JANUARY 2016 ALL ABOUT ALMONDS ORCHARD MANAGEMENT MANAGING CARPOPHILUS BEETLE IN ALMONDS PRELIMINARY MONITORING GUIDELINES, ATTRACT & KILL GUIDELINES FOR 2016 - 2017 SEASON CARPOPHILUS IN ALMONDS project includes research on the KEY POINTS distribution of different Carpophilus Carpophilus beetles comprise many species throughout orchards and in species with different preferences different almond growing regions, Almonds are most vulnerable to attack from for fruit type and fruit ripening/ testing whether the “stonefruit” lure Carpophilus Beetle during hull split. maturing stage. In recent years, is effective in almonds and how its Pheromone and co-attractant are much less almond growers have indicated potency might be improved, and effective when used separately rather than in significant crop losses due to determining the most effective combination. Carpophilus, and there is an urgent spacing of A&K traps to achieve need for an Attract and Kill (A&K) control. High priority blocks to monitor are likely to system that can control these This article contains information on include those that experience excessive pests, particularly in the ‘hull-split’ how best to apply an A&K strategy to moisture retention and humidity. development stage when almonds monitor and control Carpophilus in are most vulnerable to attack. During It is suggested that growers start with at least almonds using the current stonefruit the 2014/15 and 2015/16 seasons, one trap per orchard block (approx. 20 ha). lure. We consider this an interim five species of Carpophilus were guide for interested growers, and as detected in samples from traps in Carpophilus starts to become active and able we continue our research we aim to almond orchards, and concerns that to fly to traps as temperatures increase in provide growers with more detailed beetle populations could escalate late winter/early spring. guidelines specific to almonds, and over coming years has led to a hopefully more effective lures. research project “Management of INTRODUCTION Carpophilus beetles in almonds” to look specifically at this problem. The CARPOPHILUS BEETLES ARE SERIOUS PESTS OF ORCHARD CROPS IN AUSTRALIA. In stonefruits, two species (C. davidsoni and C. hemipterus) attack fruit and can result in annual losses of up to 30% of the crop. Damage by Carpophilus beetle is most severe as the fruit ripens/matures, with beetles penetrating the fruit and also causing indirect damage by serving as a vector for brown rot (Monilinia), which frequently develops at the sites of beetle entry. Carpophilus are highly active pests that can spread rapidly from fruit to fruit and between neighbouring orchards, leading to populations quickly escalating out of control. An effective lure has been developed for monitoring Carpophilus in stonefruit, with potential to control this pest through a mass trapping program (“Attract and Kill”). The lure combines the beetle’s aggregation pheromones with a synthetic blend of fruit odours, and is highly attractive to the male and female beetles. The lure was developed through Victorian Government (DEDJTR) research in collaboration with Horticulture Innovation Australia Ltd (Hort Innovation), and together with a suitable Carpophilus Catcha Trap Kit trap (funnel trap) it is used by the stonefruit industry to effectively control Carpophilus before fruit crops ripen. PO Box 1507 | 1801 Bookpurnong Road, Loxton SA 5333 | T +61 8 8584 7053 | E [email protected] | W growing.australianalmonds.com.au • Monitoring traps include the co-attractant solution and insecticide strip but no pheromone button. may help producers to identify HOW DO THE TRAPS WORK? infested blocks and highlight areas Pheromone from the rubber button HOW SHOULD THE TRAP COMPONENTS BE STORED? where monitoring traps should be combined with odours from the • Pheromone buttons should be stored frozen to maximise their shelf life. installed. co-attractant solution are released If this is not practical, they should at least be stored in a fridge until they from the traps and disperse into the High priority blocks to monitor are used in traps. orchard. Carpophilus can detect the are likely to include those that pheromone from over 100 metres • Synthetic co-attractant must be stored refrigerated (around 4°C) to experience excessive moisture and respond to it by flying towards prevent the rapid breakdown of critical volatile compounds. retention and humidity such as the odour. When the beetles are • Insecticide strips should be stored in a sealed bag in a cool dark place. low lying areas and sites near closer to the pheromone source, dams and other water sources. In they become less responsive to • During field trips for trap maintenance, the co-attractant and addition, blocks with a history of it and more attracted to the fruit pheromone buttons should ideally be carried in a cold esky or car fridge. insect damage, hull rot and orchard odours emitted from the co- • For safety, the co-attractant and