Morphological and molecular taxonomic analysis of the Encarsia meritoria species-complex (Hymenoptera, Aphelinidae), parasitoids of whiteflies (Hemiptera, Aleyrodidae) of economic importance (original) (raw)
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Bulletin of Entomological Research, 2002
Several series of host-reared specimens of an Encarsia species, initially thought to be the cosmopolitan Encarsia inaron (Walker), were collected in the Azores Islands (Portugal). Subsequent morphometric analysis supported the presence of two species: E. inaron and a new species, described herein as Encarsia estrellae Manzari & Polaszek sp. n. Encarsia estrellae was reared from Aleyrodes singularis Danzig, A. ?singularis, and Bemisia sp. afer-group on several host plants. In addition, the D2 region of the 28S rDNA gene was sequenced in eight individuals belonging to these species, as well as single representatives of two closely related and one distantly related species. Phylogenetic analysis of these DNA sequences, together with 23 additional Encarsia sequences retrieved from the European Molecular Biology Laboratory (EMBL) and GenBank databases, further supported the specific status of E. estrellae, and the placement of E. dichroa (Mercet) in the E. inaron species-group. Additionally, E. inaron is redescribed and some taxonomic problems in the E. inaron species-group are discussed. Aphididae: Hormaphidinae) and a few species parasitize the eggs of Lepidoptera .
Insects
The genus Dirphys Howard 1914 syn. n. is synonymized with Encarsia Förster, and treated as a species-group of Encarsia, referred to henceforth as the Encarsia mexicana species-group. The monophyly of Encarsia is discussed in relation to Dirphys. The new synonymy is based on phylogenetic analyses of the nuclear ribosomal 28S-D2 gene region (43 taxa, 510 bp). The Encarsia mexicana species-group is recovered as strongly monophyletic within Encarsia. All species of the Encarsia mexicana species-group are revised. The group includes six previously described species, and fourteen newly described species. All species are described (or redescribed) and illustrated. Detailed distributional data, and, where available, plant associate and host records are provided for all species. Encarsia myartsevae Kresslein and Polaszek nom. nov. is here proposed as a replacement name for Encarsia mexicana Myartseva, now preoccupied by Encarsia mexicana (Howard). A dichotomous identification key, supplement...
Biological Control, 2004
Encarsia sophia is a cosmopolitan parasitoid of whitefly pests and is regarded as a potential biocontrol agent of the Bemisia tabaci species-complex. However, the possibility exists that under this specific name a complex of cryptic species may be contained, whose correct identification is essential for their effective use in biological control programmes. In this paper two populations native to Pakistan and Spain, respectively, were characterized by means of morphometric analysis, crossing experiments and karyological analysis. The two populations, indistinguishable on the basis of single morphological characters, were distinguished through a canonical discriminant function analysis. Mating tests showed rare copulation attempts and no transfer of spermatozoa into the spermatheca in heterogamic crosses, thus suggesting that the Pakistani and Spanish populations are reproductively isolated. Although the two populations shared the same karyotype formula (2n ¼ 2m þ 2sm þ 6a), consistent differences were found in their chromosome sets. In the Spanish population the metacentric chromosome was almost one half of the whole genome set (rl ¼ 44.23), while in the Pakistani one, it was shorter (rl ¼ 29.55) and as long as the sub-metacentric chromosome. Moreover, silver staining provided evidence of a different localization of the active nucleolus organizer regions (NORs). Results obtained in this study suggest that the Pakistani and Spanish populations are distinct cryptic species.
