Romba Rahim, Gnankine Olivier, Drabo Samuel Fogné, Tiendrebeogo Fidèle, Henri Hélène, Mouton Laurence, Vavre Fabrice
Laboratoire d'Entomologie Fondamentale et Appliquée, Unité de Formation et de Recherche en Sciences de la Vie et de la Terre (UFR-SVT) Université Ouaga I Pr Joseph Ki Zerbo Ouagadougou Burkina Faso.
Laboratoire Mixte International Patho-Bios IRD-INERA Ouagadougou Burkina Faso.
Ecol Evol. 2018 May 20;8(12):6091-6103. doi: 10.1002/ece3.4078. eCollection 2018 Jun.
The whitefly 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 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 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 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 () were also recorded with . 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 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--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.
粉虱是全球许多农业和观赏作物的害虫，在非洲尤为严重。它是一个隐性物种复合体，食性极其广泛，在世界各地已确定有数百种寄主植物。此前在西非的调查表明，入侵的中东-北非生物型（MED-Q1和MED-Q3）与非洲物种SSA和ASL同域共存。这种情况是该复合体中各种遗传实体在当地共存的罕见案例之一。为了研究该群落中遗传实体的分布动态和丰度，并确定可能有助于共存的潜在因素，我们于2015年和2016年在布基纳法索的各种植物及其寄生蜂上进行了采样。所有四种遗传实体均有记录，这表明MED物种并未排除当地物种。虽然在属于18个科的55种植物上发现了粉虱个体，显示出这种害虫的高度多食性，但一些物种/生物型表现出更高的特异性。还记录到了两种寄生蜂物种（），其中在大多数地区和大多数植物上占主导地位。我们的数据表明，粉虱的丰度、多样性和寄生率因地区、植物和年份而异，但寄生率总体上与粉虱丰度高度相关，表明存在密度依赖性。我们的结果还表明，物种/生物型的局部多样性在不同年份存在动态变化，特别是MED-Q1和ASL物种。这项工作提供了有关西非植物-寄生蜂相互作用性质的相关信息，并确定某些遗传实体的生态位分化可能会稳定共存。然而，MED-Q1和ASL显示出广泛的生态位重叠，这最终可能导致竞争排斥。
