Technical annual report 2000-01
Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals
Dept. of Primary Industry and Fisheries
Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
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Technical Annual Report 2000/01 207 Growers of carambola and other fruits in Humpty Doo who had problems with damage to flowers were advised after inspection that the damage had not been caused by insects but by possums. The NT Wildlife Park provided advice on control measures. Cucurbits and Asian Vegetables The most common advice requested by growers was for the control of Thrips palmi Karny (Thysanoptera: Thripidae), Poinsettia whitefly, Bemisia tabaci (Gennadius) Type B (Hemiptera: Aleyrodidae) and mites. This included the control of T. palmi on cucurbits, hairy melon, bitter melon, button squash, eggplant and loofa. B. tabaci may affect okra, snake bean and bitter melon. The current recommendation for both T. palmi and whitefly is the regular use of potassium soap such as Natra Soap. Broad mite Polyphagotarsonemus latus (Banks) (Acarina: Tarsonemidae) was recorded as a severe pest on chillies on one property. The grower preferred not to use conventional miticides and instead persisted with weekly applications of petroleum oil sprays (DC Tron Oil). After three applications, the crop appeared healthy and suffered very little damage to new leaves from mites A commercial rockmelon property encountered significant plant damage and yield loss from Solenopsis geminata (Fabricius) (Hymenoptera: Formicidae) which removed the seeds and attacked the seedlings. This and other properties followed advice to regularly monitor and treat for cucumber moth based on the results of sampling. A series of insect specimens from two properties were identified for compiling a species list for the growers. Ornamentals and Nursery Plants Several flower growers had caterpillar damage to flowers and stems of Alpinia purpurata causing the flowers to be unmarketable. Horticulture and Entomology Staff inspected the affected properties. Larvae were collected and reared to adults. The specimens were identified as Conogethes near pluto. Other similar specimens have been recorded from Queensland and northern NSW but had no host records. Information on the control of this moth was supplied to Horticulture Extension Officers for distribution to growers. Plantings of ornamental sweet potato (Ipomoea batatus) on nature strips were inspected as requested by the Department of Transport and Works. The plants had suffered from leaf defoliation over a few months. Although most of the damage was old, moderate numbers of grasshoppers (Orthoptera: Pyrgomorphidae) and a chrysomelid beetle, Metriona sp. (Coleoptera: Chrysomelidae) were present. Insecticides were not recommended since the numbers were low but it was advised that fertiliser be applied and watering increased. At the end of the month the plants were reported to have recovered and were looking healthy after the advice was followed. Other common enquiries concerned mealybugs causing distortion to new shoots of palms and thrips in nursery plants. Two thrips species (Thysanoptera: Thripidae) also caused significant damage to Vanda orchid flowers owned by a hobby grower and Hymenocallis, a lily, in a nursery. The causal agents were Dichromothrips corbetti (Priesner) and Astrothrips sp., respectively. The following insect swarms were recorded from the Darwin and Darwin Rural Area during the year; Monolepta australis (Jacoby) (Coleoptera: Chrysomelidae) - in orchards. Agetinus sp. (Coleoptera: Chrysomelidae) - on young mango trees. Scarab beetles (Coleoptera: Scarabaeidae) - on ornamentals. Flea beetles (Coleoptera: Chrysomelidae) - in orchards. Graptostethus sp. (Hemiptera: Lygaeidae) - in orchards. Ginger Ants Many enquiries and associated specimens were received due to media publicity following the detection of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) in Queensland. Specimens that were collected or supplied were generally ginger ant, Solenopsis geminata (Fabricius), Odontomachus turneri Forel or Iridomyrmex sp (a brown species). S. geminata which is well established in the Darwin area was found at Katherine and in nursery stock that was sent to Alice Springs from Darwin. A local man in Katherine was admitted to hospital after ants, confirmed as S. geminata, had stung him.