Potential damages, seasonal abundance and distribution of Empoasca terminalis Distant (Homoptera: Cicadellidae) on soybean in South Sulawesi

Plant damages caused by  leafhopper, Empoasca terminalis Distant (Homoptera: Cicadellidae) on soybean were first encountered in 2007 in Makassar, South Sulawesi. The insect has been constantly associated with soybean crops in the province ever since. The purposes of the present study were to (i) evaluate potential yield loss attributable to the leafhopper in an experimental set up, (ii) seasonal abundance of E. terminalis, and (iii) distribution of E. terminalis in all major soybean-producing areas in the province. Potential yield loss due to the leafhopper was assessed in a field experiment using two large plots. One of the plots was kept leafhopper-free by weekly insecticide sprays; and the other plot was left unsprayed to allow leafhopper infestation to occur. Adult abundance was weekly monitored using a sweep net throughout the season. Nymph abundance was determined by direct count on the plant leaves. Leafhopper distribution was assessed through surveys conducted in all major soybean-producing areas in South Sulawesi, from 2009–2013. The results of the study showed that E. terminalis caused an average yield loss of 26% on susceptible crops without insecticide use. First leafhopper infestation in all planting seasons occurred two weeks after the plant emergence. Rainfall negatively correlated with the leafhopper abundance. The leafhopper existed in all major soybean production areas in the province. Therefore, our results confirmed the status of E. terminalis as an important soybean pest in the region. In addition, crops planted early in the dry season could escape from heavy leafhopper infestation

The effect of DMSO on ITS2 amplification in the molecular identification of Anopheles farauti Laveran (Diptera: Culicidae), from a colony established in the laboratory

Sibling species identification is very important in the understanding of malaria epidemiology. Morphological criteria are usually used in the identification of anopheline species, but this fails when sibling or cryptic species occur. Analysis by PCR-RFLP of rDNA ITS2 is currently the most reliable and sensitive method for distinguishing between members of the Anopheles punctulatus group. The objective of this study was to investigate the effect of DMSO concentration on ITS2 amplification of An. farauti from the colony maintained at BATAN Jakarta using PCR-RFLP based on the rDNA ITS2. The results showed that the addition of 6 % and 7 % DMSO produced ITS2 amplification products in the size 750 bp. DMSO could be used in PCR to relieve secondary structures when amplifying high GC templates. Molecular identification of An. farauti is found to be Anopheles farauti sensu stricto.Key words: molecular identification, sibling species, PCR-RFLP, rDNA ITS2, secondary structur

Preferensi dan tanggap fungsional Neoseiulus californicus McGregor (Acari: Phytoseiidae) sebagai predator Tetranychus kanzawai Kishida (Acari: Tetranychidae)

Kanzawa spider mite (KSM), Tetranychus kanzawai Kishida (Acari: Tetranychidae) is an important pest on many crops in Indonesia. Generally, farmers use acaricide to control this mite, which may cause negative side effects. One of the alternative control methods is the use of predatory mite. This research was done to determine prey preference and functional response of predatory mite Neoseiulus californicus (Acari: Phytoseiidae) on several life stages of KSM. Experiments were conducted under laboratory conditions. N. californicus were supplied with nymphs and adults of KSM to know its preference. N. californicus were also supplied with KSM eggs at several densities to know its functional response. Adult females and deutonymphs of N. californicus preferred KSM eggs than nymphs as their prey. The number of eggs consumed by adult females and deutonymphs N. californicus increased with the increase of prey density. The number of eggs laid by adult females of N. californicus increased with the increase of prey density. Searching time of the predator became faster with the increase of prey density. N. californicus showed cannibalism under low density of prey.Key words: Neoseiulus californicus, functional response, prey preferenc

Keanekaragaman dan struktur komunitas semut pada perkebunan lada di Lampung

The occurrence of ants in agricultural habitat is related to the availability of food resources as well as environmental condition for its nesting site. As predator, ants play an important role on controlling pest population in agricultural habitat. The objective of this research was to study the diversity of ants in pepper plantation. The research outcome can be used as basic information for cultivation management of pepper. Ecological observation was conducted in four regencies in Lampung Province with two selected plots on each regency. On each plot, ants were sampled using pitfall traps. In total, 28 ant species were recorded from pepper field in four regencies. Two species i.e. Anoplolepis gracilipes and Solenopsis geminataare well-known as tramp and invasive species. There is significantly different of ant species composition among regencies. The occurrence of ants in pepper plantationis probably affected by habitat condition surrounding pepper plantation and precipitation

