Parthenolecanium Corni Research Articles

Synopsis of biological control for European fruit lecanium (Parthenolecanium corni) by parasitoids in North America and preliminary findings in hybrid hazelnut orchards

Synopsis of biological control for European fruit lecanium (Parthenolecanium corni) by parasitoids in North America and preliminary findings in hybrid hazelnut orchards

Diyarbakır ve Elazığ illeri meyve bahçelerindeki Koşnil (Hemiptera:Coccomorpha: Coccidae) türleri

This study was carried out in order to determine the soft scale insects (Hemiptera: Coccomorpha: Coccidae) species, their host plants, distribution areas, densities and infestation rates on fruit production areas of Diyarbakır and Elazığ Provinces in 2017-2018. As a result of the study, 7 soft scale species were determined on 12 fruit plants. The most common species and the widest host plant range was Parthenolecanium corni (Bouché, 1844) in the study areas. Sphaerolecanium prunastri (Boyer de Fonscolombe, 1834) and Didesmococcus unifasciatus (Archangelskaya, 1923) were determined to be the most important species in the region. Didesmococcus unifasciatus caused heavy infestation on almond, Prunus dulcis (Mill.) (Rosales: Rosaceae) trees (Scale 4) at rates of 3.1% and 0,9% in Çınar district of Diyarbakır and Sivrice district of Elazığ, respectively. Sphaerolecanium prunastri caused heavy infestation on apricots, Prunus armeniaca L. (Rosales: Rosaceae) at rates of 3.8% and 4.6% in Elazığ's Central and Baskil districts, which have significant apricot production areas.

Species of the genus Parthenolecanium (Hemiptera: Coccidae) in urban environments in Serbia

Four species of soft scales from the genus Parthenolecanium have been registered in urban areas in Serbia: Parthenolecanium corni, P. fletcheri, P. pomeranicum, and P. rufulum. They all develop one generation annually and overwinter as second-instar nymphs on host twigs. P. corni reproduces by gamogenesis, while the other three species reproduce by parthenogenesis. The species were recorded on the territory of Serbia in 22 locations on 20 host plants, whereby P. corni was identified on 8 new host plants, and P. fletheri on one new host. The intensity of scale attacks and damage symptoms on the infested plants were variable. P. corni, P. fletcheri, and P. rufulum formed numerous colonies on some woody and bushy plants, causing branches of individual plants to dry and decay.

Transmission of Grapevine Leafroll-Associated Viruses and Grapevine Virus A by Vineyard-Sampled Soft Scales (Parthenolecanium corni, Hemiptera: Coccidae).

Grapevine-infecting ampelo- and vitiviruses are transmitted by scale insects belonging to several species, among which is the European fruit lecanium, Parthenolecanium corni (Bouché) (Hemiptera Coccidae). Our objective was to characterize the transmission biology of grapevine leafroll-associated viruses (GLRaV) and grapevine virus A (GVA) by this soft scale species in order to evaluate its ability to spread these viruses. In transmission experiments with nymphs sampled from different vineyards infected with GLRaV 1, 2, 3 and GVA, P. corni transmitted only GLRaV 1 and GVA to healthy vines. GVA was predominantly transmitted along with GLRaV 1, whereas the latter could be transmitted alone from single or co-infected vines. Vineyard-sampled second instar nymphs were more efficient than first instars at transmitting GLRaV 1, whereas both instars displayed similar transmission rates for GVA. Short virus inoculation access periods and the absence of virus in eggs of females living on infected grapevines fulfilled the criteria of non-circulative semi-persistent transmission mode.

Fungal Associates of Soft Scale Insects (Coccomorpha: Coccidae).

