No abstract

Population of Brown Plant Hopper (Nilaparvata lugens Stal.) and the Diversity of Its Natural Enemyin Highland Paddy Rice Field in the Village of Panyocokan, Ciwidey District, Bandung RegencyBrown lanthopper/BPH (Nilaparvata lugens Stal.) is a main pest of rice in the field. This researchwas aimed to study the population of BPH and the diversity of its natural enemy in highland paddyrice field. The survey was conducted in three paddy plots (15 m x 20 m) located in the village ofPanyocokan, Ciwidey District, Bandung Regency, West Java. The experiment was conducted in thegreenhouse of the Department of Plant Pests and Diseases, Faculty of Agriculture, UniversitasPadjadjaran. The samples of insects were collected systematically using yellow trap and net trap,and visually observed in each rice cluster. The number of BPH were recorded and accumulatedeach week. Fecundity, life cycle, and sex ratio of the new generation of BPH were observed in 3replications by using 1 pair of WBC on each replication. The result showed that the population ofBPH in the highland was below 10, which means that BPH population was still below theeconomic threshold and control threshold. Temperature, humidity, and rainfall did notsignificantly affect the BPH population. This was indicated by the regression analysis of eachtemperature (Y = 0.557-8.167x; R2 = 0.039; P = 0.465), humidity (Y = -0.077+ 9.112x; R2 = 0.045; P =0.428), and rainfall (Y = -0.118 + 3.412x; R2 = 0.136; P = 0.159). Natural enemy diversity indextended to fluctuate widely from low to moderate. In the temperature range from 21.1°C to 34.8°C,BPH could produce 127-207 new generation during its lifetime. BPH needed an average of 37.66days to produce a new generation. The ratio of male to female was 1.06 : 1.Keywords: population, brown planthopper, diversity, predator, highland paddy rice field, Ciwidey,BandungABSTRAKHama wereng batang cklat/WBC (Nilaparvata lugens Stal.) merupakan hama utama tanaman padi.Penelitian ini bertujuan untuk mempelajari populasi WBC dan keragaman musuh alaminya padatanaman padi sawah di dataran tinggi. Penelitian dilakukan dengan metode survei dan eksperimen.Survei dilakukan pada 3 petak lahan percobaan berukuran 15 mx 20 m bertempat di DesaPanyocokan, Kecamatan Ciwidey, Kabupaten Bandung dan eksperimen dilakukan di rumah kacaDepartemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Padjadjaran. Metodepengambilan sampel dilakukan secara diagonal sistematis. Populasi WBC ditentukan denganmenggunakan perangkap kuning dan perangkap jaring dan dengan pengamatan langsung padarumpun padi. Eksperimen dilakukan dengan meletakkan sepasang WBC dalam wadah, lalu diamatikeperidian, siklus hidup, dan sex ratio keturunannya. WBC yang tertangkap dihitung jumlahnyadan diakumulasikan setiap minggunya. Hasil penelitian menunjukkan bahwa kepadatan populasi dilahan survey di bawah 10 ekor/rumpun yang artinya populasi WBC masih di bawah ambangekonomi atau ambang kendali. Suhu, kelembaban, dan curah hujan tidak memberikan pengaruhyang signifikan terhadap populasi WBC. Hal tersebut ditunjukkan dengan analisis regresi masingmasingpada suhu (Y= 0,557 – 8,167x; R2 = 0,039; P= 0,465), kelembaban (Y = -0,077 + 9,112x; R2 =0,045; P = 0,428), dan curah hujan (Y = -0,118 + 3,412x; R2 = 0,136; P = 0,159). Indeks keragamanmusuh alami cenderung mengalami fluktuasi dari rendah sampai sedang. Pada kisaran suhu 21,1oC–34,8oC, hasil pengamatan keperidian menunjukkan WBC dapat menghasilkan 127-207 individubaru selama masa hidupnya. Pada pengamatan siklus hidup, WBC memerlukan rata-rata 37,66 harisampai menghasilkan generasi baru. Pengamatan sex ratio menunjukkan perbandingan (jantan :betina) 1,06 :1.Kata kunci: populasi, wereng batang coklat, keragaman, predator, sawah, dataran tinggi, Ciwidey,Bandung

