Evaluation of fluνalinate, methomyl and kinoprene on the greenhouse whitefly Trialeurodes vaporariorum West. (Homoptera: Aleyrodidae)

Σε πειράματα στο θερμοκήπιο και στο εργαστήριο (24 ± 1°C, 65 ± 5% σχετ. υγρ. και φωτοπερίοδο 16:8) μελετήθηκε η αποτελεσματικότητα των fluvalinate (συνθετική πυρεθρίνη), methomyl (οργανοφωσφορικό) και Kinoprene (ουσία με δράση ανάλογη της νεανικής ορμόνης) στον αλευρώδη των θερμοκηπίων Trialeurodes vaporariorum West. Από τα πειράματα αυτά προέκυψε ότι μόνο το fluvalinate (0,015% δ.ο.) πληρεί τις προϋποθέσεις για ικανοποιητικό έλγχο του αλευρώδη λόγω της αποτελεσματικότητας του σε όλα τα στάδια (99-100%). Τα methomyl (0,03% δ.ο.) και kinoprene (0,008% δ.ο.) είχαν την ίδια αποτελεσματικότητα. To methomyl ήταν αποτελεσματικό μόνο στα ακμαία και το πρώτο προνυμφικό στάδιο (100 και 99% αντίστοιχα) ενώ το kinoprene στο δεύτερο και τρίτο στάδιο (89,9 και 95,5% αντίστοιχα). Στα αυγά ηλικίας 24η και 76η ώρα μόνο το kinoprene προκάλεσε κάποια θνησιμότητα (11,5 και 5,7% αντίστοιχα) ενώ τα άλλα ασήμαντη (0-3%). Παρατηρήθηκε επίσης ικανοποιητικός έλεγχος των Liriomyza sp. και Plusia chalcites Esper. από το fluvalinate. μέτρια αποτελεσματικότητα είχε το methomyl, ενώ τα φυτά που ψεκάστηκαν με το kinoprene είχαν σοβαρή προσβολή και από τα δύο παραπάνω έντομα. To kinoprene επίσης δεν παρεμπόδισε σοβαρά τη δράση του ωφέλιμου παρασίτου Encarsia formosa Gahan.The effectiveness of three insecticides, fluvalinate, kinoprene and methomyl (synthetic pyrethrin, juvenile hormone analog and organophosphate, respectively), against the greenhouse whitefly, Trialeurodes vaporariorum West. (Homoptera: Aleyrodidae), was evaluated in commercial greenhouses. The impact of chemicals was studied on isolated whitefly stages in a rearing room (24 ± I”C, 65 ± 5% R.H. and L:D 16:8h). Fluvalinate was the most effective toxicant through its broad activity on whitefly life stages. Kinoprene controlled 2nd and 3rd larval instars but a moderate effectiveness was noticed on eggs, first instar larvae and pupae. Methomyl was effective against first instar larvae and adults but it had no substantial effect on the other stages. Of the three materials tested only fluvalinate approached the total control requirements for a successful whitefly suppression

First record of Polyphagotarsonemus latus (Banks 1904) (Αcari: Tarsonemidae) on greenhouse peppers in Crete

Το μικροσκοπικό άκαρι Polyphagotarsonemus atus Banks σημειώθηκε για πρώτη φορά το 1984 στην πιπεριά θερμοκηπίου στην περιοχή της Ιεράπετρας. Στην αρχή παρατηρήθηκε σε σποραδικές κηλίδες και μέχρι το 1986 εξαπλώθηκε σε όλα τα θερμοκήπια της πιπεριάς προκαλώντας σημαντικές ζημιές. Το άκαρι αυτό αναφέρθηκε για πρώτη φορά στην Ελλάδα από το Χατζήνικολή σε φύλλα βαμβακιού (1969) και στα ξυνά (1985). Προσβάλλει τις αναπτυσσόμενεςκορυφές, νεαρά φύλλα, άνθη και καρπούς προκαλώντας τα παρακάτω συμπτώματα:1. στο στέλεχος παραμόρφωση, αποχρωματiσμό γκρι ή καφέ και εσχάρωση, 2. στους καρπούς παραμόρφωση και εσχάρωση, 3. στα νεαρά φύλλα τα συμπτώματα συγχέονται με εκείνα της επίδρασης ορμονικών ζιζανιοκτόνων και 4. στα άνθη προκαλεί ανθόρροια. Τα προσβεβλημένα φυτά δύσκολα αναλαμβάνουν παρά τους επανειλημμένους ψεκασμούς με ακαρεοκτόνα.The broad mite, Polyphagotarsonemus latus Banks (Acari: Tarsonemidae), was first noticed on greenhouse pepper cv Cleopatra and Sonar in Ierapetra (Southeastern Crete) in 1984. During 1984 there were scattered mite infestations in a few greenhouses but in the following years it has become an increasingly important pest of peppers. The mite has been also found on cucumber cv Cnossos, aubergine cv Flaska and Solanum aviculare (indigenous of Amazonios) in the greenhouses of the Ierapetra Experimental Station. It atta­cks the growing points, young foliage, stem flowers and fruits. The growing points and bud are distorted, the young leaf margins down curl, the apical leaves crinkle, the leaf veins fuse and distort and the color changes to dark green, the fruits and stem crack and turn russet, mis-shape resembling like a fruit or stem scab and finally the small leaves and flowers fall off. Severely affected plants have little or no young growth, remain stunt and all fruitlets are aborted. The general look of the infested plants is similar to those affected by hormone weedkiller. Affected plants could not recover easily and the symptoms persisted for many weeks in spite of the acaricide treatments applied by the growers. In an artificial infestation of young pepper plants cv Sonar by 100-200 individuals, the symptoms of broad mite damage appeared in eight to ten days under growth chamber conditions (24±0.5°C, 60±5% R.H., 12.000 Lux for 16 hours daily).In Greece, the broad mite was first recorded on cotton leaves in 1969 and later on citrus trees. In Britain, it causes serious problems since 1978. It has been also noticed in several other countries of Europe. The spread of P. latus in many greenhouse plants in Britain was caused by the absence of acaricide treatments in green­houses where biological control against the two spotted spider mite Tetranychus urticae was ap­plied and the predator Phytoseilus persimilis was introduced by French bean leaves which was a recorded host of broad mite. The female longevity varies between 7-18 days depending mainly on temperature. The mean number of eggs/female is 40-50. The life cycle of broad mite is completed in 441, 205 and 98 hours at 14, 24 and 30°C, respectively. The developmental rate of various stages of the mite increased with the temperature but declined at about 35°C. The broad mite has been recorded on a wide range of hosts: tea plant, beans, tomatoes, cucumber, pep­pers, aubergines, citrus, zerbera, fuchsia, jasmin­um, magnolia, cotton, jute, coffee, avocado etc

