Silica and Selenium Nanoparticles Attract or Repel Scale Insects by Altering Physicochemical Leaf Traits.

Although nanoparticles have gained attention as efficient alternatives to conventional agricultural chemicals, there is limited knowledge regarding their effects on herbivorous insect behavior and plant physicochemistry. Here, we investigated the effects of foliar applications of nano-silica (SiO2NPs) and nano-selenium (SeNPs), and bulk-size silica (SiO2) on the choice behavior of the arrowhead scale insect on mandarin orange plants. One leaf of a bifoliate pair was treated with one of the three chemicals, while the other was treated with water (control). The respective SiO2, SeO2, calcium (Ca), and carbon (C) content levels in the leaf epidermis and mesophyll were quantified using SEM-EDX (or SEM-EDS); leaf toughness and the arrowhead scale density and body size were measured. First-instar nymphs preferred silica-treated leaves and avoided SeNP-treated leaves. SiO2 content did not differ between control and SiO2NP-treated leaves, but was higher in bulk-size SiO2-treated leaves. The SiO2 level in the control leaves was higher in the SiO2NP treatment compared with that in the control leaves in the bulk-size SiO2 treatment. Silica-treated leaves increased in toughness, but SeNP-treated leaves did not; leaf toughness increased with mesophyllic SiO2 content. The insect density per leaf increased with leaf toughness, SiO2 content and, in the SiO2NP treatment, with epidermal C content. There was no correlation between SeO2 content and insect density. This study highlights the potential uses of SeNPs as an insect deterrent and of silica for enhancing leaf toughness and attracting scale insects.

New records of three parasitoids, Pteroptrix chinensis, Aphytis hispanicus, and Marlattiella prima (Hymenoptera: Aphelinidae) associated with an exotic scale, Lopholeucaspis japonica (Hemiptera: Diaspididae) in Tennessee.

A survey for parasitoids of Lopholeucaspis japonica Cockerell (Hemiptera: Diaspididae), an exotic scale of woody ornamentals, resulted in the discovery of 3 species of aphelinid parasitoid wasps, Pteroptrix chinensis (Howard), Aphytis hispanicus (Mercet), and Marlattiella prima Howard. This serves as the first report of these parasitoids reared from a host in the state of Tennessee, USA. Despite routine pesticide applications in the surveyed nursery and directed treatments of the infested plants to control the scale outbreak, the percentage of parasitized scale in privet and euonymus shrubs averaged 7.0% and 7.9%, respectively. These parasitoids may be useful in the natural or managed control of this pest in the United States, but additional research is needed to understand how these parasitoids contribute to the control of L. japonica in the landscape and how nursery production practices can be modified to promote parasitoid populations.

Pest categorisation of Lepidosaphes malicola.

The EFSA Panel on Plant Health performed a pest categorisation of Lepidosaphes malicola (Hemiptera: Diaspididae), the Armenian mussel scale, for the territory of the European Union, following commodity risk assessments of Prunus persica and P. dulcis plants for planting from Türkiye, in which L. malicola was identified as a pest of possible concern. L. malicola is a polyphagous insect of temperate and arid areas, feeding on more than 60 plant species belonging to 26 families. Important crops significantly affected by L. malicola in parts of Asia include stone fruits (Prunus armeniaca, P. persica), pome fruits (Malus domestica, Pyrus communis), grapes (Vitis vinifera), pomegranate (Punica granatum), walnuts (Juglans regia) and ornamental plants (Berberis spp., Cornus spp., Jasminum spp., Ligustrum spp.). L. malicola has two generations annually. The overwintered eggs hatch from late May to early June. First-instar nymphs crawl on the host plant for a short period, then settle to feed. Nymphs reach maturity in late summer or early autumn. Plants for planting, fruits and cut flowers provide potential pathways for entry into the EU. Host availability and climate suitability suggest that southern, central and some parts of northern EU countries would be suitable for the establishment of L. malicola. Despite being a pest in Armenia, Iran and Tajikistan, there is no evidence of it being a pest in Türkiye. L. malicola was detected in Bulgaria and Greece over 30 years ago, but there have been no records since, and its status is uncertain. Its ability to cause an impact in the EU is also uncertain. It is not listed in Annex II of the Commission Implementing Regulation (EU) 2019/2072. Phytosanitary measures are available to reduce the likelihood of entry. Except for the criterion of having an economic or environmental impact, for which there is great uncertainty, L. malicola satisfies all other criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Pest categorisation of Aulacaspis tubercularis.

