OVERWINTERING ADULTS AND SPRINGTIME GENERATION OF CACOPSYLLA PICTA (SYNONYM C. COSTALIS) CAN TRANSMIT APPLE PROLIFERATION PHYTOPLASMAS

Abstract Cacopsylla picta (Förster, 1848) (Hemiptera: Pysllidae) is the main vector of apple proliferation, a phytoplasma-caused disease. It represents one of the most severe problems in apple orchards, and therefore, there is a mandatory requirement to chemically treat against this pest in the European Union. Sexual communication using substrate-borne vibrations was demonstrated in several psyllid species. Here, we report the characteristics of the vibrational signals emitted by C. picta during courtship behavior. The pair formation process can be divided into two main phases: identification and courtship. Females initiate the communication on the host plant by emitting trains of vibrational pulses and, during courtship, if males reply, by emitting a signal consisting of a series of pre-pulses and a ‘buzz’, a duet is established. Moreover, a scanning electron microscopy investigation showed the presence of a stridulatory structure on the thorax and wings of both sexes, whereas the video recordings elucidated associated wing movement. The results provide new information about the biology of this phytoplasma vector and could form a basis of an environmentally friendly pest management strategy.

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Characteristics of the Spread of Apple Proliferation by Its Vector Cacopsylla picta

Phytopathology ◽

10.1094/phyto-01-11-0012 ◽

2011 ◽

Vol 101 (12) ◽

pp. 1471-1480 ◽

Cited By ~ 11

Author(s):

Barbara Jarausch ◽

Nora Schwind ◽

Annette Fuchs ◽

Wolfgang Jarausch

Keyword(s):

Infection Rate ◽

Natural Infection ◽

Regional Scale ◽

Agricultural Practices ◽

Transmission Efficiency ◽

Apple Proliferation ◽

Female Ratio ◽

Northern Switzerland ◽

Cacopsylla Picta ◽

Candidatus Phytoplasma Mali

The distribution and natural phytoplasma infection of Cacopsylla picta were investigated during a long-term field survey between 2002 and 2009 in commercial and abandoned apple proliferation-infected orchards throughout Germany, northern Switzerland, and eastern France. Comparable population dynamics were described for the different sites whereas considerable variations in the absolute population densities were observed among the years. Individual polymerase chain reaction (PCR) testing revealed, for each year, a rather stable natural infection rate with ‘Candidatus Phytoplasma mali’ of ≈10% for overwintered adults of C. picta. Both genders were equally highly infected although more females were caught. The overall male/female ratio was 1:1.5. No direct correlation was found between the infection status of the orchard and the infection rate of overwintered C. picta. No influence of agricultural practices was seen. However, a relationship between the incidence of the disease and the vector population density became evident on a regional scale. Successful transmission of ‘Ca. P. mali’ occurred each year with overwintered individuals as well as with new adults. The transmission efficiency varied among the years within 8 to 45% for overwintered adults and 2 to 20% for individuals of the new generation. The load of single C. picta with ‘Ca. P. mali’ was determined by quantitative real-time PCR. High phytoplasma titers were measured in overwintered adults already at their first appearance in the orchards after remigration from their overwintering hosts. Thus, the data indicate the transmission of the disease on a regional scale by remigrant adults of C. picta and at a local scale within the same season by emigrant adults which developed on infected plants.

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Phytoplasma occurrence in apple trees in the Czech Republic

Plant Protection Science ◽

10.17221/3820-pps ◽

2011 ◽

Vol 39 (No. 1) ◽

pp. 7-12 ◽

Cited By ~ 1

Author(s):

R. Fialová ◽

M. Navrátil ◽

P. Válová

Keyword(s):

Fragment Length Polymorphism ◽

Rrna Gene ◽

Polymorphism Analysis ◽

Apple Proliferation ◽

Chain Reaction ◽

Apple Trees ◽

The Czech Republic ◽

High Incidence ◽

Phytoplasma Infection ◽

Polymerase Chain

The presence of phytoplasmas in apple trees with proliferation symptoms, rubbery wood symptoms and no symptoms was determined by using polymerase chain reaction assays with primers amplifying phytoplasma 16S rRNA gene. Phytoplasmas were detected in all trees with proliferation symptoms. Positive tests for phytoplasma in the group of trees with rubbery wood symptoms and of those without symptoms revealed a relatively high incidence of latent phytoplasma infection. Using restriction fragment length polymorphism analysis, phytoplasma of the same identity – apple proliferation phytoplasma (subgroup 16SrX-A) – was recorded in all positively tested trees.  

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Influence of ontogenetic and migration stage on feeding behavior of Cacopsylla picta on ‘Candidatus Phytoplasma mali’ infected and non-infected apple plants

Journal of Insect Physiology ◽

10.1016/j.jinsphys.2021.104229 ◽

2021 ◽

pp. 104229

Author(s):

Louisa Maria Görg ◽

Jürgen Gross

Keyword(s):

Feeding Behavior ◽

Cacopsylla Picta ◽

Candidatus Phytoplasma Mali ◽

And Migration

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Surveying Potential Vectors of Apple Proliferation Phytoplasma: Faunistic Analysis and Infection Status of Selected Auchenorrhyncha Species

Insects ◽

10.3390/insects12010012 ◽

2020 ◽

Vol 12 (1) ◽

pp. 12

Author(s):

Stefanie Fischnaller ◽

Martin Parth ◽

Manuel Messner ◽

Robert Stocker ◽

Christine Kerschbamer ◽

...

Keyword(s):

New Records ◽

Regional Scale ◽

Insect Vectors ◽

Infection Status ◽

Apple Proliferation ◽

Population Densities ◽

South Tyrol ◽

Candidatus Phytoplasma Mali ◽

Cacopsylla Melanoneura

Apple proliferation (AP) is one of the economically most important diseases in European apple cultivation. The disease is caused by the cell-wall-less bacterium ’ Candidatus Phytoplasma mali’, which is transmitted by Cacopsylla picta (Foerster) and Cacopsylla melanoneura (Foerster) (Hemiptera: Psylloidea). In South Tyrol (Italy), severe outbreaks were documented since the 1990s. Infestation rates of AP do not always correlate with the population densities of the confirmed vectors, implying the presence of other, so far unknown, hemipterian vectors. By elucidating the species community of Auchenorrhyncha (Insecta: Hemiptera) at a regional scale, more than 31,000 specimens were captured in South Tyrolean apple orchards. The occurrence of 95 species was confirmed, whereas fourteen species are new records for this territory. Based on the faunistical data, more than 3600 individuals out of 25 species were analyzed using quantitative PCR to assess the presence of AP phytoplasma. The pathogen was sporadically detected in some individuals of different species, for example in Stictocephala bisonia Kopp and Yonk (Hemiptera: Membracidae). However, the concentration of phytoplasma was much lower than in infected C. picta and C. melanoneura captured in the same region, confirming the role of the latter mentioned psyllids as the main insect vectors of AP- phytoplasma in South Tyrol.

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