The mealybugs (Hemiptera: Coccoidea: Pseudococcidae) are a speciose and ubiquitous group of sap‐sucking plant parasites, many of which are very serious agricultural pests. There has been much work on the alpha‐level taxonomy, amounting to the description of more than 2000 species, but suprageneric relationships remain poorly known. Downie & Gullan reviewed proposed schemes for a mealybug subfamily‐level classification and used DNA sequence data from three nuclear genes to infer the mealybug phylogeny. They recognized three subfamilies: the Rhizoecinae, the Phenacoccinae, and the Pseudococcinae; and within the Pseudococcinae, recognized the tribes Pseudococcini, Trabutinini, and Planococcini. Excepting the Trabutinini, none of these groupings was well‐supported. We improve our estimation of the mealybug phylogeny by: (i) increasing the taxon sampling by 50%; (ii) adding a morphological character matrix; and (iii) performing mixed model Bayesian and maximum likelihood inference procedures. We recover two primary clades within the Pseudococcidae, to which we apply the subfamily names Phenacoccinae and Pseudococcinae. Within the Phenacoccinae, we recover support for the monophyly of the hypogaeic mealybugs (Rhizoecini), and within the Pseudococcinae, we find support for the tribes Pseudococcini, Trabutinini, and Planococcini. Our results suggest a clear sequence of (i) β‐Proteobacteria primary endosymbionts infecting the mycetome of the most recent common ancestor of the Pseudococcinae, followed by (ii) γ‐Proteobacteria secondary endosymbionts infecting the primary β‐Proteobacteria endosymbionts. For each subfamily, we provide a morphological diagnosis and a comprehensive list of included genera. We resurrect the genus Ceroputo Šulc, currently under synonymy with the genus Puto Signoret (Putoidae), and place it in the mealybug subfamily Phenacoccinae. Greenoripersia kaiseri Bodenheimer is transferred from the Pseudococcidae to the Eriococcidae.

Since at least 2005, a possibly introduced mealybug of the genus Phenacoccus has been causing serious damage to cotton (Gossypium hirsutum) over much of the Sindh and Punjab districts of Pakistan and in north-western India. Some short papers have been published locally giving details on the structure and biology of this species and suggesting the name Phenacoccus gossypiphilous Abbas, Arif & Saeed (2005) but without designating type specimens or depositories. This name is here considered a nomen nudum. A detailed morphological study has been unable to separate this species from many specimens of Phenacoccus from the Neotropics that are believed to be Phenacoccus solenopsis Tinsley. The material from the Indian subcontinent shows considerable morphological variation in the frequency of multilocular disc pores and oral collar tubular ducts on the ventral submargin of the abdomen; this appeared to be related to conditions under which this species was reared, with those cultured in a screen-house during the non-cotton-growing season being indistinguishable from P. solenopsis from the Neotropics . This paper re-describes the adult female of P. solenopsis Tinsley based on the type specimens from New Mexico, and designates a lectotype. The type material was compared with specimens considered to be P. solenopsis from elsewhere in the New World, and from West Africa and several areas in Asia, particularly Pakistan and India. Based of our present understanding of the morphology of adult female P. solenopsis, it is concluded that the species is rather variable, that this variability may be environmentally induced, and that the species currently causing widespread damage to cotton on the Indian subcontinent is referable to P. solenopsis. Adult male P. solenopsis from North America, Pakistan and India were also studied and again no significant differences were found. Descriptions are provided of the adult male and all the immature stages of P. solenopsis, based on material from India and Pakistan. Keys are provided to (a) separate P. solenopsis from similar species of Phenacoccus currently known from Asia and (b) to identify all instars. The morphological differences between P. solenopsis, P. solani Ferris and P. defectus Ferris are reviewed and, based on the morphological variation found in the Asian material, it is considered that there is some support for the suggestion that these three species might be environmentally induced variants of a single species. A few details are given of the biology of P. solenopsis on cotton in Pakistan.

Secondary metabolites are important in plant defence against pests and diseases. Similarly, insects can use plant secondary metabolites in defence and, in some cases, synthesize their own products. The paper describes how two specialist brassica feeders, Brevicoryne brassicae (cabbage aphid) and Lipaphis erysimi (turnip aphid) can sequester glucosinolates (thioglucosides) from their host plants, yet avoid the generation of toxic degradation products by compartmentalizing myrosinase (thioglucosidase) into crystalline microbodies. We propose that death, or damage, to the insect by predators or disease causes disruption of compartmentalized myrosinase, which results in the release of isothiocyanate that acts as a synergist for the alarm pheromone E-␤-farnesene.

Abstract. Currently, 49 families of scale insects are recognised, 33 of which are extant. Despite more than a decade of DNA sequence-based phylogenetic studies of scales insects, little is known with confidence about relationships among scale insects families. Multiple lines of evidence support the monophyly of a group of 18 scale insect families informally referred to as the neococcoids. Among neococcoid families, published DNA sequence-based estimates have supported Eriococcidae paraphyly with respect to Beesoniidae, Dactylopiidae, and Stictococcidae. No other neococcoid interfamily relationship has been strongly supported in a published study that includes exemplars of more than ten families. Likewise, no well-supported relationships among the 15 extant scale insect families that are not neococcoids (usually referred to as 'archaeococcoids') have been published. We use a Bayesian approach to estimate the scale insect phylogeny from 162 adult male morphological characters, scored from 269 extant and 29 fossil species representing 43/49 families. The result is the most taxonomically comprehensive, most resolved and best supported estimate of phylogenetic relationships among scale insect families to date. Notable results include strong support for (i) Ortheziidae sister to Matsucoccidae, (ii) a clade comprising all scale insects except for Margarodidae s.s., Ortheziidae and Matsucoccidae, (iii) Coelostomidiidae paraphyletic with respect to Monophlebidae, (iv) Eriococcidae paraphyletic with respect to Stictococcidae and Beesoniidae, and (v) Aclerdidae sister to Coccidae. We recover strong support for a clade comprising Phenacoleachiidae, Pityococcidae, Putoidae, Steingeliidae and the neococcoids, along with a sister relationship between this clade and Coelostomidiidae + Monophlebidae. In addition, we recover strong support for Pityococcidae + Steingeliidae as sister to the neococcoids. Data from fossils were incomplete, and the inclusion of extinct taxa in the data matrix reduced support and phylogenetic structure. Nonetheless, these fossil data will be invaluable in DNA sequence-based and total evidence estimates of phylogenetic divergence times.