Mealybug species from Chilean agricultural landscapes and main factors influencing the genetic structure of Pseudococcus viburni

Abstract

The present study aimed to characterize the distribution of mealybug species along Chilean agro-ecosystems and to determine the relative impact of host plant, management strategy, geography and micro-environment on shaping the distribution and genetic structure of the obscure mealybug Pseudococcus viburni. An extensive survey was completed using DNA barcoding methods to identify Chilean mealybugs to the species level. Moreover, a fine-scale study of Ps. viburni genetic diversity and population structure was carried out, genotyping 529 Ps. viburni individuals with 21 microsatellite markers. Samples from 16 localities were analyzed using Bayesian and spatially-explicit methods and the genetic dataset was confronted to host-plant, management and environmental data. Chilean crops were found to be infested by Ps. viburni, Pseudococcus meridionalis, Pseudococcus longispinus and Planococcus citri, with Ps. viburni and Ps. meridionalis showing contrasting distribution and host-plant preference patterns. Ps. viburni samples presented low genetic diversity levels but high genetic differentiation. While no significant genetic variance could be assigned to host-plant or management strategy, climate and geography were found to correlate significantly with genetic differentiation levels. The genetic characterization of Ps. viburni within Chile will contribute to future studies tracing back the origin and improving the management of this worldwide invader.

Comparative development and reproduction ofPlanococcus ficusandPlanococcus citri(Hemiptera:Pseudococcidae) on grapevine under field conditions

“…These include the vine mealybug Planococcus ficus (Signoret), grape mealybug Pseudococcus maritimus (Ehrhorn), obscure mealybug Pseudococcus viburni (Signoret), long‐tailed mealybug Pseudococcus longispinus (Targioni‐Tozzetti), citrophilus mealybug Pseudococcus calceolariae (Maskell), citrus mealybug Planococcus citri (Risso) and pink pineapple mealybug Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae) (Walton & Pringle, ; Charles et al ., ; Daane et al ., ; Morandi Filho et al ., ). Planococcus ficus is a key pest in most grape‐growing areas (the Mediterranean basin, California, Mexico, Argentina, South Africa and the Middle East) (Dalla Montà et al ., ; Walton et al ., ; Daane et al ., ; Mansour et al ., ), whereas P. citri is reported as a grape pest in few countries (Brazil, Chile, India and Spain) (Morandi Filho et al ., , ; Cid et al ., ; Daane et al ., ; Correa et al ., ; Gallardo et al ., ). Mixed populations of both citrus and vine mealybugs have been reported in Tunisia (Mahfoudhi & Dhouibi, ; Mansour et al ., ) where P. ficus is considered as the key, most devastating mealybug species (Mansour et al ., ).…”

“…Mixed populations of both citrus and vine mealybugs have been reported in Tunisia (Mahfoudhi & Dhouibi, ; Mansour et al ., ) where P. ficus is considered as the key, most devastating mealybug species (Mansour et al ., ). Currently, the geographical distribution of citrus and vine mealybugs in vineyards is still unclear because the two species have been misidentified in the past (Walton & Pringle, ; Saccaggi et al ., ; Danzig & Gavrilov, ; Correa et al ., ). Indeed, the morphological discrimination of P. ficus and P. citri is time‐consuming and requires high taxonomic knowledge because the two species mainly differ with respect to the number of multilocular disc pores on the pro‐, meso‐ and metathorax, as well as the number of tubular ducts on the head and near the eighth pair of cerarii (Cox & Ben‐Dov, ; Williams & Granara de Willink, ).…”

Effect of Host Plants on the Development, Survivorship, and Reproduction ofPseudococcus viburni(Hemiptera: Pseudococcidae)

“…The obscure mealybug Pseudococcus viburni (Signoret) is a polyphagous insect recorded from 236 host-plant genera in 89 families (Garcia Morales et al 2017). Different evidences suggest that P. viburni originated in southern South America (Charles 2011;Correa et al 2015). It is a pest of several temperate fruits, including apples, pears, and grapevines (Ciampolini et al 2002;Iracheta 2004;Dapoto et al 2011).…”

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

“…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.…”

“…Chile is a particularly interesting location for studies of diversity via DNA barcoding. 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 .…”