The transcriptome of Icerya aegyptiaca (Hemiptera: Monophlebidae) and comparison with neococcoids reveal genetic clues of evolution in the scale insects.

BACKGROUND: Scale insects are worldwide sap-sucking parasites, which can be distinguished into neococcoids and non-neococcoids. Neococcoids are monophyletic with a peculiar reproductive system, paternal genome elimination (PGE). Different with neococcoids, Iceryini, a tribe in non-neococcoids including several damaging pests, has abdominal spiracles, compound eyes in males, relatively abundant wax, unique hermaphrodite system, and specific symbionts. However, the current studies on the gene resources and genomic mechanism of scale insects are mainly limited in the neococcoids, and lacked of comparison in an evolution frame. RESULT: We sequenced and de novo assembled a transcriptome of Icerya aegyptiaca (Douglas), a worldwide pest of Iceryini, and used it as representative of non-neococcoids to compare with the genomes or transcriptomes of other six species from different families of neococcoids. We found that the genes under positive selection or negative selection intensification (simplified as "selected genes" below) in I. aegyptiaca included those related to neurogenesis and development, especially eye development. Some genes related to fatty acid biosynthesis were unique in its transcriptome with relatively high expression and not detected in neococcoids. These results may indicate a potential link to the unique structures and abundant wax of I. aegyptiaca compared with neococcoids. Meanwhile, genes related to DNA repair, mitosis, spindle, cytokinesis and oogenesis, were included in the selected genes in I. aegyptiaca, which is possibly associated with cell division and germ cell formation of the hermaphrodite system. Chromatin-related process were enriched from selected genes in neococcoids, along with some mitosis-related genes also detected, which may be related to their unique PGE system. Moreover, in neococcoid species, male-biased genes tend to undergo negative selection relaxation under the PGE system. We also found that the candidate horizontally transferred genes (HTGs) in the scale insects mainly derived from bacteria and fungi. bioD and bioB, the two biotin-synthesizing HTGs were exclusively found in the scale insects and neococcoids, respectively, which possibly show potential demand changes in the symbiotic relationships. CONCLUSION: Our study reports the first I. aegyptiaca transcriptome and provides preliminary insights for the genetic change of structures, reproductive systems and symbiont relationships at an evolutionary aspect. This will provide a basis for further research and control of scale insects.

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.

Genetic variation of yellow pistachio hard scale, Lepidosaphes pistaciae Archangelskaya (Hem.: Diaspididae) populations in Kerman province, Iran revealed by ISSR markers.

Yellow pistachio hard scale, Lepidosaphes pistaciae (Hem.: Coccoidea: Diaspididae) is one of the detrimental pests to pistachio trees. This pest is distributed throughout the pistachio producing regions of Iran. It is complex species, having distinct genetic variation. As genetically diversity awareness is essential for identification and management, the diaspidid samples selected from 10 infected region and used to test hypotheses about the genetic variability between and within its populations, during 2016. Inter simple sequence repeat (ISSR) molecular marker was used to assess genetic diversity. Extracted DNA of specimens amplified with nine ISSR primers, six of primers showed the best polymorphism. After observation and scoring bands patterns, data were analyzed with NTSYS ver. 2.02 and POPGENE ver. 1.31 software. Results showed that the bands are in the range between 100 and 2000 bp. The used ISSR primers generated 63 polymorphic fragments, and the average heterozygosity for each primer was 0.266 and the maximum number of bands were recorded for primer SMR7. A dendrogram based on the Unweighted Pair Group Method with Arithmetic mean (UPGMA) method placed them in three groups also, Anar and Baft populations were the most difference among populations. The dendrogram includes the group A (comprise populations collected from Baft, Bardsir, Zarand, Sirjan and Shahrbabak), group B (including populations collected from north Kerman, south Kerman, Kabootarkhan, and Rafsanjan) and group C (including populations collected from Anar). The results showed that ISSR markers technique is able to detect the genetic diversity among the yellow pistachio hard scale populations of various commercial pistachio cultivars within the pistachio orchards, in Kerman, Iran.

Community analysis of microbial sharing and specialization in a Costa Rican ant-plant-hemipteran symbiosis.