The depth of the pupation is one of the important factors in the success of fruit flies to become imago. The objective of this study was to evaluate the effect of soil depth on survival, normality dan development time of adult interspecific hybrids of Bactrocera carambolae (Drew & Hancock) and B. dorsalis (Hendel). The experiments were carried out in a laboratory consisting of seven depths of pupation treatments (4 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, and 60 cm) with four replications. Soil depth had a significant, negative effect on the survival of the emergence and development time of B. dorsalis and B. carambolae hybrids. The emergence rate was found to decrease with the increase in pupation depth. The higher survival of the emergence of the hybrid occurred at a depth of 4 cm (95% ± 1.91) and 10 cm (86% ± 2.58), while the lower survival occurred at a depth of 50 cm (12% ± 1.63) and 60 cm (5% ± 3.79). Normal imagoes were found in all soil depths except in 60 cm depth, where all imagoes had abnormal morphology. Means of development time ranged from 8.88 to 10.63 days. The depth of pupation influences the duration of pupae development. The means of development time at a depth of 4–40 cm was similar, but at a depth of 50 cm and 60 cm, a significantly longer time of development were observed. for more effective fruit fly control, this study suggests burying rotten fruit in the soil at a depth of 50 cm or more as a preventive measure for the development of fruit flies.

Fruit fly (Bactrocera spp.) is a major pest of horticultural crops, especially fruits. Fruit fly larvae feed on the flesh of fruit, and cause the decrease of both quantity and quality of the production. Fruit fly species on certain fruit in an area is important to be identified to make a right decision in choosing the control methods. The objectives of this study were to identify the fruit fly species, and determine the dominant species and diversity index of fruit flies on mangoes Gedong Gincu, Cengkir, and Arumanis at Kecamatan Talun, Kabupaten Cirebon, Indonesia. The survey was carried out by collecting samples of mango fruit attacked by fruit flies from field, wholesaler, and retailer at Kecamatan Talun. The results showed that there were four species that attack mangoes Gedong Gincu, Cengkir, and Arumanis at Kecamatan Talun, namely B. dorsalis; B. carambolae; interspesific hybrids of B. carambolae and B. dorsalis; and B. albistrigata. The dominant species was B. dorsalis. Diversity index (H’) of fruit fly species was 0,05 ≤ H’ ≤ 0,48 (H’ < 1,5), so that the diversity was considered low.

Sclerotium rolfsii is one of the soil-borne pathogens that cause damping-off and stem rot on soybean plants. One effort to control damping-off, which is environmentally friendly, is by using biological agents. Antagonistic microorganism that has been studied intensively and has a great potential to control soil-borne diseases is Trichoderma harzianum. The objectives of this research were to comprehend the ability of T. harzianum in a formulation with carbon fiber 80 mesh and silica nanoparticles (NPs.) and to determine the concentration of silica NPs. in the formulation that suppresses the in vitro growth of S. rolfsii and control the damping-off on soybean plants. The experiment was conducted in two phases. The first phase was in vitro experiment, arranged in a completely randomized design with 11 treatments and 3 replications. The second phase was in vivo test by using randomized complete block design, with 11 treatments and 3 replications. The in-vitro test showed that each treatment with T. harzianum in the formulation of silica NPs. and carbon fiber 80 mesh in various concentrations was able to suppress the S. rolfsii growth by 58.76- 80.92%. The treatment of single T. harzianum caused the highest suppression on S. rolfsii up to 80.92%. While the results of the in vivo test showed that the highest percentage of damping-off suppression was on the treatment of T. harzianum only, with 60% suppression.