Project related activities to study the red banded mango caterpillar (RBMC) have commenced in Papua New Guinea at two locations; near Port Moresby and in East New Britain. Facilities were upgraded and, scientific equipment needed to conduct pest biology studies was purchased and sent to Kilakila and Keravat. Technical staff were recruited and employed. Two vehicles were purchased to allow regular visits to experimental sites and equipment purchased to carry out laboratory and field studies.

Data on pest incidence on mango fruit from a number of locations in the Port Moresby and East New Britain areas was undertaken from November 2003 and continued to end of the fruiting season in February 2004. This data confirmed the severity of this pest with fruit losses averaging 55% and ranging from no loss to 100% at different locations. All mango cultivars were attacked including Kensington pride which suffered losses of 50%. This indicates that the RBMC has the potential to be a serious pest of commercial and non commercial mango in Australia where Kensington Pride is the most important commercial cultivar.

A detailed work program was developed in consultation with partner country entomologists and management and this is providing the current and future work direction. This includes monitoring for adult moth emergence periods, egg laying period and start of fruit damage, obtaining information on alternative host fruits, duration of life cycle, field collection of larvae to provide pupae for pheromone studies and chemical and cultural field control studies.

The project aims to increase the knowledge of the biology and control options for the red banded mango caterpillar (RBMC), a serious pest of mango fruit. Field and laboratory studies are based near Port Moresby, Central Province and near Rabaul, East New Britain (ENB), Papua New Guinea. Project activities commenced in September 2003. Technical and field staff were employed at Kilakila (Port Moresby) and Keravat (East New Britain) and two new 4WD dual cab vehicles plus laboratory equipment purchased for project use at the two centres.

Mr David Tenakanai has co authored a draft manuscript which summarises past RBMC studies conducted near Port Moresby. This draft provides valuable descriptive information on the pest's behaviour and forms the basis for current and further laboratory and field work. Formal publication has been hampered because of insufficient data to provide statistical validity. More data is to be collected during the course of the current study.

Field studies started in September 2003 concentrating on damage assessments and larval collections from local mango trees in ENB and Port Moresby. Two commercial mango plantations near Port Moresby were selected for field studies which include investigations on the pest's diapause, evaluation of synthetic pesticides for field control and collection of larvae for laboratory based biology studies and for extraction and identification of the sex pheromone. A search for possible alternative hosts has also been conducted.

Field damage assessments in ENB showed that damage varied significantly during the 2003/4 fruit season. Levels of larval infestation in different mango cultivars and from different locations ranged from nil to 100% but more data from other seasons are required to determine if the differences are real or due to natural variation. The overall mean level of fruit infestation and anticipated yield loss was 55%. Field sampling of mature mango trees confirmed that mature larvae diapause under mango tree bark. Preliminary catches of adult moths appear to indicate that adult emergence may be triggered by tree phenology, in particular the onset of flowering but this observation has to be confirmed during subsequent seasons.

Rearing techniques for RBMC were refined and, during 2004, approximately 200 live pupae were sent to HortResearch, New Zealand for extraction and identification of the sex pheromone components. A number of candidate synthetic pheromone blends were produced and tested in the field during late 2004 but were unsuccessful. Purified synthetic blends were produced and tested successfully in the 2005 fruiting season. Testing to perfect the blend is underway and results indicate that this will be a useful monitoring tool.

Alternative hosts studies were conducted at Keravat, ENB. No-choice larval feeding studies were conducted on a number of fruits and seeds including cashew, Tahitian chestnut (Aila) (Inocarpus fagifer), Bukbuk (Burckella obovata),Pau nut (Barringtonia edulis), candle nut (Aeurites moluccana), avocado and Carambola. A few larvae feeding on Aila and Bukbuk survived to adulthood, all others died in the larval stage. Larvae assumed to be RBMC were collected from wild Aila seeds at Keravat but this requires confirmation. If confirmed as hosts, Aila and Bukbuk will be the first non-Mangifera hosts recorded for RBMC.

The first chemical field trial was completed in late 2004. Of the four synthetic pesticides tested, only thiacloprid (Calypso) showed good efficacy and protected fruit from infestation. Further testing to determine appropriate rates, application frequency and timing are underway in the 2005 fruiting season.

Project activities during 2005/06 concentrated on the pheromone identification, development of an effective synthetic blend and field evaluations. Alternative host feeding tests, biology studies and pesticide field trials were also conducted in East New Britain and Port Moresby.

Pheromone identification was carried out in New Zealand by HortResearch using pupae of the red banded mango caterpillar, Deanolis sublimbalis, (RBMC) reared in Papua New Guinea. Analysis by gas -chromatography and mass spectrometry of female pheromone glands identified two major components, (11Z)-hexadecenal (Z11-16:Ald) and (3Z,6Z,9Z)-tricosatriene (3Z,6Z,9Z-23:Hy) as being necessary for male moth attraction. In field trials, delta traps baited with 1 mg of a 1:1 mix of Z11-16 Ald and 3Z,6Z,9Z-23Hy provided good catches of moths and this blend will be used in subsequent ecological studies in PNG and in quarantine monitoring for RBMC in northern Australia.

Results from alternative host testing conducted at Keravat, East New Britain, showed that a range of fruit with large kernels including Tahitian chestnut, candle nut, Bukbuk nut, Pau nut and avocado will nut support the development of larvae. These results support other studies and it appears very likely that the red banded mango caterpillar is a monophagous species.

Chemical control trials in PNG provided confirmation of results obtained in the previous season with only thiacloprid (Calypso) reducing the incidence of fruit damage. Once again the use of other less effective broad spectrum insecticides increased the level of damage when compared to untreated trees and the removal of weaver ants by these insecticides has been implicated. New work is planned to quantify the impact of weaver ants as potential biocontrol agents. If effective, promoting the build up of weaver ants on mango trees is seen as a practical and affordable method of biocontrol of red banded mango caterpillar in Papua New Guinea.