The EFSA Panel on Plant Health performed a pest categorisation of Aulacaspis tubercularis (Hemiptera: Diaspididae), the white mango scale, for the EU. A. tubercularis is a tropical species that originates from Asia but is now established in several tropical and subtropical regions throughout the world. It also occurs within the EU and is established in Italy, Portugal and Spain. A. tubercularis is not listed in Commission Implementing Regulation (EU) 2019/2072. It is polyphagous, feeding on plants in more than 37 genera in 23 families and is most frequently reported on mango (Mangifera indica). Indeed, it is considered one of the key pests of mango crops around the world. No evidence was found indicating damage to crops other than mango. A. tubercularis is established in southern Spain (Andalusia) with four overlapping generations and two population peaks, one in summer and another in autumn. Andalusia is the main mango producing area of the EU and A. tubercularis can cause losses through downgrading of fruit. The main natural dispersal stage is the first instar, which crawls over the host plant or may be dispersed further by wind and animals. Plants for planting and fruits provide potential pathways for further entry and spread. Climatic conditions and availability of host plants in southern EU countries are conducive for establishment. Phytosanitary measures are available to reduce the likelihood of further entry and further spread. A. tubercularis satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Diversity, distribution and host plants of armored scale insects (Hemiptera: Diaspididae) in Espírito Santo, Brazil / Diversidade, distribuição e plantas hospedeiras de cochonilhas escama (Hemiptera: Diaspididae) no Espírito Santo, Brasil

Abstract: Armored scale insects (Hemiptera: Diaspididae), are phytophagous species that occur in major biogeographic regions of the world. Because of the importance of diaspidids as pests, there is widespread interest in countries that export and import unprocessed agricultural products in increased knowledge of this group which includes invasive and quarantine pests of great economic concern. The diversity, geographic distribution, and host of diaspidids were studied from November 2002 to December 2018 in 34 municipalities in the state of Espírito Santo, Brazil. Forty species of Diaspididae from 27 genera were collected and identified. The species Acutaspis perseae (Comstock), A. umbonifera (Newstead), Aonidiella aurantii (Maskell), Comstockaspis perniciosa (Comstock), Lepidosaphes beckii (Newman), Lepidosaphes gloverii (Packard), Morganella longispina (Morgan), Mycetaspis apicata (Newstead), and Thysanofiorinia nephelii (Maskel) were found for the first time in Espírito Santo. The plant families Myrtaceae, Moraceae, Arecaceae, Asparagaceae, and Rutaceae had the greatest number of host plant species of armored scale. Fifty-seven new host associations were observed for 25 species of diaspidids and 11 diaspidid species were recorded for the first time from nine families of plants. Selenaspidus articulatus (Morgan) was the most polyphagous species observed with 17 host plant species from 12 families, followed by Pseudaonidia trilobitiformis (Green), and Parlatoria proteus (Curtis). With these new records, 41 species and 28 genera of Diaspididae have been recorded in Espírito Santo.