Ants have long been renowned for their intimate mutualisms with trophobionts and plants and more recently appreciated for their widespread and diverse interactions with microbes. An open question in symbiosis research is the extent to which environmental influence, including the exchange of microbes between interacting macroorganisms, affects the composition and function of symbiotic microbial communities. Here we approached this question by investigating symbiosis within symbiosis. Ant-plant-hemipteran symbioses are hallmarks of tropical ecosystems that produce persistent close contact among the macroorganism partners, which then have substantial opportunity to exchange symbiotic microbes. We used metabarcoding and quantitative PCR to examine community structure of both bacteria and fungi in a Neotropical ant-plant-scale-insect symbiosis. Both phloem-feeding scale insects and honeydew-feeding ants make use of microbial symbionts to subsist on phloem-derived diets of suboptimal nutritional quality. Among the insects examined here, Cephalotes ants and pseudococcid scale insects had the most specialized bacterial symbionts, whereas Azteca ants appeared to consume or associate with more fungi than bacteria, and coccid scale insects were associated with unusually diverse bacterial communities. Despite these differences, we also identified apparent sharing of microbes among the macro-partners. How microbial exchanges affect the consumer-resource interactions that shape the evolution of ant-plant-hemipteran symbioses is an exciting question that awaits further research.

Common, unsightly and until now undescribed: Fumiglobus pieridicola sp. nov., a sooty mold infesting Pieris japonica from western North America.

Sooty molds (Capnodiaceae) are saprotrophs on the surfaces of leaves, and they take their nutrients from honeydew exuded by sap-sucking insects. We describe and illustrate the sooty mold Fumiglobus pieridicola sp. nov., which, to the dismay of gardeners, forms a thick black mycelial coating on the leaves and twigs of ornamental Japanese andromeda (Pieris japonica) in western North America. As a mitosporic species with a pycnidium that lacks an elongated neck and has at most a rudimentary stalk, the species belongs in the genus Fumiglobus. Although locally common, we found no specimens identified under Fumiglobus or its synonyms in regional herbaria and no record of any similar fungus in host indices. Our species differs from others in Fumiglobus in having smaller pycnidia and conidia and in having intercalary as well as apical pycnidia. We determined partial 18S and 28S ribosomal gene sequences for F. pieridicola, the first for any Fumiglobus species. Sequence analysis provides strong bootstrap support for including Fumiglobus within Capnodiaceae. We also determined 18S and 28S sequences for the type species of the mitosporic genus Conidiocarpus, also in Capnodiaceae. We confirm that Conidiocarpus is the anamorph of Phragmocapnias. Following the rules of nomenclatural priority, we propose the new combinations Conidiocarpus asiaticus, Conidiocarpus betle, Conidiocarpus callitris, Conidiocarpus fuliginodes, Conidiocarpus heliconiae, Conidiocarpus imperspicuus and Conidiocarpus siamensis. We hope that describing the mystery fungus from our region and providing sequences for its molecular identification will lead to new studies on its biology and distribution.

Karyotype and reproductive traits of the unique symbiotic mealybug Orbuspedummachinator G.-Z. (Homoptera, Coccinea).

The karyotype and reproductive features of Orbuspedummachinator Gavrilov-Zimin, 2017 (Pseudococcidae) were studied for the first time. Diploid chromosome number is 18 in females. Reproduction is probably bisexual, as indicated by the presence of characteristic Lecanoid heterochromatinization of the paternal set of chromosomes in embryonic cells of about 50% of the embryos studied. The female reproductive system has a pair of lateral oviducts merged into enlarged common oviduct; the spermatheca and accessory glands are connected to the common oviduct in its proximal part. Complete ovoviviparity occurs in ontogenesis.

Potential Global Invasion Risk of Scale Insect Pests Based on a Self-Organizing Map.

In the present study, a global presence/absence dataset including 2486 scale insect species in 157 countries was extracted to assess the establishment risk of potential invasive species based on a self-organizing map (SOM). According to the similarities in species assemblages, a risk list of scale insects for each country was generated. Meanwhile, all countries in the dataset were divided into five clusters, each of which has high similarities of species assemblages. For those countries in the same neuron of the SOM output, they may pose the greatest threats to each other as the sources of potential invasive scale insect species, and therefore, require more attention from quarantine departments. In addition, normalized ζi values were used to measure the uncertainty of the SOM output. In total, 9 out of 63 neurons obtained high uncertainty with very low species counts, indicating that more investigation of scale insects should be undertaken in some parts of Africa, Asia and Northern Europe.

Is Hyperdermium Congeneric with Ascopolyporus? Phylogenetic Relationships of Ascopolyporus spp. (Cordycipitaceae, Hypocreales) and a New Genus Neohyperdermium on Scale Insects in Thailand.

