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ScaleNet: A literature-based model of scale insect biology and systematics

Authors:
  • Systematic Entomology Laboratory, USDA, Beltsville, MD

Abstract and Figures

Scale insects (Hemiptera: Coccoidea) are small herbivorous insects found on all continents except Antarctica. They are extremely invasive, and many species are serious agricultural pests. They are also emerging models for studies of the evolution of genetic systems, endosymbiosis and plant-insect interactions. ScaleNet was launched in 1995 to provide insect identifiers, pest managers, insect systematists, evolutionary biologists and ecologists efficient access to information about scale insect biological diversity. It provides comprehensive information on scale insects taken directly from the primary literature. Currently, it draws from 23 477 articles and describes the systematics and biology of 8194 valid species. For 20 years, ScaleNet ran on the same software platform. That platform is no longer viable. Here, we present a new, open-source implementation of ScaleNet. We have normalized the data model, begun the process of correcting invalid data, upgraded the user interface, and added online administrative tools. These improvements make ScaleNet easier to use and maintain and make the ScaleNet data more accurate and extendable. Database URL: http://scalenet.info
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Database update
ScaleNet: a literature-based model of scale
insect biology and systematics
Mayrolin Garcı´a Morales
1,
*, Barbara D. Denno
2
, Douglass R. Miller
2,4
,
Gary L. Miller
2
, Yair Ben-Dov
3
and Nate B. Hardy
1
1
Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849;
2
Systematic
Entomology Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, MD,
20705;
3
Agricultural Research Organization, Volcani Centre, Beit-Dagan, Israel;
4
Division of Plant
Industry, Gainesville, FL, 32608-1201
*Corresponding author: Email: mzg0043@tigermail.auburn.edu
Citation details: Garcı´a Morales, M. Denno,B.D., Miller,D.R., et al. ScaleNet: a literature-based model of scale insect
biology and systematics. Database (2016) Vol. 2016: article ID bav118; doi:10.1093/database/bav118
Received 24 August 2015; Revised 23 November 2015; Accepted 24 November 2015
Abstract
Scale insects (Hemiptera: Coccoidea) are small herbivorous insects found on all contin-
ents except Antarctica. They are extremely invasive, and many species are serious
agricultural pests. They are also emerging models for studies of the evolution of genetic
systems, endosymbiosis and plant-insect interactions. ScaleNet was launched in 1995 to
provide insect identifiers, pest managers, insect systematists, evolutionary biologists
and ecologists efficient access to information about scale insect biological diversity. It
provides comprehensive information on scale insects taken directly from the primary lit-
erature. Currently, it draws from 23 477 articles and describes the systematics and biol-
ogy of 8194 valid species. For 20 years, ScaleNet ran on the same software platform.
That platform is no longer viable. Here, we present a new, open-source implementation
of ScaleNet. We have normalized the data model, begun the process of correcting invalid
data, upgraded the user interface, and added online administrative tools. These improve-
ments make ScaleNet easier to use and maintain and make the ScaleNet data more
accurate and extendable.
Database URL: http://scalenet.info
Introduction
Scale insects (Hemiptera: Coccoidea)
Scale insects are sap-sucking plant parasites that can be
found almost anywhere that plants grow. They get their
name from the protective waxy exudates produced by
most species. Currently, there are at least 8194 described
species, classified among 50 families. Scale insects play key
roles in ecosystems. They, along with most other plant-
feeding members of the order Hemiptera, are the only
insects that feed exclusively on phloem sap (although arm-
ored scale insects feed primarily on parenchyma cells) (1).
