An experimental study of morphological variation in mealybugs (Homoptera: Coccoidea: Pseudococcidae)

Abstract Cultures of a number of species of mealybug were reared under a variety of controlled environments and the effects of factors such as temperature, relative humidity and host plant on the morphology of the adult females examined. It was found that temperature had the greatest effect. The lengths of the appendages and setae, and the numbers of wax producing pores and ducts, vary over a wide range within a single species when specimens are reared at different temperatures. The relationship with temperature is generally linear, with size and pore numbers increasing with decreased temperature. However, some characters, noticeably the numbers of tubular ducts, reach their highest values at an intermediate temperature. It is suggested that while variation in size is a direct response to temperature, other characters are influenced by size or by a combination of size and environmental factors acting independently. Rearing mealybugs under different environmental conditions in order to induce morphological variation is shown to be a useful technique for resolving difficult species complexes.     

Evolution of chromosome number in mealybugs (Pseudococcidae: Homoptera)

Chromosome numbers of over 90 species of mealybugs are presented (71 for the first time). The diploid chromosome number (2n) ranged from 8 to 64, but over 68% of the species had 2n=10, and 10 is considered to represent the ancestral 2n in this family. Since only 4 species had 2n<10,and 26 had 2n>10, it is concluded that in this family increases in 2n occurred much more often than decreases. The data are compared to those from two other coccid families, the Diaspididae and the Eriococcidae. Unexpectedly, in both the Pseudococcidae and the Diaspididae the frequency of species with the modal 2n is lowest among species from monotypic genera and from genera from which only a single species was examined, and increases with the increase in the number of species examined per genus.(died June 10, 1977)     

New records of some potential pest mealybugs (Hemiptera: Coccoidea: Pseudococcidae) in Japan

Four species of mealybugs, Dysmicoccus neobrevipes, Phenacoccus defectus, Ph. parvus, and Ph. solenopsis (Hemiptera: Coccoidea: Pseudococcidae) are recorded for the first time from Japan in the Ry?ky? (Ryukyu) Archipelago, with brief biological notes. We discuss some features of these species compared with those of related species, D. brevipes and Ph. solani, and we consider their potential risks to Japanese agriculture and/or horticulture.     

Hot water treatment and insecticidal coatings for disinfesting limes of mealybugs (Homoptera: Pseudococcidae)

Hot water immersion and insecticidal coatings were tested to determine if they could be used to disinfest Persian limes, Citrus latifolia Tanaka, of the mealybug pests Planococcus citri Risso and Pseudococcus odermatti Miller & Williams. A 20-min 49 degrees C hot water immersion treatment is effective in killing mealybugs and all other arthropods tested found externally on limes, or under the calyx. No insects or mites were found to survive after the 20-min hot water treatment. In this test, 7,200 limes were treated with 1,308 insects killed and zero survivors. Treatment at 49 degrees C for 20 min did not significantly affect quality when treated fruit were compared with untreated control fruit. Four coatings were tested at a 3% rate: two petroleum-based oils (Ampol and Sunspray oil), a vegetable oil (natural oil), and a soap (Mpede). The coatings gave up to 94% kill (Ampol) of mealybugs, which is not sufficient to provide quarantine security. The coatings might be effective as a postharvest dip before shipment.     

Manna scale,Trabutina mannipara (Hemprich & Ehrenberg) (Homoptera: Coccoidea: Pseudococcidae)*

Abstract. The mealybug Trabutina mannipara (Hemprich & Ehrenberg, 1829) is described and illustrated, and a neotype female selected from topotypic material collected in the Sinai Peninsula. A lectotype female is designated for Trabutina palestina Bodenheimer (1927) which is shown to be a junior synonym of T.mannipara.     

Phylogenetic analyses and characteristics of the microbiomes from five mealybugs (Hemiptera: Pseudococcidae)

Associations between Sternorrhyncha insects and intracellular bacteria are common in nature. Mealybugs are destructive pests that seriously threaten the production of agriculture and forestry. Mealybugs have evolved intimate endosymbiotic relationships with bacteria, which provide them with essential amino acids, vitamins, and other nutrients. In this study, the divergence of five mealybugs was analyzed based up the sequences of the mitochondrial cytochrome oxidase I (mtCOI). Meanwhile, the distinct regions of the 16S rRNA gene of primary symbionts in the mealybugs were sequenced. Finally, high‐throughput sequencing (HTS) techniques were used to study the microbial abundance and diversity in mealybugs. Molecular phylogenetic analyses revealed that these five mealybugs were subdivided into two different clusters. One cluster of mealybugs (Dysmicoccus neobrevipes, Pseudococcus comstocki, and Planococcus minor) harbored the primary endosymbiont “Candidatus Tremblaya princeps,” and another cluster (Phenacoccus solenopsis and Phenacoccus solani) harbored “Ca. Tremblaya phenacola.” The mtCOI sequence divergence between the two clusters was similar to the 16S rRNA sequence divergence between T. princeps and T. phenacola. Thus, we concluded that the symbiont phylogeny was largely concordant with the host phylogeny. The HTS showed that the microbial abundance and diversity within P. solani and P. solenopsis were highly similar, and there was lower overall species richness compared to the other mealybugs. Among the five mealybugs, we also found significant differences in Shannon diversity and observed species. These results provide a theoretical basis for further research on the coevolution of mealybugs and their symbiotic microorganisms. These findings are also useful for research on the effect of symbiont diversity on the pest status of mealybugs in agricultural systems.     

