Note: First record in crete ofHercinothrips femoralis in greenhouse banana plantations

In 2004 the banded greenhouse thrips,Hercinothrips femoralis (Reuter) (Thysanoptera: Thripidae), was recorded for the first time in greenhouse-grown organic banana in the area of Sitia (northeastern Crete). Banana fruits were severely damaged by the thrips infestation and a typical smoky-red discoloration of the fruit was observed. Pest control was poor using either high-pressure washing with potassium fatty acids, or commercially available thrips predatorsNeoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) andOrius laevigatus (Fieber) (Hemiptera: Anthocoridae). During 2005H. femoralis was also found causing severe damage in conventional banana plantations in Arvi, the main banana-growing area of Crete. http://www.phytoparasitica.org posting Sept. 17, 2006.     

Identification of mutations in the para sodium channel of Bemisia tabaci from Crete, associated with resistance to pyrethroids

We investigated the mechanisms of resistance to α-cypermethrin in a Q biotype, highly resistant Bemisia tabaci strain (GRMAL-RP) isolated from Crete. Cytochrome P450-dependent monoxygenase activity with the substrate ethoxycoumarin, and carboxylesterase activity with the substrates α-naphthyl-acetate, β-naphthyl-acetate, and para-nitrophenol acetate were substantially elevated in the GRMAL-RP, compared to the susceptible SUD-S strain, while glutathione-S-transferase activity with the substrate 1-chloro-2,4-dinitrobenzene was not different. The metabolic inhibitors piperonyl butoxide and S,S,S-tributyl phosphorotrithioate synergised cypermethrin toxicity in the GRMAL-RP strain, however, mortality was still lower than that of the susceptible strain, indicating the presence of an additional resistance mechanism. Analysis of the sequence of the IIS4-IIS6 region of the para sodium channel gene of the GRMAL-RP strain revealed two amino acid replacements compared to that of the SUD-S susceptible strain. One is the leucine to isoleucine substitution at position 925 (L925I) previously implicated in B. tabaci pyrethroid resistance and the other is a novel kdr resistant mutation for B. tabaci, a threonine to valine substitution at position 929 (T929V). Genotype analysis showed that the L925I and T929V were present in all GRMAL-RP males tested, at an approximately 1:1 frequency, but never in combination in the same haplotype.     

Integrated pest management of Tuta absoluta: practical implementations across different world regions

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...     

Extensive damage on white variety table grapes by the Mediterranean fruit fly Ceratitis capitata (Wiedemann) in Crete

A severe attack by the Mediterranean fruit fly Ceratitis capitata (Wiedemann) was recorded for the first time in Central-Northern Crete (Greece) on white variety table grapes ( cv. Soultanina) in August 2007. The infestation was detected in hormone (gibberellic acid) treated vineyards only and was successfully controlled using cultural measures and baited application of insecticides. This report is discussed in relation to the possible effects on the table grape export market, based on the fact that C. capitata is under quarantine regulations worldwide.     

First record of Phytomyza gymnostoma Loew (Diptera: Agromyzidae) a leaf mining pest of leeks in Greece

In autumn 2007, an allium leafminer, Phytomyza gymnostoma Loew (Diptera: Agromyzidae), was recorded for the first time in non‐commercial leek crops in the areas of Elassona and Katerini in Central Greece. Leek plants were severely damaged by the leafminer larvae infestation. Typical feeding symptoms were observed, caused by the mining behaviour of larvae within inner and outer leaves of leek plants, resulting in the formation of descending galleries. Pest control was performed locally using commercial insecticides with unknown efficacy mainly due to ignorance of the species biology.     