Systematic Entomology, 2016
Encarsia pergandiella Howard, described from North America (USA), and Encarsia tabacivora Viggiani, described from South America (Brazil) (Hymenoptera: Aphelinidae), are two formally recognized taxonomic entities, that have been treated by several authors as synonyms due to lack of strong diagnostic characters. Taxonomy of these species is further complicated because several populations, geographically separated and differing in their biology, have been included under the concept of E. pergandiella. Among these, a population originally collected in Brazil and introduced to North America reproduces by thelytokous parthenogenesis and is infected by the symbiont Cardinium, while a morphologically indistinguishable population, naturally occurring in Texas, is biparental and infected by a related strain of Cardinium that induces cytoplasmic incompatibility. A third population known from California and introduced to the Old World is biparental and uninfected by intracellular symbionts. While adult females of the first two populations have entirely light yellow bodies and pupate face up (light form), those of the third population have largely brown bodies and pupate face down (dark form). Other dark form populations are known from Texas, Florida and New York. Because these parasitoids are economically important biological control agents of cosmopolitan whitefly pests, it is critical to characterize them correctly. In this study, we integrated molecular and morphometric analyses to substantiate observed differences in biological traits, and resolve the complicated taxonomy of this species complex. We sequenced the mitochondrial cytochrome c oxidase subunit I gene and the D2 region of the ribosomal 28S gene for individuals of both light form (from Texas and Brazil) and dark form (from California, Texas, Italy and Canary Islands) originating from laboratory cultures or collected in the field. Phylogenetic analysis unambiguously distinguished three well-supported groups corresponding to the Texas light form, the Brazil light form and the dark form. Individuals of these three groups, in combination with all available type material (E. pergandiella, its synonym Encarsia versicolor Girault and E. tabacivora) and additional museum specimens of the dark form from New York and Italy, were subjected to multivariate morphometric analyses using Burnaby principal component analysis followed by a linear discriminant analysis, and multivariate ratio analysis. Overall, the analyses showed that: (i) E. pergandiella and E. tabacivora are two distinct species; (ii) the thelytokous Brazil light form corresponds to E. tabacivora; (iii) the biparental Texas light form is a new species formally described
Molecular Phylogenetics and Evolution, 2001
Species of Encarsia Förster (Hymenoptera: Aphelinidae, Coccophaginae) are economically important for the biological control of whitefly and armored scale pests (Hemiptera: Aleyrodidae, Diaspididae). Whereas some regional keys for identification of Encarsia species are now available, few studies have addressed relationships within this diverse and cosmopolitan genus because of unreliable morphological data. Nuclear sequences of the D2 expansion region of 28S
Systematic Entomology, 2006
The genus Encarsiella (syn.n.) (Hymenoptera, Chalcidoidea, Aphelinidae) is synonymized with Encarsia on the basis of molecular and morphological characters. A phylogenetic analysis was conducted of the D2 expansion region of the 28S ribosomal DNA including thirty-eight Encarsia species. Our phylogenetic analysis revealed a polyphyletic origin of Encarsiella and confirmed the results of earlier analyses indicating the paraphyly of Encarsia. Four species are described as new (Encarsia bifasciata sp.n., E. caelata sp.n., E. obliqua sp.n. and E. pilosa sp.n.). The following species are transferred from Encarsiella to Encarsia: Encarsia aleurodici (Girault, 1916) comb.n., E. amabilis (Huang & Polaszek, 1998) comb.n., E. boswelli (Girault, 1915) comb.n., E. magniclava (Girault, 1915) comb.n., E. narroi Go´mez & Garcı´a comb.n., E. nepalensis (Polaszek & Hayat, 1992) comb.n., E. noyesi (Hayat, 1983) comb.n., E. pithecura (Polaszek, 1999) comb.n., E. tachii (Polaszek & Hayat, 1992) comb.n., E. taiwanensis (Chou & Chou, 1994) comb.n. and E. tamaulipeca (Myartseva & Coronado-Blanco, 2002) comb.n. The generic limits of Encarsia are redefined based on a re-assessment of morphological characters, and the results are discussed with respect to the current classification of the aphelinid subfamily Coccophaginae.
A revision of the Encarsia longifasciata species group (Hymenoptera: Aphelinidae
Systematic Entomology, 2003
The Encarsia longifasciata group is established and revised, and its relationship to other species groups of Encarsia is discussed with reference to biological, morphological and molecular evidence. Principal component analysis on all available specimens provided supporting evidence for the existence of five species, two of which are described herein as new: E. dewa Pedata & Polaszek, sp.n and E. prinslooi Pedata & Polaszek, sp.n. All species are either diagnosed or described, and illustrated, and information is given on their distribution and host range. Additional information on the biology and larval stages, and scanning electron micrographs of morphological details, are provided for E. arabica Hayat. A preliminary phylogenetic study using 28S D2 rDNA sequence data for E. arabica was inconclusive, but suggested possible affinities between the longifasciata and parvella species groups. An illustrated dichotomous key to all species of the E. longifasciata group is given.
Molecular Markers Distinguishing Encarsia formosa and Encarsia luteola (Hymenoptera: Aphelinidae)
Annals of the Entomological Society of America, 2000
Reciprocal molecular markers were developed to distinguish the closely related parasitoid species Encarsia formosa Gahan and E. luteola Howard. E. formosa is widely used in the biological control of whiteßies and yet, based upon morphology, it is extremely difÞcult to distinguish from E. luteola. The D2 expansion region of 28S rDNA was sequenced from seven strains of E. formosa and two strains of E. luteola to assess the amount of genetic variation within and between species at this locus. From parsimony analysis we Þnd that populations of E. formosa and E. luteola each form a monophyletic clade and are probably each otherÕs most closely related sister taxon. Based upon the sequence variation between species, we present a simple molecular assay to rapidly and unambiguously distinguish E. formosa and E. luteola.