Attempts to explain size variation in Drosophila and other small insects often focus on the larval stage and association between development time and size, but patterns are also influenced by direct selection on size‐related traits in the adults. Here we use multiple field releases of Drosophila melanogaster to test the association between size and one component of field fitness, the ability of Drosophila to locate resources for feeding and breeding. We find antagonistic selection between wing length and thorax length in both males and females, such that capture at baits is higher for flies with relatively larger thorax lengths and smaller wings. However flies with large wings relative to thoraces disperse further as reflected in the longer distances moved to baits. These patterns did not depend strongly on weather conditions, suggesting that selection on adult size is at least partly independent of temperature. Antagonistic selection between size traits can generate changes in size along gradients if the distribution of resources in the environment varies and selects for different dispersal patterns, particularly as dispersal is relatively higher under warmer conditions.

Characteristics and Toxicity of Nanoemulsion Formulations of Piper retrofractum and Tagetes erecta Extract Mixtures. Nanotechnology has been used in the developing of botanical insecticide formulation for improving its stability and effectiveness. The research was aimed to make nanoemulsion formulations of Piper retrofractum fruits and Tagetes erecta flowers extracts and to evaluate their toxicity against brown planthopper (Nilaparvata lugens [Stål]) nymphs. The development of nanoemulsion formulaions was carried out by using the low energy method with inversion phase emulsification.  The toxicity of the four formulations was tested against brown planthopper nymphs using a contact method. Four nanoemulsion formulations were obtained.  The study showed that in the developing of the formulations, the type and level of emulsifier materials affected the physical characteristics of formulas, such as stability, surface tension, viscosity, particle size, and particle morphology. The nanoemulsion formulation containing 1% of the mixture of P. retrofractum fruits and T. erecta flowers extracts, 1.75% Triton X-100 emulsifier showed the highest toxic on the brown planthopper nymph, with the LC95 value was 0.15%.  The study indicates that nanoemulsion formulation of P. retrofractum and T. erecta extracts are potential to be developed as botanical insecticide to control brown planthopper of rice.

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Effect of gamma irradiation [60 Co] against Bactrocera carambolae Drew & Hancock in vitro and in vivo. Bactrocera carambolae Drew & Hancock is one of the most important pests on guava fruit. According to a quarantine regulation in export-import commodities, irradiation treatment is a suitable methods for eradicating infested organism, which is relatively safe for the environment. The aim of this research was to determine mortality doses and an effective dose of [ 60 Co] gamma ray irradiation for the eradication purpose, and its implication on the survival of fruit fly B. carambolae. Two irradiation methods of in vitro dan in vivo were carried out, by exposing egg and 3 rd instar larvae of B. carambolae obtained from the laboratory reared insect. Eleven doses of gamma ray irradiation of 0, 30, 50, 75, 100, 125, 150, 175, 200, 300, 450, and 600 Gy were applied, respectively. The level of 99% fruit fly mortality was estimated by the value of LD 99 using probit analysis and the number of larvae, pupae and adult survival were evaluated by analysis of variance (ANOVA), and the means compared by Tukey's test, at 5% of significance level. These result showed that the effective lethal dose (LD 99 ) of irradiation that could be successful to eradicate eggs and 3 rd instar larvae in vitro were 2225 and 2343 Gy and in vivo were 3165 dan 3177 Gy, respectively. Almost all of the treated larvae survived and developed to pupae, therefore only the minimum irradiation dose of 30 Gy allowed the pupae to develop into adults. Key words: Bactrocera carambolae, eradication, irradiation, LD 99 ABSTRAK Pengaruh iradiasi sinar gamma [60 Co] terhadap Bactrocera carambolae Drew & Hancock in vitro dan in vivo. Bactrocera carambolae Drew & Hancock merupakan organisme pengganggu tumbuhan (OPT) penting pada buah jambu biji. Sehubungan dengan regulasi karantina dalam lalulintas komoditas ekspor, iradiasi merupakan upaya membebaskan OPT dari komoditas tersebut yang relatif aman terhadap lingkungan. Penelitian ini bertujuan menentukan dosis lethal dan dosis efektif iradiasi sinar gamma [ 60 Co] untuk mengeradikasi lalat buah B. carambolae, serta mengamati implikasi terhadap keloloshidupannya. Dua metode pengujian in vitro dan in vivo masing-masing diaplikasikan terhadap telur dan larva instar 3 B. carambolae hasil perbanyakan laboratorium. Sebelas dosis perlakuan iradiasi diaplikasikan berturut-turut: 0, 30, 50, 75, 100, 125, 150, 175, 200, 300, 450, dan 600 Gy. Tingkat mortalitas 99% (LD 99 ) ditentukan melalui program probit, dan kemampuan keloloshidupan larva, pupa, dan imago dibedakan melalui uji Tukey pada taraf 5%. Hasil perlakuan menunjukkan bahwa dosis lethal iradiasi efektif (LD 99 ) berhasil mengeradikasi telur dan larva instar 3 berturut-turut sebesar 2225 dan 2343 Gy in vitro, serta 3165 dan 3177 Gy in vivo. Hampir seluruh larva perlakuan yang lolos hidup berhasil berkembang menjadi pupa, namun hanya dosis iradiasi terendah, yaitu 30 Gy saja yang dapat berkembang menjadi imago.