Hybrid One-Shot 3D Hand Pose Estimation by Exploiting Uncertainties

Model-based approaches to 3D hand tracking have been shown to perform well in a wide range of scenarios. However, they require initialisation and cannot recover easily from tracking failures that occur due to fast hand motions. Data-driven approaches, on the other hand, can quickly deliver a solution, but the results often suffer from lower accuracy or missing anatomical validity compared to those obtained from model-based approaches. In this work we propose a hybrid approach for hand pose estimation from a single depth image. First, a learned regressor is employed to deliver multiple initial hypotheses for the 3D position of each hand joint. Subsequently, the kinematic parameters of a 3D hand model are found by deliberately exploiting the inherent uncertainty of the inferred joint proposals. This way, the method provides anatomically valid and accurate solutions without requiring manual initialisation or suffering from track losses. Quantitative results on several standard datasets demonstrate that the proposed method outperforms state-of-the-art representatives of the model-based, data-driven and hybrid paradigms.Comment: BMVC 2015 (oral); see also http://lrs.icg.tugraz.at/research/hybridhape

Entomopathogens of Anαcridium αegyptium L. in Crete

Στα πλαίσια ενός τριετούς ερευνητικού προγράμματος για τις ακρίδες στην Κρήτη ερευνήθηκε η nύπαρξη ιθαγενων εντομοπαθογόνιον μικροοργανισμοί για την βιολογική καταπολέμηση τους. Απομονιόθηκε για πρώτη φορά ο μύκητας Beauveria bassiana (Bals) Vuill., αξιολογήθηκε η αποτελεσματικότητα του στα ακμαία και νύμφες πρώτης ηλικίας της ακρίδας Anacridium aegyptiumL., είδος βλαβερό σε αμπέλια και λαχανικά, και συγκρίθηκε με το στέλεχος τουεντομοπαθογόνου μύκητα Metarhizium anisopliae var. acridum (IMI 330189). Τα πειράματα έδειξαν ότι το ιθαγενές στέλεχος του μύκητα Β. bassiana που ναπομονώθηκε είχε εξαιρετική αποτελεσματικότητα σε ακμαία και νύμφες πρώτης ηλικίας της ακρίδας Α. aegyptium, δεν υστερεί νσε αποτελεσματικότητα από το μύκητα M. flavoviride και ενδείκνυται για το βιολογικό έλεγχο και προγράμματα ολοκληρωμένης διαχείρισης.The entomopathogenic fungus Beauveria bassiana (Bals.) Vuil. was recorded for the first time on Anacridium aegyptium L. in Crete. The insects were fed on pieces of leaf subjected to a serial dilution of spores over three to four orders of magnitute. Comparative studies on the virulence of B. bassiana (I 91612 local isolate) and Metarhizium anisopliae var. acridum (IMI 330189 standard isolate of IIBC) showed that M. anisopliae var. acridum was more virulent than B. bassiana at a conidial concentration lower or equal to 106 per ml while they were similarly virulent on first stage nymphs at 107 conidia per ml

First Record of the South American Leafminer Liriomyzα huidobrensis (Blanchard) (Diptera: Agromyzidae) in Greece

