Potential Side Effects of the Entomopathogenic Fungus Metarhizium anisopliae on the Egg Parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) Under Controlled Conditions.

The purpose was to evaluate the side effects of strains Metarhizium anisopliae (Metsch.) Sorokin sensu lato Unioeste 43 and M. anisopliae sensu stricto ESALQ 1641 on Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) under controlled conditions. A free-choice test for parasitism was performed, with the confinement of T. pretiosum females mated with cards (1 × 5 cm) containing age-standardized Anagasta kuehniella Zeller eggs, either sprayed with a fungal strain (109 conidia/ml) or 0.01% v/v Tween 80 (control). For the no-choice tests, T. pretiosum females mated were confined with cards sprayed with fungal strains before or after parasitism, and cards with fungal applications at different times. The number of parasitized eggs, percentage of emergence, longevity, egg-to-adult period, sex ratio, total and confirmed mortality by the fungus, and longevity of females that parasitized previously sprayed eggs, were assessed. Histological analysis of immature phases was also performed. The fungus was repellent to T. pretiosum in the free-choice test, while in the no-choice test, fungal applications before and after parasitism did not affect the number of eggs parasitized by T. pretiosum or the sex ratio of emerging adults. However, both strains affected adult emergence rates, the egg-to-adult period, and longevity. Overall, both M. anisopliae strains had minor effects on these biological parameters of T. pretiosum under controlled conditions. Hyphae were not detected in histological observations of immature stages of the parasitoid.

Field Assessments to Control the Lesser Mealworm (Coleoptera: Tenebrionidae) Using Diatomaceous Earth in Poultry Houses.

Control of the lesser mealworm (Alphitobius diaperinus Panzer, 1797 [Coleoptera: Tenebrionidae]) is usually conducted with chemical insecticides, which have limited efficacy as well as environmental and health risks. Diatomaceous earth (DE) is safe and effective in controlling many insects including lesser mealworm. However, little is known of DE efficacy against this pest. Thus, an assessment of DE was conducted for the first time in commercial broiler houses in Brazil, with the aim of developing a strategy for the use of DE in the control of this insect. The efficacy of DE was determinate to a minimum concentration, and the application was directed to the most infested sites. The DE applied to the entire poultry house (280 g/m2) was verified to control the insects. DE was also comparable to chemical treatments, with a reduction of 80% in the insect population. DE controlled the lesser mealworm and is recommended for application at a concentration of 280 g/m2 when applied to the surface of new poultry litter, before the first lot of birds is housed. Thereafter, DE should be reapplied before the housing of each lot of birds, in the same concentration, only in the housing area and under the feeders and near the walls and pillars. In addition to being a control strategy, DE can be an important tool in the management of lesser mealworm insecticide resistance.

Beauveria Bassiana Applied to Broiler Chicken Houses as Biocontrol of Alphitobius Diaperinus Panzer (Coleoptera: Tenebrionidae), an Avian Pathogens Vector

Beauveria bassiana is naturally found in broiler chicken houses, and has been shown to be active against the lesser mealworm, Alphitobius diaperinus. The effectiveness of soil application of B. bassiana in emulsifiable oil-type formulation (Unioeste 4 isolate) to control the lesser mealworm in commercial poultry house was evaluated. The fungus was applied to the dirt floor of poultry house at 4.2 × 109 conidia/m2 (treated aviary) and the insect population was assessed before and 96, 146 and 216 days after application (DAA). In the control aviary, no treatment was performed to control those insects. Molecular techniques were used to confirm the presence of the fungus in dead A. diaperinus. Significant treatment effects were observed, with 56% and 73% of insect population reduction on 96 and 146 DAA, respectively. However, on 216 DDA, insect population resumed to values close to those initially observed. In the control aviary, the population grew steadily, reaching almost 110% the initial population on 96 DAA, and close to 200% on 216 DDA. The results demonstrate the potential of the applied control strategy, even with a single application of the fungus; however, reapplications may be required after 3-6 months for more effective control.(AU)

Beauveria Bassiana Applied to Broiler Chicken Houses as Biocontrol of Alphitobius Diaperinus Panzer (Coleoptera: Tenebrionidae), an Avian Pathogens Vector