Ophiocordyceps fungi are commonly known as virulent, specialized entomopathogens; however, recent studies indicate that fungi belonging to the Ophiocordycypitaceae family may also reside in symbiotic interaction with their host insect. In this paper, we demonstrate that Ophiocordyceps fungi may be obligatory symbionts of sap-sucking hemipterans. We investigated the symbiotic systems of eight Polish species of scale insects of Coccidae family: Parthenolecanium corni, Parthenolecanium fletcheri, Parthenolecanium pomeranicum, Psilococcus ruber, Sphaerolecanium prunasti, Eriopeltis festucae, Lecanopsis formicarum and Eulecanium tiliae. Our histological, ultrastructural and molecular analyses showed that all these species host fungal symbionts in the fat body cells. Analyses of ITS2 and Beta-tubulin gene sequences, as well as fluorescence in situ hybridization, confirmed that they should all be classified to the genus Ophiocordyceps. The essential role of the fungal symbionts observed in the biology of the soft scale insects examined was confirmed by their transovarial transmission between generations. In this paper, the consecutive stages of fungal symbiont transmission were analyzed under TEM for the first time.

First Records of Coccomorpha (Hemiptera) Species in Diyarbakır, Turkey

AbstractPlants in gardens and parks within Diyarbakir Province (Bağlar, Kayapınar, Sur, and Yenişehir) of Turkey were sampled throughout the years of 2016 and 2017. These collections yielded 10 species from the superfamily Coccoidea (Hemiptera: Coccomorpha) including 3 species from the family Coccidae (Parthenolecanium corni [Bouché], Didesmococcus unifasciatus [Archangelskaya], Sphaerolecanium prunastri [Boyer de Fonscolombe]), 5 species from the family Diaspididae (Leucaspis pusilla [Löw], Pseudaulacaspis pentagona [Targiona-Tozzetti], Mercetaspis halli [Green], Salicicola kermanensis [Lindinger], Parlatoria oleae [Colvée]), and 1 species each from family Eriococcidae (Gossyparia spuria [Modeer]) and family Pseudococcidae (Planococcus vovae [Nasonov]). The diaspids L. pusilla, Pseudaulacaspis pentagona, and Salicicola Kermanensis; the eriococcid G. spuria; and the pseudococcid Planococcus vovae represent the first records for the Diyarbakır Province insect fauna.

Survey of five major grapevine viruses infecting Blatina and Žilavka cultivars in Bosnia and Herzegovina.

The sanitary status of grapevines has not yet been considered sufficiently in vineyards throughout Bosnia and Herzegovina (BiH). An extensive survey of five major grapevine viruses in the country was carried out in 2019. A total of 630 samples from the two dominant autochthonous cultivars, named Žilavka and Blatina, were tested by DAS-ELISA for the presence of grapevine leafroll-associated viruses (GLRaV-1 and 3), grapevine fleck virus (GFkV), grapevine fanleaf virus (GFLV) and Arabis mosaic virus (ArMV). Eighty-eight % of the samples were positive for at least one virus, and all five viruses were detected, thought with different incidence, i.e. GLRaV-3 (84%), GFLV (43%), GLRaV-1 (14%), GFkV (10%) and ArMV (0.2%). The majority of infected plants (about 75%) were asymptomatic. Specific virus symptoms were observed in the remaining infected plants, together with the reported GLRaV vectors, Planococcus ficus and Parthenolecanium corni, while nematodes of the Xiphinema genus were not found in the GFLV- or ArMV-infected vineyards. The GLRaV-3 CP phylogenetic analyses showed 75–100% nucleotide identity between the BiH and reference isolates, and the BiH isolates clustered into the major group. The dNS/dS ratio indicated a negative selection of the virus population, and the lack of geographical structuring within the population was observed. In addition, putative GLRaV-3 recombinants with breakpoints in the 5’ of the CP gene were detected, while no recombinant strains were identified for the other four viruses. The obtained results indicate a deteriorated sanitary status of the cultivated grapevines, the prevalence and intraspecies genetic diversity of GLRaV-3 throughout the country. The establishment of certified grapevine material and adequate virus vector control is therefore of primary importance to prevent further spread of these viruses. This study presents the results of the first molecular characterisation of grapevine viruses in Bosnia and Herzegovina.

