Diaspididae Research Articles

Field efficacy of insecticides for suppressing white mango scale insect (Aulacaspis tubercularis Newstead) (Hemiptera: Diaspididae) in southwest Ethiopia

White mango scale (WMS) Aulacaspis tubercularis Newstead (Hemiptera: Diaspididae) is a polyphagous armored scale insect which is considered one of the key pests of mango (Mangifera indica L.) around the world. Mango is widely grown in Ethiopia whereas its production is challenged by WMS in the last decade. Effective formulations that could help manage the scale as part of IPM practice were sought from field experiments at Seka mango farm, Ethiopia in 2019 and 2020 seasons. The study aimed to evaluate the efficacy of some formulations against WMS on mango trees. Randomized complete block designs with three replications were used for the experiments and each tree served as a plot. Allocation of each treatment within each replication was done randomly. The treatments were applied sequentially three times at 14 days interval using motorized Knapsack sprayer coinciding with peak period of natural infestation. Scale numbers before and after each spray were counted using a microscope with LCD. Sum of live crawler, female and male was registered as WMS count data. Results showed that dimethoate, diazinon, imidacloprid & λ-cyhalothrin sprayed alone; dimethoate rotated with imidacloprid & λ-cyhalothrin, chlorpyrifos-ethyl rotated with paraffin, and diazinon rotated with azadirachtin, caused total mortality of the scales. The results also showed that, chlorpyrifos-ethyl, deltamethrin, paraffin oil and λ-cyhalothrin sprayed alone caused percent reduction with range 83–95 % in both seasons. Hence, the study revealed that dimethoate, diazinon, imidacloprid & λ-cyhalothrin applied individually, dimethoate rotated with imidacloprid & λ-cyhalothrin, chlorpyrifos-ethyl rotated with paraffin and diazinon rotated with azadirachtin fully protect mango trees from WMS and significantly superior to other treatments. Therefore, chemical control of A. tubercularis may consider the use of these materials as foliar application and can be used as components for integrated pest management plans for WMS. However, application in the form of rotation is preferred to the alone spray as the former could substantially reduce the likelihood of inducing pesticide resistance. Cost implications and effects of the products on the natural enemy and residual toxicity in fruits need to be studied.

A new species of Odonaspis Leonardi, 1897 (Hemiptera: Coccomorpha: Diaspididae) from China

A new species of armoured scale insect (Hemiptera: Coccomorpha: Diaspididae: Aspidiotinae: Odonaspidini), Odonaspis renhuaiensis Chen, Jian & Xing sp. nov. is described and illustrated from Guizhou Province, China. The type specimens are deposited at the Institute of Entomology, Guizhou University, Guiyang, China. An identification key based on the morphology of adult females is provided to separate all the species of Odonaspis Leonardi, 1897.

Mixed insect pest populations of Diaspididae species under control of oligonucleotide insecticides: 3′-end nucleotide matters

