One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/
M. sacchari infests the undersides of leaves, which show red spots, patches, blotches or streaks, later becoming completely red or brown-red. Stems of infested plants are crooked, and heading is affected. The leaf surface is covered with honeydew, leading to mildew or sooty moulds.
According to the level of aphid damage, Wang et al. (1961) and Jia (1959) reported five effective methods of cultural control against M. sacchari: improving the soil; irrigation; close planting; applying fertilizer; and enhancing field management by cutting grass in the autumn, when the pests migrate from sorghum to grass to overwinter.
When reared on resistant varieties of sorghum, M. sacchari showed increased mortality and decreased fecundity (Liu et al., 1990). Studies in China, Taiwan, Japan, South Africa, India and elsewhere have identified resistance in sorghum lines to M. sacchari (e.g. Setokuchi, 1976; Chang, 1981; Hagio et al., 1985; He et al., 1991; Teetes et al., 1995; Wenzel et al., 1998; Ghuguskar et al., 1999). Transgenic lines of sorghum may be developed in the future with resistance to M. sacchari (Hagio, 1999).
Due to the variable regulations around (de-)registration of pesticides, we are for the moment not including any specific chemical control recommendations. For further information, we recommend you visit the following resources:
M. sacchari is a common pest of sorghum in tropical Africa, Asia, the Far East and the Americas. All growth stages can be infested, but economic damage usually occurs during the later growth stages. Sap is sucked from abaxial leaf surfaces, with heavily infested leaves turning prematurely brown. Plants may have stunted growth and poor grain yields. As many as 30,000 aphids may infest a single plant (Rensburg, 1973b). Despite the lack of objective assessments of crop losses, M. sacchari is ranked as a major pest of sorghum in East Asia.
Heavy infestations of M. sacchari occur in sorghum-growing areas of north China, north-eastern Mongolia, Shangdong Province and Hebei Province (Zhang and Zhong, 1983). Reductions in sorghum yield and quality have been reported (Wang et al., 1961). In central Taiwan, heavy infestations of M. sacchari on sorghum at the booting and heading stages seriously reduce both grain quality and yield (Chang and Fang, 1984). In Japan, the effects of infestation by M. sacchari on the yield and quality of forage sorghum were studied by Setokuchi (1979). In 1974-76, damage caused by aphid feeding, and by the sooty mould that developed on honeydew, reduced the yield of dry matter. The two types of damage operate independently. The reduction in dry matter attributed to aphid feeding amounted to about 1-1.3% as compared with uninfested plants. In South Africa, unchecked aphid populations can result in up to 77% loss in grain yield (Rensburg and Hamburg, 1975). Flattery (1982) described grain damage in Botswana.
In general, damage to sorghum is heavier in sandy soils, especially during dry periods. Well-developed seedlings tend to be more resistant than less-developed seedlings. Damage to hybrid sorghum is particularly heavy in extensive cultivation. Most damage is caused from mid-June to mid-July when the temperature is very high and humidity is very low, and natural enemies are still low in number.
Its status as an economic pest on sugarcane remains unclear. However, yield reductions can occur due to the presence of honeydew after severe infestations, and the aphid acts as a vector in the spread of Sugarcane mosaic virus (SCMV) and other diseases. For these reasons, concern about yield losses have been expressed in areas where this aphid has recently become established, for example, in Louisiana, USA (White et al., 2001) and in the Caribbean (Schotman, 1989).
M. sacchari is a vector of the persistent Millet red leaf virus, for example, in the USA (Denmark, 1988). It also readily transmits certain strains of the non-persistent SCMV. In India, M. sacchari primarily transmits SCMV strain H (Kondaiah and Nayudu, 1984). A SCMV subgroup of potyviruses causes sorghum red stripe disease in India; a distinct disease-causing sugarcane potyvirus is spread from sugarcane to sorghum by M. sacchari (Mali, 2001). Sugarcane yellow leaf syndrome is caused by Sugarcane yellow leaf virus (ScYLV), which is transmitted by M. sacchari (Scagliusi and Lockhart, 2000; Schenk, 2001). ScYLV affects many sugarcane-growing areas worldwide, including those in the USA, the West Indies and Colombia (Daugrois et al., 1999; Victoria et al., 1999).