Ο υπονομευτής φΰλλων της Ν. Αμερικής Liriomyza huidobrensis (Blanchard) επισημάνθηκε για πρώτη φορά το 1992 σε θερμοκηπιακές και υπαίθριες καλλιέργειες κηπευτικων και ανθέων στη Κρήτη και σε δείγμα φΰλλων πεπονιάςαπό τον Πύργο (Πελοπόννησος) και φΰλλων πατάτας από τη Χαλκίδα (Εΰβοια). Το έντομο αυτό προκάλεσε σοβαρές ζημιές στις φασολιές, κουκιά, μαροΰλια, πεπόνια και αγγουριές ενώ προσέβαλε επίσης σε μικρότερο βαθμό πατατόφυτα, κρεμμΰδια, αγγινάρες και σπανάκι. Σήμερα αποτελεί το επικρατέστερο είδος υπονομευτή και εξαπλώθηκε σε όλη την Κρήτη. Αντιμετωπίζεται δύσκολα με τα συνήθως χρησιμοποιούμενα εντομοκτόνα για τους άλλους υπονομευτές. Η αντιμετώπιση του μπορεί να γίνει μόνο από ένα πολΰ περιορισμένο αριθμό εντομοκτόνων (abamcctin, triazophos, imidacloprid, hcptcnophos κλπ.). Τα υμενόπτερα παράσιτα Diglyphus isaea (Walter) και Dacnusa sibirica Telenga υπάρχουν ως ιθαγενή στην πανίδα της Κρήτης και ελέγχουν αποτελεσματικάτον νέο αυτό υπονομευτή.In mid autumn 1992 the South American leaf-miner Liriomyza huidobrensis (Blanchard) was firstly recorded on greenhouse cucumbers, melons, beans and outdoor beans, broad beans and lettuce in the following locations of Crete: 1) Mires, Tymbaki, Antiskari at Messara valley of Southern Crete 2) Filissia in the midland and 3) Platanias and Kokini Chani in Northern Crete. The following year L. huidobrensis had spread all over Crete (Ierapetra, Stomion, Koutsoura, Chania etc.) while melon and potato leaves which were sent to our laboratory from mainland Greece, Pirgos (Peloponissos) and Chalkida (Evia island), were found heavily damaged by the same leafmincr. The different types of mines (it usually mines the leaf alongside the veins), the colour of pupae (blackish) and the sudden attack of some plants (lettuce, broad beans, onions) which have never been damaged by the known local leafminers as yet, indicated that it was a newly introduced species. The new leafminer alerted the growers due to the high crop losses on outdoor and greenhouse vegetables (lettuce, broad beans, beans etc) despite the frequent application of registered insecticides. In the following year an extensive survey started to investigate its distribution and host plant in the greenhouses and outdoor vegetables and ornamentals in Crete. L. huidobrensis, a quarantine insect, is a polyphagous leafminer distributed in most biogeographical regions. It is native in South American countries from which it was spread soon in North America, Asia and Europe. In Europe it was first noticed in Holland, England and France in 1989 causing considerable damage to vegetables and ornamentals. It mines the spongy mesophyll reducing the photosynthesis more than the other leafminers. This type of mines is not easily visible, unless the leaf is observed through transmitted sunlight or artificial light. This method was applied to ensure accurate detection of larvae and their parasitoids under a stereoscope. In our observations we found mines in leaves and cucumber fruits as well. Studies of its life cycle on greenhouse beans and melons revealed that most pupae (98%) remain on the bean leaves outside a hole in the autumn, while a few fall on the ground. The number of pupae collected from ten leaves per 24h was: 5.7±1.6 on lettuce, 17.07±4.1 on beans, 24.2±7.3 on melon, 6.0±2 on broad bean leaves. During the survey the following host plants were recorded: Chemical control could be effective by applying certain insecticides (abamectin, triazophos, imidacloprid, heptenophos etc.) while biological control seems to be rather effective by the known parasitoids, which are already used against the tomato leafminer Liriomyza bryoniae Kalt. Biological control of L. huidobrensis was effective on lettuce by means of repeated releases of Dacnusa sibirica Telenga and Diglyphus isaea (Walker) but so far native parasitoids proved to be able to control the pest. Mass trapping with coloured sticky traps seems to be also a potential method in IPM programmes. The mortality of pupae collected from heavily treated greenhouse plants with insecticides varied from 65 to 74% while that of untreated plants was between 18-25%. No pupal parasitoids were recorded but D. isaea and D. sibirica were both recorded as larval parasitoids. D. isaea was abundant all over the year while D. sibirica only in spring-summer period. These two parasitoids were able, in certain cases, to control sufficiently the leaf miner in untreated greenhouse cucumber and bean plants. The neem seed extract (Azadirachta indica) applied on outdoor tomatoes in Antiskari (Southern Crete) proved harmless both on hymenoptera and on the mirid predator Macrolophus caliginogus Wagner. Despite its weak larvicide action on L. huidobrensis it was very effective in conjuction with parasitoids consisting of a promising candidate in IPM programmes

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