Pathogenicity of  Beauveria bassiana Bals. Vuill. (Deuteromycotina:Hyphomycetes) on various stages of eggs and nymphs of the green stink bug (Nezara viridula L.) . The green stink bug (Nezara viridula L.) is one of the important soybean pod-sucking bug besides brown stink bug (Riptortus linearis) and  green stink bug (Piezodorus hybneri). Up to now, pest control mostlyrely on the chemical insecticides,  The objectiveof this experiment was to study the pathogenicity of Beauveria bassianaon various stages of eggs and nymphs of the  green stink bug.  Experiment was conducted in the laboratory of Entomology, Indonesian Legumes and Tuber Crops Research Institute (ILETRI) Malang, from January to June 2011. The treatments consists of various eggs and nymphs stages of green stink bug. The results showed that B. bassiana was able to infect the eggs green stink bug both of the newly laid and the six days old eggs.   As a results of this infection, 96% eggs did not hatched.  The younger of eggs, the more susceptible to B. bassiana. The infected egg prolonged hatching periods to three days. B. bassianawas also toxic to all stages of  the green stink bug, especially to the first and second instarswith mortality  rate of 69-96%. The nymph of third, fourth, ad fifth instar and adult  stage were more tolerant to the B. bassiana infection. This study suggest that one way to control green stink bug be  the use of entomopathogen B. bassiana againts their ggs or younginstar.

Beauveria bassiana merupakan salah satu jenis cendawan entomopatogen yang termasuk dalam divisi Ascomycota, kelas Sordariomycetes, ordo Hypocreales dan famili Clavicipitaceae. B. bassiana dapat membunuh seluruh stadia serangga pada berbagai jenis hama tanaman dari ordo Homoptera, Hemiptera, Coleoptera, Lepidoptera, Orthoptera, Isoptera, Diptera, dan Hymenoptera. Efikasi B. bassiana dipengaruhi oleh berbagai jenis enzim yang dihasilkan yaitu: kitinase, protease, amilase, dan lipase yang berfungsi sebagai pendegradasi lapisan integumen serangga. Efikasi cendawan juga dipengaruhi oleh produksi toksin yang terdiri dari beauvericin, bassianin, bassiacridin, beauvericin, bassianolide, cyclosporine, oosporein, dan tenellin yang dapat mengganggu sistem syaraf dan membunuh serangga sasaran. Keunggulan B. bassiana bersifat ovisidal yang dapat menggagalkan penetasan telur selain membunuh stadia nimfa/larva maupun imago, sehingga dapat menekan perkembangan populasi dan menghambat terjadinya peledakan hama. Kelebihan lain B. Bassiana, yaitu bersifat endofit yang dapat menghambat perkembangan patogen tular tanah maupun penyakit karat daun (Phakospsora pachyrhizi), embun tepung (Microsphaera diffusa), dan embun bulu (Peronospora mansyurica). Cendawan B. Bassiana juga bersifat ramah lingkungan sehingga aman terhadap kelangsungan hidup musuh alami dan hewan ternak serta tidak mencemari sumber air maupun lingkungan. Aplikasi B. bassiana dapat menekan terjadinya resistensi maupun resurjensi. Waktu aplikasi B. bassiana dianjurkan pada sore hari dengan frekuensi aplikasi tiga kali. Cendawan B. bassiana prospektif untuk digunakan sebagai biopestisida dalam mengendalikan hama dan penyakit tanaman, ramah lingkungan, serta dapat digunakan sebagai alternatif pengganti pestisida sintetik.

ABSTRAKGejala tulang daun kuning (vein yellowing) dan malformasi daun yang diduga disebabkan oleh virus ditemukan pada ubi jalar IR Melati di daerah Kendalpayak, Malang, Jawa Timur. Amplifikasi DNA/cDNA menggunakan primer universal Begomovirus, Potyvirus, dan Cucumovirus menunjukkan positif teramplifikasi DNA dengan primer universal Begomovirus, dan Potyvirus, namun negatif dengan primer universal Cucumovirus. Berdasarkan runutan sikuen nukleotida, gejala tulang daun kuning dan malformasi daun disebabkan oleh infeksi ganda Pepper yellow leaf curl virus (PYLCV) dan Sweet potato virus C (SPVC). Analisis identitas DNA dengan perangkat lunak BioEdit menunjukkan homologi paling tinggi sebesar 98.5% terhadap PYLCV isolat cabai dari Bangli Bali, dan sebesar 98% terhadap SPVC dengan isolat ubi jalar asal Jepang dan Amerika Serikat. Laporan ini merupakan temuan baru infeksi alami PYLCV dan SPVC pada ubi jalar di Indonesia. ABSTRACTVirus-like infection with vein yellowing and leaf malformation symptoms were observed on sweet potato IR Melati at Kendalpayak, Malang, East Java. Amplification of DNA/cDNA was carried out using universal primer of Begomovirus, Potyvirus and Cucumovirus showed successfully amplified by universal primer of Begomovirus and Potyvirus, while negatively to universal primer of Cucumovirus. Based on nucleotide sequences, the vein yellowing and leaf malformation symptoms on sweet potato caused by double infection of Pepper yellow leaf curl virus (PYLCV) and Sweet potato virus C (SPVC). DNA identity analysis using BioEdit software showed highest homology up to 98.5% to one of PYLCV isolates from Bali, and up to 98.0% to sweet potato isolate of SPVC from Japan and USA. This is a new finding of natural infection of PYLCV and SPVC on sweet potato in Indonesia.