Phloem is rich in sugars but poor in amino acids, and
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phloem-feeding is an inefficient process. The waste is copi-
ous amounts of honeydew, i.e. sugar-rich excrement that is
an important food source for birds, mammals and espe-
cially other insects (1). The availability of honeydew can
affect insect communities in ways that alter ecosystem
processes such as herbivore assemblage, soil structure, and
predation (2,3). Many scale insect species are agricultural
pests, damaging plants through sap loss, encouraging the
growth of sooty molds and vectoring plant diseases. Scale
insects can be difficult to detect, and are extremely inva-
sive. For example, scale insects account for only 1% of the
total insect fauna of the United States, but for 13% of the
introduced insect fauna, and on average one new invasive
species is established as a pest in the USA per year (4). The
host plant associations of scale insects have been excep-
tionally well documented, and the breadth of these associ-
ations is unusually variable. As is the case for other plant-
feeding insects, most scale insect species are host-plant spe-
cialists. However, some species are among the most pol-
yphagous insect species known. For example, the brown
soft scale, Coccus hesperidum, can successfully develop on
host plants in at least 121 plant families, and 325 plant
genera. Scale insects are also noteworthy for the unparal-
leled diversity of their genetic systems, and for the diversity
and complexity of their relationships with endosymbionts
(5). In addition to being a taxing problem for applied
biologists, they are emerging as models for research ad-
dressing questions about the evolution of reproductive
modes, genetic conflict and collaboration, and niche
breadth evolution. There is high demand for synoptic in-
formation about the biological diversity of scale insects.
That demand is met by ScaleNet.
ScaleNet
ScaleNet is a manually-curated, web-accessible database
that models the biological diversity of scale insects through
300 years of published research. ScaleNet manages infor-
mation about the systematics, ecological associations (host
plants, natural enemies and mutualists), geographic distri-
butions, life histories, economic importance and morph-
ology of each scale insect species. As a model of the scale
insect literature, the core of ScaleNet is an exhaustive bibli-
ography. The rest of the information in the database can be
thought of as annotations of that literature. ScaleNet began
as a collaboration between Yair Ben-Dov (Agricultural
Research Organization, Israel Department of Entomology),
Douglass R. Miller (US Department of Agriculture) and
Gary A.P. Gibson (Agriculture and Agri-Food Canada),
with funding from the USA–Israel Binational Agricultural
Research and Development Fund. It was developed as a
Microsoft FoxPro application, using the BASIS (Biological
and Systematic Information System) database schema en-
gineered by Gary Gibson and Jennifer Read (Agriculture
and Agri-Food Canada) to manage taxonomic bibliogra-
phies. It first went online in 1995 (6). For 20 years, the
ScaleNet data grew and evolved, but the ScaleNet applica-
tion did not. By 2015, ScaleNet was running on an unsup-
ported, insecure, closed-source software platform and was
no longer tenable. Here, we describe a new version of
ScaleNet.
Methods
Redeveloping ScaleNet
Our overarching goals for the redevelopment of ScaleNet
were to (i) keep it online, (ii) make the software and data
store easier to maintain, (iii) improve quality control and
(iv) make it easier to extend and articulate with other bio-
diversity resources. Our new version of ScaleNet is a
Django application (a Python web framework: https://
www.djangoproject.com/) with an SQLite database engine
(https://www.sqlite.org/), that currently runs on Linux, be-
hind an Apache web server (http://httpd.apache.org/), but
which can be configured to run in other environments.
Django follows a Model-View-Controller architecture, i.e.
the controller (logic) receives user requests and fetches in-
formation from the model (data store) to be displayed in a
view (HTML). We normalized the data model (Figure 1)
and performed the data migrations with a set of custom
Python scripts. As part of the migration we performed a
number of data cleaning and standardization routines. We
standardized the valid scientific names and classifications
of all ecological associates following the schema of the
Catologue of Life (CoL: http://www.catalogueoflife.org/)
2015 annual checklist. To amend spelling errors in the
names of ecological associates, we used the fuzzy matching
feature of the Global Names Resolver API (http://resolver.
globalnames.biodinfo.org/). In addition to adding the CoL
classification of ecological associates to the ScaleNet
schema, we added a class for the classification of scale in-
sect taxa (absent from the original schema) and another for
nested relationships of the geopolitical and zoogeograph-
ical units that are used to describe the geographic distribu-
tions of scale insects.
As ScaleNet is a model of the scale insect primary litera-
ture, all ScaleNet data need to be associated with a publi-
cation. However, early in its initial development, ScaleNet
was seeded with information from databases compiled by
Y.B-D. to summarize the biological diversity of the scale
insect families Coccidae and Pseudococcidae (7,8). At that
time validation sources for host and distribution records
were not being recorded. These data are invalid in the new
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Figure 1. Diagram of the ScaleNet data model. The central tables to the database are the Citations, Scale Classification, Species and Genera tables.