Coccids distribution and food chains on ornamental cultures in the Nikitsky Botanical Gardens

The entomological inventory survey results of super-family Coccoidea in four Arboretum parks - Upper, Lower, Coastal and Montedor - are presented, the predominate species, the distributional pattern and food chains have been found. Four basic coccid groups have been specified according to the pattern of distribution on plants and the food chains. The coccid species composition in the Arboretum is presented by 19 phytophagan species out of 6 families. In all the parks the representatives of the family Coccidae dominate outman and injuriousness. Two coccid species Parthenolecanium corni Bouché. and Parthenolecanium pomeranicum Kaw. are the new ones for the coccid fauna of the Nikitsky Botanical Gardens. The coccid fauna and its food chains were studied present with the decorative cultivars guided by visual analysis of leaves, tree trunks and boughs. The determined coccids coupled with a part of a forage plant were looked through by means the binocular. The trivial belonging was defined according to N.S. Borhsenius method [1]. The distribution and forage plants occupancy rating was determined by 4 - scorecard scale: 0 ̶ crop pest is not detected; 1 ̶ sporadical plant invasion; 2 ̶ is present often but in small amounts; 3 ̶ mass plants occupancy [4]. The elicited coccid species were divided into polyphagans (P), monophagans (M) and oligophagans (O). As the result of entomological coccid fauna inventory survey in the Arboretum of the Nikitsky Botanical Gardens 19 species, which are of six families, were found. Families Diaspididae and Coccidae are the most numerous. The richest species diversity appears in Lower Arboretum park. According to food chains character 8 monophagans, 1 oligophagan and 10 polyphagans have been found. According to the coccid distribution on plants there are 4 groups: the first group includes coccids, which are inhabitants of evergreen shrubbery; the second one occupies leaves and young off-shoots; the third one settles by colonies on tree trunks, skeletal boughs or by rogue specimens; the fourth coccid group is confined to roots. Two new coccid species - Parthenolecanium pomeranicum Kaw. ̶ on common yew and Parthenolecanium corni Bouché. ̶ on high cranberry in the territory of the Arboretum have been found.

The efficacy of European fruit lecanium, Parthenolecanium corni (Bouché, 1844) control using natural products

European fruit lecanium, Parthenolecanium corni (Bouché, 1844) is among the leading worldwide pests of fruits such as plums, currants, jostaberry, grapevine and many others. This study is focused on testing the effectiveness of natural insecticide treatments compared with conventional insecticides on overwintering nymphs of the European fruit lecanium. In February of 2017, two experiments were conducted under laboratory conditions. The tested products were Boundary SW<sup>®</sup> (plant extract), Konflic<sup>®</sup> (plant extract), Ekol<sup>®</sup> (canola oil) and a tank-mix of Ekol<sup>®</sup> + Reldan 22<sup>®</sup> (canola oil and chlorpyrifos-methyl) as a chemical standard. The most effective product tested was the chemical standard tank-mix of Ekol<sup>®</sup> and Reldan 22<sup>®</sup>, which was 100% effective in all experiments. High efficiency was also achieved with Ekol<sup>®</sup> (canola oil) in high concentrations. We can summarize, that using canola oil in high concentration has almost the same effect as the chemical standard. Using canola oil against European fruit lecanium meets the principles of Integrated Pest Management (IPM) and also the need to design cropping systems that are less dependent on synthetic pesticides.

Epidemiology and Genetic Diversity of Grapevine Leafroll-Associated Viruses in British Columbia.

