Compatibility between the predators Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) and Chrysoperla externa (Neuroptera: Chrysopidae) in the control of Planococcus citri (Hemiptera: Pseudococcidae) associated with rose crop

ABSTRACT Rose crops are attacked by many pests, including mealybugs. Although Planoccocus citri is not registered as a main pest of roses in Brazil, it is an increasing problem on roses inside greenhouses. Chrysoperla externa and Cryptolaemus montrouzieri are options against P. citri and other pests on roses, however using two predators in biological control programs may face problems like intraguild predation. This work aimed to assess the consumption of 1st instar nymphs and adult females of P. citri by adults of C. montrouzieri and 3rd instar larvae of C. externa, as well as the interaction between these predators when confined together. The following treatments were performed with ten replications in a completely randomized design: 1 - C. externa + 200 nymphs of P. citri; 2 - C. externa + 10 adults of P. citri; 3 - C. montrouzieri + 500 nymphs of P. citri; 4 - C. montrouzieri + 15 adults of P. citri. Each replication was set on rose leaflets inside a Petri dish (9cm Ø). Intraguild interaction was assessed by releasing both predators inside dishes containing 700 nymphs of P. citri. Before the releases, predators stayed 24 hours without food. We evaluated the prey consumption and intraguild predation for three hours. C. externa consumed significantly less (85,4±2,99) nymphs than did C. montrouzieri (387,0±3,02). There was no difference in adult mealybugs consumed, with an average of 1,85±0,19. No intraguild predation was observed, and an increase of 11,8% in consumption was observed when predators were released together compared to the scenario of no competition.

Orchidists' profile, management and perception of the main pests in orchid cultivation

This study investigated the profile of orchidists, their cultivation practices, and their knowledge about pests in orchid cultivation in the state of Bahia. There were applied 74 questionnaires to producers (amateurs and commercials) in 23 municipalities. The data were submitted to univariate statistics using the chi-square test, the Mann­Whitney U-test and the Kruskal­Wallis H-test. The survey shows that orchid cultivation is mostly practiced by women (67.6%) and those with higher education (48.7%). Most respondents were amateurs (87.8%). Insects (39.9%) and diseases (32.5%) were the main organisms associated with phytosanitary problems. The presence of insects was reported to occur mainly in the leaves (47%), mainly mealybugs (46.3%). Correspondence was significant between commercial and amateur groups according to the pairwise Mann­Whitney U-test(1) = 370.04 and p < 0.01. The Kruskal­Wallis H-test(27) = 924.78 and p < 0.01 discriminated categories between the groups. Despite the growing interest in orchid cultivation in the state of Bahia, most orchidists are amateurs. The study warns about the risk of pest dispersion between crops since exchanging plants and purchasing specimens in open markets are common practices.

Ocorrência natural de Beauveria bassiana (Bals. ) Vuill. (Moniliales: Moniliaceae) e patogenicidade sobre Protortonia navesi Fonseca (Hemiptera: Monophlebiidae) na cultura da mandioca, em Marechal Cândido Rondon, Paraná / Natural occurrence of Beauveria bassiana (Bals. ) Vuill. (Moniliales: Moniliaceae) and pathogenicity on Protortonia navesi Fonseca (Hemiptera: Monophlebiidae) in cassava plantation, in Marechal Cândido Rondon, Paraná

O objetivo deste estudo foi registrar a primeira ocorrência natural e patogenicidade da associação entre Beauveria bassiana e Protortonia navesi na cultura da mandioca. Para isso, ninfas e adultos de P. navesi infectados foram coletados em amostragens realizadas quinzenalmente, na área do Instituto Agronômico do Paraná, em Marechal Cândido Rondon, de janeiro a dezembro de 2012. Amostras foram analisadas e, utilizando-se meio de cultura seletivo de aveia, foi isolado o fungo a partir dos cadáveres, sendo identificado como Beauveria bassiana (Bals.) Vuill., armazenado na Coleção de Fungos Entomopatogênicos do Laboratório de Biotecnologia Agrícola, sob o código Unioeste 78. Para comprovar sua patogenicidade, foi adotado o postulado de Koch, aplicando-se o fungo (10 9 conídios/mL) sobre ninfas e adultos de P. navesi obtidos da criação de laboratório. Após 10 dias de incubação, verificou-se 18% de mortalidade confirmada, sendo considerada baixa a atividade sobre a cochonilha P navesi.(AU)

The objective of this study was to record the first natural occurrence and pathogenicity of the association between Beauveria bassiana and Protortonia navesi in the cassava crop. Infected P. navesi nymphs and adults were collected in samples fortnightly in the Agronomic Institute of Paraná, in Marechal Cândido Rondon, from January to December 2012. Samples were analyzed at the Laboratory of Agricultural Biotechnology. The entomopathogenic fungus was isolated from corpses using selective oatmeal culture medium, and multiplied for sporulation being identified as Beauveria bassiana (Bals.) Vuill. The fungus was stored in the Collection of Entomopathogenic Fungi Laboratory of Agricultural Biotechnology, identified as Unioeste 78. To prove the pathogenicity of the found isolate, bioassays were performed following the postulate of Koch, the fungi suspension was sprayed (10 9 conídios mL), on nymphs and adults of P. navesi obtained from laboratory rearing. After 10 days of incubation there was 18% mortality confirmed, being considered low activity on mealybugs Protortonia.(AU)