Together these tables validate the currently accepted valid names of scale insects, which are then used throughout the database to track ecological
associations, distributions, taxonomic keys, etc. The figure depicts relationships between the tables using Crow’s Foot Notation. The symbol krepre-
sents a one-and-only-one relationship. The crow’s foot symbol represents a one-or-many relationship. Relationships can be asymmetrical, and the
nature of the relationship of object A to object B is specified at the connection with B. For example, the relationship between Keys and Keys Stages
would be read as ‘One key can have one and only one key stage; a key stage can be in one or many keys.’
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ScaleNet, and were not migrated. Instead, they were
flagged and given to the ScaleNet curators to be manually
restructured and added to the new database.
Results and discussion
Database overview
Currently, ScaleNet contains 23 477 bibliographic records,
pertaining to 9509 currently valid scale insect names (8194
of which are species combinations). Complete nomencla-
tural histories are available for each genus and species
name, and ScaleNet associates 1955 common names with
1161 valid scientific names. Because of the agricultural im-
portance of scale insects, the ScaleNet information about
ecological associations and geographic ranges are particu-
larly rich. There are 47 341 records of ecological associ-
ations between scale insects and their hosts, natural
enemies and mutualists. The geographic ranges of scale in-
sect species are described by 32 641 records of occurrence
in specific geopolitical or zoogeographic regions.
User interface
The public user interface exposes five major queries: (i) In
the catalog query, users submit an available genus or spe-
cies name to retrieve all of the information in the database
associated with the valid form of that name. According to
the rules of zoological nomenclature, a valid name is
defined as the oldest available name for a genus or species,
i.e. the one that has priority. An available species name is
defined as any published binomial that is linked to a type
specimen, and an available genus name is any published
name that is linked to a type species. Users entering any of
the available names associated with a species or genus will
retrieve the data for the current valid name. The returned
data view presents a nomenclatural history, lists of ecolo-
gical associates and geopolitical units in which the taxon
occurs, remarks on economic importance, biology, system-
atics and morphology and a complete bibliography. (ii) The
places query allows users to retrieve a checklist of all of the
scale insect species known to occur in a specified geopolit-
ical or zoogeographic region. It is possible to constrain
these searches to particular scale insect subgroups, e.g. spe-
cific genera. (iii) The ecological associates query returns a
list of scale insect species associated with a specified host
plant, natural enemy or mutualist. As in the places query,
the results can be constrained to a scale insect subgroup.
(iv) The references query gives users the ability to search
the scale insect literature by author, year and keywords. (v)
The common names query helps users make the connection
between common and scientific names of scale insect
species. Users can also peruse the taxonomic diversity of
scale insects and access catalogs by drilling down (and up)
through a searchable scale insect classification.
Administrative interface
Previously, ScaleNet data were managed through FoxPro
desktop clients. In the new version of ScaleNet, data man-
agement is through online administrative interfaces that
Django automatically generates from the model metadata.
The new ScaleNet affords curators considerably more
flexibility in terms of where they work on ScaleNet. It is
also more flexible in terms of who can manage the
data. For most of its history, the ScaleNet curators were
Y. Ben-Dov and D.R. Miller. Currently, ScaleNet is cura-
ted primarily by B.D. Denno. For a period of time follow-
ing the retirement of Y. Ben-Dov and D.R. Miller, no one
maintained the ScaleNet data. By the time B.D. Denno
started her tenure as curator, ScaleNet was several years
out of date, and many known data errors had gone uncor-
rected. Should there be a period in the future in which no
one is able to assume a major responsibility for the cur-
ation of ScaleNet data, it may be possible to open the
administrative interface up to the community of scale
insect workers at large.
