114 research outputs found
First report of Antigastra catalaunalis on sesame in Greece.
In August 2016, severe infestations of sesame crops by the sesame leaf webber and capsule borer, Antigastra catalaunalis (Duponchel) (Lepidoptera: Crambidae), were recorded in rural areas of the Regional Unit of Drama, Northern Greece. Larval feeding-damage symptoms were observed on leaves and capsules. Infestations were recorded in all of the inspected sesame fields. The infestation levels were considerable high resulting in significant economic loss. To our knowledge, this is the first report of A. catalaunalis severe infestation on sesame in Greece
First report of the bordered straw, Heliothis peltigera, οn sunflower in Greece
Τον Ιούνιο 2015, καταγράφηκαν προσβολές καλλιεργειών ηλιάνθου από το έντομο Heliothis peltigera (Lepidoptera: Noctuidae) σε αγροτικές περιοχές της Περιφερειακής Ενότητας Δράμας. Παρατηρήθηκαν διαβρώσεις στα φύλλα και στους οφθαλμούς από τις προνύμφες του εντόμου, κυρίως στα προανθικά στάδια ανάπτυξης. Οι προσβολές παρατηρήθηκαν στο 80% των αγρών που επισκοπήθηκαν, ωστόσο το επίπεδο προσβολής των φυτών ήταν χαμηλό (<5%) και δεν διαπιστώθηκε πρόκληση οικονομικής ζημίας στις καλλιέργειες. Το H. peltigera έχει αναφερθεί από τη Νότια και Κεντρική Ευρώπη, τον Καναδά, τη Μέση Ανατολή και την Αφρική να προσβάλλει διάφορους ξενιστές. Προσβολές σε καλλιέργειες ηλιάνθου έχουν αναφερθεί από την Ινδία, το Πακιστάν και το Σουδάν. Στην εργασία αυτή παρέχονται τα διαθέσιμα στοιχεία βιοοικολογίας του εντόμου και οι δυνατότητες αντιμετώπισής του. Από όσο γνωρίζουμε, αυτή είναι η πρώτη αναφορά προσβολών του H. peltigera σε καλλιέργειες ηλιάνθου στην Ελλάδα και πιθανώς στην Ευρώπη.In June 2015, infestations of sunflower crops by the bordered straw Heliothis peltigera (Lepidoptera: Noctuidae) were recorded in rural areas of the Regional Unit of Drama, N. Greece. Larval feeding-damage symptoms were observed on leaves and buds of sunflower plants, mostly at pre-flowering growth stages. Infestations were recorded in approximately 80% of the inspected sunflower fields, the infestation levels, however, were low (<5%) apparently resulting in no economic damage. The presence of H. peltigera has been reported in Southern and Central Europe, Canada, the Middle East and Africa, infesting several hosts. Infestations of sunflower crops have been reported in India, Pakistan and Sudan. To our knowledge, this is the first report of H. peltigera infestations on sunflower crops in Greece and possibly in Europe
Susceptibility of adult cat fleas (Siphonaptera: Pulicidae) to insecticides and status of insecticide resistance mutations at the Rdl and knockdown resistance loci
This is an Open Access article. © 2015 The Author(s). Published by Springer Berlin Heidelberg.The susceptibility of 12 field-collected isolates and 4 laboratory strains of cat fleas, Ctenocephalides felis was determined by topical application of some of the insecticides used as on-animal therapies to control them. In the tested field-collected flea isolates the LD50 values for fipronil and imidacloprid ranged from 0.09 to 0.35 ng/flea and 0.02 to 0.19 ng/flea, respectively, and were consistent with baseline figures published previously. The extent of variation in response to four pyrethroid insecticides differed between compounds with the LD50 values for deltamethrin ranging from 2.3 to 28.2 ng/flea, etofenprox ranging from 26.7 to 86.7 ng/flea, permethrin ranging from 17.5 to 85.6 ng/flea, and d-phenothrin ranging from 14.5 to 130 ng/flea. A comparison with earlier data for permethrin and deltamethrin implied a level of pyrethroid resistance in all isolates and strains. LD50 values for tetrachlorvinphos ranged from 20.0 to 420.0 ng/flea. The rdl mutation (conferring target-site resistance to cyclodiene insecticides) was present in most field-collected and laboratory strains, but had no discernible effect on responses to fipronil, which acts on the same receptor protein as cyclodienes. The kdr and skdr mutations conferring target-site resistance to pyrethroids but segregated in opposition to one another, precluding the formation of genotypes homozygous for both mutations.Peer reviewedFinal Published versio
Ryanodine receptor point mutations confer diamide insecticide resistance in tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae).
