TANAMAN KECUBUNG (Datura metel L.) SEBAGAI BAHAN BAKU INSEKTISIDA BOTANIS UNTUK MENGENDALIKAN HAMA Aspidomorpha milliaris F.

<p>ABSTRAK<br />Kecubung (Datura metel L.) adalah salah satu tanaman obat<br />tradisional yang berpotensi sebagai sumber insektisida botanis, namun<br />sampai saat ini belum banyak diteliti. Tujuan penelitian ini adalah untuk<br />mengetahui efektivitas tanaman kecubung sebagai bahan insektisida<br />botanis, terhadap serangga Aspidomorpha milliaris F (Coleoptera:<br />Crysomelidae). Penelitian dilakukan di KP. Laing Solok mulai bulan April<br />sampai Oktober 2012, dengan menggunakan rancangan acak lengkap (9<br />perlakuan dan 3 ulangan). Perlakuan yang diuji adalah ekstrak daun<br />kecubung pada konsentrasi 250, 500, 750, 1000, 1500, 2000, 2500, dan<br />3500 ppm, serta 0 ppm sebagai kontrol. Perlakuan diaplikasikan secara<br />kontak maupun non kontak. Serangga uji yang dipakai pada setiap<br />perlakuan adalah 20 ekor larva instar III, IV, V, VI, dan 10 ekor imago.<br />Parameter pengamatan meliputi persentase kematian, penurunan volume<br />makan larva dan imago, fekunditas, serta periode prereproduktif imago.<br />Hasil penelitian menunjukkan ekstrak daun kecubung yang diaplikasikan<br />secara kontak lebih toksik dibandingkan dengan non kontak. Ekstrak daun<br />kecubung kosentrasi 3500 ppm bersifat toksik, menolak makan, dan<br />mengurangi fekunditas A. milliaris. Tingkat kematian larva A. milliaris<br />instar III, IV, V, dan VI berkisar 28,46-39,51%, sedangkan penurunan<br />volume makan sebesar 10,44-15,76%. Fekunditas A. milliaris menurun<br />21,77%. Oleh karena itu, ekstrak daun kecubung dapat dikembangkan<br />sebagai insektisida botanis.<br />Kata kunci: kecubung, insektisida botanis, Aspidomorpha milliaris F.</p><p>ABSTRACT<br />Amethyst (Datura metel L) is one of a potential plants used as raw<br />material of botanical insecticides, but until now it had not been prived.<br />The purpose of the research is to determine the potential of the amethyst<br />as a botanical insecticide to Aspidomorpha milliaris F. (Coleoptera:<br />Crysomelidae). The research carried out in Laing Solok Experimental<br />Garden from April to October 2012, in a completely randomized design (9<br />treatments and 3 replications). The treatments were amethyst leaf aqueous<br />extract at concentrations of 250, 500, 750, 1000, 1500, 2000, 2500, 3500<br />ppm, and 0 ppm as a control. The treatments were applied contact and<br />non-contact. Test insects used in each treatment was 20 larvae instar III,<br />IV, V, VI and 10 imagos. Observation parameters include the mortality<br />percentage and eating volume decrease of larvae and imago, fecundity,<br />and imago prereproductive period. The results showed that the leaf extract<br />amethyst which were applied contactly was more toxic than the non-<br />contact. The amethyst leaf extracts at 3500 ppm concentration are toxic. It<br />also could refuse to eat and reduce fecundity of A. milliari. The mortality<br />rate for larval instar III, IV, V, and VI ranged 28.46-39.51%, while a<br />decrease of eat volume ranged 10.44-15.76%. The fecundity of A.<br />milliaris decreased 21.77%. Therefore, the leaf amethyst extract can be<br />developed as a botanical insecticide.<br />Keywords: amethyst, botanical insecticides, Aspidomorpha milliaris, F</p>

Effects ofmti-2Transgenic Potato Plants on the AphidMyzus persicae(Sternorrhyncha: Aphididae)

Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitormti-2gene. Among the 35 independent transgenic potato lines obtained viaAgrobacterium tumefascienstransformation, four (DM6, DM7, DM11, and DM19) were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition). Feeding assays were carried out to evaluate their effects on the green-peach aphid,Myzus persicae(Sternorrhyncha: Aphididae). Prereproductive period, nymphal mortality, adult fecundity, and doubling time ofM. persicaepopulations were monitored on nontransformed potato plants (NT) and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect onM. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhancedM. persicaedaily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history ofM. persicaebut did not show any insecticidal effect on the aphid.

Different modulation of aromatase activity in frog testis in vitro by ACE and ANG II

The aim of the present research was to study the role of angiotensin-converting enzyme (ACE) and ANG II in amphibian ( Rana esculenta) testicular steroidogenesis and prostaglandin production. Hormonal effects of ACE, ACE inhibitors, synthetic bullfrog ANG I, and [Val5]ANG II were determined in frog testis of prereproductive period. Production of 17β-estradiol, progesterone, androgens, and PGE2 and PGF2α was determined by incubating frog testes with ACE (2.5 mU/ml), captopril (0.1 mM), lisinopril (0.1 mM), [Val5]ANG II (1 μM), and synthetic bullfrog ANG I (1 μM). The analysis of the data showed an independent modulation of 17β-estradiol and androgen production by ACE and ANG II. The ACE pathway caused a decrease of 17β-estradiol production and an increase of androgen production in frog testes; on the other hand, the ANG II pathway increased 17β-estradiol production and decreased androgen production. The determination of testicular aromatase activity showed a positive regulation by ANG II and a negative regulation by ACE. As for prostaglandin production, only ANG II influenced PGF2α. These results suggest a new physiological role of ACE and ANG II in modulating steroidogenesis and prostaglandin production.

Population demography and sex ratio in a Neotropical damselfly (Odonata: Coenagrionidae) in Costa Rica

ABSTRACTThroughout the latter part of the dry season (January-April) of 1985 and 1986, we studied the demography of mature adults in a small population of Argia chelata along a stream at Monteverde, Costa Rica. Males defended sunlit spots along the stream between 1030 h and 1400 h central standard time each day and females visiting these sunlit spots were soon mated. By individually marking all mature adults in the population we found that there was no significant difference between the sexes in daily survival rates (0.85 for males and 0.86 for females). Lifetime mating success was positively correlated with longevitiy in both males and females but the ability of males to obtain a mate appeared to be independent of age.Although the sex ratio at emergence was 1:1, that of mature adults at the stream was strongly male-biased (87% male), perhaps as a result of a longer or more risky prereproductive period in females related to the costs of egg formation. We argue that the strongly male-biased sex ratio has important effects on the mating system of this species in that the male contact-guards the female for the entire oviposition period each day. Although this limits each male to mating with one female per day, it probably ensures that the male will fertilize most of the eggs laid by the female that day.

The influence of the host plant or males on ovarian development or oviposition in the diamondback moth Plutella maculipennis (Curt.)

The conditions of larval development, especially food quality and larval density, affected appreciably the length of the adult prereproductive period. The isolation of females from males after adult eclosion did not affect this prereproductive period but increased the preoviposition period. The presence of host tissue reduced the prereproductive period of adult females. Presence of non-host plants (wheat broad bean, and pea) did not significantly affect the length of the prereproductive period. The effect of the host on egg production was successfully simulated by exposing females to allyl isothiocyanate, a characteristic constituent of the food plants. The processes regulating number of eggs produced were discussed.