Summerfruit tοrtriχ, Adoxophyes orana: life cycle, warning system and control

Το Λεπιδόπτερο Adoxophyes orana F.v.R., είναι ένας εχθρός που προσαρμόσθηκε πρόσφατα στις εντατικές καλλιέργειες μηλιάς και αχλαδιάς. Οι προνύμφες αναπτύσσονται αρχικά επάνω σε νεαρά φύλλα και βλαστούς και ευκαιριακά προσβάλλουν την επιφάνεια του καρπού. Στην Ελβετία υπάρχουν δύο πτήσεις το χρόνο, ενώ στην Ελλάδα υπάρχουν τρεις πτήσεις με τη δεύτερη και τρίτη να επικαλύπτονται. Οι διαπαύουσες προνύμφες διαχειμάζουν όταν είναι στο τρίτο στάδιο (L?) και αρχίζουν πάλι να αναπτύσσονται την άνοιξη. Υπάρχουν τρεις περίοδοι που οι προνύμφες είναι δραστήριες. Οι μέθοδοι προειδοποίησης είναι: η οπτική εξέταση των λουλουδιών την άνοιξη, οι παγίδες με φορομόνες φύλου και η οπτική εξέταση των βλαστών και καρπών το καλοκαίρι. Ένα μοντέλο, που περιγράφει το βιολογικό κύκλο σε συνάρτηση με τη θερμοκρασία, επιτρέπει τον καθορισμό του καλύτερου χρόνου δειγματοληψίας ζημιών και εφαρμογής φαρμάκων σε σχέση με τον τρόπο δράσης τους. Μερικά κλασικά εντομοκτόνα προσφέρουν θεραπευτική καταπολέμηση αλλά η αποτελεσματικότητα τους πάντοτε μειώνεται εναντίον προνυμφών προχωρημένης ηλικίας. Τα καλύτερα αποτελέσματα επιτυγχάνονται κατά την εκκόλαψη των ωών της πρώτης γενεάς. Ο ρυθμιστής ανάπτυξης των εντόμων (IGR), fenoxycarb, είναι πολύ αποτελεσματικός όταν εφαρμόζεται την άνοιξη εναντίον του τελευταίου προνυμφικού σταδίου (Ls) της διαχειμάζουσας γενεάς. Ένας ειδικός ιός επίσης δίνει καλά αποτελέσματα εναντίον των διαχειμαζουσών προνυμφών. Τον καιρό αυτό μελετώνται η τεχνική της παρεμπόδισης των συζεύξεων και οι παρεμποδιστές ανάπτυξης των εντόμων (IGI) που εμποδίζουν τον σχηματισμό της χιτίνης. Για όλα τα προϊόντα που χρησιμοποιήθηκαν για την καταπολέμηση του Α. orana ο χρόνος που μεσολαβεί είναι πολύ σημαντικός για τη μέγιστη αποτελεσματικότητα.The summerfruit tortrix, Adoxophyes orana F.v.R., is a pest which has recently adapted to the intensive culture of apple and pear. The larvae develop primarily on the young leaves and shoots and occasionally feed on the surface of the fruit. Under Swiss conditions there are two flights per year though there are three in Greece with the second and third overlapping. The diapausing larvae hibernate in the third stage (L3) and begin development again in the spring. There are three periods in which the larvae are active. The methods used to sample populations for making management decisions are: visual examination of flower clusters in spring, sex pheromone traps, and visual examination of shoots and fruit in summer. A model describing the life cycle as a function of temperature allows for the determination of the best time to sample damage and to apply treatments with regard to their particular mode of action. Some classical insecticides provide control curatively but efficiency is always reduced against older larvae. The best results are obtained at egg eclosion following the first flight. The insect growth regulator (IGR), fenoxycarb, is very effective when applied in the spring against the last stage larvae (Ls) of the overwintering generation. A specific virus also gives good control in the spring against overwintering larvae. The mating disruption technique and insect growth inhibitors (ICI), which prevent the formation of chitin, are currently being studied. For all the products used to control A. orana, the timing of the application is extremely important in order to obtain the bes

Field and Laboratory Responses of Male Leaf Roller Moths, Choristoneura rosaceana and Pandemis pyrusana, to Pheromone Concentrations in an Attracticide Paste Formulation