Diaspididae are one of the most serious small herbivorous insects with piercing–sucking mouth parts and are major economic pests as they attack and destroy perennial ornamentals and food crops. Chemical control is the primary management approach for armored scale infestation. However, chemical insecticides do not possess selectivity in action and not always effective enough for the control of armored scale insects. Our previous work showed that green oligonucleotide insecticides (olinscides) are highly effective against armored and soft scale insects. Moreover, olinscides possess affordability, selectivity in action, fast biodegradability, and a low carbon footprint. Insect pest populations undergo microevolution and olinscides should take into account the problem of insecticide resistance. Using sequencing results, it was found that in the mixed populations of insect pests Dynaspidiotus britannicus Newstead and Aonidia lauri Bouche, predominates the population of A. lauri. Individuals of A. lauri comprised for 80% of individuals with the sequence 3′-ATC-GTT-GGC-AT-5′ in the 28S rRNA site, and 20% of the population comprised D. britannicus individuals with the sequence 3′-ATC-GTC-GGT-AT-5′. We created olinscides Diasp80–11 (5′-ATG-CCA-ACG-AT-3′) and Diasp20–11 (5′-ATA-CCG-ACG-AT-3′) with perfect complementarity to each of the sequences. Mortality of insects on the 14th day comprised 98.19 ± 3.12% in Diasp80–11 group, 64.66 ± 0.67% in Diasp20–11 group (p < 0.05), and 3.77 ± 0.94% in the control group. Results indicate that for maximum insecticidal effect it is necessary to use an oligonucleotide insecticide that corresponds to the dominant species. Mortality in Diasp80–11 group was accompanied with significant decrease in target 28S rRNA concentration and was 8.44 ± 0.14 and 1.72 ± 0.36 times lower in comparison with control (p < 0.05) on the 10th and 14th days, respectively. We decided to make single nucleotide substitutions in Diasp20–11 olinscide to understand which nucleotide will play the most important role in insecticidal effect. We created three sequences with single nucleotide transversion substitutions at the 5′-end – Diasp20(5′)-11 (A to T), 3′-end – Diasp20(3′)-11 (T to A), and in the middle of the sequence – Diasp20(6)-11 (6th nitrogenous base of the sequence; G to C), respectively. As a result, mortality of mixed population of the field experiment decreased and comprised 53.89 ± 7.25% in Diasp20(5′)-11 group, 40.68 ± 4.33% in Diasp20(6)-11 group, 35.74 ± 5.51% in Diasp20(3′)-11 group, and 3.77 ± 0.94% in the control group on the 14th day. Thus, complementarity of the 3′-end nucleotide to target 28S rRNA was the most important for pronounced insecticidal effect (significance of complementarity of nucleotides for insecticidal effect: 5′ nt < 6 nt < 3′ nt). As was found in our previous research works, the most important rule to obtain maximum insecticidal effect is complete complementarity to the target rRNA sequence and maximum coverage of target sequence in insect pest populations. However, in this article we also show that the complementarity of 3′-end is a second important factor for insecticidal potential of olinscides. Also in this article we propose 2-step DNA containment mechanism of action of olinscides, recruiting RNase H. The data obtained indicate the selectivity of olinscides and at the same time provide a simple and flexible platform for the creation of effective plant protection products, based on antisense DNA oligonucleotides.

Two new species of Aulacaspis Cockerell, 1893 (Hemiptera: Coccomorpha: Diaspididae) from China, with an identification key to Chinese species.

Two new armoured scale insect species (Hemiptera: Coccomorpha: Diaspididae) are described and illustrated from Guizhou Province, China. Aulacaspis pericampylus sp. n. was collected from Pericampylus glaucus (Menispermaceae) and Aulacaspis multispinata sp. n. was collected from Cinnamomum camphora (Lauraceae). The type specimens of both new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC). A key to the Aulacaspis species known from China, based on the morphology of the adult females, is provided.

Improving DNA barcoding library of armored scale insects (Hemiptera: Diaspididae) in China.

DNA barcoding is used to identify cryptic species, survey environmental samples, and estimate phyletic and genetic diversity. Armored scale insects are phytophagous insects and are the most species-rich taxa in the Coccoidea superfamily. This study developed a DNA barcode library for armored scale insect species collected from southern China during 2021-2022. We sequenced a total of 239 specimens, recognized as 50 morphological species, representing two subfamilies and 21 genera. Sequencing analysis revealed that the average G + C content of the cytochrome oxidase subunit I (COI) gene sequence was very low (~18.06%) and that the average interspecific divergence was 10.07% while intraspecific divergence was 3.20%. The intraspecific divergence value was inflated by the high intraspecific divergence in ten taxa, which may indicate novel species overlooked by current taxonomic treatments. All the Automated Barcode Gap Discovery, Assemble Species by Automatic Partitioning, Taxon DNA analysis and Bayesian Poisson Tree Process methods yielded largely consistent results, indicating a robust and credible species delimitation. Based on these results, an intergeneric distance threshold of ≤ 5% was deemed appropriate for the differentiation of armored scale insect species in China. This study establishes a comprehensive barcode library for the identification of armored scale insects, future research, and application.

Discovery of the primary aphid (Hemiptera: Aphidomorpha) and scale insect (Hemiptera: Coccomorpha) type specimens from the collection of Theodor Hartig (18051880).

Theodor Hartigs aphid and scale insect type specimens have been presumed lost or destroyed for the last 140 years. Here we document their discovery at the Bavarian State Collection of Zoology (Zoologische Staatssammlung Mnchen, ZSM), in Munich, Germany. These specimens include primary types for 24 aphid, three adelgid, and two armored scale insect species named by Hartig between 1834 and 1851, as well as other specimens of unknown importance.