Beauveria bassiana is naturally found in broiler chicken houses, and has been shown to be active against the lesser mealworm, Alphitobius diaperinus. The effectiveness of soil application of B. bassiana in emulsifiable oil-type formulation (Unioeste 4 isolate) to control the lesser mealworm in commercial poultry house was evaluated. The fungus was applied to the dirt floor of poultry house at 4.2 × 109 conidia/m2 (treated aviary) and the insect population was assessed before and 96, 146 and 216 days after application (DAA). In the control aviary, no treatment was performed to control those insects. Molecular techniques were used to confirm the presence of the fungus in dead A. diaperinus. Significant treatment effects were observed, with 56% and 73% of insect population reduction on 96 and 146 DAA, respectively. However, on 216 DDA, insect population resumed to values close to those initially observed. In the control aviary, the population grew steadily, reaching almost 110% the initial population on 96 DAA, and close to 200% on 216 DDA. The results demonstrate the potential of the applied control strategy, even with a single application of the fungus; however, reapplications may be required after 3-6 months for more effective control.

Atividade inseticida de extratos vegetais e do óleo de nim sobre adultos de alphitobius diaperinus panzer (coleoptera, tenebrionidae)

ABSTRACT The use of insecticidal plants seems to be a promising method for insect control, however there are few studies in relation to their effect on Alphitobius diaperinus (Panzer). The present study was carried out to evaluate the insecticidal activity of plant extracts for the alternative control of this insect in poultry houses. Tests were made using ethanolic (E), dichlorometanic (D), hexanic (H) and aqueous (A) extracts from Annona muricata, Chenopodium ambrosioides, Eucalyptus grandis, Melia azedarach, Ocimum basilicum, Ruta graveolens andTagetes erecta, and a commercial oil from Azadirachta indica (Dalneem®). Extracts and oil were diluted at 10% and sprayed on the insects, kept in Petri dishes, and the control consisted of distilled water. The most effective treatments were: A. indica commercial oil (97.5%), extracts from R. graveolens (E) (61.3%), C. ambrosioides (H) (32.5%) and leaf extracts from M. azedarach (E and D) (both 26.3%). The direct application of the neem oil on the insect was also tested in comparison to its application on the surface with which the insect would be in contact;in this case the efficiency was higher when sprayed on the insects (100%) in relation to the contact with treated surface (40.9%). Comparing different concentrations of the neem oil sprayed on the insects, a direct relation between insecticidal activity and concentration was observed, although no effect was observed at the lowest concentration (0.1%). However, the neem oil did not present activity on the insects when applied in the poultry litter.

RESUMO A utilização de plantas inseticidas tem se mostrado uma ferramenta promissora para controle de insetos, contudo ainda há muito pouco no que diz respeito ao efeito sobre Alphitobius diaperinus (Panzer). Portanto, o objetivo do trabalho foi avaliar a atividade inseticida de extratos vegetais visando o controle desse inseto em aviários. Foram testados extratos etanólicos (E), diclorometânicos (D), hexânicos (H) e aquosos (A) de Annonamuricata, Chenopodiumambrosioides, Eucalyptus grandis, Melia azedarach, Ocimum basilicum, Ruta graveolens e Tagetes erecta, e um óleo comercial à base de nim, Azadirachta indica (Dalneem®). Os extratos e o óleo foram diluídos na concentração de 10% e pulverizados sobre os insetos, mantidos em placas de Petri. O controle recebeu aplicação de água destilada. Os tratamentos mais eficientes foram óleo comercial de A. indica (97,5%), extrato de R. graveolens (E) (61,3%), C. ambrosioides (H) (32,5%) e de folhas de M. azedarach (E e D) (ambos 26,3%). Comparou-se também a aplicação direta do óleo sobre o inseto e aplicação na superfície com a qual o inseto ficaria em contato, sendo maior a eficiência quando pulverizado sobre os insetos (100%) em relação ao contato com superfície tratada (40,9%). Comparando-se diferentes concentrações do óleo pulverizado nos insetos, observou-se relação direta entre atividade inseticida e concentração utilizada, não havendo efeito apenas na menor concentração (0,1%). Contudo, o óleo não apresentou atividade sobre os insetos quando aplicado na cama do aviário.

Eficiência da aplicação de inseticida químico no solo para o controle de alphitobius diaperinus panzer (coleoptera: tenebrionidae) em aviário de frango de corte

ABSTRACT Although the use of insecticides is the most common means to control the lesser mealworm ( Alphitobius diaperinus), irregular treatment causes insufficient control. Therefore, the present study was aimed to evaluate the effect of soil treatment with chemical insecticide on the lesser mealworm population. The experiment was carried out in a commercial poultry house, in Cascavel, state of Paraná, Brazil. Before application, in order to quantify beetle population, various Arends traps were placed in the poultry house litter for 6 months. After the poultry house was cleaned, the insecticide was applied (cypermethrin, chlorpyriphos and citronellal) on the soil (5 L of water solution/m2; 2.5 mL insecticide/L of water). Subsequently, the insect population was checked for 6 months. The results showed a mean of 775 larvae and 89 adults/trap before treatment and 166 larvae and 23 adults/traps afterward. In the soil, high larval and pupal mortality were observed, due to contact with the insecticide that infiltrated the soil on average 13 cm deep.

