°C umidade relativa 70 ± 10% e fotofase 14 h), avaliando-se a mortalidade apos 24, 48 e 72 h. Tambem foram avaliados o percentual de empupamento e o peso das pupas dos insetos sobreviventes. Nenhum dos extratos apresentou efeito inseticida para A. gemmatalis e efeito negativo para os cristais de Btk. A mortalidade acumulada causada pelos extratos de uva-do-japao, jambolao, urucum e mamona foram, respectivamente, de 54,73; 46,09; 47,19 e 65,73%; diferindo significativamente da testemunha (95,74%). O peso medio das pupas nao diferiu significativamente entre os tratamentos. A associacao dos extratos de uva-do-japao, colorau e mamona com Btk provocou mortalidade acumulada de 100% em A. gemmatalis.

Oviposition Behaviour of Cleruchoides noackae (Hymenoptera: Mymaridae) in the Laboratory

Thaumastocoris peregrinus has become a major pest in eucalyptus. The most promising control method is the use of the parasitoid, Cleruchoides noackae, but little is known about its biology. Thus, the aim of this study was to investigate the oviposition behaviour of C. noackae in T. peregrinus eggs laid on strips of paper towel in the laboratory. 12 copulated females were placed in a plastic petri dish containing five T. peregrinus eggs and their behaviour was observed for 30 min/female. Several behavioural events were performed: searching for the host, host evaluation, insertion of the ovipositor, internal recognition and oviposition. Time elapsed between the insertion of the ovipositor and its removal varied from two to ten minutes. Learning more about C. noackae biology is very important to understand the dynamics between the parasitoid and its host, aiming at its biological control.

OCORRÊNCIA ESPONTÂNEA DE Beauveria bassiana (Bals. Criv.) Vuill. 1912 (ASCOMYCETES: CLAVICIPITACEAE) SOBRE Thaumastocoris peregrinus (HEMIPTERA: THAUMASTOCORIDAE)

Exemplars of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), insect pest of the genus Eucalyptus , were found dead in the Eucalyptus grandis plantation in the city of Realeza, the southwest region of the state of Parana, Brazil, with white mycelial growth on the surface of the body. Isolation procedures were performed (in Potato-Dextrose-Agar culture) and identification of the pathogen, whereas the ratio between the microorganism and the insect has been established by Kochs postulate. The fungus through standard procedures, was identified as Beauveria bassiana. In the laboratory testing pathogenicity were performed and caused mortality confirmed in 72.2% of the insects at the concentration of 1.0 x 10 8 conidia.mL -1 after six days inoculation. Studies on the selection of isolates should be performed and justified by the growing demand of the forest sector in search of control strategies for this insect pest. Thus, was verified that Beauveria bassiana naturally infects Thaumastocoris peregrinus, occurring spontaneously in the Parana state.

Produtos Alternativos para Controle de Thaumastocoris peregrinus e Indução de Resistência em Plantas

This study aimed to evaluate the effect of alternative insecticide on Thaumastocoris peregrinus, as well as the potential to act in the resistance induction process in plants. Leaves of Eucalyptus camaldulensis were immersed in the solution of Orobor®, Topneem®, Rotenat®, Rotenat CE®, Baicao®, Compostonat®, Pironat®, Assist®, garlic extract and bordeaux mixture. They were subsequently transferred to tubes containing 10 adults of T. peregrinus, assessing daily the number of dead insects. The products with insecticidal effect were tested for their potential to induce resistance, evaluating the synthesis of the phytoalexin glyceollin (pterocarpanoide) and phenylpropanoids route activation in soybean cotyledons by the enzyme phenylalanine ammonia-lyase. We used water as control and chitosan (1%) as an inductor of reference. Rotenat®, Compostonat®, Rotenat CE® and Topneem® showed insecticidal effect while Rotenat CE® and Topneem® showed potential as resistance inducers, expressing significant amounts of phytoalexins and activity of PAL (phenylalanine ammonia-lyase).