Genomic architecture of resistance to latania scale (H. lataniae) in kiwifruit (A. chinensis var. chinensis)

BackgroundLatania scale (Hemiberlesia lataniae Signoret) is an armoured scale insect known to cause damage to kiwifruit plants and fruit, which ultimately reduces crop values and creates post-harvest export and quarantine issues. Resistance to H. lataniae does exist in some commercial cultivars of kiwifruit. However, some of the commercial cultivars bred in New Zealand have not inherited alleles for resistance to H. lataniae carried by their parents. To elucidate the architecture of resistance in the parents and develop molecular markers to assist breeding, these experiments analysed the inheritance of resistance to H. lataniae from families related to commercial cultivars.ResultsThe first experiment identified a 15.97 Mb genomic region of interest for resistance to H. lataniae in rtGBS data of 3.23 to 19.20 Mb on chromosome 10. A larger population was then QTL mapped, which confirmed the region of interest as the sole locus contributing to H. lataniae resistance. inDel markers mapping the region of low recombination under the QTL peak further narrowed the region associated with H. lataniae resistance to a 5.73 Mb region.ConclusionsThe kiwifruit populations and genomic methods used in this study identify the same non-recombinant region of chromosome 10 which confers resistance of A. chinensis var. chinensis to H. lataniae. The markers developed to target the H. lataniae resistance loci will reduce the amount of costly and time-consuming phenotyping required for breeding H. lataniae scale resistance into new kiwifruit cultivars.

Armored scale insects (Hemiptera: Diaspididae) associated with avocados (Persea americana) in Mxicos main production areas, with keys for identification and natural enemies.

Avocado orchards in eight avocado-producing states of Mxico were sampled to collect and identify the armored scale insect species (Hemiptera: Diaspididae) that attack the crop and their natural enemies. Sixteen species of armored scales were identified, 12 from the subfamily Aspidiotinae and four from Diaspidinae. A dichotomous key is provided for the identification of the 18 armored scale species associated with avocado in central Mxico. Forty species of associated natural enemies were also recorded, the most important belonging to Hymenoptera: Aphelinidae, Encyrtidae, Eulophidae, and Signiphoridae, and to Coleoptera: Coccinellidae. For each species of armored scale, brief general information on its distribution, host varietal preferences and natural enemies is given.

SPECIES OF ARMORED SCALE INSECTS (DIASPIDIDAE) IN THE CONDITIONS OF KARAKALPAKSTAN, CHARACTERISTICS OF BIOECOLOGICAL DEVELOPMENT

The article presents species of armored scale insects (Diaspididae) in the conditions of karakalpakstan, characteristics of bioecological development. KEY WORDS: insects, phytophages, entomophages, ticks, agroecosystem, insect fauna, sucking pests.

Species of Diaspididae (Hemiptera: Coccomorpha) on citrus in southern Lao PDR, new records for Việt Nam, and revised records for Indochina

The Diaspididae (Hemiptera: Coccomorpha), also known as armoured scale insects, is a diverse family of obligate, phytophagous parasites that include major economic pests of terrestrial plants. There are over 2,700 diaspidid species, about 116 of which have been recorded worldwide feeding on species and hybrids of citrus. Citrus is widely cultivated in the Lao People’s Democratic Republic (Lao PDR) and has been promoted by the country’s government as a poverty alleviation crop. However, little is known about the pest and disease issues faced by farmers of this crop. To help address this, in 2018 we conducted surveys of diaspidids on citrus in southern Lao PDR and found 14 species infesting citrus growing in orchards and home gardens. Identifications were based on morphological features of adult females and 28S, COI and COII DNA sequences. An identification key to the species based on morphological characters is provided. Records of diaspidid species on citrus in Myanmar, Thailand and Cambodia are updated, and records from Peninsular Malaysia provided. The first record on citrus of a Pseudaulacaspis species in Indochina is reported from Việt Nam, and an undescribed species of Pseudaonidia is recorded on citrus in Lao PDR.

A new species of Aulacaspis and a revived combination of Diaspididae (Hemiptera, Coccomorpha) from China.

A new species of armored scale insect, Aulacaspisfanjingshanensissp. nov. is described and illustrated based on adult female specimens collected on Rosaceae plants in China. A key to the Aulacaspis species known from Guizhou Province of China is provided. Our molecular study suggests that Aulacaspisschizosoma (Takagi, 1970) is not a true member of the genus Aulacaspis; the genus Superturmaspis Chen, 1983 is revived and A.schizosoma is transferred to it as Superturmaspisschizosoma (Takagi, 1970), revived combination, based on a molecular phylogeny.