Current status of insecticide resistance in Q biotype Bemisia tabaci populations from Crete

BACKGROUND: A major problem of crop protection in Crete, Greece, is the control of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) with chemical insecticides owing to the rapid development of resistance. The aim of this study was to investigate the establishment of resistance and the underlying mechanisms to major insecticide classes with classical bioassays and known biochemical resistance markers. RESULTS: During a 2005–2007 survey, 53 Q biotype populations were collected. Application history records showed extensive use of neonicotinoids, organophosphates, carbamates and pyrethroids. High resistance levels were identified in the majority of populations (>80%) for imidacloprid (RF: 38–1958×) and α‐cypermethrin (RF: 30–600×). Low resistance levels (RF < 12) were observed for pirimiphos‐methyl. A strong correlation between resistance to imidacloprid and the number of applications with neonicotinoids was observed. Significant correlations were observed between COE and P450‐dependent monoxygenase activity with resistance to α‐cypermethrin and imidacloprid respectively. A propoxur‐based AChE diagnostic test indicated that iAChE was widespread in most populations. Resistance levels for α‐cypermethrin were increased when compared with a previous survey (2002–2003). Differentiation of LC₅₀ values between localities was observed for imidacloprid only. CONCLUSION: Bemisia tabaci resistance evolved differently in each of the three insecticides studied. Imidacloprid resistance seems less established and less persistent than α‐cypermethrin resistance. The low resistance levels for pirimiphos‐methyl suggest absence of cross‐resistance with other organophosphates or carbamates used. Copyright © 2008 Society of Chemical Industry     

Insecticide resistance in Bemisia tabaci (Homoptera: Aleyrodidae) populations from Crete

The resistance levels to alpha-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for alpha-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and alpha-cypermethrin.     

Determination of baseline susceptibility of European populations of Tuta absoluta (Meyrick) to indoxacarb and chlorantraniliprole using a novel dip bioassay method

BACKGROUND: Tuta absoluta(Meyrick) is one of the most serious pests of tomato recently introduced in the Mediterranean region. A novel bioassay method designed for the accurate determination of insecticide toxicity on T. absoluta (IRAC method No. 022) was validated by three different laboratories [Greece (NAGREF), Italy (UC) and Spain (UPCT)] on European populations. RESULTS: The insecticides indoxacarb and chlorantraniliprole were used as reference products. The IRAC leaf dip method is easy to perform, producing repeatable, homogeneous responses. LC₅₀ values for indoxacarb ranged between 1.8 and 17.9 mg L^?1 (NAGREF), 0.93 and 10.8 mg L^?1 (UC) and 0.20 and 0.70 mg L^?1 (UPCT), resulting in a tenfold, 12‐fold and fourfold difference between the least and most susceptible populations at each laboratory respectively. For chlorantraniliprole, LC₅₀ values ranged between 0.10 and 0.56 mg L^?1 (NAGREF), 0.23 and 1.34 mg L^?1 (UC) and 0.04 and 0.24 mg L^?1 (UPCT), resulting in a sixfold difference in all three cases. Overall, UPCT reported lower mean LC₅₀ to indoxacarb, while UC reported higher LC₅₀ to chlorantraniliprole. CONCLUSIONS: The new bioassay is reliable, providing a useful tool in the design of IRM strategies. Within each country/lab, the variability observed in the results for both indoxacarb and chlorantraniliprole can be attributed to natural variation. Future research is necessary to determine the extent to which it is possible to compare results among laboratories. Copyright © 2012 Society of Chemical Industry     

Current status of the tomato leafminer Tuta absoluta in Greece

The tomato leafminer, Tuta absoluta (Meyrick), was recorded in Crete (Greece) for the first time in June 2009. The species was subsequently identified in various geographically distant regions in Crete, Peloponnesus and Western Greece. Damage has been reported in tomato and aubergine greenhouse crops as well as in open field tomato crops. In two cases, infestations of the indigenous lepidopteran species Phthorimaea operculella (Zeller) erroneously alarmed farmers and local agronomists, as symptoms caused by the two species on tomato leaves and fruits are identical macroscopically. In collaboration with the Ministry of Rural Development and Food an official survey is under way to accurately define the extent of the T. absoluta distribution in the country, while constructing the basis for integrated management of the pest.