RESUMO Embora os inseticidas químicos sejam os mais utilizados no controle do cascudinho dos aviários (Alphitobius diaperinus), falhas no emprego levam ao insucesso do método. Assim, objetivou-se avaliar o efeito do tratamento do solo com inseticida químico sobre a população do cascudinho em aviário de frango de corte. O experimento foi realizado em um aviário comercial, em Cascavel, PR, acompanhando-se a população dos insetos por 6 meses previamente à aplicação, com armadilhas modificadas de Arends. No solo, a população foi monitorada pela retirada de amostras em três momentos: previamente à aplicação, logo após a ela e 3 meses após o tratamento. Após a retirada da cama, aplicou-se um inseticida comercial (cipermetrina, clorpirifós e citronelal) no solo do aviário (5 L de calda/m 2, 2,5 mL do produto/L de água), antes da colocação da nova cama e do alojamento do novo lote. A população dos insetos foi monitorada por igual período e com o mesmo tipo de armadilha. A média obtida antes do tratamento foi de 755 larvas e 89 adultos/armadilha. Após a aplicação, a média de larvas e adultos reduziu-se, para 166 e 23 indivíduos/armadilha, respectivamente. No solo, verificouse elevada mortalidade de larvas e pupas, devido ao contato com o produto que infiltrou, em média, 13 cm.

Técnicas para avaliação do efeito in vitro de fungicidas sobre bacillus thuringiensis var. kurstaki

ABSTRACT The aim of this study was to compare techniques for the invitro evaluation of the effect of fungicides on Bacillus thuringiensis var. kurstaki (Btk). The fungicides epoxiconazole, fentin hydroxide, azoxystrobin, tebuconazole, and carbendazim were tested at two concentrations, on cells and spores, in nutrient agar (NA) solid medium (SM), and in nutrient broth (NB) liquid medium (LM), with an evaluation also being made of their metabolization (MT) by Btk. For cells, the fungicides in NA were tested incorporated into the medium and on filterpaper disks. The evaluation consisted, respectively, of the number of CFU/mL and of the formation of an inhibition halo. For cells, the Bt+products + NB mixture was incubated in Erlenmeyer flasks (30 ± 2° C, 150rpm, 24h) and then was diluted and inoculated onto NA; the number of CFU/mL was evaluated. The MT and spore tests were performed in liquid medium (water). The effects of the products varied with their concentration, technique used, contact time, and developmental stage of the pathogen. The LM test is the most recommendable for evaluating the effect on cells. It was observed that most fungicides were compatible with cells, and only epoxiconazole and azoxystrobin were metabolized. Fentin hydroxide was the only fungicide incompatible with spores.

RESUMO Objetivou-se comparar técnicas para a avaliação in vitro do efeito de fungicidas sobre Bacillus thuringiensis var. kurstaki (Btk). Foram testados os fungicidas epoxiconazole, fentin hidróxido, azoxystrobin, tebuconazole e carbendazin em duas concentrações, sobre células e esporos, em ágar nutriente (AN)-sólido (MS) e caldo nutriente (CN)-líquido (ML), além da metabolização (MT) destes por Btk. Para células em AN, os fungicidas foram testados incorporados ao meio e em discos de papel-filtro. Avaliou-se, respectivamente, as UFC/mL e a formação de halo de inibição. Para células, a mistura Bt + produtos + CN foi incubada em erlemmeyers (30 ± 2° C, 150 rpm, 24h), e em seguida, diluida e inoculada em AN, avaliandose o número de UFC/mL. Os testes de MT e esporos foram realizados em líquido (água). O efeito dos produtos variou conforme a concentração, técnica, tempo de contato e fase/estágio do desenvolvimento do patógeno. O teste ML é o mais indicado para a avaliação do efeito em células, sendo observado que a maioria dos fungicidas mostrou-se compatível com as mesmas, e apenas epoxiconazole e azoxystrobin foram metabolizados. Fentin hidróxido foi o único incompatível com esporos.