Diaspididae Research Articles

The mutualism of Melissotarsus ants and armoured scale insects in Africa and Magadascar: distribution, host plants and biology

Species of the ant genus Melissotarsus Emery are widespread in the Afrotropical region (three species, namely M. beccarii Emery, M. emeryi Forel and M. weissi Santschi) and in the Madagascar region (one species, namely M. insularis Santschi). The ants of all these species tunnel their galleries in live wood of various dicotyledonous trees, close to the bark surface. The ants maintain within these galleries populations of different species of armoured scale insects. A review is presented on the geographical distribution of mutualism, of the Melissotarsus species, the associated 10 species of armoured scale insects, and the host plants on which the mutualism takes place. The ecology of the mutualism is discussed also, together with suggestions on the benefits that the partners gain from the associations.

PHYLOGENETIC PLACEMENT OF THE WHITE COCONUT SCALE, PARLAGENA BENNETTI WILLIAMS (HEMIPTERA DIASPIDIDAE)

Parlagen a bennetti Williams (Hemiptera: Diaspididae) is commonly known as the coconut scale and has only been collected in some islands in the Caribbean, Central America and the northernmost countries of South America. The species P. bennetti has been placed in Parlagena , a genus of few species currently considered as closely related to Parlatoria Targioni Tozzetti, but it has never been involved in molecular phylogenetic analysis. Here we include data from three genes of P. bennetti with 32 other armored scale insects and one outgroup to determine the correct placement of this species among armored scale insects. Both combined analysis and individual genealogies demonstrate the probable placement of this species in the subfamily Diaspidinae, likely as part of the tribe Lepidosaphidini.

DETERMINATION OF DEVELOPMENTAL AND LIFE TABLE PARAMETERS OF RHYZOBIUS LOPHANTHAE BLAISDELL (COLEOPTERA COCCINELLIDAE) ON THREE ARMORED SCALE INSECTS (HEMIPTERA DIASPIDIDAE)

Scale insects are the most damaging pests of citrus production in Turkey. Rhyzobius lophanthae Blaisdell (Coleoptera: Coccinellidae), a polyphagous coccinellid, is one of the most important predators of these pests. In this study, the life tables of R. lophanthae on three different armored scale insects, Aonidiella aurantii (Maskell), Aspidiotus nerii Bouche, Chrysomphalus dictiyospermi (Morgan) (Hemiptera: Diaspididae), were produced. The study was conducted in a climate chamber under constant conditions of 26°C, 60% relative humidity and 16-hour photoperiod. The net reproductive rate ( R 0 ), intrinsic rate of increase ( r m ) and mean generation time ( T 0 ) were 36.027, 12.520 and 6.600 females/female/generation, 0.120, 0.061 and 0.041 females/female/day, and 30.005, 41.151, 45.826 days, respectively, when R. lophanthae was reared on A. nerii, C. dictiyospermi and A. aurantii , respectively. The doubling time (DT) and finite rates of increase (λ) were 5.803, 11.286 and 16.832 days, 1.127, 1.063 and 1.042 individuals/female/day, respectively, when R. lophanthae was reared on A. nerii, C. dictiyospermi and A. aurantii , respectively.

THE ARMORED SCALE INSECTS (HEMIPTERA DIASPIDIDAE) OF ALABAMA, USA

A continuing survey of the armored scale insects of Alabama has resulted in recording 113 species in 47 genera, among the tribes Aspidiotini, Diaspidini, and Odonaspidini. Alabama now ranks second among states in the southeastern United States in number of species of armored scales, trailing only Florida with its 150+ species. Comments on some of the more notable diaspidids, not previously collected in Alabama, are made along with notes on their hosts and distribution in the State.

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 zunyiensis sp. n. is described and illustrated from collections on cycads in China. A key to the Aulacaspis species known from China is provided.

Armoured scale insects (Hemiptera: Diaspididae) intercepted at the ports of entry in the Republic of Korea over the last 20 years

A total of 88 species of armoured scale insects from 40 different countries were intercepted by quarantine inspectors in the Republic of Korea on consignments of plants and plant products at the ports of entry in the Republic of Korea from 1996 to 2015. A list of all the species identified, along with a dichotomous key to the 88 intercepted species of armoured scale insects, is provided to help in the detection and identification of species of this important group of plant pests.

A new species of Octaspidiotus (Hemiptera, Diaspididae) from China.