Asosiasi antara marka SSR dengan ketahanan terhadap wereng batang coklat pada varietas dan calon galur harapan padi

Development of resistant rice varieties to brown planthopper (BPH, Nilaparvata lugens Stål) must be countinuously conducted to overcome the spatial and temporal genetic change in BPH into more virulent ones which can adapt to resistance rice. The availability of linked molecular markers with BPH resistant trait can speed up selection of hybridization progenies. Close-linked markers with trait of interest can be identified using association studies between markers and phenotypic data of unrelated individuals without the need to generate hybridization progenies as an alternative method to linkage studies which use mapping population. The objective of this study was to analyze the association of rice simple sequence repeat (SSR) markers with resistance to BPH. Forty-four rice varieties and promising lines with known resistance degree to BPH biotype 3 were assessed using 30 rice microsatellite markers previously mapped in the rice chromosomal regions with effects on resistance to BPH. Association test between SSR markers and BPH resistance scores revealed eight markers (RM17, RM38, RM125, RM144, RM250, RM287, RM328, dan RM536) which were significantly associated with BPH resistance (R2=0,18 to 0,89; P<0,05). Twenty-one varieties and 11 promising lines were detected to contain SSR alleles that were associated with BPH resistance. Marker RM17 was detected in 15 varieties and 11 promising lines which were scored as resistant and moderately resistant to BPH and therefore it is potentially the most useful as early diagnostic marker to detect BPH resistance alleles. Nevertheless, to obtain SSRs that can be used as reliable selection markers for BPH resistance, marker analysis in segregating populations for the eight markers is still needed as well as associtaion test of more SSR markers widely distributed in rice chromosomes

Keanekaragaman jenis dan perilaku menggigit vektor malaria (Anopheles spp.) di Desa Lifuleo, Kecamatan Kupang Barat, Kabupaten Kupang, Nusa Tenggara Timur

Malaria is a preventable and treatable mosquito-borne diseases, whose main victims are children and pregnant women. Indonesia is the second most affected region in South East Asia and has the the highest malaria burden after India. The research was aimed to study the species diversity and biting activity of malaria vectors (Anopheles spp.) in Lifuleo Village, West Kupang District, Kupang Regency, East Nusa Tenggara Province. The mosquitoes was collected by using (1) the human landing collection technique, (2) aspirators for collecting mosquitoes resting on the wall of houses and cow barn, and (3) light traps. The research was done for four months. The result showed that there were six species of Anopheles i.e., An. barbirostris, An. subpictus, An. annularis, An. vagus, An. umbrosus and An. indefinitus. An. barbirostris and An. subpictus were two species with the highest density. The value of man hour density (MHD) indoor  and outdoor  for An. barbirostris were 5.45 and 6.23 respectively, and for An. subpictus were 1.35 and 1.56, respectively. The blood sucking activity  indoor and outdoor for An. barbirostris occured at 22:00 to 4:00 and 21:00 - 04 respectively, whereas for An. subpictus at 8:00 p.m. to 21:00 and 22:00 to 23:00, respectively. Based on the value of man hour density the mosquito Anopheles spp. in Lifuleo village were exophagic and exophilic

Pemodelan fenologi populasi penggerek batang padi kuning Scirpophaga incertulas (Walker) berbasis pengaruh iklim

Rice stem borer abundance are largely influenced by climate. This research aims to (i) develop a population dynamic model of yellow stem borer (YSB) and (ii) to assess the model’s ability to predict abundance and population peak of YSB under climate change scenario SRES A1FI and B1. Modeling the YSB requires two major components: climate parameter and lower developmental threshold temperatures (To) to describe life cycle of YSB from the egg, larva, pupa, and adult stages. The research utilized DYMEX software to describe development, mortality, transfer of individuals from one to the next life stages, fecundity and reproduction of YSB. The coefficient of determination (R2) of calibration models between predictions and observations showed a strong positive correlation of 0.65. Model validation could well predict the peak population, with R2 = 0.42. The simulations showed that the trend of population peak occur at high rainfall i.e. in March to April, July to September, and November to December. The model predicted YSB population in the Sukamandi reaches 3 generations per year, while in Kuningan 2 generations per year. Simulation models under climate change scenarios SRES A1FI and B1 showed differences in the sensitivities. Trend of YSB population is increasing in the regions Kuningan and decreasing in region Sukamandi. Under changing climate, environment conditions in Kuningan become more suitable for the proliferation of YSB, allowing an increase in the number of generations per year