During surveys of insect pathogenic fungi (IPF) in Thailand, fungi associated with scale insects and plants were found to represent five new species of the genus Ascopolyporus in Cordycipitaceae. Their macroscopic features resembled both Hyperdermium and Ascopolyporus. Morphological comparisons with the type and known Ascopolyporus and Hyperdermium species and phylogenetic evidence from a multigene dataset support the appointment of a new species of Ascopolyporus. Moreover, the data also revealed that the type species of Hyperdermium, H. caulium, is nested within Ascopolyporus, suggesting that Hyperdermium is congeneric with Ascopolyporus. The specimens investigated here differ from other Ascopolyporus species by phenotypic characters including size and color of stromata. Phylogenetic analyses of combined LSU, TEF1, RPB1 and RPB2 sequences strongly support the notion that these strains are distinct from known species of Ascopolyporus, and are proposed as Ascopolyporus albus, A. galloides, A. griseoperitheciatus, A. khaoyaiensis and A. purpuratus. Neohyperdermium gen. nov. is introduced for other species originally assigned to Hyperdermium and Cordyceps occurring on scale insects and host plants as epiphytes, accommodating two new combinations of Hyperdermium pulvinatum and Cordyceps piperis.

Predicting the habitat suitability of the invasive white mango scale, Aulacaspis tubercularis; Newstead, 1906 (Hemiptera: Diaspididae) using bioclimatic variables.

BACKGROUND: The white mango scale, Aulacaspis tubercularis (Hemiptera: Diaspididae), is an invasive pest that threatens the production of several crops of commercial value including mango. Though it is an important pest, little is known about its biology and ecology. Specifically, information on habitat suitability of A. tubercularis occurrence and potential distribution under climate change is largely unknown. In this study, we used four ecological niche models, namely maximum entropy, random forest, generalized additive models, and classification and regression trees to predict the habitat suitability of A. tubercularis under current and future [representative concentration pathways (RCPs): RCP4.5 and RCP8.5 of the year 2070] climatic scenarios, using bioclimatic variables. Models' performance was evaluated using the true skill statistic (TSS), the area under the curve (AUC), correlation (COR), and the deviance. RESULTS: All models sufficiently predicted the occurrence of A. tubercularis with high accuracy (AUC ≥ 0.93, TSS ≥ 0.81 and COR ≥ 0.77). The random forest algorithm had the highest accuracy among the four models (AUC = 0.99, TSS = 0.93, COR = 0.90, deviance = 0.26). Temperature seasonality (Bio4), mean temperature of the driest quarter (Bio9), and precipitation seasonality (Bio15) were the most important variables influencing A. tubercularis occurrence. Models' predictions showed that countries in east, south, and west Africa are highly suitable for A. tubercularis establishment under current conditions. Similarly, Mexico, Brazil, India, Myanmar, Bangladesh, Thailand, Laos, Vietnam, and Cambodia are also highly suitable for the pest to thrive. Under future conditions, the suitable areas might slightly decrease in many countries of sub-Saharan Africa under both RCPs. However, the range of expansion of A. tubercularis is projected to be higher in Australia, Brazil, Spain, Italy, and Portugal under the future climatic scenarios. CONCLUSION: The results reported here will be useful for guiding decision-making, developing an effective management strategy, and serving as an early warning tool to prevent further spread toward new areas. © 2022 Society of Chemical Industry.

Fungal Associates of Soft Scale Insects (Coccomorpha: Coccidae).

Ophiocordyceps fungi are commonly known as virulent, specialized entomopathogens; however, recent studies indicate that fungi belonging to the Ophiocordycypitaceae family may also reside in symbiotic interaction with their host insect. In this paper, we demonstrate that Ophiocordyceps fungi may be obligatory symbionts of sap-sucking hemipterans. We investigated the symbiotic systems of eight Polish species of scale insects of Coccidae family: Parthenolecanium corni, Parthenolecanium fletcheri, Parthenolecanium pomeranicum, Psilococcus ruber, Sphaerolecanium prunasti, Eriopeltis festucae, Lecanopsis formicarum and Eulecanium tiliae. Our histological, ultrastructural and molecular analyses showed that all these species host fungal symbionts in the fat body cells. Analyses of ITS2 and Beta-tubulin gene sequences, as well as fluorescence in situ hybridization, confirmed that they should all be classified to the genus Ophiocordyceps. The essential role of the fungal symbionts observed in the biology of the soft scale insects examined was confirmed by their transovarial transmission between generations. In this paper, the consecutive stages of fungal symbiont transmission were analyzed under TEM for the first time.