Saputro TB, Prayogo Y, Rohman FL, Alami NH. 2019. The virulence improvement of Beauveria bassiana in infecting Cylas formicarius modulated by various chitin based compounds. Biodiversitas 20: 2486-2493. Sweet potato (Ipomoea batatas L.) is one of alternative carbohydrate source with an important role in food production, animal feed industries, and as raw materials for other derivatives. However, severe losses are constantly occured in its production due to a notorious pest known as sweet potato weevil (Cylas formicarius). The chemical insecticides commonly used to treat the pest, but have not been efficient in eliminating C.formicarius. Beauveria bassiana is well known as a biological control agent, has been identified to effectively eliminate the pest. The aim of this research is to observe the optimum concentration of several chitin-based compounds in improving the virulence of B. bassiana. The research was conducted by the addition of chitin from various sources -insects, crustaceans and mollusk shells in a growth medium of B. Bassiana. Moreover, conidia produced by B.bassiana was exposed to C.formicarius to investigate the mortality rate of this insect. The results showed four different characteristics of colonies -velvety, wooly, pellicular, and farinaceous. The 1% chitin from Tellina sp, (P9), was found to be the best treatment which increased the growth of the colony diameter attaining 6.7cm in 20 days, increased the conidia viability that reaches 93.5%. In addition, the highest mortality percentage of C. formicarius was 91.67% in P9 at 6 days after infection. Overall, this research gave new potential sources of chitin that can be applied in improving the virulence of B. Bassiana in eliminating C. formicarius.

Comparing application methods of entomopathogenic fungus Beauveria bassiana to control Cylas formicarius (Coleoptera: Curculionidae). Cylas formicarius is a major pest of sweet potatoes. The tuber damage caused by C. formicarius reaches 100%. The research objective was to compare application methods of entomopathogenic fungi Beauveria bassiana to control C. formicarius. The research was conducted at the entomology screen house of Indonesian Legume and Tuber Crops Research Institute (ILETRI) at Malang, East Java, from January to September 2013. The treatment consisted of 12 application methods, each was repeated three times. The results showed that application of B. bassiana into the planting pit, soaking the sweet potato cuttings into the conidial suspension of B. bassiana for 30 minutes before planting, followed by spray application with two week interval (2 to 12 weeks after planting, WAP) or P4 was effective in suppressing C. formicarius population and tuber damage. Tuber weight obtained from P4 treatment was 1.4 kg plant -1 , while from the chemical insecticide was only 1.1 kg plant -1 . Tuber damage from P4 treatment was lower ( 5%) than that from chemical insecticide treatment (42%). Therefore, application of B. bassiana conidial suspension in the planting pit, continued by soaking the sweet potato cuttinginto the B. bassiana conidial suspension for 30 minutes before planting, and followed by spray applications of B. bassiana conidial suspension at two-week intervals ( 2-12 WAP) or P4 method can be recommended to control C. formicarius.Key words: adult, egg, larvae, tuber damage, tuber weight ABSTRAKPerbandingan metode aplikasi jamur entomopatogen Beauveria bassiana untuk pengendalian Cylas formicarius (Coleoptera:Ccurculionidae). Cylas formicarius merupakan hama utama ubi jalar. Kerusakan yang disebabkan C. formicarius mencapai 100%. Penelitian ini bertujuan untuk membandingkan metode aplikasi jamur entomopatogen, Beauveria bassiana dalam mengendalikan C. formicarius. Penelitian dilakukan di rumah kasa entomologi, Balai Penelitian Tanaman Aneka Kacang dan Umbi (BALITKABI), Malang pada bulan Januari sampai dengan September 2013. Perlakuan terdiri atas 12 metode aplikasi, masing-masing perlakuan diulang tiga kali. Hasil penelitian menunjukkan bahwa aplikasi konidia B. bassiana ke dalam lubang tanam, perendaman stek ke dalam suspensi konidia jamur B. bassiana selama 30 menit sebelum tanam, dilanjutkan aplikasi semprot dengan interval dua minggu mulai umur 2 sampai dengan 12 minggu setelah tanam (MST) (P4) efektif menekan populasi C. formicarius dan kerusakan umbi. Berat umbi perlakuan P4 mencapai 1,4 kg tanaman -1 , sedangkan perlakuan aplikasi insektisida kimia hanya 1,1 kg tanaman -1 . Kerusakan umbi perlakuan P4 hanya 5%, sedangkan kerusakan umbi pada aplikasi insektisida kimia mencapai 42%. Efikasi perlakuan P4 dapat dilihat dari populasi telur, larva maupun imago pada waktu panen lebih sedikit dibandingkan dengan perlakuan lainnya. Oleh karena itu, aplikasi suspensi konidia B. bassiana pada luba...