Adult females of a new species of armored scale insect, Octaspidiotus shanghaiensis sp. n. are described and illustrated from specimens collected in China. A key is provided for the all described species of Octaspidiotus.

Conoideocrella krungchingensis sp. nov., an entomopathogenic fungus from Thailand

Conoideocrella krungchingensis, a fungal pathogen infecting armored scale insects (Diaspididae) on a dicotyledonous plant, is described and illustrated as a new species from Thailand. The new taxon morphologically resembled C. luteorostrata but could be distinguished from the latter using the sequences of the partial nuclear large subunit rRNA (LSU) and the elongation factor (EF-1α) genes. Apart from it, asci and ascospores of C. krungchingensis were found notably shorter than those of C. luteorostrata and C. tenuis. All three species of Conoideocrella have been reported from Thailand, including C. krungchingensis.

Four putative entomopathogenic fungi of armoured scale insects on Citrus in Australia

This study led to the discovery of four putative entomopathogenic fungi of armoured scale insects on citrus trees in coastal New South Wales. Two of these species belong in Podonectria as P. coccicola (Ellis & Everh.) Petch (syn. Tetracrium coccicola (Hohn.) Ellis & Everh.) and P. novae-zelandiae Dingley. Members of this genus are grown in culture for the first time. Formerly placed in the Pleosporales, Tubeufiaceae, or more recently in the Tubeufiales, these species are herein placed in the new family Podonectriaceae fam. nov., Pleosporales. Another species is placed in the Hypocreales, Bionectriaceae as Clonostachys coccicola (J.A. Stev.) H.T. Dao comb. nov. (basionym Tubercularia coccicola J.A. Stev., syn. Nectria tuberculariae Petch). The fourth species is Myriangium citri Henn. (Myriangiales, Myriangiaceae). Each fungal species is characterized and the phylogenetic placement confirmed by molecular analyses of the ITS and 28 s rDNA regions. In addition, their biology is noted, including location of the fungi within tree canopies.

Microarray analysis of kiwifruit (Actinidia chinensis) bark following challenge by the sucking insect Hemiberlesia lataniae (Hemiptera: Diaspididae).

Both commercial and experimental genotypes of kiwifruit (Actinidia spp.) exhibit large differences in response to insect pests. An understanding of the vine's physiological response to insect feeding and its genetic basis will be important in assisting the development of varieties with acceptable levels of pest resistance. This experiment describes transcriptome changes observed in the bark of kiwifruit 2 and 7 days after the commencement of feeding by the armored scale insect pest, Hemiberlesia lataniae. Using a cDNA microarray consisting of 17,512 unigenes, we measured transcriptome changes and analyzed these into functional ontology categories using MapMan. Results are available in the GEO database GSE73922 and are described fully in Ref. Hill et al. (2015) [1]. After 7 days, transcripts associated with photosynthesis were down-regulated and secondary metabolism was up-regulated. Differential expression of transcripts associated with stress response was consistent with a defense response involving both effector and herbivore-triggered immunities, with predominant involvement of the salicylic acid phytohormonal pathway. This hypothesis was supported by the results of two laboratory experiments. The methods described here could be further adapted and applied to the study of plant responses to a wide range of sessile sucking pests.

Evaluation of Reduced-Risk Insecticides for Armored Scales (Hemiptera: Diaspididae) Infesting Ornamental Plants

ABSTRACT Armored scale insects (Hemiptera: Diaspididae) are economically important pests of ornamental trees and shrubs in nurseries and landscapes. The cycad aulacaspis scale, Aulacaspis yasumatsui Takagi, and the tea scale, Fiorinia theae Green, are economically important armored scale pests of cycads, Cycas spp., and camellia, Camellia spp., respectively, in the southeastern United States. Our objective was to evaluate fungal, botanical, and chemical insecticides that were applied as foliar sprays or drenches when the motile crawler stages were active. In tests with A. yasumatsui over two years, products based on a mineral oil (SuffOil-X®), azadirachtin (Molt-X®), an entomopathogenic fungus (BotaniGard®-ES), and an azadirachtin/fungus combination applied three times, significantly reduced the number of scales on cycads, Cycas revoluta Thunb., over 3–4 months, but were less effective overall compared with the insecticidal standard dinotefuran (Safari®). In tests with F. theae, spinetoram + sulfoxaflor ...