First record of Aulacaspis tubercularis (Hemiptera: Diaspididae) in Costa Rica, a scale insect affecting mango (Mangifera indica) in Alajuela urban environments

Introduction. Mango (Mangifera indica L.) is widely cultivated around the world and in Costa Rica nearly 8200 hectares are dedicated to the production of this crop. More than 400 species of phytophagous insects and mites have been reported on mango worldwide. Among them are around 73 species of armored scale insects (Hemiptera: Diaspididae), of which Aulacaspis tubercularis Newstead is one of the most serious pests of mangos in many parts of the world. Objective. In the present work, we report for the first time the occurrence in Costa Rica of the white mango scale, A. tubercularis. Materials and methods. Mango tree samples were collected in San Rafael, a town located in the central canton of Alajuela province in the Greater Metropolitan Area of Costa Rica. Insects found on leaves were examined under a stereomicroscope, counted and classified according to the condition of their wax covers, which provided evidence of activity by natural enemies. Slide mounts of adult females were prepared and examined under a light microscope. Results. The armored scale was identified as A. tubercularis and the frequency of occurrence on the mango trees sampled was 90%, where 12% of adult females showed evidence of predation and 2.5% showed evidence of parasitization. Conclusion. A. tubercularis was recorded for the first time in Costa Rica. Further investigations on the population dynamics and natural enemies are needed to provide useful information in order to implement adequate control strategies.

First Report of the Scale Insect Family Conchaspididae and of Conchaspis angraeci Cockerell (Hemiptera: Coccomorpha) on Hoya spp. (Apocynaceae) in the Philippines

The occurrence of the scale insect family Conchaspididae (Hemiptera: Coccomorpha) in the Philippines is reported for the first time, based on a collection of false armored scale insects from Hoya landgrantensis Kloppenburg et al. (Apocynaceae), and a few other wax plants that are endemic to the Philippines. The minute scale insects belong to the genus Conchaspis Cockerell, and are identified as Conchaspis angraeci Cockerell, the only widespread species in this family. The occurrence of C. angraeci on H. cagayanensis, H. landgrantensis, and H. pimenteliana also constitute new host records and the potential of this insect to become a pest of domesticated ornamental Hoya is also noted, should their population reach levels injurious to plants.

New armored scale insect (Hemiptera: Coccomorpha: Diaspididae) species to Hungary on imported tropical fruits

AbstractScale insect (Hemiptera: Coccomorpha) fauna on imported tropical and subtropical fruits collected between 2013 and 2021 was investigated. The study revealed two armored scale insect (Diaspididae) species new to the fauna of Hungary (namely Aonidiella citrina (Coquillett) and Lepidosaphes pinnaeformis (Bouché)). Number of species of the Hungarian scale insect fauna increased to 279, while number of species collected on imported tropical and subtropical fruits changed to 16.

Insect herbivore and fungal communities on Agathis (Araucariaceae) from the latest Cretaceous to Recent.

Agathis (Araucariaceae) is a genus of broadleaved conifers that today inhabits lowland to upper montane rainforests of Australasia and Southeast Asia. A previous report showed that the earliest known fossils of the genus, from the early Paleogene and possibly latest Cretaceous of Patagonian Argentina, host diverse assemblages of insect and fungal associations, including distinctive leaf mines. Here, we provide complete documentation of the fossilized Agathis herbivore communities from Cretaceous to Recent, describing and comparing insect and fungal damage on Agathis across four latest Cretaceous to early Paleogene time slices in Patagonia with that on 15 extant species. Notable fossil associations include various types of external foliage feeding, leaf mines, galls, and a rust fungus. In addition, enigmatic structures, possibly armored scale insect (Diaspididae) covers or galls, occur on Agathis over a 16-million-year period in the early Paleogene. The extant Agathis species, throughout the range of the genus, are associated with a diverse array of mostly undescribed damage similar to the fossils, demonstrating the importance of Agathis as a host of diverse insect herbivores and pathogens and their little-known evolutionary history.

A new species of the genus Formosaspis Takahashi, 1932 (Hemiptera: Coccomorpha: Diaspididae) from China.

