Natural enemies of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccoidae) in Chile: molecular and morphological identification (original) (raw)
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PLOS ONE
Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18˚S) to Frutillar (41˚S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 41 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. Species delimitation was confirmed using ABGD, GMYC and PTP model. In Chalcidoidea, 23 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile.
Scientific Reports, 2017
Scale insects (Sternorrhyncha: Coccoidea) are one of the most invasive and agriculturally damaging insect groups. Their management and the development of new control methods are currently jeopardized by the scarcity of identification data, in particular in regions where no large survey coupling morphological and DNA analyses have been performed. In this study, we sampled 116 populations of armored scales (Hemiptera: Diaspididae) and 112 populations of soft scales (Hemiptera: Coccidae) in Chile, over a latitudinal gradient ranging from 18°S to 41°S, on fruit crops, ornamental plants and trees. We sequenced the COI and 28S genes in each population. In total, 19 Diaspididae species and 11 Coccidae species were identified morphologically. From the 63 COI haplotypes and the 54 28S haplotypes uncovered, and using several DNA data analysis methods (Automatic Barcode Gap Discovery, K2P distance, NJ trees), up to 36 genetic clusters were detected. Morphological and DNA data were congruent, except for three species (Aspidiotus nerii, Hemiberlesia rapax and Coccus hesperidum) in which DNA data revealed highly differentiated lineages. More than 50% of the haplotypes obtained had no high-scoring matches with any of the sequences in the GenBank database. This study provides 63 COI and 54 28S barcode sequences for the identification of Coccoidea from Chile. Scale insects (Hemiptera: Coccoidea) are key pests on crops and ornamental plants worldwide. The three most important families in terms of economic damage and number of genera are Diaspididae (419 genera), Pseudococcidae (272 genera) and Coccidae (170 genera) 1. Scale insects can cause economic damage directly, through sap sucking, the injection of toxins and the transmission of viruses that weaken the plant, lowering fruit quality and yield. Mealybugs (Pseudococcidae) and soft scales (Coccidae) may also cause indirect damage, by excreting honeydew onto the plant surface, thereby favoring the development of sooty mold fungi. Scale insects are also invasive pests 2 for which quarantine is required in several markets, leading to the rejection of products during international trade. As a result, active inspections for these insects are carried out by national phytosanitary services, and their presence is monitored by most farm advisors. One of the principal problems in scale insect management concerns the difficulty of their identification. Morphological identification is possible but difficult: it requires high level of expertise and the examination of adult females, which are not always found in the field or in the commercial products. Moreover, even when adult females are examined, it is sometimes difficult to distinguish between very similar species 3, 4. These difficulties have resulted in an overall lack of knowledge for fine-scale taxonomic identification 5, 6 and, probably, widespread errors in management, with the implementation of control methods that are inappropriate for the species actually present in the target area 7. In this context, the use of DNA barcoding has gradually increased over the last decade, as a means of disentangling complexes of cryptic species and surveying the biodiversity occurring in various regions of the world 8, 9. Studies have been performed on the Diaspididae 10-12 , Pseudococcidae 12-16 and Coccidae 3, 17. Phylogenetic studies have also provided useful
Annals of the Entomological Society of America, 2010
ÔHassÕ avocado, Persea americana Miller, fruit being imported into California from Mexico are infested with high levels of a previously unknown species of armored scale insect (Hemiptera: Diaspididae). This species has recently been described and given the name Abgrallaspis aguacatae Evans, Watson & Miller. However, the validity of morphological characters used to diagnose genera within the tribe Aspidiotini (Diaspididae) is the subject of continued debate. Here, we seek to circumnavigate the inherent problems associated with interpretation of somewhat plastic phenotypic characters. We use two different nuclear gene regions (28S and Elongation Factor 1␣) and three different analysis methods (maximum parsimony, maximum likelihood, and Bayesian analyses) to infer phylogeny from DNA sequence data for 35 aspidiotine species. Our analyses suggest that the new species is misplaced in the genus Abgrallaspis Balachowsky and that this genus and several closely allied genera are paraphyletic or polyphyletic. The Þndings of our analyses are discussed speciÞcally in relation to the current placement of A. aguacatae and more broadly in relation to the longrecognized problem of deÞning generic boundaries between Abgrallaspis, Diaspidiotus Berlese, and Hemiberlesia Cockerell.