Resumo: As cochonilhas escama (Hemiptera: Diaspididae), são espécies fitófagas que ocorrem nas principais regiões biogeográficas do mundo. Devido à importância dos diaspidídeos como pragas, existe um amplo interesse nos países que exportam e importam produtos agrícolas não processados no aumento do conhecimento desse grupo, o que inclui pragas invasoras e quarentenárias de grande importância econômica. A diversidade, distribuição geográfica e hospedeiros de diaspidídeos foram estudadas de novembro de 2002 a dezembro de 2018 em 34 municípios do estado do Espírito Santo, Brasil. Quarenta espécies de Diaspididae de 27 gêneros foram coletadas e identificadas. As espécies Acutaspis perseae (Comstock), A. umbonifera (Newstead), Aonidiella aurantii (Maskell), Comstockaspis perniciosa (Comstock), Lepidosaphes beckii (Newman), Lepidosaphes gloverii (Packard), Morganella longispina (Morgan), Mycetaspis apicata (Newstead) e Thysanofiorinia nephelii (Maskel) foram encontradas pela primeira vez no Espírito Santo. Cinquenta e sete novas associações de hospedeiros foram observadas, em um total de 25 espécies de diaspidídeos; estes incluem 13 novos registros de famílias em um total de 11 espécies de diaspidídeos e nove famílias de plantas. Myrtaceae, Moraceae e Arecaceae foram as famílias botânicas com o maior número de espécies de diaspidídeos observadas. Selenaspidus articulatus (Morgan) foi a espécie mais polífaga, com 17 espécies de plantas hospedeiras de 12 famílias observadas, seguida por Pseudaonidia trilobitiformis (Green) e Parlatoria proteus (Curtis). Com esses novos registros, 41 espécies e 28 gêneros de Diaspididae foram registrados no Espírito Santo.

Nonadaptive host-use specificity in tropical armored scale insects.

Most herbivorous insects are diet specialists in spite of the apparent advantages of being a generalist. This conundrum might be explained by fitness trade-offs on alternative host plants, yet the evidence of such trade-offs has been elusive. Another hypothesis is that specialization is nonadaptive, evolving through neutral population-genetic processes and within the bounds of historical constraints. Here, we report on a striking lack of evidence for the adaptiveness of specificity in tropical canopy communities of armored scale insects. We find evidence of pervasive diet specialization, and find that host use is phylogenetically conservative, but also find that more-specialized species occur on fewer of their potential hosts than do less-specialized species, and are no more abundant where they do occur. Of course local communities might not reflect regional diversity patterns. But based on our samples, comprising hundreds of species of hosts and armored scale insects at two widely separated sites, more-specialized species do not appear to outperform more generalist species.

Biological Control: A Major Component of the Pest Management Program for the Invasive Coconut Scale Insect, Aspidiotus rigidus Reyne, in the Philippines.

The coconut scale insect, Aspidiotus rigidus Reyne, caused a major pest outbreak in coconut plantations and stands in the Southern Tagalog region of Luzon Island in the Philippines between 2010 and 2015. To determine if parasitism by Comperiella calauanica Barrion, Almarinez and Amalin, a native encyrtid, could have been a factor in the eventual management of the outbreak by 2015, we estimated and assessed its parasitization levels on A. rigidus colonies on field-collected samples from selected points in three provinces in the Southern Tagalog Region across three sampling periods. We observed that C. calauanica consistently occurred only in areas where A. rigidus populations occurred, with high parasitization levels in the Southern Tagalog sites from 2014 to 2015. Results of correlation and regression of total scale count against parasitized scale count suggest putative host density-dependent parasitism by C. calauanica in the field. A marked decrease in the abundance of A. rigidus was recorded concurrently with visually observable recovery of coconut trees from the third quarter of 2014 up to the second quarter of 2016. Similar results of significant reduction in A. rigidus populations concurrent with high percent parasitization by mass-reared and released C. calauanica were found in the Zamboanga Peninsula from 2018 to 2020. Our findings and observations altogether suggest that host-specific parasitization by C. calauanica effected biological control, which may have contributed to the eventual management of the A. rigidus outbreak in the Southern Tagalog Region, and also in the Zamboanga Peninsula where similar recovery of coconut trees were observed within a year after inoculative releases of C. calauanica.