Serological studies on five species of Pseudococcidae (Homoptera)

Abstract. Populations of Planococcus cini, Planococcus ficus, Pseudococcus obscurus, Pseudococcus calceolanae and Pseudococcus longispinus were selected for immunoelectrophoretic tests from which correlation and distance coefficients were calculated. Cluster analysis of serological data allowed construction of a dendrogram in which the phylogenetic relationships among the five species are presented. The conclusions were found to be in agreement with modern views on taxonomic interrelations among the five species based on female and male morphology. The recent separation of Planococcus citn' and Planococcus ficus as independent species is emphasized.     

New and earlier unnoted mealybugs and felt scale (Homoptera: Coccinea: Pseudococcidae,Eriococcidae) from Morocco

Two new species of mealybugs (Pseudococcidae), Puto (Ceroputo) chetverikovi n. sp. and Fonscolombia toubkalensis n. sp., are described and illustrated. Thirteen other species are noted for the first time to fauna of Morocco or to Africa as a whole. Additionally, one species of closely related family Eriococcidae, Acanthococcus ericae (Signoret, 1875), is also reported for the first time to Morocco.     

Phylogenetic relationships of the endosymbionts of mealybugs (Homoptera: Pseudococcidae) based on 16S rDNA sequences.

A portion of the gene coding for the 16S ribosomal RNA from the endosymbionts of three species of mealybugs [Pseudococcus longispinus (Targioni-Tozzetti), Pseudococcus maritimus (Ehrhorn), and Dysmicoccus neobrevipes (Beardsley)] was cloned, sequenced, and compared to a homologous fragment from bacteria representative of aphid endosymbionts as well as major subdivisions of the Proteobacteria. Parsimony analysis of the sequences indicated that the mealybug endosymbionts are related and belong to the beta-subdivision; in contrast, previous studies showed that aphid endosymbionts are part of the gamma-subdivision. These findings suggest that the endosymbiosis of mealybugs is a consequence of a single bacterial infection and indicate that this ancestor was different from the ancestor involved in aphid endosymbiosis.     

宁夏粉蚧科昆虫研究（半翅目：蚧总科）

记述宁夏同族自治区粉蚧科Pseudococcidae昆虫24属41种,其中包括2新种:宁夏草粉蚧Fonscolombia ningxiana,sp.nov.和冰草长粉蚧Longicoccus agropyri.sp.nov.;2中国新记录种:多管刺粉蚧spinococcus multitubulatus(Danzig,1980)和孤独条粉蚧Trionymus singularis Schmutterer,1952:1新组合:赖草长粉蚧Longicoccus leymicola(Tang,1992),comb.n.(移自少粉蚧属Mirococcus Borchsenius);Puto jarudensis Tang(1992)为Ceroputopilosellae Sulc.1898的新异名.模式标本保存在山西农业大学蚧虫研究中心.     

Metadenopsis Matesova, 1966 and similar mealybug genera (Homoptera,Coccinea: Pseudococcidae) from Russia and neighboring countries

Seven mealybug genera, Kalaginella gen. n., Archanginella gen. n., Metadenopsis Matesova, Metadenopus ?ulc, Glycycnyza Danzig, Inopicoccus Danzig, and Volvicoccus Goux, all with a simplified anal apparatus and lacking cerarii, are revised and illustrated. Kalaginella intermedia gen. et sp. n. and Archanginella kyzylkumica gen. et sp. n. are described from the Kara Kum and Kyzyl Kum deserts, correspondingly. Mirococcopsis stipae Borchsenius, 1949 is considered a junior synonym of Volvicoccus volvifer Goux, 1945.     