insecticide strips should not be kept in hygiene issues should be given attractant solution. Beetles enter the fridges that are used to store food or drinks. attention. trap and find it difficult to escape because of the funnel design, and HOW ARE THE TRAPS USED FOR MONITORING? HOW ARE THE TRAPS USED are subsequently killed by the Considering the limited information regarding Carpophilus in almonds, FOR ATTRACT AND KILL? insecticide strip. we recommend growers begin to monitor this pest using the synthetic co- Growers who are concerned by the numbers they catch in A crucial factor for the effectiveness attractant and insecticide strip without pheromone, and manage traps with monitoring traps and choose to of A&K traps is the combination weekly servicing as detailed below. employ the current A&K system, of odours that attract Carpophilus Carpophilus have been found in spring in almond mummies on the ground must understand that it has over long distances (pheromone) near dripper lines where the nuts are kept moist. Inspection of these nuts not yet been fully evaluated or and short distances (co-attractant). adapted for almonds and has not Both the pheromone and co- been registered for that purpose. attractant are much less effective Remember - the only difference when used separately rather than in between the two systems is that combination. A&K traps include the long-range To simply detect and monitor aggregation pheromone as well as Carpophilus activity in orchard the synthetic co-attractant solution blocks, the traps are used without and insecticide strip. the pheromone buttons. This Once Carpophilus beetles infest ensures that the traps attract beetles and start to feed on stone fruit, they only from the local area, and do not emit their own pheromone which draw more beetles in from outside competes with the pheromone used the blocks being monitored. in A&K traps. In addition, ripening fruit and nuts at hull split or beyond WHAT IS A CARPOPHILUS also emit odours that attract the TRAP COMPRISED OF? Above: Carpophilus hemipterus (Driedfruit beetle) Source of images: Walker, K. (2007) PaDIL - http://www.padil.gov.au beetles and compete against the A plastic funnel trap containing: traps. Therefore, to be effective, • A tub of liquid co-attractant A&K traps need to be installed early (fruit odour) covered with enough to kill the maximum number mesh to keep insects out of the of beetles before the fruit or nuts solution become susceptible to Carpophilus • A rubber button (septum) damage. The aim is to prevent fruit containing Carpophilus or nut infestation by the beetles. As aggregation pheromone suggested earlier, successful use • A piece of insecticide strip to kill of A&K to protect stone fruit relies beetles that enter the trap on reducing beetle populations to below a threshold level before fruit The only difference between traps becomes susceptible to damage, used for monitoring vs A&K is that: i.e. before ripening. This is likely to • A&K traps include the co- be equally important for almonds, attractant solution, insecticide although the threshold levels in the strip and pheromone button. Above: Carpophilus davidsoni (Australian sap beetle) two crops may differ. Source of images: Walker, K. (2007) PaDIL - http://www.padil.gov.au Page 2 PO Box 1507 | 1801 Bookpurnong Road, Loxton SA 5333 | T +61 8 8584 7053 | E [email protected] | W growing.australianalmonds.com.au TRAPPING METHODOLOGY HOW MANY TRAPS ARE REQUIRED? • The high trapping densities used in high-value stone fruit orchards (e.g. 1 trap/ ha to monitor and 2-3 traps/ha for A&K) are not likely to be feasible in large almond orchards for economic and management reasons. For monitoring therefore, it is suggested that growers start with at least one trap per orchard block (approx. 20 ha) to gain some preliminary information on the distribution of the pest within their orchard. • We cannot advise on the number or placement of A&K traps in almonds until the A&K system for Carpophilus is adapted and registered for use in almonds. Above: Carpophilus mutilatus (Confused sap beetle) WHERE SHOULD TRAPS BE LOCATED? Source of images: Walker, K. (2007) PaDIL - http://www.padil.gov.au • Given the very low trapping density likely to be used in almonds no specific recommendation can be made for locating traps for monitoring, • Insert the trap, containing the tub with 250 ml co-attractant, insecticide other than placing them at least 15 metres inside the orchard blocks strip and pheromone button (for A&K only) into the metal ring, taking and taking block history into account (e.g. nut damage, mummy care not to spill the co-attractant. infestation as mentioned above). • For A&K in stone fruit, traps should be placed specifically in the HOW SHOULD TRAPS BE SERVICED? appropriate corner of orchard blocks to allow for the most predominant • Service each trap routinely on the same day of the week, so that every spring and summer winds to distribute the pheromone into the blocks.