Page 70 - SA Fruit Journal VOLUME 14

time should reduce post-harvest risks associ- ated with FCM.Bud mite T.G. GROUTThe period February to May is the optimal time for bud mite sprays and Mitigate (fen- pyroximate) can be used during this period at 150 ml per 100 L water. The preharvest inter- val for most countries is 28 days but for Can- ada and for citrus types other than mandarins going to South Korea the preharvest interval is 150 days, or no applications after the end of October. Orchards with fruit going to mar- kets that do not have an MRL can be sprayed immediately after removing all fruit in winter. In trials with Mitigate, this product was found to have similar efficacy to Acarol against bud mite so although a spray after harvest is not at the optimal time it will still have more im- pact against this pest than other unregistered options. Mitigate will also suppress citrus red mite when sprayed during autumn for bud mite and CRI research has shown that it is also effective against citrus grey mite.Fruit fly A. MANRAKHANFruit flies are pests of phytosanitary concern. There is a zero tolerance of fruit fly larvae and eggs in fruit consignments for export. Prior to 2013, fruit fly management practices focused on two indigenous pests of citrus: Ceratitis cap- itata (Mediterranean fruit fly or Medfly) and Ceratitis rosa (Natal fly). In 2013, a new inva- sive fruit fly pest - Bactrocera invadens recently synonymised with Bactrocera dorsalis (Oriental fruit fly) was declared present in the Vhembe district in the Limpopo Province of South Africa. Throughout most of 2013 and 2014, Bactrocera dorsalis specimens were continu- ously detected also in the remaining districts of Limpopo Province as well as in some districts of the other Provinces in the north of South Africa: North-West (Ngaka Modiri Molema & Platinum districts), Mpumalanga (Ehlanzeni district), KwaZulu-Natal (ilembe, Harry Gwa-la, Ugu, uMkhanyakude, uThungulu districts) and Gauteng (City of Tshwane Metropolitan district). All affected areas were placed under quarantine and the Department of Agriculture, Forestry and Fisheries (DAFF) have been con- ducting delimiting surveys and control actions in these areas in accordance with the South Af- rican Bactrocera invadens Action Plan. In areas affected by B. dorsalis, additional control prac- tices would have to be implemented in the fruit fly management programme.Fruit fly management practices should be initiated two months before the earliest expected harvest date. However for farms ei- ther with mixed fruit crops (such as mangoes or deciduous fruit) or near fruit types prone to high fruit fly infestation, fruit fly manage- ment practices should be implemented even earlier in line with the ripening and har- vesting of the other fruit types. The fruit fly management package consists of two com- ponents: monitoring and control.Monitoring of Medfly and Natal fly should be carried out using Capilure and Questlure baited Sensus traps. Monitoring of B. dorsalis per Production Unit Code (PUC) is a require- ment for phytosanitary registration of citrus, deciduous and subtropical fruit for export to the special markets (USA, Japan, South Korea, China and the European Union - EU). Moni- toring of B. dorsalis is conducted using bucket type traps such as Chempac Bucket trap, Mo- roccan trap and Lynfield trap baited with Me- thyl Eugenol (ME). Each PUC should have at least one ME baited trap for monitoring of B. dorsalis. Trapping guidelines for surveillance of B. dorsalis in fruit production areas should be followed. Guidelines are available at http:// www.daff.gov.za under Plant Health Divi- sion or at http://www.citrusres.com/market- access. Trap details and trap servicing should be recorded as per trapping guidelines. All trapping results should be supplied to Early Warning Systems (e-mail: janhendrikv@ daff.gov.za) at the end of each export season.Trapping density should be between 2 and 5 traps per 100 ha in areas where B. dorsalis is considered present or where B. dorsalis speci- mens were detected. All fruit fly traps must be checked weekly and trapping records should be documented. Lures and insecticides inside traps must be replaced every 6-8 weeks. Traps are used to determine the presence/absence of a fruit fly pest and to indicate whether the con- trol strategy is adequate. Detection of suspect B. dorsalis specimens in areas considered free of this pest should be reported immediately to the relevant surveillance co-ordinator or to DAFF (Citrus- Aruna Manrakhan: aruna@cri. co.za, 013 759 8000; Deciduous- Leslie Brown: Leslie@hortgro.co.za, 082 853 1471; DAFF- Jan Hendrik Venter: janhendrikv@daff.gov. za, 012 319 6384). Trap thresholds should be adhered to. For Medfly, the threshold in a Capilure baited trap is 4 males per week. For Natal fly, the threshold in a Capilure baited trap is 2 males per week. When using Quest- lure in a Sensus trap, the threshold is one female fly per trap per week for both Medfly and Natal fly. In areas affected by B. dorsalis, catches should preferably be kept below 7 flies per trap per week. If trap thresholds are ex- ceeded, control actions must be increased.Fruit fly baiting and good orchard sanita- tion form the core of fruit fly control practic- es. For fruit fly baiting, the use of either one or a combination of the following methods are recommended: weekly protein hydro- lysate bait sprays, weekly GF-120 sprays and M3 bait stations. For the use of malathion in bait sprays, there is a pre-harvest interval of 28 days. For Medfly and Natal fly, Last Call FF is also available as an additional control method. In areas affected by B. dorsalis, the Male Annihilation Technique (MAT) must be used to control B. dorsalis males in addi- tion to normal baiting. In MAT, B. dorsalis males are targeted using ME and killed by an insecticide incorporated with ME. With high levels of male kills, the number of matingsTECHNOLOGY 67 FEB | MARCH 2015