Phylogenetic analysis of mealybugs (Hemiptera: Coccoidea: Pseudococcidae) based on DNA sequences from three nuclear genes, and a review of the higher classification

Abstract. Mealybugs (Hemiptera: Pseudococcidae) are small, plant‐sucking insects which comprise the second largest family of scale insects (Coccoidea). Relationships among many pseudococcid genera are poorly known and there is no stable higher level classification. Here we review previous hypotheses on relationships and classification and present the first comprehensive phylogenetic study of the Pseudococcidae based on analysis of nucleotide sequence data. We used three nuclear genes, comprising two noncontiguous fragments of elongation factor 1α (EF‐1α 5′ and EF‐1α 3′), fragments of the D2 and D10 expansion regions of the large subunit ribosomal DNA gene (28S), and a region of the small subunit ribosomal DNA gene (18S). We sampled sixty‐four species of mealybug belonging to thirty‐five genera and representing each of the five subfamilies which had been recognized previously, and included four species of Puto (Putoidae) and one species each of Aclerda (Aclerdidae) and Icerya (Margarodidae), using Icerya as the most distant outgroup. A combined analysis of all data found three major clades of mealybugs which we equate to the subfamilies Pseudococcinae, Phenacoccinae and Rhizoecinae. Within Pseudococcinae, we recognize the tribes Pseudococcini (for Pseudococcus, Dysmicoccus, Trionymus and a few smaller genera), Planococcini (for Planococcus and possibly Planococcoides) and Trabutinini (represented by a diverse range of genera, including Amonostherium, Antonina, Balanococcus, Nipaecoccus and non‐African Paracoccus), as well as the Ferrisia group (for Ferrisia and Anisococcus), some ungrouped African taxa (Grewiacoccus, Paracoccus, Paraputo and Vryburgia), Chaetococcus bambusae and Maconellicoccus. The ‘legless’ mealybugs Antonina and Chaetococcus were not closely related and thus we confirmed that the Sphaerococcinae as presently constituted is polyphyletic. In our analyses, the subfamily Phenacoccinae was represented by just Phenacoccus and Heliococcus. The hypogeic mealybugs of the Rhizoecinae usually formed a monophyletic group sister to all other taxa. Our molecular data also suggest that the genera Pseudococcus, Dysmicoccus, Nipaecoccus and Paracoccus are not monophyletic (probably polyphyletic) and that Phenacoccus may be paraphyletic, but further sampling of species and genes is required. We compare our phylogenetic results with published information on the intracellular endosymbionts of mealybugs and hypothesize that the subfamily Pseudococcinae may be characterized by the possession of β‐Proteobacteria (primary endosymbionts) capable of intracellular symbiosis with γ‐Proteobacteria (secondary endosymbionts). Furthermore, our data suggest that the identities of the secondary endosymbionts may be useful in inferring mealybug relationships. Finally, cloning polymerase chain reaction products showed that paralogous copies of EF‐1α were present in at least three taxa. Unlike the situation in Apis and Drosophila, the paralogues could not be distinguished by either the presence/absence or position of an intron.     

The type-species of Lindingaspis MacGillivray (Homoptera: Coccoidea: Diaspididae)

Melanaspis samoana Lindinger the type-species of Lindingaspis is re-described and illustrated from syntype specimens and a lectotype is selected.     

Chromosome systems in the eriococcidae (Coccoidea Homoptera)

Spermatogenesis is described in two eriococcid species and the observations are compared to those previously reported. In Gossyparia spuria the diploid chromosome number is 28 in both males and females. In the female all the chromosomes are euchromatic. In most male tissues 14 of the chromosomes are euchromatic (E) and 14 are heterochromatic (H). Prior to the first meiotic division in males the number of H chromosomes was reduced. During prophase I all the cells showed 14 E chromosomes and from 1 to over 9 H chromosomes. The range of chromosome numbers in metaphase I was similar to that in prophase I. All the chromosomes divided in anaphase I, and, following differential uncoiling at interkinesis, the E and H groups of chromosomes segregated from each other at anaphase II. Only the E groups formed sperm. The presence of a variable number of H chromosomes and a haploid number of E chromosomes in spermatogenesis suggested the presence of the multiple-D variant of the Comstockiella chromosome system. In this system some of the H chromosomes become euchromatic prior to prophase I of spermatogenesis and pair with their E homologues. All the remaining H chromosomes are thus univalents, while among the E elements, some are univalents and the rest are bivalents. The observed reduction in the number of H chromosomes in the first meiotic division which was previously attributed to pairing among the H chromosomes, is now interpreted to be the result of the return of some of the H chromosomes to a euchromatic state and to their subsequent pairing with their E homologues. Spermatogenesis in Eriococcus araucariae was similar to that of G. spuria except that the reduction in the number of H chromosomes was not as extensive. The chromosome systems of the two species are compared to those of other eriococcids and the differences are briefly discussed.Supported by grant GB1585 from the National Science Foundation, Washington, D. C.     

热带平刺粉蚧的检疫鉴定

【目的】明确热带平刺粉蚧Rastrococcus tropicasiaticus Williams的鉴别特征,建立平刺粉蚧属种类检索表。【方法】随机抽样、形态学观察和测量。【结果】从进口越南龙眼鲜果中截获热带平刺粉蚧,头胸部腹面多格腺以单排排列,体背面大五格腺少是其识别的主要形态学特征;编制了平刺粉蚧属16种检索表。【结论】热带平刺粉蚧为我国口岸首次检出,研究结果为进口水果中该类粉蚧的检疫鉴定提供了重要的参考资料。