A new species of armoured scale insect, Formosaspis fanjingensis sp. n. (Hemiptera: Coccomorpha: Diaspididae), is described; it was found on Chimonobambusa spp. (Poaceae; Bambusoideae) in Guizhou Province, China. Habitat photographs and taxonomic illustrations are provided. The type specimens are deposited at the Institute of Entomology, Guizhou University, Guiyang, China (GUGC). An identification key based on the morphology of adult females is provided to separate all the species in the genus.

Sex-based de novo transcriptome assemblies of the parasitoid wasp Encarsia suzannae, a host of the manipulative heritable symbiont Cardinium hertigii.

Parasitoid wasps in the genus Encarsia are commonly used as biological pest control agents of whiteflies and armored scale insects in greenhouses or the field. They are also hosts of the bacterial endosymbiont Cardinium hertigii, which can cause reproductive manipulation phenotypes, including parthenogenesis, feminization, and cytoplasmic incompatibility (the last is mainly studied in Encarsia suzannae). Despite their biological and economic importance, there are no published Encarsia genomes and only one public transcriptome. Here, we applied a mapping-and-removal approach to eliminate known contaminants from previously-obtained Illumina sequencing data. We generated de novo transcriptome assemblies for both female and male E.suzannae which contain 45,986 and 54,762 final coding sequences, respectively. Benchmarking Single-Copy Orthologs results indicate both assemblies are highly complete. Preliminary analyses revealed the presence of homologs of sex-determination genes characterized in other insects and putative venom proteins. Our male and female transcriptomes will be valuable tools to better understand the biology of Encarsia and their evolutionary relatives, particularly in studies involving insects of only one sex.

Coccoidea (Hemiptera: Coccomorpha) Infesting Coconut Infructescence in The Philippines

During a series of field surveys on several coconut-planting provinces in the Philippines, scale insects, including mealybugs, were observed to attack the infructescence and fruits of coconuts, Cocos nucifera L. (Arecaceae). Three families of Coccomorpha, composed of six species of Diaspididae (armored scale insects), including the serious pest Aspidiotus rigidus Reyne, one species of Pseudococcidae [the mealybugs, Nipaecoccus nipae (Maskell)]; and one species of Monophlebidae (giant or cottony cushion scales, Icerya sp.), were noted to attack on coconut infructescences. Two species, Aspidiotus destructor Signoret and Lepidosaphes sp. aff. tapleyi were observed to feed on the fruit directly. Pseudaulacaspis pentagona (Targioni Tozzetti) and P. sp. aff. cockerelli (Cooley) were observed to feed on the leaf petiole and infructescence peduncle. Nipaecoccus nipae (Maskell) and Icerya sp. were found on the calyx, while Hemiberlesia lataniae (Signoret) were found in pedicels and peduncles of the infructescences.

A new species of Unachionaspis MacGillivray, 1921 (Hemiptera: Coccomorpha: Diaspididae) from China.

A new armoured scale insect (Hemiptera: Coccomorpha: Diaspididae) species, Unachionaspis multiglandularis sp. n., is described and illustrated; it was found on Chimonobambusa spp. (Poaceae: Bambusoideae) in Guizhou Province, China. An updated description of Unachionaspis tenuis (Maskell 1897) is given, based on samples collected in Guizhou, China. Habitat photographs and illustrations for both species are provided. The type specimens of U. multiglandularis and Chinese study material of U. tenuis are deposited at the Institute of Entomology, Guizhou University, Guiyang, China. An identification key to separate the four species in Unachionaspis, based on the morphology of adult females, is provided.

Two new species of Aulacaspis Cockerell, 1893 (Hemiptera: Coccomorpha: Diaspididae) from China.

Two new armoured scale insects in the genus Aulacaspis (Hemiptera: Coccomorpha: Diaspididae) are described and illustrated from Guizhou Province, China. Aulacaspis paralonganae sp. n. was collected from the host-plant Schima superba (Theaceae) and A. guiyangensis sp. n. was collected from Cinnamomum camphora (Lauraceae). Aulacaspis longanae Chen, Wu Su 1980 is redescribed and a new host-plant record is reported. The type specimens of the two new species and material of A. longanae are deposited in the Institute of Entomology, Guizhou University, Guiyang, China. An identification key based on adult females is provided to separate Chinese species of Aulacaspis.