Seletividade de produtos naturais comerciais a Trichogramma pretiosum (Riley, 1879) (Hymenoptera: Trichogrammatidae)

The selectivity of natural products to parasitoids is not well known. Thus, the objective of this work was to evaluate the selectivity of this commercial natural products to Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). The products used in the experiment were the following: Baicao®, Orobor® and Topneem® at doses recommended by the manufacturers and were sprayed on cards containing sterilized eggs of Anagasta kuehniella Zeller (Lepidoptera: Pyralidae). For the free-choice test, a T. pretiosumfemale was confined with two cards, one of them was sprayed with the natural products and the other was considered control, evaluating the percentage of parasitism. The no-choice test consisted in spraying treatments on cards previously or subsequently to parasitism. The number of parasitized eggs, percentage of emergence and longevity of adults were evaluated in both tests. Topneem® and Baicao® showed increase in parasitism of T. pretiosum in the free-choice test. Baicao® sprayed previously on cards containing eggs of A. kuehniellahad a negative effect on the emergency of T. pretiosum in the no-choice test. A reduction in the number of parasitizedeggs was found when Baicao® was sprayed previously in the parasitism treatment. Orobor® was selective to T. pretiosum in the experiment conditions and it did not affect negatively the parameters evaluated. Baicao® was not selective to T. pretiosum, it affected negatively most of the parameters evaluated, and classified as slightly harmful for toxicity to T. pretiosum adults under laboratory conditions.

Métodos físicos e cal hidratada para manejo do cascudinho dos aviários

The stability of in the modern poultry industry has been favored the proliferation of insect pests. In this scenario, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae), commonly known as lesser mealworm, emerges as major cosmopolitan insect infesting poultry litter. In this sense, the objective of this study was to evaluate the factors hydrated lime, temperature and humidity in the poultry litter on the A. diaperinus mortality under laboratory conditions. Laboratory bioassays were performed, simulating the poultry environment with litter in each experimental unit, with the addition of adults and larvae of A. diaperinus. The response variable was mortality at seven and 10 days after installation of the experiments. The addition of hydrated lime in the poultry litter at a dosage of 400g m-² promoted partial mortality of the adult population (35.62%±2,74) and larvae (45.62%±1,75) of A. diaperinus. The moisture in the litter, regardless of percentage, did not cause significant mortality of adults of A. diaperinus. The temperature in the litter at 45°C caused total mortality of adults and larvae of A. diaperinus at the conditions studied.

Ação repelente, inseticida e fagoinibidora de extratos de pimenta dedo-de-moça sobre o gorgulho do milho

The objective of this study was to evaluate thee repellent, insecticide and anti-feeding effect of red pepper Capsicum baccatum (Willd.) Eshb. (Solanaceae) extracts on the maize weevil Sitophillus zeamais (Coleoptera: Curculionidae). The determination of the repellent effect of plant extracts was assessed using four arenas/replicates in which the extracts were added at concentrations of 0, 2.5, 5, 10 and 20% and 140 insects; and 24 hours after, we performed the counting of insects. For the insecticidal activity, in plastic containers, 1 mL of the extract was applied, at the concentrations previously mentioned, on adult insects; and after stirring for 10 seconds they were transferred to Petri dishes, using four replicates of 20 insects each. Assessment of mortality was performed daily for ten days. To test the anti-feeding activity, insects evaluated for insecticidal activity were weighed on an analytical balance, four insects per replicate. It was found that the aqueous extracts of seeds of pepper had repellent activity at a concentration of 20%; and the insecticide activity was independent of concentration. The correlative effect was obtained with fruit alcoholic extracts, which showed insecticidal and anti-feeding activity at a concentration of 20%. The use of red pepper plant extracts could be an alternative to control the maize weevil.

Registro de Thaumastocoris peregrinus Carpintero e Dellapé na Região Sudoeste do Paraná

In June 2012, the occurrence of bronze bug of eucalyptus, Thaumastocoris peregrinus, was recorded in the southwest region of Parana state, attacking trees of Eucalyptus camaldulensis Dehn (Myrtaceae). The occurrence was recorded in the municipality of Realeza (SAD 69 Coordinates UTM: 245000 E; 7153682 S).