Developmental duration and predation rate of the coccidophagous coccinellid Rhyzobius lophanthae (Blaisdell) (Coleoptera: Coccinellidae) on Aspidiotus nerii Bouche.

The consumption rate, survival, and developmental duration of the coccidophagous coccinellid Rhyzobius lophanthae (Blaisdell) (Coleoptera: Coccinellidae), a predator of the armored scale insect, Aspidiotus nerii Bouche (Hemiptera: Diaspididae) were studied under laboratory conditions at two temperature regimes of 25 ± 1 and 30 ± 1°C, 50-65% RH, and 16L:8D. Developmental time (egg to adult) significantly decreased with increase in the temperature. It lasted 27.5 days at 25 ± 1°C and 21.3 days at 30 ± 1°C. The development threshold of R. lophanthae immature stages was 7.823°C, while the thermal constant was 472.379 degree-days. No mortality was recorded during the incubation period. The total mortality rate amongst the larval instars was with 3.33% at 25 ± 1°C and 6.77% at 30 ± 1°C. The sex ratio male to female was 1:1.06. The consumption rate significantly increased with increasing temperatures and within the larval instars. The four larval instar consumed 24.3 and 33.5 adults of A. nerii at 25 ± 1 and 30 ± 1°C, respectively. Overall, micro-climate temperature had a significant impact on the biological parameters of R. lophanthae.

Molecular phylogenetics of Aspidiotini armored scale insects (Hemiptera: Diaspididae) reveals rampant paraphyly, curious species radiations, and multiple origins of association with Melissotarsus ants (Hymenoptera: Formicidae).

The armored scale insect tribe Aspidiotini comprises many pest species that are globally invasive and economically damaging. The taxonomy of scale insects is based almost solely upon morphological characters of adult females, and little prior work has been done to test the classification of aspidiotines against molecular evidence. To address these concerns, we reconstruct a molecular phylogeny for aspidiotine armored scales that expands greatly upon taxonomic and character representations from previous studies. Our dataset includes 127 species (356 terminal taxa) and four gene regions: 28S, EF-1α, COI-COII, and CAD. Nearly 50% of the species treated are identified as pests and several more may represent emerging pests. Phylogenetic data were analyzed in a Bayesian framework using MC3 iterations. The majority of sampled aspidiotine genera are not monophyletic as currently defined. Monophyly constraints for 'worst offenders' were imposed on the phylogeny and stepping-stone MCMC was performed to calculate marginal likelihood scores. Comparisons of marginal likelihoods from runs with constrained vs. informative priors support the interpretation that pest-rich genera are not monophyletic. We use character mapping to illustrate signal and convergence for selected traits that have been used to define or recognize genera and evaluate consistency and retention indices for these traits. The phylogeny illustrates a pervasive pattern in which extremely polyphagous pests - typically having large populations and wide geographical distributions - are frequently intertwined with range-limited specialists on the phylogeny. Finally, the phylogeny recovers three origins of ant association among the Aspidiotini. The history of ant/diaspidid symbioses involves periods of sustained partner fidelity, spanning multiple speciation events, which have been punctuated by opportunistic switches to novel partners.

New Faunistic Records of Armoured Scale Insects of Southern Iran (Hemiptera: Diaspididae)

ABSTRACT As a result of recent field work in southern Iran from 2012 to 2016, twenty species of armoured scale insects were collected, representing two subfamilies (Aspidiotinae and Diaspidinae) and 4 tribes including Aspidiotini (8 species in 5 genera), Diaspidini (4 species in 2 genera), Leucaspidini (5 species in 4 genera) and Parlatoriini (3 species in 1 genus). The species Diaspidiotus gigas (Thiem and Gerneck), is illustrated and redescribed from Iran for the first time. In addition, four species are reported and redescribed from south of Iran for the first time: Aspidiotus nerii Bouché, Diaspidiotus armenicus Borchsenius, Leucaspis pusilla Löw, Melanaspis louristana Balachowsky and Kaussari.

