Rauf, Aunu, Indonesia

• Buletin Hama dan Penyakit Tumbuhan Vol. 11 No. 2 (1999): Buletin Hama dan Penyakit Tanaman - Articles
  

  The research was conducted in sub-district of Ciledug (Cirebon) with the objectives to study the infexiation and larvaal population development id onion armyworm. Spodoptera exigua (Habner) (Lepidoptera: Noctuidae), on shallots grown in lowland. Monitoring of egg masses and leaf damage were made at 3-4 days internal while of larvae at 1 week internal. Outbreak took place during the dry season of August-October 1995 when population density reached 0.8 egg mass and 23 larvae per hill, and subsequently all hills were heavily damaged. Throughout the rainy season of December 1995-February 1996, egg masses and larvae were difficult to find. Result of hand-picking showed that larval population during dry season was 78 times higher than those of rainy season. Larvae exhibited body color vartations. During the epidemics 80 percent of the larvae were dark whereas,during the endemics only 10 percent, the rest were light green. Level of egg parasitization was 0,9 percent coused by Tricogramma xp. (Hymenoptera; Trichogrammatidae) and telenomus sp. (hy menoptera; sceltonidae ), and larval parasitization 5.7 percent coused by Microplitis sp. (Hymenoptera; Braconidae), Euplectrus sp. and stenomesius sp (Hymeno[tera; Eulophidae), and Peribaea sp. (Diptera; Tachinidae). Low level of parasitization together with the abundance of food supply and dry season were believed to be the main foctors contributing to the population outbreaks. Hand-picking of egg masses and larvae conducted regularly, as practiced by the farmer group in the village of Dukuh wringin (Brebes(, should be adopted as a key activity for mitigating S. exigua infestation during dry season; and therefore, this practice should disseminated to farmers in other areas.

  
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• Buletin Hama dan Penyakit Tumbuhan Vol. 11 No. 1 (1999): Buletin Hama dan Penyakit Tanaman - Articles
  A farmer survey, to determine the way potato farmers perceived the leafininer fly and methods they employed to control the pest, was conducted in ten highland vegetable production centers in five provinces jhm June to September 1998. The total number of potato farmers interviewed was 309. The study revealed that the farmers were familiar with the leafininer as a new pest that have caused heavy damage since 3-6 years ago. However, only few farmers (5.5%) were knowledgeable that L. huidobrensis was an exotic pest. Most farmers (>75%) reported that leafininer infestation caused more than 40% yield losses, and the crops have to be harvested 2-4 weeks earlier than was the nomal practice. All respondents applied insecticides to control the leafininer twice a week. Insecticides mostly used were pyrethmids and organophosphates. Selection of pesticides was based on farmer's own experiences, other farmers experiences, and based on suggestion jhm pesticide kiosk's owners. Although insecticides were used intensively, most farmers (72%) were dissatisfied with the efficacy of control. Biological control with parasitoids may pegom satisfatorily only if it B accompanied by minimizing insecticide use.
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• Buletin Hama dan Penyakit Tumbuhan Vol. 12 No. 1 (2000): Buletin Hama dan Penyakit Tanaman - Articles
  

  Parasitization of the white rice stem bore< Scirpophaga innotata (Walker) (Lepidoptera: Pyralidae), was studied in Karawang during an outbreak in 1991/1992. The percentage of egg masses parasitized averaged 85.5%, whereas the percentage of individual eggs parasitized 44.2%. Egg masses attacked by parasitoids yielded 1 to 100 wlth arz average of 53.9 borer larvae. A mean of 56.6parasitoid wasps emerged from the parasitized egg masses. Based on the proportion of egg masses parasitized and the number of wasps emerged, the predominant parasitoid was Telenomus rowani Gahan, followed by Trichogramma japonicum Ashmead, and the least was Tetrastichus schoenobii Ferriere. The level of individual egg parasitization was 22.7% for T. japonicum 55.8% for T. rowani, and 92.1% for T. schoenobii. A mean of 66.5 borer larvae survived after attack by T. japonicum, 19.4 lawae by T. rowani, and only 0.8 larvae per egg mass by T. schoenobii. The last mentioned species was the most efJicient and efective parasitoid, and the borer outbreak was considered to be related to the low level of eggparasitization by T. schoenobii.

  
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