Reproductive strategy of the Nearctic leafhopper Scaphoideus titanus Ball (Hemiptera: Cicadellidae)

2008 ◽  
Vol 99 (4) ◽  
pp. 401-413 ◽  
Author(s):  
Valerio Mazzoni ◽  
Janez Prešern ◽  
Andrea Lucchi ◽  
Meta Virant-Doberlet

AbstractMating behaviour of Scaphoideus titanus Ball, the vector of the grapevine disease Flavescence dorée, was investigated in order to determine the role of substrate-borne vibrational signals in intra-specific communication and pair formation. Vibrational signals were recorded from grapevine leaves with a laser vibrometer. Signalling activity of single males changed throughout the day and the peak in activity was associated with twilight and early night when ‘call and fly’ behaviour was observed. Pair formation began with the spontaneous emission of male signals. The male calling signal consisted of a single series of pulses, partially accompanied with a ‘rumble’. The male courtship phrase consisted of four consecutive sections characterized by two sound elements, pulse and ‘buzz’. Female vibrational signals were emitted only in response to male signals. The female response was a single pulse that closely resembled male pulses and was inserted between pulses within the male signals. All recorded vibrational signals of S. titanus have a dominant frequency below 900 Hz. A unique feature of vibrational communication in S. titanus is well-developed intrasexual competition; males may use alternative tactics, in the form of disturbance signals, or silently approach duetting females (satellite behaviour). While the male-female duet appears to be essential for successful localization of females and copulation, it is also vulnerable to, and easily disrupted by, alternative tactics like masking.

2014 ◽  
Vol 87 (4) ◽  
pp. 671-679 ◽  
Author(s):  
Luciana Galetto ◽  
Dimitrios Miliordos ◽  
Chiara Roggia ◽  
Mahnaz Rashidi ◽  
Dario Sacco ◽  
...  

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 169
Author(s):  
Federico Lessio ◽  
Alberto Alma

This paper reviews the existing predictive models concerning insects and mites harmful to grapevine. A brief conceptual description is given on the definition of a model and about different types of models: deterministic vs. stochastics, continuous vs. discrete, analytical vs. computer-based, and descriptive vs. data-driven. The main biological aspects of grapevine pests covered by different types of models are phenology, population growth and dynamics, species distribution, and invasion risk. A particular emphasis is put on forecasting epidemics of plant disease agents transmitted by insects with sucking-piercing mouthparts. The most investigated species or groups are the glassy-winged sharpshooter Homalodisca vitripennis (Germar) and other vectors of Xylella fastidiosa subsp. fastidiosa, a bacterium agent of Pierce’s disease; the European grape berry moth, Lobesia botrana (Denis and Schiffermuller); and the leafhopper Scaphoideus titanus Ball, the main vector of phytoplasmas agents of Flavescence dorée. Finally, the present and future of decision-support systems (DSS) in viticulture is discussed.


2014 ◽  
Vol 9 (5) ◽  
pp. 543-549
Author(s):  
Sándor Koczor ◽  
Andrej Cokl

AbstractThe European tarnished plant bug (Lygus rugulipennis Poppius) is among the most serious pests in the family Miridae, and therefore there is increasing interest in understanding the behaviour of this species. In the present study, laboratory recordings were taken using a laser vibrometer on adult males and females to ascertain whether acoustic signals are involved in intraspecific communication. Recordings were both carried out on plant and loudspeaker membrane substrates. Males and females emitted vibratory signals and the present results indicate that these signals are important during courtship. The basic signal characteristics measured were the dominant frequency, pulse duration, repetition time and number of pulses per group within the signal. Male and female signals did not differ in respect to any of these characteristics. Plant recorded signals were longer because of different mechanical properties of substrates. Additionally, the high frequency components were attenuated due to the low-pass filtering properties of plants. As this is the first study on vibratory communication of the European tarnished plant bug, we believe these findings may contribute considerably to the better understanding of the mating behavior of this important pest species.


2016 ◽  
Vol 17 (9) ◽  
pp. 1563 ◽  
Author(s):  
Luciana Galetto ◽  
Dimitrios Miliordos ◽  
Mattia Pegoraro ◽  
Dario Sacco ◽  
Flavio Veratti ◽  
...  