Data curation
Scale insect papers are added to ScaleNet after they have
been identified through weekly Internet searches, or have
been sent directly to ScaleNet curators by authors. Updates
to the database will be performed on a monthly basis. We
aim for ScaleNet to include all published papers that deal
with scale insects, but data entry is prioritized by subject,
with the top priority going to papers that deal with the tax-
onomy and systematics of scale insects. Once a paper has
been added to ScaleNet, curators extract information from
that paper about the biological diversity of scale insects,
and use that paper as a validation source for new records
in various ScaleNet data classes (e.g. species names and
geographic distributions). ScaleNet is meant to be a faith-
ful representation of the literature; as a result, the data in
ScaleNet is only as good as the data in the published litera-
ture. For the most part, ScaleNet curators do not judge
the quality of the published information. If published in-
formation is erroneous, it needs to be corrected in a subse-
quent publication before that error will be corrected in
ScaleNet. Nevertheless, ScaleNet curators may exercise
their discretion on issues of nomenclature and classifica-
tion. Nomenclature changes in ScaleNet must comply with
the International Code of Zoological Nomenclature, and if
a taxonomic paper fails to do so, the proposed changes
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will not be committed to ScaleNet. Furthermore, ScaleNet
is a comprehensive resource for a global fauna. It may be
impossible for ScaleNet curators to commit published
changes to scale insect systematics that apply to non-
monophyletic groups, e.g. a family-level reclassification of
only the Palaearctic species of a global radiation.
The future of ScaleNet
One impetus for the normalization of the ScaleNet data
model was to increase the quality of the data through
structural validations. However, because these validations
were lacking in the original application, a considerable
amount of the data was invalid, and failed to be success-
fully migrated to the new platform. At the time of writing,
manual restructuring and addition of these data is under-
way. Another impetus was to make ScaleNet more easily
extendable, that is, increase the kinds of information ac-
cessible through ScaleNet. Some of what ScaleNet models,
e.g. geographic ranges, can be more accurately modeled
from specimen data, i.e. the metadata associated with
physical insect specimens within natural history collec-
tions. Increasingly, these specimen data are available
through web resources, such as the Global Biodiversity
Information Facility’s data portal (http://www.gbif.org/)
and Discover Life (http://www.discoverlife.org/). In the
past few years, data from hundreds of thousands of hemip-
teran specimens held in non-federal insect collections in
the USA have been digitized by the Tri-Trophic Database
project, an NSF-funded effort in the Advancing
Digitization of Biological Collections program. In the fu-
ture, we aim to include specimen-level data in ScaleNet’s
characterizations of scale insect biology.
ScaleNet is used heavily by insect identifiers as a diag-
nostic tool. The extreme invasiveness of scale insect species
stems in part from high propagule pressure, i.e. the sheer
number of individuals which are brought along with plant
materials to ports of entry. Scale insect species identifica-
tions are among the highest volume and most difficult jobs
performed by inspection services. In the future we plan to
make ScaleNet more useful as a diagnostic aid, by adding
habitus images, taxonomic illustrations and complete taxo-
nomic descriptions to catalog entries. ScaleNet is used in-
creasingly by ecologists and evolutionary biologists. For
example, recent studies have used ScaleNet data to address
questions about the evolution of parthenogenesis (9) and
diet breadth (10,11). To facilitate the compilation of com-
parative datasets from ScaleNet data, we plan to develop a
ScaleNet web service API, i.e. more machine-friendly
mechanisms for getting information from ScaleNet.
Acknowledgements
Mention of trade names or commercial products in this publication
is solely for the purpose of providing specific information and does
not imply recommendation or endorsement by the USDA; USDA is
an equal opportunity provider and employer.
Funding
This work was supported by a Specific Cooperative Agreement be-
tween N.B.H. at Auburn University and G.L.M. at the United States
Department of Agriculture, Systematic Entomology Lab.
Conflict of interests. None declared.
References
1. Douglas,A.E. (2006) Phloem-sap feeding by animals: problems
and solutions. J. Exp. Bot., 57, 747–754.
2. Styrsky,J.D. and Eubanks,M.D. (2007) Ecological consequences
of interactions between ants and honeydew-producing insects.
Proc. R. Soc. B, 274, 151–164. doi: 10.1098/rspb.2006.3701.
3. Stadler,B., Michalzik,B., Muller,T. (1998) Linking aphid ecol-
ogy with nutrient fluxes in a coniferous forest. Ecology, 79,
1514–1525.
4. Miller,D.R., Miller,G.L., Hodges,G.S. et al. (2005) Introduced
scale insects (Hemiptera: Coccoidea) of the United States and
their impact on U.S. agriculture. Proc. Entomol. Soc. Wash.,
107, 123–158.
5. Normark,B.B. (2003) The evolution of alternative genetic sys-
tems in insects. Annu. Rev. Entomol., 48, 397–423.
