Abundance of Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and its parasitoids on vegetables and cassava plants in Burkina Faso (West Africa)

Abstract

The whitefly Bemisia tabaci is a pest of many agricultural and ornamental crops worldwide and particularly in Africa. It is a complex of cryptic species, which is extremely polyphagous with hundreds of host plants identified around the world. Previous surveys in western Africa indicated the presence of two biotypes of the invasive MED species (MED‐Q1 and MED‐Q3) living in sympatry with the African species SSA and ASL. This situation constitutes one of the rare cases of local coexistence of various genetic entities within the B. tabaci complex. In order to study the dynamics of the distribution and abundance of genetic entities within this community and to identify potential factors that could contribute to coexistence, we sampled B. tabaci populations in Burkina Faso in 2015 and 2016 on various plants, and also their parasitoids. All four genetic entities were still recorded, indicating no exclusion of local species by the MED species. While B. tabaci individuals were found on 55 plant species belonging to eighteen (18) families showing the high polyphagy of this pest, some species/biotypes exhibited higher specificity. Two parasitoid species (Eretmocerus mundus and Encarsia vandrieschei) were also recorded with E. mundus being predominant in most localities and on most plants. Our data indicated that whitefly abundance, diversity, and rate of parasitism varied according to areas, plants, and years, but that parasitism rate was globally highly correlated with whitefly abundance suggesting density dependence. Our results also suggest dynamic variation in the local diversity of B. tabaci species/biotypes from 1 year to the other, specifically with MED‐Q1 and ASL species. This work provides relevant information on the nature of plant–B. tabaci‐parasitoid interactions in West Africa and identifies that coexistence might be stabilized by niche differentiation for some genetic entities. However, MED‐Q1 and ASL show extensive niche overlap, which could ultimately lead to competitive exclusion.

Genetic Diversity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Colonizing Sweet Potato and Cassava in South Sudan

“…MED is a globally important B. tabaci haplotype group which is thought to have originated from Africa. Consequently, there are numerous other reports of its prevalence on a wide range of crop and weed hosts [59,60,64]. B. tabaci MED has been reported to be extremely polyphagous and invasive [54], causing damage to both field and greenhouse crops [82].…”

Cytotype Affects the Capability of the Whitefly Bemisia tabaci MED Species To Feed and Oviposit on an Unfavorable Host Plant

“…Taken together, our results indicate that lantana is a particularly challenging host for B. tabaci complex members. This could explain why, in the field, populations reported on this plant are restricted to MED ( 39 , 41 , 58 ), including in areas where other B. tabaci species co-occur, such as the close relative polyphagous MEAM1 (Middle East Asia minor 1) species ( 59 ). It is tempting to associate this impairment with the lowest nutritional quality of lantana, which contains the smallest amount of the four EAAs, Ile, Leu, Phe, and Val, among the three plants considered in our study.…”

Analyses of symbiotic bacterial communities in the plant pest Bemisia tabaci reveal high prevalence of Candidatus Hemipteriphilus asiaticus on the African continent

“…Indeed, previous research demonstrated that aphid performance is associated with the aminoacid composition of the phloem sap (44)(45). It could explain why Hemipteriphilus was not present in the SSA species which, contrary to MED and ASL which have been found in several host plant species, has only been detected on cassava in Burkina Faso (34). Analysis of the genome of Hemipteriphilus, with a special focus on genes involved in metabolic pathways, would give further insight into its putative nutritional role.…”

“…In this country, B. tabaci is a pest of primary importance, with a severe impact on economic activity (28). Indeed, B. tabaci is a cryptic species complex (42 species reported till now based on a 657bp portion of the mitochondrial cytochrome oxidase 1 ( mtCOI ) DNA sequence: 29–33), and in Burkina Faso individuals belong either to SSA (Sub-Saharan Africa), ASL (Africa Silver-Leafing) or MED (Meditteranean) species (34). Using universal bacterial primer sets we detected few bacterial species and, more importantly, no new putative S-symbiont.…”