The European pepper moth Duponchelia fovealis (Zeller, 1847) (Lepidoptera: Crambidae), despite being among the principal pests of strawberries in Brazil. However, biological control methods are rarely documented for this pest. In the current study, the goal was to select promising Trichogramma strains to enable the control of D. fovealis and to determine the acceptance of different ages of host eggs by the parasitoid. In the first bioassay, evaluations were done on the biological parameters of five strains of Trichogramma pretiosum Riley and one of Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae). The best performance came from the strains, Tp18 (T. pretiosum) and Tg (T. galloi), showing parasitism and viability higher than 50 and 90%, respectively. Another bioassay revealed the acceptance of both these species (Tp18 and Tg) for different ages of D. fovealis eggs. All host ages were accepted by T. pretiosum (Tp18) and T. galloi, with a preference for younger eggs (65% parasitism). Adult emergence, number of individuals per egg and sex ratio revealed no significant differences with respect to the host age. The current study provides pertinent data on the selection and performance of Trichogramma species on D. fovealis eggs of different ages.
IIIParâmetros biológicos e tabela de vida de Tetranychus urticae (Acari: Tetranychidae) em cultivares de mamão
Palavras-chave: fitossanidade, ácaro-rajado, Carica papaya.
ABSTRACTThe study was conducted to evaluate the Tetranichus urticae development and reproduction in commercial Carica papaya cultivars. The assayed cultivars belongs to the "Formosa" ("Tainung 01" and "Calimosa") and from the "Solo" ("Golden" and "Sunrise")
RESUMO Este trabalho teve como objetivo avaliar a influência de diferentes inseticidas e fungicidas, sobre Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae), em diferentes hospedeiros. Os testes foram realizados com adultos de T. pretiosum nos hospedeiros Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae) e Helicoverpa zea (Boddie, 1850) (Lepidoptera: Noctuidae). Os resultados mostraram que os agrotóxicos estudados tiveram efeitos diferentes sobre T. pretiosum, em função do hospedeiro. Os inseticidas IMIDACLORIPRIDO + BETA-CIFLUTRINA e METHOMYL foram os mais agressivos, reduzindo o parasitismo dos adultos de T. pretiosum em ambos os hospedeiros, enquanto, para os fungicidas, DIMETOMORPH + MANCOZEB e MANCOZEB foram os mais influentes. Diante dos resultados, conclui-se que o hospedeiro pode influenciar na ação seletiva dos inseticidas e fungicidas sobre parasitoides do gênero Trichogramma, visto que T. pretiosum foi mais susceptível ao inseticida METHOMYL e ao ACIBENZOLAR-S-METHYL, quando criado em A. kuehniella, e ao fungicida DIMETOMORPH + MANCOZEB, quando criado em H. zea. Não houve reduções expressivas dos percentuais de emergência dos descendentes, quando os fungicidas foram aplicados.
In this study, the effect of temperature on the growth of the European pepper moth, Duponchelia fovealis (Zeller), was assessed at five constant temperatures (18, 21, 24, 27 and 30 °C). The European pepper moth was observed to complete its developmental stages (from egg to adult) at all the temperatures evaluated. From the results, it was evident that temperature affected the rate and development time of all the growth stages, to a significant degree. The length in time of the embryonic, larval, pupal and total (egg-adult) stages was observed to drop as the temperature rose from 18 to 24 °C, but remained constant between 27 and 30 °C. The developmental time in the pre-pupal stage dropped between 18 and 30 °C. The European pepper moth takes 454 degree-days to complete development at 11.7 °C temperature threshold. The D. fovealis survival was thus inversely proportional to temperature over range of 18 to 30 °C. On assessing the number of annual generations for the five largest strawberry-producing municipalities in Espírito Santo State, an average of 5.5 generations per year was estimated. This is a first report of temperature on D. fovealis development.
-The insect Dysmicoccus brevipes (Hemiptera: Pseudococcidae) has been reported as an important pest for several crops, especially coffee. The citrus essential oils can be obtained as by-products of the citrus-processing industry and have been tested as an alternative to control different insect groups. Therefore, the objective of this work was to determine the chemical composition and evaluate the toxicity of commercial sweet orange (Citrus sinensis), bitter orange (Citrus aurantium) and Sicilian lemon (Citrus limon) essential oils and pure monoterpene D-limonene on D. brevipes. The essential oils were analyzed by gas chromatography. Two bioassays were conducted; the first assessing the insect mortality in all oils and the second assessing the lethal concentrations (LC 50 and LC 95 ) of the most effective oils. The main components of the oils were D-limonene (83.33%) and Linalool (8.91%) (sweet orange); D-limonene (78.53%) and γ-terpinene (12.65%) (bitter orange); D-limonene (59.78%), beta-pinene (14.71%) and γ-terpinene (10.19%) (Sicilian lemon) and the compound D-limonene had 97% of purity. The highest mortalities were found with the use of the Sicilian lemon (98.68%) and sweet orange (94.11%)oils. The sweet orange oil presented lethal concentrations at 2.21% (LC 50 ) and 3.55% (LC 95 ), and the Sicilian lemon oil at 0.72% (LC 50 ) and 2.91% (LC 95 ). The main component of the sweet orange and Sicilian lemon essential oils was the D-limonene, and the Sicilian lemon oil was most effective oil to control D. brevipes.
Keywords:Cochineal. Mortality. Natural products.
CARACTERIZAÇÃO QUÍMICA E TOXICIDADE DE ÓLEOS ESSENCIAIS CÍTRICOS SOBRE
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