6. Miller,D.R., Ben-Dov,Y., and Gibson,G.A.P. (1999) ScaleNet: A
Searchable Information System on Scale Insects. Entomologica,
33, 37–46.
7. Ben-Dov,Y. (1994) A Systematic Catalogue of the Mealybugs of
the World (Insecta: Homoptera: Coccoidea: Pseudococcidae:
Putoidae). Intercept Ltd., Andover, UK, p. 686.
8. Ben-Dov,Y. (1993) A systematic catalogue of the soft scales of
the world (Insecta: Homoptera: Coccoidea: Coccidae). Flora and
Fauna Handbook No. 9, Sandhill Crane Press, Gainesville,
Florida, USA, p. 536.
9. Ross,L., Shuker,D.M., Normark,B.B. et al. (2012) The role of
endosymbionts in the evolution of haploid-male genetic systems
in scale insects (Coccoidea). Ecol. Evol., 2, 1071–1081.
10. Lin,Y.P., Cook,D.H., Gullan,P.J. et al. (2015) Does host-plant
diversity explain species richness in insects? A test using
Coccidae (Hemiptera). Ecol. Entomol., 40, 299–306. doi:
10.1111/een.12191.
11. Peterson,D.A., Hardy,N.B., Morse,G.E. et al. (2015)
Phylogenetic analysis reveals positive correlations between adap-
tations to diverse hosts in a group of pathogen-like herbivores.
Evolution, 69, doi: 10.1111/evo.12772.
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... Matsucoccus massonianae Young & Hu is an insect within the order Hemiptera and family Matsucoccidae. Its common name is the Massonian pine bast scale or the Chinese pine bast scale (Kosztarab and Koz ar, 1988;Ben-Dov, 2011;Garc ıa Morales et al., 2016). M. massonianae has no synonyms. ...
... Expansion of the geographical distribution of a pest within an area (FAO, 2021) Pseudolarix amabilis is listed as a host by Ben-Dov (2011) and Garc ıa Morales et al. (2016), but this might be an error in interpreting a study by Hu and Wang (1976) Young et al. (1976) believe that M. massonianae could have a wider distribution in China and also in Taiwan. However, no records were found to support this. ...
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Interactions between ants and honeydew-producing hemipteran insects are abundant and widespread in arthropod food webs, yet their ecological consequences are very poorly known. Ant-hemipteran interactions have potentially broad ecological effects, because the presence of honeydew-producing hemipterans dramatically alters the abundance and predatory behaviour of ants on plants. We review several studies that investigate the consequences of ant-hemipteran interactions as 'keystone interactions' on arthropod communities and their host plants. Ant-hemipteran interactions have mostly negative effects on the local abundance and species richness of several guilds of herbivores and predators. In contrast, out of the 30 studies that document the effects of ant-hemipteran interactions on plants, the majority (73%) shows that plants actually benefit indirectly from these interactions. In these studies, increased predation or harassment of other, more damaging, herbivores by hemipteran-tending ants resulted in decreased plant damage and/or increased plant growth and reproduction. The ecological consequences of mutualistic interactions between honeydew-producing hemipterans and invasive ants relative to native ants have rarely been studied, but they may be of particular importance owing to the greater abundance, aggressiveness and extreme omnivory of invasive ants. We argue that ant-hemipteran interactions are largely overlooked and underappreciated interspecific interactions that have strong and pervasive effects on the communities in which they are embedded.
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1. The megadiverse herbivores and their host plants are a major component of biodiversity, and their interactions have been hypothesised to drive the diversification of both.2. If plant diversity influences the diversity of insects, there is an expectation that insect species richness will be strongly correlated with host-plant species richness. This should be observable at two levels (i) more diverse host-plant groups should harbour more species of insects, and (ii) the species richness of a group of insects should correlate with the richness of the host groups it uses. However, such a correlation is also consistent with a hypothesis of random host use, in which insects encounter and use hosts in proportion to the diversity of host plants. Neither of these expectations has been widely tested.3. These expectations were tested using data from a species-rich group of insects – the Coccidae (Hemiptera).4. Significant positive correlations were found between the species richness of coccid clades (genera) and the species richness of the host-plant family or families upon which the clades occur. On a global scale, more closely related plant families have more similar communities of coccid genera but the correlation is weak.5. Random host use could not be rejected for many coccids but randomisation tests and similarity of coccid communities on closely related plant families show that there is non-random host use in some taxa. Overall, our results support the idea that plant diversity is a driver of species richness of herbivorous insects, probably via escape-and-radiate or oscillation-type processes.
