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Fernandes F.S.,Biological Control Unit Embrapa Algodo | Ramalho F.S.,Biological Control Unit Embrapa Algodo | Nascimento A.R.B.,Biological Control Unit Embrapa Algodo | Malaquias J.B.,Biological Control Unit Embrapa Algodo | And 2 more authors.
Annals of the Entomological Society of America | Year: 2012

It is known that intercropping systems maintain biodiversity and control pest populations. The aim of this study was to describe the vertical and horizontal distribution of the cotton aphid, Aphis gossypii Glover, within the cotton plant (Gossypium hirsutum L.) in cotton with colored fibers and cotton-fennel (Foeniculum vulgare Miller) intercropping system over time, during two cotton seasons. Measurements of the aphid population's dynamics and distribution in the cotton plants were recorded at intervals of 7 d, from plant emergence until the appearance of the first open bolls. The number of aphids and their specific locations on the plant were recorded in relation to reference points (nodes on the plant's main stem as well as on leaves and fruit structures). The number of cotton aphids found on the cotton crop (11,444 cotton aphids) was significantly higher than the number found on the cotton-fennel intercrop (8,106). Considering the vertical distribution of cotton aphids on the plants, no significant interactions were observed among the crop system, plant age and plant region, between the crop system and plant age, or between the crop system and plant region. In the cotton system, aphid populations peaked between 74 and 95 d, whereas in the cotton-fennel intercropping system, aphid populations peaked between 74 and 102 d. The results obtained in this study could be useful in decision-making, implementing controls and determining the timing of population peaks of this aphid. © 2012 Entomological Society of America. Source


Ramalho F.S.,Biological Control Unit Embrapa Algodo | Fernandes F.S.,Biological Control Unit Embrapa Algodo | Nascimento A.R.B.,Biological Control Unit Embrapa Algodo | Junior J.L.N.,Biological Control Unit Embrapa Algodo | And 2 more authors.
Journal of Economic Entomology | Year: 2012

The fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a major pest of fennel, Foeniculum vulgare Miller in northeast region of Brazil. We hypothesize that intercropping can be used as an alternative pest management strategy to reduce aphid yield loss in fennel. Thus, we investigated the severity of fennel plant damage in relation to infestation by the fennel aphid and predation by Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) (spotless lady beetle), green lacewing, Chrysoperla cornea (Stephens) (Neuroptera: Chrysopidae), and Scymnus spp. (Coleoptera: Coccinellidae) in sole fennel plots and plots of fennel intercropped with cotton with colored fibers. The fennel aphid populations in nontreated plots were significantly larger in sole fennel plots than in intercropped plots. The highest densities of C. sanguinea, green lacewings and Scymnus spp., associated with the suppression of fennel aphid populations was found in fennel in the intercropping systems. Fennel aphids reduced the fennel seed yield by 80% in the sole fennel plots compared with ≈30% for all intercropping systems. The results obtained in this research are of practical significance for designing appropriate strategies for fennel aphid control in fennel-cotton intercropping systems. In summary, intercropping fennel with cotton with colored fibers apparently promoted biocontrol of fennel aphid in fennel. © 2012 Entomological Society of America. Source

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