Taxonomic and identification review of adventive Fiorinia Targioni Tozzetti (Hemiptera, Coccomorpha, Diaspididae) of the United States.

This work provides general descriptions, illustrations, molecular diagnostic data, taxonomic keys, slide mounting recommendations, and Florida distribution records for Fiorinia Targioni Tozzetti species occurring in the USA. Species treated are F.externa Ferris, F.fioriniae (Targioni Tozzetti), F.japonica Kuwana, F.pinicola Maskell, F.phantasma Cockerell & Robinson, F.proboscidaria Green, and F.theae Green. New descriptions of second-instar males and females of all seven species in addition to first-instar nymphs and adult females of F.phantasma and F.proboscidaria are presented. Taxonomic keys to second-instar males and females are developed for the first time and previously available taxonomic keys to first-instar nymphs and adult females are improved. DNA sequences were used to further evaluate the monophyly of Fiorinia and provide additional diagnostic tools for Fiorinia species. Multigene phylogenetic analyses, COI barcoding methods, and examination of type material indicate that F.yongxingensis Liu, Cai & Feng, 2020, syn. nov. is a junior synonym of F.phantasma. A morphological survey of the genus demonstrates, for the first time, the utility of second-instar males for diagnostics. This study will help inform regulatory and pest management decisions by facilitating morphological and molecular identification of adventive Fiorinia species occurring in the USA.

Sex, males, and hermaphrodites in the scale insect Icerya purchasi.

Androdioecy (the coexistence of males and hermaphrodites) is a rare mating system for which the evolutionary dynamics are poorly understood. Here, we investigate the cottony cushion scale, Icerya purchasi, one of only three reported cases of androdioecy in insects. In this species, female-like hermaphrodites have been shown to produce sperm and self-fertilize. However, males are ocassionally observed as well. In a large genetic analysis, we show for the first time that, although self-fertilization appears to be the primary mode of reproduction, rare outbreeding events do occur in natural populations, supporting the hypothesis that hermaphrodites mate with males and hence androdioecy is the mating system of I. purchasi. Thus, this globally invasive pest insect appears to enjoy the colonization advantages of a selfing organism while also benefitting from periodic reintroduction of genetic variation through outbreeding with males.

Two new species of Coccomorpha (Hemiptera: Sternorrhyncha) collected from Japanese silver grass, Miscanthus sinensis (Poaceae) in Okinawa Island, Japan.

Two new species of Coccomorpha collected from Japanese silver grass, Miscanthus sinensis Andersson (Poaceae), in Okinawa Island, Japan, are described based on the morphology of adult females: Aspidiella kijimuna sp. nov. (Diaspididae) and Dysmicoccus bunagaya sp. nov. (Pseudococcidae). Aspidiella kijimuna is similar to A. phragmitis (Takahashi, 1931) but differs from it by having relatively well-developed and recognisable third lobes, and median lobes with rounded apices. Dysmicoccus bunagaya is similar to Trionymus okiensis Tanaka, 2018 but differs from it by having more than eight pairs of cerarii. Keys to all the Japanese species of Aspidiella and Dysmicoccus are provided.

Introduction to the study of chromosomal and reproductive patterns in Paraneoptera.

This paper opens the themed issue (a monograph) "Aberrant cytogenetic and reproductive patterns in the evolution of Paraneoptera", prepared by a Russian-Bulgarian research team on the basis of long-term collaborative studies. In this first part of the issue, we provide the basic introductory information, describe the material involved and the methods applied, and give terminology and nomenclature of used taxonomic names.

The Cotton Mealybug Is Spreading along the Mediterranean: First Pest Detection in Italian Tomatoes.

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an extremely polyphagous invasive pest that can cause serious damages to cultivated plants. The pest is native to America but invaded Asian and Mediterranean countries during the last decades. Tomato (Lycopersicon esculentum Mill., Solanaceae) is an economic relevant crop worldwide and its production can be threatened by numerous insect pests including P. solenopsis. We recorded for the first time P. solenopsis in association with tomato in greenhouse crops and urban landscapes in Sicily (Italy) during the fall season in 2020. The species was identified as P. solenopsis based on the morphological characters and DNA amplification of an ≈800 bp portion of mitochondrial cytochrome oxidase subunit I (mtCOI) gene. The phylogenetic analysis among the obtained P. solenopsis mtCOI sequences with those already available in GenBank suggests Asian countries as a potential source of new introduction. This is the first record of P. solenopsis attacking tomato plants in Italy and may represent a potential threat for tomato production in Europe and nearby countries. For this reason, actions should be taken to avoid the uncontrolled spread of this alien species.

