Current knowledge and future research perspectives on cassava (Manihot esculenta Crantz) chemical defenses: An agroecological view

Landscape context does not constrain biological control of Phenacoccus manihoti in intensified cassava systems of southern Vietnam

“…Being long-season crops exposed to comparatively few disturbances, cassava systems provide habitats of prolonged durational stability and vegetational complexity for myriad natural enemies. The secretion of extra-floral nectar by the cassava plant also constitutes a favorable trait for multiple beneficial organisms, including hymenopteran parasitoids (e.g., Pinto-Zevallos et al, 2016). Anagyrus lopezi itself equally possesses an exceptional dispersal potential of 20 km per generation, a high degree of adaptation to varying agro-ecological conditions, host-feeding capabilities and an ability to persist at low P. manihoti densities (Neuenschwander et al, 1989).…”

Peer Review #1 of "Continental-scale suppression of an invasive pest by a host-specific parasitoid underlines both environmental and economic benefits of arthropod biological control (v0.2)"

“…30%) levels from smallholder plots in Africa's savanna (Hammond and Neuenschwander, 1990). Factors ensuring this exceptional parasitoid efficacy and resulting pest control are a) unique features of the cassava crop, including prolonged durational stability, vegetational complexity and a constitutive secretion of energy-rich nectar for foraging parasitoids (Pinto-Zevallos et al, 2016); b) spatiotemporal continuity of mealybug-infested crops at a landscape level (Schellhorn et al, 2014), especially in locations where farmers employ staggered planting and piece-meal harvesting; c) favorable ecological traits of A. lopezi, including high dispersal ability, environmental adaptability and density-dependent parasitism (Neuenschwander et al, 1989) Manuscript to be reviewed use of (prophylactic) insecticides, except for Thailand and parts of southern Vietnam; and e) human-assisted dispersal of A. lopezi, via (parasitized) mealybug-infested planting material (Herren et al, 1987). Furthermore, substantial fertilizer inputs and suitable water management in areas with intensified cassava production -e.g., Vietnam's Tay Ninh province, or parts of eastern Thailand such as Nakhon Ratchassima-likely benefited biological control further by boosting A. lopezi development and fitness (Wyckhuys et al, 2017a).…”

Phytoplasma infection of a tropical root crop triggers bottom-up cascades by favoring generalist over specialist herbivores

“…More so, certain phytotoxins accumulate along trophic chains and cause ‘toxic environmental effects’ [ 52 ]. This is particularly relevant for cassava, a plant that employs extensive chemical defenses such as cyanogenic and flavonoid glycosides and hydroxycoumarins [ 53 ]. Quantitative variation in some of these allelochemicals can differentially impact the development of herbivores of varying dietary specialization [ 13 , 54 , 55 ].…”