The aphids (Homoptera: Aphididae) of British Columbia 10. Further additions

Five species of aphids and new host records were added to the taxonomic list of the aphids of British Columbia

A rapid non-destructive DNA extraction method for insects and other arthropods

Preparation of arthropods for morphological identification often damages or destroys DNA within the specimen. Conversely, DNA extraction methods often destroy the external physical characteristics essential for morphological identification. We have developed a rapid, simple and non-destructive DNA extraction technique for arthropod specimens. This technique was tested on four arthropod orders, using specimens that were fresh, preserved by air drying, stored in ethanol, or collected with sticky or propylene glycol traps. The technique could be completed in twenty minutes for Coleoptera, Diptera and Hemiptera, and two minutes for the subclass Acarina, without significant distortion, discolouration, or other damage to the specimens

Diversity, distribution and phenology of Lygus species (Hemiptera: Miridae) in relation to vegetable greenhouses in the lower Fraser Valley, British Columbia, and southwestern Ontario

Lygus spp. were collected from near and inside vegetable greenhouses during three years in the lower Fraser Valley, British Columbia (BC) and in Leamington, Ontario (ON). In BC, the dominant species was Lygus shulli, followed in abundance by L. elisus and L. hesperus; L. lineolaris was not collected in the lower Fraser Valley. In ON, only L. lineolaris was collected. In BC, L. shulli was generally distributed throughout the region, whereas L. hesperus was captured in sweep net samples only in coastal areas. Lygus hesperus appeared to be univoltine in BC. All other species in ON and BC were apparently bivoltine. In ON, numbers of adults collected outside of greenhouses correlated with numbers collected inside greenhouses whereas this was not the case in BC. Differences in flight behaviour, abundance and greenhouse construction may account for this latter difference. Our results highlight the need for different approaches to IPM of pest Lygus species in the ON and BC greenhouse industries

Effect of kaolin clay on migrant alate aphids (Hemiptera: Aphididae) in blueberry fields in the context of Blueberry scorch virus

The efficacy of kaolin clay (Surround® WP) in reducing the number of migrant aphids on blueberry, Vaccinium corymbosum L. (Ericaceae) and the incidence of Blueberry scorch virus (BlScV) was determined. Two applications of kaolin clay reduced the number of alatae collected on treated ‘Berkeley’ plants by as much as a factor of eight between 4 June and 16 August. However, five of 100 test plants located near infected fields and exposed only to migrant alatae between 10 May and 16 August became infected with BlScV: three controls and two treated with kaolin clay. The work demonstrates the importance of migrant alatae in the spread of BlScV; 5% transmission is consistent with previous estimates of annual virus spread by winged and non-winged aphids. Three of the plants became infected between 10 and 27 May (one control and two treated with kaolin clay), indicating the importance of aphid flights in May for virus transmission. Rainfall removed much of the kaolin clay and this may have affected its efficacy. The aphid data demonstrated that migrant alatae are able to discriminate between untreated and kaolin—treated blueberry plants, and that Ericaphis fimbriata (Richards), which utilizes blueberry as a host, discriminates better than other migrant species. Water trap data do not necessarily reflect the total migrant aphid composition found on plants in the field. Plant growth was not affected by the kaolin clay, but the fruit had clay residues amongst the bracts of the calyx limiting the use of this product on producing fields to the period before fruit set. Kaolin clay may be best suited to protection of nursery stock, but further work is needed to improve efficacy during wet weather and determine optimal application frequency.Note: Use of trade names or trademarks does not imply endorsement of the companies or products named nor criticism of similar ones not named

Relationships within aphids Cinara (Cupressobium) (Hemiptera) based on mitochondrial and nuclear DNA sequences

The relationships between Cinara (Cupressobium) aphids inhabiting woody parts and leaves of conifers belonging to Cupressaceae have been studied using a mitochondrial gene (COI) and a nuclear gene (EF1-α). Based on the COI sequences, genetic distances between species ranged from 5.6 % between Cinara (C.) tujafilina (del Guercio) and Cinara (C.) juniperi (De Geer) to 10.5 % between C. (C.) tujafilina and Cinara (C.) mordvilkoi (Pašek). Genetic distances among EF1-α sequences were lower and showed from 0.1 % between C. cupressi and C. juniperi to 2.3 % between C. tujafilina and C. mordvilkoi. Molecular phylogenetic trees were constructed using the Bayesian inference (BI) phylogenetic analysis and maximum parsimony (MP) criterion. Phylogenetic trees obtained based on COI and EF1-α marker genes created two sister clades. Our results indicate that Cinara (Cupressobium) are a monophyletic group of aphids. Phylogenetic relationships amongst Cupressobium aphids do not result from the association with the host plant, but from the feeding site on the host plant or an ability to change the microhabitat on the plant. As closely related species inhabit similar microhabitats on different host plants, it suggests that the host switching is the main mode of speciation in this subgenus

DNA barcoding and a precise morphological comparison revealed a cryptic species in the Nippolachnus piri complex (Hemiptera: Aphididae: Lachninae)

Nippolachnus is a small Palaearctic-Oriental genus of very characteristic aphids that live on the leaves of woody Rosaceae. One species, N. piri, has hitherto been regarded to be widely distributed and relatively polyphagous. Members of this genus are considered to be easy to recognize due to the absence of the ocular tubercle and triommatidia on the head. We conducted research on the morphology and generic characters of Nippolachnus piri complex using scanning electron microscopy (for the first time) and DNA barcoding. We analyzed N. piri populations on Pyrus and other plants (Eriobotrya, Rhaphiolepis and Sorbus) in Japan and the Republic of Korea. Specifically, a high genetic divergence value was found between the N. piri populations associated with different host plants. SEM investigation of the head capsule revealed that a triommatidium is present under the compound eye, despite their lack of an ocular tubercle. We propose Nippolachnus micromeli Shinji, 1924 stat. nov. as a cryptic species in the N. piri complex based on a morphological comparison, DNA barcoding and different host-plant associations. Illustrations and descriptions of studied species are given. Morphological keys to the apterae and alatae of all known species of the genus Nippolachnus are also provided