Pengendalian Aphis craccivora Koch. dengan kitosan dan pengaruhnya terhadap penularan Bean common mosaic virus strain Black eye cowpea (BCMV-BlC) pada kacang panjang

Aphis craccivora is one of the important pests on yard long bean. It causes direct damage and also has an indirect effect as insect vector of the Bean common mosaic virus (BCMV). The research was done to test the effectiveness of chitosan in suppressing aphid population growth, feeding preference and its ability in transmiting BCMV. Chitosan with concentration ranging of 0.1–1.0% were applied on leaves using spraying method at 1 day before BCMV transmission. BCMV was transmitted by using 3 individuals of viruliferous aphids on each plant. Results show that chitosan treatments on leaves or plants significantly suppressed the population and feeding preferences of A. craccivora. Further, treated plants showed lower disease incidence, severity and BCMV titre significantly compared with untreated control plants. The positive effects of chitosan in suppressing population growth as feeding preferences and BCMV transmission might be due to the anti-feedant effect of chitosan on A. craccivora. Based on the result, chitosan at concentration 0.9% is the most effective concentration in suppressing BCMV and its vector A. craccivora

Pola sebaran kelompok telur Ostrinia furnacalis Guenée (Lepidoptera: Crambidae) pada lahan jagung

Asian corn borer, Ostrinia furnacalis Guenée, is known as an important pest of maize, Zea mays L., in both whorl and reproductive stages. Management decisions based on egg-mass density is useful because decision is made before damage occurs. Observation on O. furnacalis egg-mass distribution in maize-field was carried out in Agricultural Training, Research, and Development Station (ATRD) UGM, Yogyakarta. The number of egg-masses laid on each plant surface in maize-field was sampled in reproductive stage of corn at 52 – 58 days after planting. The spatial dispersion was analyzed using the ratio variance-to-mean (σ2/μ = Iδ), Morista’s Index (Iγ), and the negative binomial parameter (κ-value). The results showed that horizontal and vertical distributions were aggregated distributions (σ2 > μ or σ2/μ > 1). In line with the increasing age of plant,  the degree of clustering or aggregation likely tended to decline (the κ-value increased, Morisita index decreased) indicating the possible departure from aggregation to randomness (Poison distribution) due to the heterogeneity of the environment, such as microclimate, preferred parts of the plants, and occurrence of natural enemies. The results concluded that the horizontal and vertical distributions of egg-masses of O. furnacalis on corn in generative phase were clustered with the degree of clustering tended to decrease by the increase of age of corn. These findings provide the bases for further study on the ecology and biology of O. furnacalis for management decision-making process

Aras kerusakan ekonomi (AKE) larva Ostrinia furnacalis (Lepidoptera: Crambidae) pada tiga fase pertumbuhan tanaman jagung

The Asian corn borer, Ostrinia furnacalis (Guenée) is an important economic pest of corn and is widely distributed in the Asia-Pacific region, including Indonesia. The objective of this research is to investigate the effect of infestation levels of O. furnacalis larvae per plant on corn grain yield reductions, and to determine economic injury levels (EIL) of O. furnacalis larvae at three growth stages (V10, R1, and R2) of corn. The experiment was designed in a split-plot randomized complete block with blocks replicated three times. Differences in grain weight between the uninfested and highest infestation levels (six larvae per plant) V10, R1, and R2 were 59.81; 58.76; and 49.20 g/plant, respectively. For each additional infestation by one larvae per plant at V10, R1, dan R2, there is reduction in grain weight of 4.94%, 4.56% and 3.76% respectively. The calculation of EILs was based on the proportion of yield loss per larvae per plant on three corn growth stages with the assumption that pesticide control reduced 67% of O. furnacalis population. The lowest EIL was 0.31 larvae per plant at V10 when the cost of control reaching Rp.125,000 per ha and crop value of Rp.12,000,000 per ha. The highest EIL of 1.24 larvae per plant was found at R2 with the cost of control of Rp.250,000 per ha and crop value of Rp.8,000,000 per ha