Molecular and morphological characterization of mealybugs (Hemiptera: Pseudococcidae) from Chilean vineyards

Abstract

Mealybugs are major pests of grapevines worldwide. They cause economic losses by lowering the cosmetic value of fruits, reducing yields, transmitting viruses and resulting in the quarantine or rejection of produce in international trade. Knowledge of the species present in a vineyard is important for the adjustment of management strategies. We surveyed and accurately characterized the mealybugs infesting vineyards in one of the main production areas of Chile; 164 mealybugs were sampled from 26 vineyards in four regions of Chile and identified by DNA sequencing for two markers (cytochrome oxidase I and internal transcribed spacer 2) and morphological examination. Pseudococcus viburni (Signoret) was the most common species, followed by Pseudococcus meridionalis Prado and Pseudococcus cribata González. Molecular variability at the COI and ITS2 loci was observed in both P. viburni and P. cribata. A comparison of haplotypes of P. viburni worldwide provides support for a recent hypothesis that this species is native to South America, a finding with direct consequences for management. Neither Pseudococcus longispinus (Targioni & Tozzetti) nor Planococcus ficus Signoret were found.

Molecular and Morphological Identification of Mealybug Species (Hemiptera: Pseudococcidae) in Brazilian Vineyards

“…The first subgroup (consisting of all multilocus haplotypes containing 28S-6) displayed remarkable genetic diversity at LCO and C1, whereas the second subgroup had a unique multilocus haplotype 28S-08, 16S-01, LCO-06, C1-07 and ITS2-15. The second subgroup actually includes haplotypes also found in France, Italy, Spain, and Chile [17], [23], [25], [26], whereas the haplotypes from the first subgroup had previously been observed only in southern Brazil (as in this study) by Malausa et al . [23].…”

“…Several genomic regions have successfully been used for the identification of mealybugs and other scale insects. These regions include 28S-D2 and internal transcribed spacer 2 (ITS2) in the nuclear DNA, the mitochondrial cytochrome oxidase subunit I (COI) gene, and the leuA-16S region located in the DNA of the primary endosymbionts of most Pseudococcidae, Tremblaya princeps [17]–[26]. Furthermore, the DNA sequencing data obtained can be used to develop species-specific Polymerase Chain Reactions (PCR), making it possible to identify species molecularly, on the basis of the size of the sequence amplified [18], [27]–[29].…”

Genetic diversity of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccidae) in Chile

“…Its unique geography resembles that of an island and its environmental features create highly diverse agroecosystems and structured insect populations 23 . These conditions favor the establishment of new invading pests and the colonization of crops by native species, as observed for mealybugs infesting vineyards 14, 25 . Survey data are also of direct interest to stakeholders in Chile, such as the Chilean National Agricultural and Livestock Service ( Servicio Agrícola y Ganadero ), which carries out phytosanitary checks on exported products and prevents the introduction of new pests that might seriously damage Chilean agriculture.…”

“…Morphological studies have been performed on scale insects from South America 20–22 , but the marked lack of genetic information for scale insects from this continent is problematic for the efficient management of these pest species in this region. Previous DNA barcoding studies on scale insects have focused on the Pseudococcidae in Chile 14, 23 and Brazil 24 . The Diaspididae and Coccidae families remain poorly characterized and underexplored.…”

A survey of mealybugs infesting South-Brazilian wine vineyards

“…Mealybugs associated with grapes showed a lower diversity in several other grape-producing countries such as Argentina, Chile, Italy, New Zealand, Portugal, South Africa and Tunisia, which show an average of three species present in the culture (Borbón et al, 2004;Walton and Pringle, 2004;Mahfoudhi and Dhouibi, 2009;Walton et al, 2009;Bertin et al, 2010;Charles et al, 2010;Correa et al, 2012;Mansour et al, 2012;Maia, 2013). The high species diversity in vineyards difficult the deployment of efficient control programs due to their different life cycles and respond differently to chemical and biological management strategies.…”