Grapevine leafroll disease (GLD) is a complex associated with one or more virus species belonging to the family Closteroviridae. The majority of viruses in this complex are vectored by one or more species of mealybugs (Pseudococcidae) and/or scale insects (Coccidae). Grape-growing regions of British Columbia (BC), including Okanagan, Similkameen, and Fraser valleys and Kamloops (BC central interior), Vancouver, and Gulf islands, were surveyed during the 2014 and 2015 growing seasons for the presence of four major grapevine leafroll-associated viruses, including Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, and GLRaV-4. In total, 3,056 composite five-vine samples were collected from 153 Vitis vinifera and three interspecific hybrid vineyard blocks. The results showed GLRaV-3 to be the most widespread, occurring in 16.7% of the composite samples, followed by GLRaV-4 (3.9%), GLRaV-1 (3.8%), and GLRaV-2 (3.0%). Mixed infections of two or more GLRaVs were found in 4.1% of the total samples. The relative incidence of GLRaVs differed among regions and vineyard blocks of a different age. Characterization of partial CO1 region from a total of 241 insect specimens revealed the presence of Pseudococcus maritimus, Parthenolecanium corni, and other Pulvinaria sp. in BC vineyards. Spatial patterns of GLRaV-3 infected grapevines in three vineyard blocks from three different regions in the Okanagan Valley showed variable degrees of increase in disease spread ranging from 0 to 19.4% over three growing seasons. Regional differences in the relative incidence and spread of GLD underline the need for region-based management programs for BC vineyards.

PARTHENOLECANIUM CORNI (BOUCHÉ) (HEMIPTERA COCCIDAE) IN VINEYARDS IN PORTUGAL: MORPHOLOGY, SEASONAL DEVELOPMENT, LIFE CYCLE AND REPRODUCTION

Due to the type of damage associated with scale insects of genus Parthenolecanium sp. (Hemiptera Coccidae) on vineyards and the increase of its importance, these pests have been studied in central region of Portugal. We addressed the following objectives: i) identification and morphological characterization of soft scales occur in vineyards and the parasitoids associated; ii) seasonal development and life cycle; iii) reproduction. The examined scale were identified as Parthenolecanium corni (Bouche, 1844), despite the existence of some morphological differences and fertility levels recorded in the two regions studied. Coccophagus lycimnia (Walker, 1839) (Hymenoptera Aphelinidae) and Metaphycus dispar (Mercet, 1925) (Hymenoptera Encyrtidae) parasitize the studied P. corni . Based on laboratory and field bioassays, some aspects of morphology as well the seasonal development, life cycle and reproduction are presented.

SCALE INSECTS (HEMIPTERA COCCOIDEA) ON MULBERRY TREES IN TURKEY

In Turkey commonly cultivated mulberry species are Morus alba L., M. nigra L., and M. rubra L (Moraceae). Mulberry fruits are widely consumed freshly or as traditional products such as mulberry molasses and mulberry dried fruit pulp. Mulberry leaves are used for sericulture. In this study, scale pests of mulberry trees were investigated mainly in Ankara and some other regions in Turkey. Eight scale insect species namely Ceroplastes japonicus Green , C. rusci (L.) , Neopulvinaria innumerabilis (Rathvon) , Parthenolecanium corni (Bouche) (Coccidae), Pseudaulacaspis pentagona Targioni-Tozzetti (Diaspididae), Phenacoccus aceris (Signoret) , Planococcus ficus (Signoret) and Pseudococcus comstocki (Kuwana) (Pseudococcidae) were found on the Moru s spp. P. pentagona was the most common and important pest species of the mulberry trees in research area. Populations of C.japonicus, N. innumerabilis, and P.comstocki are found at very high levels in some local gardens.