Male leafroller moths, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) and Pandemis pyrusana (Kearfott), were evaluated for responses to a paste formulation loaded with a range of concentrations of the two species' pheromone blends and evaluated in a laboratory wind tunnel and in the field. Response criteria were flight, flight towards the pheromone source, and contact with the pheromone source for the wind tunnel assays, and capture of moths in traps for the field tests. In the wind tunnel and field, responses of males of both species to the paste generally increased as the pheromone concentration in the paste was increased. There was little response by either species to paste with less than 0.16% pheromone. The relationship between pheromone concentration and response for P. pyrusana was linear and for C. rosaceana was sinusoidal over the range of pheromone concentrations tested. These patterns were seen both in the wind tunnel and in the field. Initial release rates from the paste of (Z)-11-tetradecenyl acetate, the main component of the pheromone blends of both species was 3.6–3.8 ng/h. Inhibitory thresholds for responses were not reached for either species, using pheromone concentrations as high as 16%, in either the wind tunnel or the field. For both species, response of males to rubber septa with one mg pheromone loads was similar to the response to the paste with pheromone at concentrations greater than 3–4%. For C. rosaceana, rates of contact with the paste in the wind tunnel were statistically similar to rates of contact in response to conspecific females, with paste pheromone concentrations above 1.6%. Response rates for males of P. pyrusana were significantly lower to the paste than to conspecific females at all paste pheromone concentrations tested. Overall, the optimum pheromone concentration in the paste for moth attraction to contact was 3.2 % for C. rosaceana and 8% for P. pyrusana

Impact of Climate Change on Voltinism and Prospective Diapause Induction of a Global Pest Insect – Cydia pomonella (L.)

Global warming will lead to earlier beginnings and prolongation of growing seasons in temperate regions and will have pronounced effects on phenology and life-history adaptation in many species. These changes were not easy to simulate for actual phenologies because of the rudimentary temporal (season) and spatial (regional) resolution of climate model projections. We investigate the effect of climate change on the regional incidence of a pest insect with nearly worldwide distribution and very high potential for adaptation to season length and temperature – the Codling Moth, Cydia pomonella. Seasonal and regional climate change signals were downscaled to the hourly temporal scale of a pest phenology model and the spatial scale of pest habitats using a stochastic weather generator operating at daily scale in combination with a re-sampling approach for simulation of hourly weather data. Under future conditions of increased temperatures (2045–2074), the present risk of below 20% for a pronounced second generation (peak larval emergence) in Switzerland will increase to 70–100%. The risk of an additional third generation will increase from presently 0–2% to 100%. We identified a significant two-week shift to earlier dates in phenological stages, such as overwintering adult flight. The relative extent (magnitude) of first generation pupae and all later stages will significantly increase. The presence of first generation pupae and later stages will be prolonged. A significant decrease in the length of overlap of first and second generation larval emergence was identified. Such shifts in phenology may induce changes in life-history traits regulating the life cycle. An accordingly life-history adaptation in photoperiodic diapause induction to shorter day-length is expected and would thereby even more increase the risk of an additional generation. With respect to Codling Moth management, the shifts in phenology and voltinism projected here will require adaptations of plant protection strategies to maintain their sustainability

Mating disruption of citrus leafminer mediated by a noncompetitive mechanism at a remarkably low pheromone release rate.

The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a worldwide pest of citrus. A season-long investigation was conducted that evaluated mating disruption for this pest. Effective disruption of the male P. citrella orientation to pheromone traps (98%) and reduced flush infestation by larvae was achieved for 221 d with two deployments of a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal/(Z,Z)-7,11-hexadecadienal at a remarkably low rate of 1.5 g active ingredient (AI)/ha per deployment. To gain insight into the mechanism that mediates the disruption of P. citrella, male moth catch was quantified in replicated plots of citrus treated with varying densities of pheromone dispensers. The densities of septum dispensers compared were: 0 (0/ha, 0.0 g AI/ha), 0.2 (one every fifth tree or 35/ha, 0.05 g AI/ha), 1 (215/ha, 0.29 g AI/ha), and 5 per tree (1,100/ha, 1.5 g AI/ha). Profile analysis by previously published mathematical methods matched predictions of noncompetitive mating disruption. Behavioral observations of male P. citrella in the field revealed that males did not approach mating disruption dispensers in any of the dispenser density treatments. The current report presents the first set of profile analyses combined with direct behavioral observations consistent with previously published theoretical predictions for a noncompetitive mechanism of mating disruption. The results suggest that disruption of P. citrella should be effective even at high population densities given the density-independent nature of disruption for this species and the remarkably low rate of pheromone per hectare required for efficacy