ABSTRACT
Environmental variables may markedly influence egg parasitoid performance and must be considered when choosing the best release strategy. Thus, this study aimed to investigate the effects of light, temperature, soil moisture, and precipitation on the emergence and parasitism of parasitoid releases of unprotected and encapsulated pupae. The presence of light favored the parasitism of Trichogramma pretiosum Riley, 1879, and Telenomus remus (Nixon, 1937) but did not impact the parasitism of Telenomus podisi (Ashmead, 1893). The release strategy adopted (release of encapsulated or unprotected pupae) also impacted the results. On one hand, card capsules gave protection against rainfall, limited to 10 mm regarding Tr. pretiosum, while on the other hand, card capsules led to a reduction in the number of captured adults for Te. podisi at 25°C and 30°C. Therefore, Tr. pretiosum, Te. remus, and Te. podisi can be released using both encapsulated and unprotected pupae, with advantages and disadvantages for each strategy, depending on each studied environmental variable. In addition, parasitoid pupae should be released so that the majority emerge during daylight, especially for Te. remus and Tr. pretiosum, since parasitism was greatly reduced in dark environments. Telenomus podisi is not affected by this variable as it demonstrated similar parasitism in light and dark environments.
Subject(s)
Hymenoptera , Animals , Hymenoptera/parasitology , Light , Pupa , Rain , TemperatureABSTRACT
The metropolitan area of Londrina has the presence of strong agribusiness and agroservices and it is an important center for agricultural production, especially soybean and corn. We evaluated the technical aspects and characteristics of farming and crop handling by the producers of soybean and corn, through a semi-structured questionnaire. Two hundred and forty responses were recorded: 120 from soybean farmers and 120 from corn farmers, which represented 10% of the farmers in the city of Londrina. Farmers reported that bedbugs and caterpillars are the main pests. Farmers use organo-synthetic insecticides as the primary means to control pests, but also employ crop-growing measures such as tillage, crop rotation, and the use of transgenic seeds in the management of insect pests affecting soybean and corn.(AU)
A região metropolitana de Londrina tem forte presença no mercado de agronegócios e agroserviços, sendo um importante centro de produção agrícola, especialmente de soja e milho. Na pesquisa, foi utilizado um questionário semiestruturado para avaliar os aspectos técnicos e as características de cultivo e manejo de culturas pelos produtores de soja e milho na região, com ênfase nas estratégias usadas para o controle de pragas. Foram registradas 240 respostas: 120 de produtores de soja e 120 de plantadores de milho, o que representou 10% dos agricultores da cidade de Londrina. Os agricultores relataram que percevejos e lagartas são as pragas mais comuns que atacam suas culturas. Como o principal meio para controle, são aplicados inseticidas organossintéticos, mas também são empregadas medidas de cultivo, como o preparo do solo, a rotação de culturas e o uso de sementes transgênicas no manejo de pragas de insetos que afetam a soja e o milho.(AU)