Scale insects (Hemiptera: Coccoidea) associated with arabica coffee and geographical distribution in the neotropical region

ABSTRACT Coffee is one of the most important Brazilian agricultural commodities exported, and Minas Gerais and Espírito Santo States are the main coffee producers. Scale insects are important coffee pests, and 73 species of Cerococcidae (3), Coccidae (18), Diaspididae (6), Eriococcidae (1), Ortheziidae (3), Pseudococcidae (21), Putoidae (2) and Rhizoecidae (19) have been associated with roots, branches, leaves, flowers and fruits of Arabica coffee in the Neotropics. Eight species were found associated with Arabica coffee in Minas Gerais and Espírito Santo States in this study, and Coccidae was the most frequent family. Coccus alpinus, Cc. celatus, Cc. lizeri, Cc. viridis, and Saissetia coffeae (Coccidae) were found in both states; Alecanochiton marquesi, Pseudaonidia trilobitiformis (Diaspididae), and Dysmicoccus texensis (Pseudococcidae) were only found in Minas Gerais. Alecanochiton marquesi and P. trilobitiformis are first reported in Minas Gerais, and Cc. alpinus in Espírito Santo, on Arabica coffee. All scale insect species were associated with coffee leaves and branches, except D. texensis, associated with coffee roots. Fourty seven scale insect species have been found occurring in Brazilian Arabica coffee, and in Espírito Santo (28) and Minas Gerais (23). Widespread and geographical distribution of each species found are discussed.

Local phytochemical response of Musa acuminata × balbisiana Colla cv. 'Bluggoe' (ABB) to colonization by Sternorrhyncha.

The interaction of two Sternorrhyncha species, the banana aphid (Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae, Aphidinae)), vector of the banana bunchy top virus (BBTV), and the latania scale (Hemiberlesia lataniae Signoret (Hemiptera: Diaspididae, Diaspidinae)) with Musa acuminata × balbisiana Colla (ABB Group) 'Bluggoe' (Musaceae) was investigated by a combination of conventional and spatially resolved analytical techniques, 1H NMR, UHPLC-MS, and matrix-free UV-laser desorption/ionization MS imaging. After infestation, the feeding sites of P. nigronervosa on the pseudostem and the exocarp of banana fruit developed a red tinge, in which tissue-specific accumulations of phenylphenalenones were discovered. Phenylphenalenones were also detected in the black mats of sooty molds growing on the banana aphid exudates and in the dorsal scales of H. lataniae. This suggests that although these secondary metabolites play a role in the reaction of banana plants towards attack by sucking insects, an aphid and an armored scale have established mechanisms to exude these metabolites before they deploy their deleterious effect.

A new species of Aulacaspis Cockerell, 1893 from China with a key to Chinese species (Hemiptera, Coccoidea, Diaspididae).

A new species of armored scale insect, Aulacaspis zunyiensissp. n. is described and illustrated from collections on cycads in China. A key to the Aulacaspis species known from China is provided.

Armored Scales and Their Parasitoids on Commercial Avocados Grown in California or Imported from Mexico.

Levels of armored scales (Hemiptera: Diaspididae) on Mexican Hass avocados imported into California over May 2008-June 2009 were monitored on 135 trucks entering the state via the Blythe border station, the entry point receiving the highest volume of fruit. Levels of live sessile scales were 3.9-fold higher than indicated in a previous survey (September 2007-April 2008) although levels of live eggs and crawlers were similar to previous levels. A survey of avocado fruit in California infested with armored scales detected four species known to be endemic but failed to find any of the seven exotic Diaspididae entering the state on Mexican fruit. Monitoring of Mexican armored scales on imported avocados from September 2007 to December 2010 recovered 10 species of parasitoids predominated by two species of Signiphora Ashmead (Hymenoptera: Signiphoridae). One of these species, Signiphora flavopalliata Ashmead, comprised 36% of all collected Mexican parasitoids and is a known hyperparasitoid. A survey of armored scale parasitoids present on commercial California avocados detected 17 genetic signatures, with only four of these in common with those detected on imported Mexican fruit. The implications of these findings are discussed.