<I>Pseudococcus maritimus</I> (Hemiptera: Pseudococcidae) and <I>Parthenolecanium corni</I> (Hemiptera: Coccidae) Are Capable of Transmitting Grapevine Leafroll-Associated Virus 3 Between <I>Vitis</I> x <I>labruscana</I> and <I>Vitis vinifera</I>

The grape mealybug, Pseudococcus maritimus (Ehrhorn), and European fruit lecanium scale, Parthenolecanium corni (Bouché), are the predominant species of Coccoidea in Washington State vineyards. The grape mealybug has been established as a vector of Grapevine leafroll-associated virus 3 (GLRaV-3) between wine grape (Vitis vinifera L.) cultivars, elevating its pest status. The objective of this study was to determine if GLRaV-3 could be transmitted between Vitis x labruscana L. and V. vinifera by the grape mealybug and scale insects. Three transmission experiments were conducted with regard to direction; from V. vinifera to V. x labruscana L., from V. x labruscana L. to V. x labruscana L., and from V. x labruscana L. to V. vinifera. Each experiment was replicated 15 times for each vector species. Crawlers (first-instars) of each vector species were allowed 1-wk acquisition and inoculation access periods. The identities of viral and vector species were confirmed by reverse transcription-polymerase chain reaction, cloning, and sequencing of species-specific DNA fragments. GLRaV-3 was successfully transmitted by both species in all experiments, although Ps. maritimus was a more efficient vector under our experimental conditions. To the best of our knowledge, this study represents the first documented evidence of interspecific transmission of GLRaV-3 between two disparate Vitis species. It also highlights the potential role of V. x labruscana L. in the epidemiology of grapevine leafroll disease as a symptomless source of GLRaV-3 inoculum.

Relative Resistance or Susceptibility of Landscape-suitable Elms (Ulmus spp.) to Multiple Insect Pests

The National Elm Trial is a cooperative project to assess landscape suitability of Dutch elm disease-resistant elms (Ulmus spp.) in various regions of the United States. Researchers evaluated 20 cultivars of American, Asian, and hybrid elms for relative resistance or susceptibility to multiple insect pests in central Kentucky over seven years. Ratings for Japanese beetle, European elm flea weevil (EEFW), and several other pests were previously published. This paper reports data for seven additional pests, including honeydew-excreting scale insects (Parthenolecanium corni, Eriococcus spuria, and Pulvinaria innumerabilis), leaf-distorting woolly elm and woolly apple aphids (Eriosoma spp.), elm cockscomb gall aphid (Colopha ulmicola), and an invasive weevil (Oedophrys hilleri) not previously known to damage elms. Rankings for all 12 of the monitored pests are summarized. Most U. americana cultivars were relatively susceptible to the scale insects and likewise, Eriosoma spp. and C. ulmicola only infested the American elms. O. hilleri is a new state record for Kentucky. Its adults, active in mid- to late summer, chewed notches in edges of leaves. Cultivars of the Asian species U. parvifolia and U. propinqua, including ‘Athena Classic Lacebark’, ‘Everclear Lacebark’, ‘Emer II Allee’, and ‘Emerald Sunshine’ were top-rated for insect resistance. They were nearly pest-free except for foliar damage by EEFW, to which nearly all elms were susceptible. Insect resistance should be considered when re-introducing elms to urban landscapes. The data may help city foresters, landscapers, and others re-introducing elms to urban landscapes to select relatively pest-free cultivars requiring minimal inputs for insect control.

Karyotyping of European Fruit Scale Parthenolecanium corni (Bouché) on almond trees in Village of Rankous (Damascus Countryside Governorate) Syria

karyotyping of European Fruit Scale Parthenolecanium corni(Bouché) studied on almond trees in Village of Rankous-Syria in 2008. Results showed there are 16 chromosomes of the insect by using the technique of squashing preparations described by Gavrilov and Trapeznikova (2007) without use of dry ice and substituting it with freezing at -140°C (Cryo Freezer).

