Bioactivity of essential oils from Artemisia against Diaphania hyalinata and its selectivity to beneficial insects

ABSTRACT: The demand for effective insecticides in pest control with low toxicity to the non-target organisms, such as natural enemies and pollinators, is increasing steadily. A good alternative for synthetic insecticides is natural compounds, including essential oils (EO). This work assessed toxicity of essential oils extracted from Artemisia annua, A. absinthium, A. camphorata, A. dracunculus and A. vulgaris against the melonworm Diaphania hyalinata (Linnaeus, 1758) (Lepidoptera: Crambidae) larvae, a pest of Cucurbitaceae, and their selectivity for fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and jataí bee Tetragonisca angustula (Latreille) (Meliponinae). The plants were grown in a greenhouse with mineral fertilization and were used for EO extraction. The insects in the bioassay belonged to the second instar of D. hyalinata and adult forms of S. saevissima and T. angustula. Essential oil from A. annua induced a high mortality rate in D. hyalinata (96 %) over a 48 h period. The same essential oil was selective for predator S. saevissima (42 % mortality) and pollinator T. angustula (74 % mortality), while causing high mortality in D. hyalinata. The insecticidal activity of A. annua oil was attributed to the synergism of its constituents viz., camphor and 1,8-cineole. Therefore, this essential oil contains constituents that are promising for effective use as insecticide due to its high toxicity and rapid action against D. hyalinata as well as low toxicity for predator and pollinator.

Bioactivity of essential oils from Artemisia against Diaphania hyalinata and its selectivity to beneficial insects

ABSTRACT: The demand for effective insecticides in pest control with low toxicity to the non-target organisms, such as natural enemies and pollinators, is increasing steadily. A good alternative for synthetic insecticides is natural compounds, including essential oils (EO). This work assessed toxicity of essential oils extracted from Artemisia annua, A. absinthium, A. camphorata, A. dracunculus and A. vulgaris against the melonworm Diaphania hyalinata (Linnaeus, 1758) (Lepidoptera: Crambidae) larvae, a pest of Cucurbitaceae, and their selectivity for fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and jataí bee Tetragonisca angustula (Latreille) (Meliponinae). The plants were grown in a greenhouse with mineral fertilization and were used for EO extraction. The insects in the bioassay belonged to the second instar of D. hyalinata and adult forms of S. saevissima and T. angustula. Essential oil from A. annua induced a high mortality rate in D. hyalinata (96 %) over a 48 h period. The same essential oil was selective for predator S. saevissima (42 % mortality) and pollinator T. angustula (74 % mortality), while causing high mortality in D. hyalinata. The insecticidal activity of A. annua oil was attributed to the synergism of its constituents viz., camphor and 1,8-cineole. Therefore, this essential oil contains constituents that are promising for effective use as insecticide due to its high toxicity and rapid action against D. hyalinata as well as low toxicity for predator and pollinator.

Bioactivity of essential oils from Artemisia against Diaphania hyalinata and its selectivity to beneficial insects

The demand for effective insecticides in pest control with low toxicity to the non-target organisms, such as natural enemies and pollinators, is increasing steadily. A good alternative for synthetic insecticides is natural compounds, including essential oils (EO). This work assessed toxicity of essential oils extracted from Artemisia annua, A. absinthium, A. camphorata, A. dracunculus and A. vulgaris against the melonworm Diaphania hyalinata (Linnaeus, 1758) (Lepidoptera: Crambidae) larvae, a pest of Cucurbitaceae, and their selectivity for fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and jataí bee Tetragonisca angustula (Latreille) (Meliponinae). The plants were grown in a greenhouse with mineral fertilization and were used for EO extraction. The insects in the bioassay belonged to the second instar of D. hyalinata and adult forms of S. saevissima and T. angustula. Essential oil from A. annua induced a high mortality rate in D. hyalinata (96 %) over a 48 h period. The same essential oil was selective for predator S. saevissima (42 % mortality) and pollinator T. angustula (74 % mortality), while causing high mortality in D. hyalinata. The insecticidal activity of A. annua oil was attributed to the synergism of its constituents viz., camphor and 1,8-cineole. Therefore, this essential oil contains constituents that are promising for effective use as insecticide due to its high toxicity and rapid action against D. hyalinata as well as low toxicity for predator and pollinator.(AU)

Desempenho de trichogramma spp. (hymenoptera: trichogrammatidae) em ovos de diaphania hyalinata (l.) (lepidoptera: pyralidae) tratados com metarhizium anisopliae e beauveria bassiana

ABSTRACT Diaphania hyalinata (L., 1758) is one of the most important pests of the Cucurbitacae, and biological control is an alternative method to replace chemicals. Compatibility between biological control agents was evaluated measuring the performance of females of Trichogramma atopovirilia and Trichogramma pretiosum in eggs of Diaphania hyalinata treated with the entomopathogenic fungi Metarhizim anisopliae and Beauveria bassiana. Twenty eggs of D. hyalinata were immersed in a suspension of Metarri®, Boveril® and distilled water (control) and offered daily for the parasitism for 24 hours until the death of the parasitoids. Evaluation was made of the daily, accumulated and total parasitism, number of parasitized eggs, viability, sex ratio and longevity. The formulations of M. anisopliae and B. bassiana did not affect the reproductive characteristics and survival of the two species of Trichogramma, and T. pretiosumshowed higher parasitism thanT. atopovirilia in eggs of D. hyalinata. The results obtained in this work showed that it is possible to integrate the use ofT. atopoviriliaand theentomopathogenic fungi M. anisopliae and B. bassiana in cucurbit IPM systems.

RESUMO Diaphania hyalinata (L., 1758) é uma das principais pragas de Cucurbitacea e ênfase tem sido dada ao controle biológico desta praga em substituição ao controle químico. A compatibilidade de agentes de controle biológico foi avaliada pelo desempenho de fêmeas de Trichogramma atopovirilia Oatman & Platner, 1983 e Trichogramma pretiosum Riley, 1879 em ovos de D. hyalinata pulverizados com os fungos entomopatogênicos Metarhizium anisopliae (Metsh.) Sorok, 1883 e Beauveria bassiana (Balls.) Vuill. Vinte ovos de D. hyalinata foram imersos em suspensão de Metarril®, Boveril® e água destilada (testemunha) e oferecidos diariamente para o parasitismo por 24h até a morte dos parasitoides. Foram avaliados o parasitismo diário, acumulado e total, número de ovos parasitados, viabilidade, razão sexual e longevidade. Os fungos entomopatogênicos M. anisopliae e B. bassiana não afetaram as características reprodutivas e de sobrevivência das duas espécies do gênero Trichogramma, sendo que T. pretiosum apresentou maior parasitismo que T. atopovirilia em ovos de D. hyalinata. Os resultados obtidos neste trabalho mostram que é possível a integração de T. atopovirilia e os fungos entomopatogênicos M. anisopliae e B. bassiana em programas de manejo integrado de pragas de cucurbitáceas.