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Flows of dissolved organic carbon (DOC) in throughfall and soil solutions in forest ecosystems vary spatially and temporally. However, the reasons for the variability of DOC flows are unknown. Phytophagous insects such as aphids have not been considered a potential source of organic carbon, even though aphids feeding on trees excrete copious amounts of honeydew. We followed the key processes determining the origin, flow, and path of honeydew from the phyllosphere of a Norway spruce stand to the soil. We analyzed the chemical composition of needle leachates, throughfall, and soil solution to calculate fluxes of DOC and hexose-C in an aphid-infested and an uninfested Norway spruce stand. At the individual aphid level, the amount of honeydew produced was dependent on temperature, developmental stage, and the nutritional status of spruce. At the population level, colony growth and natural enemies influenced the amount of honeydew available in the phyllosphere. The growth rates of microorganisms on spruce needles were significantly increased when honeydew was available. This study of the fate of honeydew and associated metabolites within a forest stand shows that the concentrations of DOC and hexose-C in throughfall were reduced on the way to the soil and that there were no differences in the soil solutions from infested and uninfested stands. However, the distribution and abundance of honeydew-producing Homoptera had a marked effect on the spatial and temporal variability in the DOC concentrations in throughfall. High DOC concentrations in throughfall during summer are not exclusively due to the leaching of nutrients from leaves, but may also be attributed to the excreta of aphids. Our results highlight the importance of studying physiological and life history processes in addition to taking the traditional biomass approach to ecosystem studies. We discuss our results with regard to the types of information that are preserved, transformed, or lost when crossing the conceptual border between one scale of observation and another. We emphasize the importance of identifying key processes at different spatiotemporal scales by linking the biology of individuals and populations with flows of energy and matter within an ecosystem, while stressing the need to identify ecosystem changes at different scales of observation.
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The incidence of phloem sap feeding by animals appears paradoxical. Although phloem sap is nutrient-rich compared with many other plant products and generally lacking in toxins and feeding deterrents, it is consumed as the dominant or sole diet by a very restricted range of animals, exclusively insects of the order Hemiptera. These insects display two sets of adaptations. First, linked to the high ratio of non-essential:essential amino acids in phloem sap, these insects contain symbiotic micro-organisms which provide them with essential amino acids. For example, bacteria of the genus Buchnera contribute up to 90% of the essential amino acids required by the pea aphid Acyrthosiphon pisum feeding on Vicia faba. Second, the insect tolerance of the very high sugar content and osmotic pressure of phloem sap is promoted by their possession in the gut of sucrase-transglucosidase activity, which transforms excess ingested sugar into long-chain oligosaccharides voided via honeydew. Various other animals consume phloem sap by proxy, through feeding on the honeydew of phloem-feeding hemipterans. Honeydew is physiologically less extreme than phloem sap, with a higher essential:non-essential amino acid ratio and lower osmotic pressure. Even so, ant species strongly dependent on honeydew as food may benefit from nutrients derived from their symbiotic bacteria Blochmannia.
A Systematic Catalogue of the Mealybugs of the World (Insecta: Homoptera: Coccoidea: Pseudococcidae: Putoidae). Intercept Ltd
  • Y Ben-Dov
Ben-Dov,Y. (1994) A Systematic Catalogue of the Mealybugs of the World (Insecta: Homoptera: Coccoidea: Pseudococcidae: Putoidae). Intercept Ltd., Andover, UK, p. 686.
A systematic catalogue of the soft scales of the world (Insecta: Homoptera: Coccoidea: Coccidae). Flora and Fauna Handbook
  • Y Ben-Dov
Ben-Dov,Y. (1993) A systematic catalogue of the soft scales of the world (Insecta: Homoptera: Coccoidea: Coccidae). Flora and Fauna Handbook No. 9, Sandhill Crane Press, Gainesville, Florida, USA, p. 536.