POSSIBILITY OF REDUCING CHEMICAL TREATMENTS AIMED AT CONTROL OF PLUM INSECT PESTS

During the last two years the main insect pests on plum trees in the region of Plovdiv (Central-South Bulgaria) were black and yellow plum sawflies (Hoplocampa minuta and H. flava) that destroyed 68-84% of fruitlets after bloom. Red plum maggot (Grapholitha funebrana) damaged more than 24-32% of fruits. Other important pests were two aphids (Hyalopterus pruni and Brachycaudus helichrysi), infesting 86-95,3% of shoots and brown scale (Parthenolecanium corni). Leaf sawfly (Neurotoma nemoralis), fall webworm (Hyphantria cunea), and plum ermine moth (Yponomeuta padellus) caused significant damage on leaves too. Some secondary pests, such as weevils, Rhynchites sp. and Phyllobius sp. as well as pear lace-bug (Stephanitis pyri) and others, damaged buds, fruits and leaves. Plant protection systems recommended for control of plum pests commonly include 10-12 chemical treatments. The experiments carried out in the orchards of the Agricultural University - Plovdiv have shown that the number of treatments may be significantly reduced without any negative effect on the trees or on the crop quantity and quality. This can be done by optimisation of the date of treatments, selection of proper insecticides and use of pheromones for mating disruption.

Pathogen‐tested material of grapevine varieties and rootstocks

Pathogen‐tested material of grapevine varieties and rootstocks

The parasitoid complex ofParthenolecanium corniBouché in the city of Tbilisi and its surroundings and comparison with some other European countries

The European fruit lecanium (EFL), Parthenolecanium corni Bouché (Hemiptera: Coccoidea), is a common and harmful soft scale, which attacks Fraxinus oxycarpa Willd. and other ornamental and orchard plants in Tbilisi, Georgia. This study investigates the phenology, degree of plant damage and effect of parasitoids on this scale in Tbilisi, a densely populated area. We present data on the 32 species of chalcidoid parasitoids recorded from EFL in Georgia and south-eastern Europe. The scale is heavily parasitized in Tbilisi, but we did not find any variation in seasonal abundance. The most common parasitoid of EFL was Blastothrix longipennis (Hymenoptera: Encyrtidae).

Improving Liquid Bait Programs for Argentine Ant Control: Bait Station Density

Argentine ants, Linepithema humile (Mayr), have a positive effect on populations of mealybugs (Pseudococcus spp.) in California vineyards. Previous studies have shown reductions in both ant activity and mealybug numbers after liquid ant baits were deployed in vineyards at densities of 85-620 bait stations/ha. However, bait station densities may need to be <85 bait stations/ha before bait-based strategies for ant control are economically comparable to spray-based insecticide treatments-a condition that, if met, will encourage the commercial adoption of liquid baits for ant control. This research assessed the effectiveness of baits deployed at lower densities. Two field experiments were conducted in commercial vineyards. In experiment 1, baits were deployed at 54-225 bait stations/ha in 2005 and 2006. In experiment 2, baits were deployed at 34-205 bait stations/ha in 2006 only. In both experiments, ant activity and the density of mealybugs in grape fruit clusters at harvest time declined with increasing bait station density. In 2005 only, European fruit lecanium scale [Parthenolecanium corni (Bouché)] were also present in fruit clusters, and scale densities were negatively related to bait station density. The results indicate that the amount of ant and mealybug control achieved by an incremental increase in the number of bait stations per hectare is constant across a broad range of bait station densities. The results are discussed in the context of commercializing liquid ant baits to provide a more sustainable Argentine ant control strategy.

Descriptions and Illustrations of the First Instars of Parthenolecanium corni (Bouché) and Parthenolecanium quercifex (Fitch) (Hemiptera: Coccidae)

Adult female specimens of Parthenolecanium corni (Bouche) and Parthenolecanium quercifex (Fitch) are often times confused for one another and misidentified. Members of the Parthenolecanium do show host-induced morphological dimorphisms, and the adult female is heavily sclerotized which can make key morphological characters obscure. Utilization of morphological characters of the first instar can help in the accuracy of the identification process. Key characters in distinguishing P. corni from P. quercifex are the absence of large (&amp;gt;5 μm) in the dorsal pore pattern.