Review of the efficacy of baits used for ant control and eradication Margaret C. Stanley Landcare Research Private Bag 92170 Auckland New Zealand Landcare Research Contract Report: LC0405/044 PREPARED FOR: Ministry of Agriculture and Forestry PO Box 2526 WELLINGTON DATE: November 2004 Reviewed by: Approved for release by: Richard Harris Phil Cowan Scientist Biosecurity and Pest Management Perth, Australia Science Manager Landcare Research © Landcare Research New Zealand Ltd 2004 No part of this work covered by copyright may be reproduced or copied in any form or by any means (graphic, electronic or mechanical, including photocopying, recording, taping, information retrieval systems, or otherwise) without the written permission of the publisher. Disclaimer The findings in this report are specific to this project. Landcare Research accepts no responsibility where information in the report is used for any other purpose, and will not be liable for any loss or damage suffered as a result of such other use. 2 Summary Final Report - Operational Research 2004/2005 Project Code: MBS356 Business/Institution: Landcare Research Ltd Programme Leader: Margaret Stanley Programme Title: Review of ant bait efficacy Goal: To identify information gaps on the efficacy of baits used to attract and kill invasive ant species. Context of the project: Biosecurity New Zealand is currently responding to a series of incursions of exotic invasive ant species. To date, Biosecurity New Zealand has relied heavily on a small number of baits and toxins for control of incursions. The success of responses to new incursions of invasive ants may be compromised in the absence of effective baits. As a first step to ensuring effective incursion response, Biosecurity New Zealand has commissioned Landcare Research to review international information on baits and toxins used for ant control. The next step is to test the most promising of these against a selected group of high risk invasive ant species. Approach: Information was obtained by: searching computer databases (CAB abstracts, Current Contents, Agricola, Biological Abstracts) for relevant scientific papers, and technical reports; checking internet sites; cross-referencing; and contact with and querying of international ant researchers and biosecurity workers. Outcomes: There is a lack of rigorous research testing toxins and baits against pest ant species. Most research has focussed on Solenopsis invicta and the development of commercial baits with lipid attractants for the management of this species. Hydramethylnon and fipronil are toxins that give effective control of ant populations for several different species. Amdro® (hydramethylnon) is very effective at controlling S. invicta and Wasmannia auropunctata. Presto® (fipronil) and Xstinguish® (fipronil) appear to be highly effective baits and the protein-based matrices of these baits make them highly attractive to species previously thought difficult to attract with baits. The Australian-manufactured insect growth regulator (IGR) baits developed for S. invicta control – Engage® (methoprene) and Distance® (pyriproxyfen) – appear to be the most effective IGR ant baits available. However, they have a lipid attractant and are unlikely to be attractive to species such as Linepithema humile, Tapinoma melanocephalum and Paratrechina longicornis. Indoxacarb is a new ‘reduced risk’ 3 toxin that gives excellent suppression of S. invicta populations when used in the commercial ant bait Advion®. ERMA approval and registration should be sought for: Distance®; Engage®; Amdro® (high priority baits) and also Presto 01®; Advion®; Chipco Firestar® (lower priority). For S. invicta, S. richteri, Monomorium destructor, W. auropunctata and Anoplolepis gracilipes, baiting strategies exist overseas (albeit not in temperate climates), and if the recommended baits are registered, control strategies could be implemented rapidly. For S. geminata, the S invicta strategy may be applicable but this has not been tested. P. longicornis, T. melanocephalum, and A. gracilipes are likely to have highly restricted distributions in New Zealand and Lasius neglectus has a low likelihood of arrival. We recommend focussing research efforts on the species that lack effective strategies and pose some risk to New Zealand (P. longicornis, T. melanocephalum and L. neglectus) to determine which baits can be used to effectively manage them. In an incursion event now, Xstinguish® should be used, but research is required to determine the most effective baits. Given the frequency of incursions around New Zealand, highest research priority should be given to identifying effective baits with which to manage P. longicornis incursions. Field trials are required for several species to determine food preferences and the efficacy of various commercial baits (bait acceptability + toxin efficacy). Testing food preferences and bait acceptability can be achieved through choice tests reasonably quickly. Bait efficacy testing, however, is more complex and requires long-term monitoring. Summary: The success of responses to new incursions of invasive ants may be compromised in the absence of effective baits. As a first step to ensuring effective incursion response, Biosecurity New Zealand has commissioned Landcare Research to review international information on baits and toxins used for ant control. Information was obtained by searching the databases for relevant scientific papers, and technical reports; checking internet sites; cross-referencing; and and querying of international ant researchers. Hydramethylnon and fipronil are toxins that give effective control of ant populations for several different species. Amdro® (hydramethylnon) is very effective at controlling S. invicta and Wasmannia auropunctata. Presto® (fipronil) and Xstinguish® (fipronil) appear to be highly effective baits and the protein-based matrices of these baits make them highly attractive to several species. The Australian-manufactured insect growth regulator (IGR) baits developed for S. invicta control – Engage® (methoprene) and Distance® (pyriproxyfen) – appear to be the most effective IGR ant baits available. ERMA approval and registration should be sought for: Distance®; Engage®; Amdro® (high priority) and also Presto 01®; Advion®; Chipco Firestar® (lower priority). If these baits are registered, baiting strategies could be implemented rapidly for S. invicta, S. richteri, M. destructor, W. auropunctata and A. gracilipes. For S. geminata, the S invicta strategy may be applicable but this has not been tested. In an incursion event, Xstinguish® should be used on P. longicornis, T. melanocephalum, and A. gracilipes, but research is required to determine the most effective baits for incursion management. Publications: Stanley, M.C. 2004. Review of Efficacy of Baits Used for Ant Control and Eradication. Landcare Research Contract Report: LC0405/044. 4 5 Contents 1. Introduction............................................................................................... 9 1.1 Rationale............................................................................................................ 9 1.2 Background – ant control using toxic baits....................................................... 9 2. Objectives................................................................................................. 10 2.1 Scope ............................................................................................................... 10 3. Methods.................................................................................................... 11 4. Results ...................................................................................................... 12 4.1 Toxins............................................................................................................... 12 4.1.1 Rapid mortality toxins...................................................................................... 12 4.1.2 Insect growth regulators................................................................................... 15 4.2 Bait efficacy: ant species.................................................................................. 17 4.2.1 Priority ant species: high threat risk to New Zealand ...................................... 17 4.2.2 Introduced ant species of concern established in New Zealand: baits for management ..................................................................................................... 28 5. Conclusions.............................................................................................. 40 5.1 Bait acceptance................................................................................................. 40 5.2 Toxins............................................................................................................... 40 5.3 Commercial ant baits........................................................................................ 41 5.4 Bait efficacy research....................................................................................... 42 5.5 New Zealand environment ............................................................................... 43 5.6 Ant control and eradication programmes ......................................................... 44 6. Recommendations ................................................................................... 44 7. Acknowledgements ................................................................................. 46 8. References...............................................................................................