Insecticide Trial for Cycad Aulacaspis Scale on Sago Palm, 2014: Table 1

The cycad aulacaspis scale (CAS) is a significant invasive pest on cycads, especially among the genera Cycas . Damage by CAS, an armored scale insect, has resulted in the removal of millions of cycads from Florida landscapes. The objective of this study was to assess efficacy of biological and botanical insecticides for control of CAS relative to that of insecticidal standard. The trial was conducted at the University of Florida Research and Education Center in Apopka, Florida, on 3-yr-old sago palms potted in 7-gal containers. A total of 25 naturally …

Transcriptome Analysis of Kiwifruit (Actinidia chinensis) Bark in Response to Armoured Scale Insect (Hemiberlesia lataniae) Feeding.

The kiwifruit cultivar Actinidia chinensis ‘Hort16A’ is resistant to the polyphagous armoured scale insect pest Hemiberlesia lataniae (Hemiptera: Diaspididae). A cDNA microarray consisting of 17,512 unigenes selected from over 132,000 expressed sequence tags (ESTs) was used to measure the transcriptomic profile of the A. chinensis ‘Hort16A’ canes in response to a controlled infestation of H. lataniae. After 2 days, 272 transcripts were differentially expressed. After 7 days, 5,284 (30%) transcripts were differentially expressed. The transcripts were grouped into 22 major functional categories using MapMan software. After 7 days, transcripts associated with photosynthesis (photosystem II) were significantly down-regulated, while those associated with secondary metabolism were significantly up-regulated. A total of 643 transcripts associated with response to stress were differentially expressed. This included biotic stress-related transcripts orthologous with pathogenesis related proteins, the phenylpropanoid pathway, NBS-LRR (R) genes, and receptor-like kinase–leucine rich repeat signalling proteins. While transcriptional studies are not conclusive in their own right, results were suggestive of a defence response involving both ETI and PTI, with predominance of the SA signalling pathway. Exogenous application of an SA-mimic decreased H. lataniae growth on A. chinensis ‘Hort16A’ plants in two laboratory experiments.

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.

Life stage-dependent susceptibility of Aphytis melinus DeBach (Hymenoptera: Aphelinidae) to two pesticides commonly used in citrus orchards

The assessment of pesticides compatibility with natural enemies is recommended before including agrochemicals in integrated and organic pest management schemes. The lethal and sublethal effects of a mineral oil and a juvenile hormone mimic (pyriproxyfen), on adults and larvae of Aphytis melinus, a key ectoparasitoid of armored scale insect pests of citrus, such as Aonidiella aurantii, were evaluated. Mineral oil caused very high mortality on the adults, while a lower acute toxicity was recorded on young instars. No significant effects on their reproduction capacity and on the sex-ratio of the progeny were observed. Pyriproxyfen had neither lethal nor sublethal effects (in terms of survived female fertility) on A. melinus adults. However, parasitoid larvae exposed to this insecticide suffered strong acute toxicity and fertility reduction (progeny number and proportion of female progeny). When adults were offered the choice to parasitize treated and untreated scales they significantly preferred the control ones, and when they were exposed to only treated scaled the parasitism rate was significantly lower only with mineral oil-treated hosts. The significant differences in the susceptibility of the two parasitoid instars highlight the importance of including this aspect in pesticide risk assessment procedures and in the choice of the pesticide and of the treatment timing in the field. Overall, the results indicate potential for integrating A. melinus, both naturally present and artificially released, and these insecticides only by appropriate timing of insecticide spraying and parasitoid releases.

Diaspidídeos e parasitoides associados ao cultivo da videira no Rio Grande do Sul, Brasil

As cochonilhas-com-escudo (Hemiptera, Diaspididae) têm causado prejuízos significativos à cultura da videira no Rio Grande do Sul, principalmente em Vitis labrusca L. da cv. Niágara. No período de setembro de 2009 a outubro de 2011, foi realizado um inventário das espécies de Diaspididae ocorrentes no tronco das videiras e dos parasitoides associados. Foram avaliadas 32 propriedades localizadas nos municípios de Bento Gonçalves, Caxias do Sul, Flores da Cunha e Sarandi-RS. A espécie mais frequente e abundante foi Hemiberlesia lataniae (Signoret, 1869). Melanaspis arnaldoi (Costa Lima, 1924) e Pseudaonidia marquesi Costa Lima, 1924 foram registradas pela primeira vez em V. labrusca. Todas as espécies de cochonilhas apresentaram perfurações nos escudos indicando níveis de parasitismo natural que variaram de 11,3 a 76,5% para H. lataniae, de 9 a 58,8% para M. arnaldoi e de 3,4 a 22,2% para P. marquesi. As seguintes associações entre parasitoides e cochonilhas foram encontradas: Encarsia sp. (Aphelinidae), Plagiomerus sp. (Encyrtidae), Amitus sp. (Platygastridae) e o hiperparasitoide Chartocerus sp. (Signiphoridae) a H. lataniae; Homalopoda sp. (Encyrtidae) a P. marquesi e Chartocerus sp. a M. arnaldoi. Amitus sp., Homalopoda sp. e Chartocerus sp. foram associados pela primeira vez com estes diaspidídeos.