African Entomology, 2014
Scale insects (Sternorrhyncha: Coccoidea) are one of the most invasive groups of insects. They are sedentary, cryptic, and often resemble the plant parts that they feed on. This coupled with increased international trade in fresh agricultural produce, makes them a major quarantine risk. An important limitation in controlling these pests involves species identification. When scale insects are intercepted on imported produce, they must be rapidly and accurately identified, using morphology-based keys. This is time-consuming and requires extensive taxonomic experience. In addition, intercepted specimens are often immature or damaged, making identification difficult or impossible. A reliable complementary tool is needed for identification. DNA barcoding may be of great value for this purpose. In this study we investigate the suitability of the nuclear regions 18S and 28S as complementary DNA barcodes to the mitochondrial CO1 gene, across 10 scale insect families. Combining multiple criteria, our results indicate that the concatenation of CO1 and 28S greatly improves the identification success rate of scale insects to 91.5 %, demonstrating the utility of DNA barcoding in pest management.
2013
The multicicatrices fluted scale, Crypticerya multicicatrices Kondo and Unruh (Hemiptera: Coccoidea: Monophlebidae) is reported from the islands of San Andres and Providencia, Colombia, as a recent invasive species. This scale insect is polyphagous, and attacks numerous plants of economic importance such as avocado, breadfruit, mango, papaya and tropical ornamental plants. A compiled list of 95 host plant species of C. multicicatrices is given. A diagnosis of the adult female of C. multicicatrices and a revised taxonomic key to the species of the tribe Iceryini (Hemiptera: Monophlebidae) known from South America is provided. The pink hibiscus mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Coccoidea: Pseudococcidae), also is reported for the first time from the island of San Andres, where it is found commonly on Hibiscus spp. and Malvaviscus arboreus Cav. The need for the implementation of a classical biological control program in the archipelago in order to control invasive ...
African Entomology
Scale insects (Sternorrhyncha: Coccoidea) are one of the most invasive groups of insects. They are sedentary, cryptic and often resemble the plant parts they feed on. Thiscoupled with increased international trade of fresh produce, makes them a major quarantine risk. The major limitations in controlling these pests are linked to species identification. If intercepted, scale insects must be quickly and accurately identified, based on morphological keys. This procedure is time-consuming and requires extensive taxonomic experience. In addition, intercepted specimens are often immature or damaged, making identification almost impossible. A reliable complementary tool is needed for identification. DNA barcoding may be of great value for this purpose. In this study we investigate the suitability of the nuclear regions 18S and 28S as complementary DNA barcodes to the mitochondrial CO1 gene, across 10 scale insect families. Combining multiple criteria, our results indicate that the combinat...
Biological Control, 2008
The lobate lac scale Paratachardina pseudolobata Kondo & Gullan (Kerriidae) is a polyphagous pest of woody plants in Florida (U.S.A.) the Bahamas, Christmas Island (Australia) and it has been reported from Cuba. Its recent appearance as a pest in these places indicates that this scale is introduced; however, its native range is unknown. Until 2006, this pest species was identified mistakenly as Paratachardina lobata (Chamberlin) [now P. silvestri (Mahdihassan)], which is native to India and Sri Lanka. Quarantine laboratory acceptance trials with Indian P. silvestri parasitoids indicated a strong immune response from P. pseudolobata. Gregarious development of encyrtid wasps was the only observed parasitism, but parasitization levels were below 3%. Identification of the native range of P. pseudolobata would facilitate the search for natural enemies better adapted to the scale. Sequence data from the D2-D3 region of the nuclear large subunit ribosomal RNA gene (LSU rRNA, 28S) and the mitochondrial gene cytochrome oxidase I (COI) distinguished P. pseudolobata from the morphologically similar species P. silvestri and P. mahdihassani Kondo & Gullan, and showed P. pseudolobata to be more closely related to these Indotropical species than to an Australian species of Paratachardina Balachowsky. Paratachardina pseudolobata was genetically uniform throughout its exotic range, consistent with a single geographic origin, although lack of variation in these genes is not unusual for scale insects. Molecular identification of morphologically similar Paratachardina species was possible using the D2-D3 region of 28S, despite its length variation, suggesting that this gene region might be suitable as a non-COI barcoding gene for scale insects.
ZooKeys, 2019
Aspidiotini is a species-rich tribe of armored scale insects that includes several polyphagous and specialist pests that are commonly encountered at ports-of-entry to the United States and many other countries. This article describes a newly available online interactive tool that can be used to identify 155 species of Aspidiotini that are recognized as minor to major pests or that are potentially emergent pests. This article lists the species and features included with a description of the development and structure of the key. The interactive key is free to access at https://idtools.org/id/scales/aspidiotini/about\_index.php.