Within-Plant Distribution of Cotton Aphid (Hemiptera: Aphididae), in Cotton with Colored Fibers and Cotton-Fennel Intercropping System

Abstract

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.

Interspecific Associations between Cycloneda sanguinea and Two Aphid Species (Aphis gossypii and Hyadaphis foeniculi) in Sole-Crop and Fennel-Cotton Intercropping Systems

“…foeniculi than A . gossypii , as previously reported by Fernandes, et al [ 12 , 13 ]. Number of cotton aphids found on a cotton plant for the entire cotton season (11,444 aphids) was significantly higher than the number found on the intercropped plots (8,106 aphids) [ 13 ].…”

“…gossypii , as previously reported by Fernandes, et al [ 12 , 13 ]. Number of cotton aphids found on a cotton plant for the entire cotton season (11,444 aphids) was significantly higher than the number found on the intercropped plots (8,106 aphids) [ 13 ]. The number of apterous aphids and alate aphids found per fennel plant in the sole fennel (27,922 apterous and 703 alate aphids) for the entire season were significantly higher than the number found in the fennel-cotton intercropped system (13,012 apterous and 369 alate aphids) [ 12 ].…”

“…According to Osawa [ 31 ], ladybug populations show a pattern of dispersal between subpopulations and the establishment of populations is determined by evaluation and accessibility of aphid colonies. This is important in our context because, if farmers maintain different crops in which beneficial insects are present, reduction of aphids is highly probable and will likely result in a significant increase in productivity [ 13 ].…”

Plant volatiles mediate Aphis gossypii settling but not predator foraging in intercropped cotton

“…48 Similar phenomena are recorded in cotton × fennel and cotton × mung bean systems, where enhanced vegetational diversity leads to higher natural enemy numbers, more stable arthropod communities and lessened aphid pest pressure. [49][50][51] In these systems, enhanced natural pest control is thus largely due to predator spillover from the intercrop or added nutritional resources in, for example, mung bean extrafloral nectaries. 52 Unlike the earlier-mentioned, differences in predator seasonal abundance in our study system are likely mediated by the phenology of either companion plant while aphid colonization is impeded by (Alliaceae) plant volatiles.…”

Dynamics and pest and natural enemies dispersion in cowpea and colored cotton in sole or intercropping systems

“…As in intercropping systems, two or more crops can be planted in the same area (Tung et al 2016), maintaining the biodiversity of floral and feeding resources for natural enemies, thus contributing to the reduction of pest population in cotton (Fernandes et al 2012;Rao et al 2012), causing impact on insect dynamics in intercropping systems (Altieri & Letourneau 1982). Several studies have shown that agroecosystem diversification can reduce pest infestation (Jankowska & Wojciechowicz-Żytko 2016).…”