Armored scale insect endosymbiont diversity at the species level: genealogical patterns of Uzinura diasipipdicola in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex (Hemiptera: Coccoidea: Diaspididae).

Armored scale insects and their primary bacterial endosymbionts show nearly identical patterns of co-diversification when viewed at the family level, though the persistence of these patterns at the species level has not been explored in this group. Therefore we investigated genealogical patterns of co-diversification near the species level between the primary endosymbiont Uzinura diaspidicola and its hosts in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex. To do this we generated DNA sequence data from three endosymbiont loci (rspB, GroEL, and 16S) and analyzed each locus independently using statistical parsimony network analyses and as a concatenated dataset using Bayesian phylogenetic reconstructions. We found that for two endosymbiont loci, 16S and GroEL, sequences from U. diaspidicola were broadly associated with host species designations, while for rspB this pattern was less clear as C. heterophyllae (species S1) shared haplotypes with several other Chionaspis species. We then compared the topological congruence of the phylogenetic reconstructions generated from a concatenated dataset of endosymbiont loci (including all three loci, above) to that from a concatenated dataset of armored scale hosts, using published data from two nuclear loci (28S and EF1α) and one mitochondrial locus (COI-COII) from the armored scale hosts. We calculated whether the two topologies were congruent using the Shimodaira-Hasegawa test. We found no significant differences (P = 0.4892) between the topologies suggesting that, at least at this level of resolution, co-diversification of U. diaspidicola with its armored scale hosts also occurs near the species level. This is the first such study of co-speciation at the species level between U. diaspidicola and a group of armored scale insects.

An annotated checklist of scale insects (Hemiptera: Coccoidea) of Saint Lucia, Lesser Antilles.

An annotated list of 83 scale insect species (Hemiptera: Sterorrhyncha: Coccoidea) recorded from Saint Lucia is presented, based on data gathered from UK quarantine interceptions, samples collected in an urban coastal habitat in the North West of the Island in 2013, and published records. Thirty-three species (40%) are recorded for the first time for the country, including Dysmicoccus joannesiae (Costa Lima), a South American mealybug, and Poliaspoides formosana (Takahashi), an Asian armoured scale insect pest of bamboo, which are new for the Caribbean region. The economic, environmental and social impacts caused by introduced exotic species of scale insect are discussed. Two predatory midges Diadiplosis ?coccidivora (Felt) and Diadiplosis multifila(Felt) (Diptera: Cecidomyiidae) are recorded for the first time from Saint Lucia. The latter species was observed causing 90% mortality of a large infestation of passion vine mealybug Planococcus minor (Maskell) on soursop fruit.

Aspidiotus rigidus Reyne (Hemiptera: Diaspididae): a devastating pest of coconut in the Philippines

Abstract The Philippines is the second largest producer of coconut products and, in some areas, coconut farming is the main source of livelihood. A damaging armoured scale insect (Hemiptera: Diaspididae) infesting coconut palms was first found in the Philippines on Luzon Island (Batangas province) in 2009, and is now affecting most of the provinces of southern Luzon. The scale pest is still spreading in the Visayan Islands and Mindanao. Infestation stops photosynthesis; the leaves yellow and dry; fruits form less nutmeat and the coconut‐water is sour; weak new leaflets bend over or break off; and the tree dies in 6 months or less. The scale pest is identified in the present study as Aspidiotus rigidus Reyne; it presents a significant quarantine threat to coconut‐producing countries worldwide. Characters enabling the identification of A. rigidus, its host range and distribution are given. Some literature on the natural enemies and control of A. rigidus is reviewed briefly.

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.