Scale Insects (Hemiptera: Coccoidea) on Myrciaria dubia (Myrtaceae) in Brazil.

Commercial cultivation of the fruit tree Myrciaria dubia (Myrtaceae) is being developed in Brazil but phytophagous insects, including scale insects (Hemiptera: Coccoidea), can become pests in plantations. The coccids Ceroplastes jamaicensis White, Coccus viridis (Green), Parasaissetia nigra (Nietner), Pseudokermes vitreus (Cockerell) (Coccidae), and the diaspidid Pseudaonidia trilobitiformis (Green) were collected on M. dubia in the municipality of Belém and Tomé-Açu, state of Pará (PA), metropolitan and Northeast Pará mesoregions, Brazil. A key to species of Coccoidea recorded on M. dubia, based on adult females, is provided. Photographs for all scale insects reported on M. dubia are provided. Ceroplastes jamaicensis is recorded for the first time for Brazil and is herein reported for the first time associated with this host.

Phylogenetic analysis reveals positive correlations between adaptations to diverse hosts in a group of pathogen-like herbivores.

A jack of all trades can be master of none-this intuitive idea underlies most theoretical models of host-use evolution in plant-feeding insects, yet empirical support for trade-offs in performance on distinct host plants is weak. Trade-offs may influence the long-term evolution of host use while being difficult to detect in extant populations, but host-use evolution may also be driven by adaptations for generalism. Here we used host-use data from insect collection records to parameterize a phylogenetic model of host-use evolution in armored scale insects, a large family of plant-feeding insects with a simple, pathogen-like life history. We found that a model incorporating positive correlations between evolutionary changes in host performance best fit the observed patterns of diaspidid presence and absence on nearly all focal host taxa, suggesting that adaptations to particular hosts also enhance performance on other hosts. In contrast to the widely invoked trade-off model, we advocate a "toolbox" model of host-use evolution in which armored scale insects accumulate a set of independent genetic tools, each of which is under selection for a single function but may be useful on multiple hosts.

Molecular Identification of Diaspididae and Elucidation of Non-Native Species Using the Genes 28s and 16s.

Armored scale insects pose a serious threat to habitat conservation across the globe because they include some of the most potent invasive species in the world. They are such a serious concern because their basic morphology, small size, and polyphagous feeding habits often allow them to exist undetected by growers and quarantine experts. In order to provide a potential solution to the problem, we have attempted to elucidate the effectiveness of molecular identification techniques using ribosomal 28s and endosymbiotic 16s rRNA. Sequence data was obtained from many field-collected insects to test the feasibility of identification techniques. A protocol for quick species determination based on sequence data is provided.

A new species of Pseudaulacaspis MacGillivray, 1921 from China (Hemiptera, Coccoidea, Diaspididae) with a key to Chinese species.

A new species of armored scale, Pseudaulacaspis zhenyuanensis Wei & Feng, sp. n. is described and illustrated from specimens collected on Spermadictyon suaveolens in China. A key to armored scale species known from China is provided.

A new species of armored scale, Mycetaspis ailynaomi (Hemiptera, Diaspididae, Aspidiotinae), associated with Mammea americana L. (Malpighiales, Calophyllaceae) from Puerto Rico.

A new species of armored scale, Mycetaspis ailynaomi Dones and Evans is described and illustrated from specimens collected on mamey (Mammea americana) from Puerto Rico. A key to the species of Mycetaspis is provided.