Page 51 - SA Fruit Journal VOLUME 14

Fruitfly Africa moves in the right directionAs South African deciduous fruit producers enter a new harvest season, and with it a rise in fruit fly population levels in production areas, it is perhaps time to evaluate past successes in population control programs and take stock of what has been learnt.In November 2014 FruitFly Africa (FFA) compiled a progress report of the past four seasons. From this it seems that the programis moving in the right direction and that pro- ducers can rest assured that all their efforts to make population control of fruit flies in their area a success have not been in vain.The mean FTD’s (Flies per Trap per Day) for all areas under the full control program, including SIT, have decreased considerably since the 2010/2011 season.Changes in mean FTD’s for the period 2010/2011 to 2013/2014 per region were as follows:Of course the main objective of the area-wide integrated pest management program is to ensure continued access to existing markets, and to enable exporters to gain access to new markets, through creating areas of low pest prevalence. For this reason one should also consider the impact of the program on the number of rejections for fruit fly infestation by PPECB in areas under the program. When comparing the number of rejections during the 2013/14 season to the highest number of rejections in previous years, the decreases are as follows:• Hex River Valley 84% decrease • EGVV 58% decrease • Ceres area 100% decrease(no rejectionsthe previous season)There are a number of factors influencing these successes over the past couple of years, one of which is the fact that sterile male (ster- iles) production and release has grown sub- stantially. In 2010 the weekly production of steriles was 15 million during summer, with production being cut down to 8 million in winter months. The rearing facility in Stellen- bosch now produces 25 million flies per week year round. This allows for high sterile to wild ratios during periods where wild populations are naturally suppressed by cold conditions. Areas thus enter the harvesting season with a low population base that is easier to control later on as fruit starts to ripen.Due to technical changes to the produc- tion process, after visits to international Med- fly rearing facilities in Valencia and El Pino, production is now more stable than ever andinterest to us as it supplements other control strategies and it can be easily integrated into control programmes.The “take home message” from the sym- posium was that Bactrocera dorsalis repre- sents a significant threat to us. Having said that, there is help available as there are a number of active research programmes un- der way. For example, fruit fly researchers from a number of sub-Saharan countries met during the symposium to coordinate re- search and monitoring programmes.There are several challenges associated with the regional approach to pest manage- ment, but none of us are alone in this and co- operative programmes are needed. In addition to that there are other Bactrocera species with- in Africa that pose a threat to us, and due at- tention needs to be paid to the problem. I still• Hex River Valley • EGVV• Ceres area4.5 to 3 (-33.3%) 0.4 to 0.2 (-50%) 1.0 to 0.3 (-70%)B. dorsalis us- ing fungal based biopesticides was authored by Sunday Ekesi (International Centre of Insect Physiology and Ecology (ICIPE), Nai- robi, Kenya) and others. The main aim of the research was to evaluate the practicality of using fungi in a device which attracts fruit flies. The flies are thus exposed to the fungal spores and then disseminate the fungi in the environment and to other fruit flies. The re- search revealed that the fungus Metarhizium anisopliae is effective and that it significantly reduced fruit fly populations in mango or- chards in Kenya. In addition it was found that a high proportion of flies in the mango orchards were contaminated with the fungus, this indicates that the fungus can be transmit- ted horizontally (from fly to fly). The tech- nique is very attractive and would be a greatCONTINUED FROM PAGE 471st CGA CITRUS SUMMIT11th and 12th March 2015at The Hans Merensky Hotel, Phalaborwa, Mpumulanga.Special rates available from the Hans Merensky Hotel on proof of registration,on a first come, first served basis.R1 000 - early registration up to 15 Feb. R1 500 - late registrationFor more information please contact the CGA officeson 031 765 2514TEGNOLOGIE 48 FEB | MAART 2015