Menezes CWG, Soares MA, Santos JB, Assis Júnior SL, Fonseca AJ & Zanuncio JC (2012). Reproductive and toxicological impacts of herbicides used in Eucalyptus culture in Brazil on the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae). Weed Research52, 520–525. Summary The expansion of eucalyptus tree plantations in Brazil has raised concerns that the use of herbicides may reach non‐target organisms and compromise the environment where parasitoids are used to control Lepidoptera defoliators. So, the effect of herbicides used in eucalyptus crops on the parasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) was evaluated in terms of the impact on reproduction and survival. Treatments consisted of commercial doses of the herbicides sulfentrazone, oxyfluorfen, glyphosate and isoxaflutole with a water‐only control. The herbicides were sprayed on the pupae of the alternative host Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae), which were exposed to parasitism by six females of P. elaeisis per pupa. Glufosinate and oxyfluorfen reduced parasitism and emergence of this parasitoid and were considered more harmful to the P. elaeisis females. Glyphosate and isoxaflutole resulted in higher numbers of individuals and females produced per female; thus these herbicides were less harmful to P. elaeisis and maybe used in IPM programmes in eucalyptus plantations.
O milho tem sido cultivado em duas safras anuais no Brasil e consumido por humanos e animais. O uso de herbicidas no controle de plantas daninhas nessa cultura pode comprometer o ambiente em função dos efeitos sobre organismos não alvos. O objetivo deste trabalho foi avaliar a seletividade de atrazine e nicosulfuron sobre o predador Podisus nigrispinus. Os tratamentos constaram da aplicação de atrazine, nicosulfuron e da mistura destes, em doses equivalentes à comercial, mais um tratamento controle à base de água. A solução com os herbicidas foi aspergida sobre ovos de dois dias de idade de P. nigrispinuse em cada um dos cinco estádios ninfais e fase adulta do inseto. A viabilidade dos ovos de P. nigrispinus diminuiu sob ação dos herbicidas, sem eles diferirem quanto ao tempo de eclosão. A sobrevivência de ninfas foi baixa sob ação dos herbicidas, sendo mais afetada negativamente sob ação da mistura destes. Para a aplicação em cada estádio, observou-se baixa sobrevivência de ninfas do primeiro ao terceiro estádio sob ação do herbicida atrazine, isolado ou em mistura, e até o segundo estádio para o nicosulfuron. Também ficou evidente em todos os demais estádios do inseto a menor seletividade à mistura dos herbicidas, em comparação ao efeito isolado. Conclui-se que ovos de P. nigrispinus são sensíveis aos herbicidas testados e que a aplicação na cultura do milho desses produtos poderá diminuir o controle biológico de pragas promovido por esse inseto.
ABSTRACT:Several studies have reported the importance of phytophagy in the history of life from predator stinkbugs. However, knowledge of the nutrients acquired by these insects, from plant materials, is scarce. The phytophagy studies of zoophytophagous predators benefit biological control programs, making them more effective, since the best resources may be offered to these insects, increasing the potential for predation and, thus obtaining, success in pest control. Thus, this study investigated the development and zoophytophagy of predator Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) in eucalyptus seedlings, deficient in macronutrients. The experiment was conducted in a greenhouse and the treatments consisted of individual nitrogen omission, phosphorus, potassium, calcium, magnesium and sulfur nutrient solution, where the eucalyptus seedlings were being conducted. The pupae of Tenebrio molitor L. (Coleoptera: Teneobridae) were offered ad libitum. The results of this experiment demonstrated the importance of nutrition in plants for the development and predation of P. nigrispinus. The plants deficient in nitrogen and magnesium reduce the predation efficiency of this zoophytophagous. The omission of calcium, magnesium and sulfur adversely affected the development of this insect predator, extending its immature stages. The proper nutritional balance of the plants is essential for the success in biological control programs that use zoophytophagous predators.
Bees are considered important pollinators due to their fidelity to plants, enabling the maintenance of gene flow between plant species. The objective of this study was to recognize the visit of bees in two Candeia species, Eremanthus erythropappus and Eremanthus incanus (Asteraceae), as well as to analyze the pollen content carried by bees in a regeneration area. Nine samplings were taken in each plant species using entomological nets. The pollen grains were obtained in 338 bees from their legs and bodies. The species Trigona spinipes, Apis mellifera, and Bombus pauloensis were most frequent. Candeias are essential in the study area because they have high adaptive potential, but besides them, other plants are also important for attracting bees searching for pollen and/or nectar.Melastomataceae, mainly Tibouchina sp., appear to be important sources of pollen. The presence, in greater quantity, of Bombus spp. in Eremanthus flowers probably occurs more by the demand for nectar, since the pollen frequency of other families such as Melastomataceae and Myrtaceae was higher. However, the use of Eremanthus spp. pollen is more frequent by A. mellifera and T. spinipes. CONCLUSIONS • The eusocial bees Bombus pauloensis, Trigona spinipes,and Apis mellifera were the ones with the highest occurrence in the two species of Eremanthus.• The pollen of Eremanthus spp. showed higher frequency in Trigona spinipes and Apis mellifera.
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