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 353-353 ◽  
Author(s):  
M. Šeruga Musić ◽  
D. Škorić ◽  
I. Haluška ◽  
I. Križanac ◽  
J. Plavec ◽  
...  

Flavescence dorée (FD) and Bois noir (BN) phytoplasmas are principal grapevine yellows (GY) agents in the wider Euro-Mediterranean Region. While BN phytoplasma belongs to the ribosomal subgroup 16SrXII-A, the FD agents belong either to the ribosomal subgroups 16SrV-C or -D. During the official GY survey in 2009, 40 symptomatic grapevines (Vitis vinifera L.) were sampled throughout grapevine-growing regions in Croatia. Typical GY symptoms of leaf yellowing or reddening were evident on white and red varieties, respectively. Leaf rolling as well as irregular lignification of the shoots and withering of clusters were also observed. Phloem tissue from cuttings and leaf veins from mature vines were sampled for total DNA extraction and amplification of phytoplasma 16S rRNA gene by using generic primers P1/P7 in a direct PCR assay followed by a nested PCR using primer pair R16F2n/R2 (2). Phytoplasma ribosomal group affiliation was determined by restriction fragment length polymorphism (RFLP) analysis of the nested PCR products with enzyme Tru1I (Fermentas, Vilnius, Lithuania). These initial findings were validated and augmented by a triplex real-time PCR assay targeting the nonribosomal map gene. This assay enables simultaneous detection of BN and FD (16SrV-C and -D) phytoplasmas in grapevine (3). Assay results revealed the majority of GY positive vines (19 of 40) contained BN phytoplasma which is widespread. For the first time in Croatia, two red variety samples, Pinot Noir and Plemenka Crvena, from the vicinity of Ozalj (Vivodina) and Zagreb (Brezje), respectively, were found to harbor FD-related phytoplasmas. Fragments amplified by P1/P7 primers from latter samples were cloned and sequenced. Sequence analyses using online interactive tool iPhyClassifier (4) revealed that the phytoplasma under study from Pinot Noir sample (GenBank Accession No. HQ712064) is a member of 16SrV-C subgroup and shares 99.87% similarity with 16S rDNA sequence of the reference strain (GenBank Accession No. AF176319). The sequence from the Plemenka Crvena sample (GenBank Accession No. HQ712065) shares 99.54% similarity with the reference strain and has the most similar virtual RFLP pattern to the one of the 16SrV-C subgroup (GenBank Accession No. AY197642). These findings are currently limited to vineyards in northwestern Croatia. Even so, the presence of FD principal cicadellid vector Scaphoideus titanus in the country and the occurrence and distribution of FD in neighboring countries (1,2) are factors indicating that the spread of FD in Croatia is highly probable. References: (1) L. Filippin et al. Plant Pathol. 58:826, 2009. (2) S. Kuzmanović et al. Vitis 47:105, 2008. (3) C. Pelletier et al. Vitis 48:87, 2009. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.


2022 ◽  
Vol 23 (2) ◽  
pp. 765
Author(s):  
Matteo Ripamonti ◽  
Luca Cerone ◽  
Simona Abbà ◽  
Marika Rossi ◽  
Sara Ottati ◽  
...  

Scaphoideus titanus (Hemiptera: Cicadellidae) is the natural vector of Flavescence dorée phytoplasma, a quarantine pest of grapevine with severe impact on European viticulture. RNA interference (RNAi) machinery components are present in S. titanus transcriptome and injection of ATP synthase β dsRNAs into adults caused gene silencing, starting three days post injection (dpi) up to 20 dpi, leading to decrease cognate protein. Silencing of this gene in the closely related leafhopper Euscelidiusvariegatus previously showed female sterility and lack of mature eggs in ovaries. Here, alteration of developing egg morphology in S. titanus ovaries as well as overexpression of hexamerin transcript (amino acid storage protein) and cathepsin L protein (lysosome proteinase) were observed in dsATP-injected females. To evaluate RNAi-specificity, E.variegatus was used as dsRNA-receiving model-species. Different doses of two sets of dsRNA-constructs targeting distinct portions of ATP synthase β gene of both species induced silencing, lack of egg development, and female sterility in E. variegatus, indicating that off-target effects must be evaluated case by case. The effectiveness of RNAi in S. titanus provides a powerful tool for functional genomics of this non-model species and paves the way toward RNAi-based strategies to limit vector population, despite several technical and regulatory constraints that still need to be overcome to allow open field application.


Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 200-220 ◽  
Author(s):  
Michael D. Greenfield ◽  
Todd E. Shelly

AbstractAlternative tactics of male mating behaviour, broadly classifiable as "dominant/ territorial" versus "subordinate/non-territorial", have now been described for numerous species. Furthermore, across diverse taxa the mating tactics of subordinate/non-territorial males often appear as one of two distinct types, satellite or transient behaviour. Despite general recognition of this dichotomy, though, little effort has been made to identify the circumstances under which one of these behaviours is adopted over the other. We compared the mating systems of two congeneric species of desert grasshoppers (genus Ligurotettix) to investigate specifically the role of resource dispersion in shaping the behaviour of subordinate males. The utility of the comparative approach derives from two basic similarities between the species: both Ligurotettix coquilletti and Ligurotettix planum feed almost exclusively on a single host plant species, and the majority of males in both species defend individual host plants to gain access to females. However, the two species are associated with host plants that are dispersed very differently; i.e., L. coquilletti encounter a small number of large plants and L. planum a large number of small ones. In L. coquilletti, subordinate males, individuals noted by their lack of success in aggression and in obtaining matings, were characterized as satellites that remained silent on host plants defended by territorial males. Subordinate males in L. planum, however, were transients that sang regularly but moved frequently among different host plants. We propose that this behavioural discrepancy results from (1) the large difference between the number of potential female encounter sites (i.e., individual host plants) available to the males of the two species and (2) the large difference between the sizes of resource patches defended by the two species, which influences the ability of dominant males to eject subordinates.


Behaviour ◽  
1993 ◽  
Vol 127 (3-4) ◽  
pp. 265-277 ◽  
Author(s):  
Marion Petrie ◽  
Fiona M. Hunter

AbstractThe aim of this paper is to present a verbal theoretical model that could account for the among pair variability in courtship and copulation behaviour that occurs both during and after pair formation in socially monogamous species. We assume that copulation acts to prevent mate loss, by reducing the availability of an individual to other potential partners. Variation in copulation and courtship frequency then arises as a result of variation in the risk of mate loss. Because of the constraints on free or ideal choice, pairs will form in which it may be possible for one individual to improve upon the quality of its partner. In a mismatched pair it will pay the poorer quality mate to guard the higher quality individual and prevent it from leaving to pair with a better quality mate. The poor quality individual will therefore solicit copulations at a high frequency while it's partner may not always respond. We predict that high levels of courtship and solicitation will relate to a high risk of mate loss and that a lack of response by a partner will relate to the potential opportunities it has to improve on partner quality. Our thesis is that variation in mating behaviour arises as a result of any deviations from assortative mating that may exist in a population.


Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 925-930 ◽  
Author(s):  
Marta Martini ◽  
Ermanno Murari ◽  
Nicola Mori ◽  
Assunta Bertaccini

Grapevine yellows associated with phytoplasmas of the elm yellows group (16SrV), better known as flavescence dorée (FD), is a serious quarantine problem in some important grapevine growing regions in the European Union. A survey was carried out in 1997 to 1998 in Veneto region (Italy) where a serious outbreak of FD was in progress. Phytoplasma identification by nested polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) analyses on 275 grapevine samples and on batches of Scaphoideus titanus was carried out. RFLP analyses of the 16S rDNA/spacer region with TaqI detected the presence of two distinct elm yellows phytoplasma subgroups designated 16SrV-C and 16SrV-D in 77 FD-infected grapevine samples. Only phytoplasmas of the 16SrV-D subgroup were detected in S. titanus. In 1997, the two phytoplasma subgroups appeared to be located in two diverse geographic areas; but in 1998, the 16SrV-D type also was detected in the provinces where in 1997 only 16SrV-C type was identified. The sequencing of a 400-bp fragment at the 3′ end of 16S rDNA plus spacer region allowed a specific primer construction that was successfully employed for detection of both FD types in grapevine by direct PCR.


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