THE CASSAVA PLANT Cassava, Manihot esculenta Crantz (Euphorbiaceae) ( Figure ), is a perennial root crop native to tropical America and introduced into . Abstract: The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) feeds by sucking the sap of cassava plants, causing damage directly by. Abstract: The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) feeds cassava plants, causing damage directly by sucking the sap and.
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Decreasing the rate of stress accumulation DHCS to Ann Soc Entomol Fr We added a temperature threshold mechanism to the model to simulate the effects of more than one mralybug per week [ 25 ].
Phenacoccus manihoti – Wikipedia
Social Impact Top of page The accidental introduction of P. In cassava and on Manihot glaziovii, the pest causes stunting, leaf distortion and loss, dieback and weakening of stems used for crop propagation. Journal of Applied Ecology, 25 3: Multilocular disc pores on venter present at least as far forward as abdominal segment IV ……………………………………………………. Neuenschwander and Herren, ; Zeddies et al. The net increase rate R omean generation time Tintrinsic rate of increase r m and doubling time D T were Large-scale and sustained field studies have, however, recorded excellent biological control of the pest by A.
The influence of the cassava mealybug, Phenacoccus manihoti Mat. In lanesP. Sternorrhyncha in Southeast Asia and West Africa. More modern tools used for molecular analysis have shown them to be genetically diverse, however. Smooth short pegs directly contact the stylet and act as mechanoreceptorssmooth long pegs are mechanoreceptors as well as a contact chemosensory organ, and grooved pegs have numerous pores on their cuticle which suggests they function as an olfactory organ.
A new scale-insect injurious to cassava in Equatorial Africa, Phenacoccus manihoti sp. Thirdly, as half of the grid cells adjacent to Mbeya are climatically suitable for the persistence of P. When the plants had eight fully developed leaves, they were used for the experiment according to the methodology described by Rheinheimer et al.
An additional species, Phenacoccus solenopsis Tinsley, not listed in ScaleNet, has been reported on cassava increasing the number of species recorded on cassava to 24 and 27 on the genus Manihot.
The patterns of the amplified products of P. Two parameters captured mortality due to extreme heat, mainly limiting distributions in the African Sahel. Investigations on cassava in the Republic of Zaire. Cassava mealybug on cassava-Malawi. Contrary to insecticide use, biological pest control provided a self-sustaining, cost-effective and environmentally-sound solution for mealybug suppression across the African cassava belt.
The final model was validated against the distribution points provided for Asia by Parsa et al. In this article, we use an integrative modeling approach to predict P.
The potential mealtbug of invading Helicoverpa armigera in North America: In Asia, our model performs well, capturing all areas mentioned as having P. The more restricted potential distributions in northwestern South America, central Africa, and in south-eastern Asia using melaybug Parsa et al.
Accordingly, the risk map does not take into account the effects of natural enemies and human intervention, among other limiting factors that should further restrict P. Finally, two parameters captured mortality due to rainfall; limiting distributions in the Congo Basin but not in the west, south and southwest of the Democratic Republic of the Congo previously Zaire ; thereby approximating mealybug distribution maps for that country .
Model fitting and validation We started with the parameter values Table 1 published by Parsa et al. Hence, a single immature or adult may be sufficient to start an outbreak.
1. Cassava and mealybugs
CLIMEX has been used to estimate the potential range of a huge number of pests and pathogens, providing reliable prognoses of their future expansion and indicating the regions at risk [ 15 — 20 ]. The life cycle consists of an egg and four instar stages with the fourth being the adult mealybug. Viable containment tactics include domestic quarantines, insecticide treatments and classical biological control at the expanding population front .
This biological control effort was effectively replicated in Southeast Asia, where P. You can suggest to your library or institution to subscribe to the program OpenEdition Freemium for books. Cassava Manihot esculenta is a food staple for millions of people worldwide, and is especially important in Africa, mealtbug accounts for half of the global production [ 1 ].
Pseudococcidae with a description of a new species. Body length and breadth measurements are, respectively, 0. Hydrol Earth Syst Sci Disc. The mealybuh records for P. The first authoritatively-verified specimens of P.
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Santis L de, The role of climatic mapping in predicting the potential geographical distribution of non-indigenous pests under current and future climates. Dassava of the cassava mealybug Phpnacoccus manihoti; Hom.: Because species can invade and establish in areas with climates that are different from those that are found in their native range, it is essential to define robust range-limiting mechanisms in niche models.
Conclusions Based on this study, Ph. The EI reflects the annual balance between population growth during favorable seasons captured by the annual growth index [GI A ] and mortality during unfavorable seasons cassavw by stress indices for cold [CS], heat [HS], drought [DS] and wetness [WS] .