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Insect ryanodine receptors (RyR) are the molecular target-site for the recently introduced diamide insecticides. Diamides are particularly active on Lepidoptera pests, including tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae). High levels of diamide resistance were recently described in some European populations of T. absoluta, however, the mechanisms of resistance remained unknown. In this study the molecular basis of diamide resistance was investigated in a diamide resistant strain from Italy (IT-GELA-SD4), and additional resistant field populations collected in Greece, Spain and Brazil. The genetics of resistance was investigated by reciprocally crossing strain IT-GELA-SD4 with a susceptible strain and revealed an autosomal incompletely recessive mode of inheritance. To investigate the possible role of target-site mutations as known from diamondback moth (Plutella xylostella), we sequenced respective domains of the RyR gene of T. absoluta. Genotyping of individuals of IT-GELA-SD4 and field-collected strains showing different levels of diamide resistance revealed the presence of G4903E and I4746M RyR target-site mutations. These amino acid substitutions correspond to those recently described for diamide resistant diamondback moth, i.e. G4946E and I4790M. We also detected two novel mutations, G4903V and I4746T, in some of the resistant T. absoluta strains. Radioligand binding studies with thoracic membrane preparations of the IT-GELA-SD4 strain provided functional evidence that these mutations alter the affinity of the RyR to diamides. In combination with previous work on P. xylostella our study highlights the importance of position G4903 (G4946 in P. xylostella) of the insect RyR in defining sensitivity to diamides. The discovery of diamide resistance mutations in T. absoluta populations of diverse geographic origin has serious implications for the efficacy of diamides under applied conditions. The implementation of appropriate resistance management strategies is strongly advised to delay the further spread of resistance.The work of Hellenic Agricultural Organisation - 'Demeter' was partially supported by an ARIMnet2 StomP grand to A.T and E.R. This work was also partially funded from a fellowship granted to H.A.A.S. (CNPq - PQ - Proc 308461/2013-4). The Universidad Politécnica de Cartagena group would like to thank for partial financial support the Ministerio de Economía y Competitividad of Spain and FEDER (AGL2011-25164). Lidia García-Vidal holds a grant from the MECD (FPU13/01528). The Tuta absoluta strain from Gela, Sicily was collected under the frame a resistance monitoring program established among the Hellenic Agricultural Organisation - 'Demeter' and DuPont De Nemurs (data published in 2015). Finally, the Hellenic Agricultural Organisation - 'Demeter' would like to thank Fytochem S.A., Neo Mirtos, Ierapetra for supplies of plant material
European grapevine moth, Lobesia botrana. Part II: Prevention and management.
Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), commonly known as the European grapevine moth (EGVM), is a primary pest of vineyards. This article provides an updated review of its monitoring, modelling, and management tools. EGVM management strategies analysed here include insecticide-based control, insecticide resistance, side-effects (particularly those caused by the exposure to sublethal doses of pesticides), cultural control, sterile insect technique, pheromone-mediated control strategies (with special reference to pheromone-based mating disruption), biological control, and area-wide control programs. Lastly, we outline significant challenges for future EGVM research and sustainable control implementation
European grapevine moth, Lobesia botrana. Part I: Biology and ecology.
Though the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) can feed on more than forty plant species, grapevine is the preferred crop worldwide. This moth is a western palearctic species that has recently spread to Chile, Argentina, and California. The possible further expansion in other regions of the Americas is greatly feared and should be monitored carefully in the near future. In this framework, we provide an updated review of the current knowledge on its taxonomy, morphology, biology, ecology, genomics, geographic distribution, and invasiveness. Then, in the last section, we develop a research agenda pointing out significant challenges for future investigations on bio-ecology and invasion biology, which are tightly connected with the prevention and management strategies
Pyrosequencing the Bemisia tabaci Transcriptome Reveals a Highly Diverse Bacterial Community and a Robust System for Insecticide Resistance
BACKGROUND: Bemisia tabaci (Gennadius) is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes. METHODOLOGY AND PRINCIPAL FINDINGS: Using Roche 454 pyrosequencing, 857,205 reads containing approximately 340 megabases were obtained from the B. tabaci transcriptome. De novo assembly generated 178,669 unigenes including 30,980 from insects, 17,881 from bacteria, and 129,808 from the nohit. A total of 50,835 (28.45%) unigenes showed similarity to the non-redundant database in GenBank with a cut-off E-value of 10-5. Among them, 40,611 unigenes were assigned to one or more GO terms and 6,917 unigenes were assigned to 288 known pathways. De novo metatranscriptome analysis revealed highly diverse bacterial symbionts in B. tabaci, and demonstrated the host-symbiont cooperation in amino acid production. In-depth transcriptome analysis indentified putative molecular markers, and genes potentially involved in insecticide resistance and nutrient digestion. The utility of this transcriptome was validated by a thiamethoxam resistance study, in which annotated cytochrome P450 genes were significantly overexpressed in the resistant B. tabaci in comparison to its susceptible counterparts. CONCLUSIONS: This transcriptome/metatranscriptome analysis sheds light on the molecular understanding of symbiosis and insecticide resistance in an agriculturally important phloem-feeding insect pest, and lays the foundation for future functional genomics research of the B. tabaci complex. Moreover, current pyrosequencing effort greatly enriched the existing whitefly EST database, and makes RNAseq a viable option for future genomic analysis
Assessment of different Lippia sidoides genotypes regarding their acaricidal activity against Rhipicephalus (Boophilus) microplus
Biological invasion of European tomato crops by Tuta absoluta: ecology, geographic expansion and prospects for biological control
The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating pest of tomato originating from South America. After its initial detection in eastern Spain in 2006, it rapidly invaded various other European countries and spread throughout the Mediterranean basin. If no control measures are taken, then the pest can cause up to 80-100% yield losses in tomato crops in recently invaded areas and may pose a threat to both greenhouse and open-field tomato production. The exceptional speed and extent of T. absoluta invasion have called for studies documenting its biology and ecology, while indicating an urgent need for efficient and sustainable management methods. The development of approaches to manage T. absoluta would be facilitated through a detailed revision of information on this pest in its area of origin. This review combines information on the invasion by T. absoluta, its ecology, and potential management strategies, including data that may help the implementation of efficient biological control programs. These programs, together with a variety of other management tactics, may allow efficient integrated pest management of T. absoluta in Europe and Mediterranean Basin countries. © 2010 Springer-Verlag
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