Phlebopus roseus, a new edible bolete from China, is associated with insects and plants.

Phlebopus roseus is described as new based on collections from southwest China. Phylogenetic analyses of nuclear rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and portions of nuclear 28S rDNA (28S), translation elongation factor 1-alpha (tef1), and the largest and second largest subunits of RNA polymerase II (rpb1, rpb2) support P. roseus as a novel species in the genus Phlebopus (Boletinellaceae, Boletales). The new species resembles P. portentosus but differs from it in that mature basidiomata have a bright rose-red-colored stipe and a radiate tubular hymenophore with nested pores. Despite extensive searching, P. roseus has only been found at four sites within a 24-hectare orchard dominated by Eriobotrya japonica, which is agriculturally important given its fruit production (loquats). Therefore, this species appears to be endemic and geographically restricted. The ecology of this bolete is also unique. In line with the trophic behavior of other species in the Boletinellaceae, our observations indicate that P. roseus forms a symbiotic association with the scale insect Coccus hesperidum, identified through sequence analysis of its mitochondrial cytochrome c oxidase subunit I (COI) region, to form fungus-insect galls that develop on roots of E. japonica trees. Phlebopus roseus is an edible mushroom species and is collected from the type location by farmers and sold commercially in limited quantities at local markets alongside P. portentosus and other fungi.

Scale insect genus names and their families in the scale insects (Hemiptera: Sternorrhyncha: Coccomorpha), a supplement.

A list of genus names in the scale insects published between 2014 and the end of 2019 is provided; it follows on from an earlier comprehensive list of the names published between 1758 and the end of 2013. Each genus name and its type species are assigned to one of the 53 scale insect families now recognised.

The challenge of Coccidae (Hemiptera: Coccoidea) mitochondrial genomes: The case of Saissetia coffeae with novel truncated tRNAs and gene rearrangements.

There have been few reports of complete mitochondrial genomes (mitogenomes) of scale insects, and it has been indicated that complex and novel structures in their mitogenomes may lead to difficulties in sequencing, assembly and annotation. Transfer RNAs (tRNAs) usually possess typical cloverleaf secondary structures, and truncated tRNAs are rarely found in insect mitogenomes. Here, we report a complete Saissetia coffeae mitogenome (15,389 bp) with high A+T content (84.7%) sequenced by next-generation sequencing (NGS) methods. Genes in the mitogenome were annotated, and nine tRNAs were not found using MITOS. Most of the detected tRNAs were significantly truncated without the dihydrouridine (DHU) arm or the TΨC (T) arm. In addition, the 9 "lost" tRNAs containing mismatched base pairs were retrieved based on the tRNA annotation workflow for Coccidae described in our study. The gene arrangement in the Saissetia coffeae mitogenome was significantly different from that in other hemipteran insects. Additionally, Bayesian and maximum likelihood trees based on the mitochondrial genes showed a long branch of the Saissetia lineage, indicating significant nonsynonymous substitutions or high evolutionary rates in the Saissetia lineage. We provide a reference mitogenome for the assembly and annotation of the Coccidae mitogenome and offer insights into the evolution of scale insects.

Five new species of Aspidiotini (Hemiptera, Diaspididae, Aspidiotinae) from Argentina, with a key to Argentine species.

Five new species of armored scale insect from Argentina are described and illustrated based upon morphological and molecular evidence from adult females: Chortinaspis jujuyensis sp. nov., Clavaspis patagonensis sp. nov., Hemiberlesia ozolita sp. nov., Melanaspis lilloi sp. nov., and Melanaspis targionoides sp. nov. The genera Chortinaspis and Melanaspis are recorded for the first time from this country. An identification key to all recorded species from tribe Aspidiotini occurring in Argentina is provided.

Homologous series by Nikolai Vavilov in the phylogeny of Homoptera.

The paper briefly discusses the most impressive examples of the Nikolai Vavilov's "Law of homologous series" in the evolution of one of the largest animal groups, homopterous insects, which comprise about 65,000 recent species in the world fauna. Different taxonomic and phylogenetic characters (morpho-anatomical, cytogenetic, reproductive and others) are considered at the taxonomic ranks of the order, suborder, superfamily and family.