Fusarium wilt disease caused by pathogenic fungus F. oxysporum f. sp. cubense is an important disease in banana plants. This research was aimed to identifiy Fusarium spp. collected from banana plants showing wilt disease based on morphology and molecular characters.  The fungi isolates obtained was further examined for its pathogenicity and distribution in various parts of banana plants.  Based on morphological characters, i.e. growth rate, total conidia, colony color, macroconidium, microconidium, and chlamydospores, F. oxysporum f. sp. cubense can be differentiated from other species of Fusarium, but not the strain. Molecular analysis using specific primers VCG 01213/16 and Foc1/Foc 2 successfully identified 13 and 7 isolates of F. oxysporum f. sp. cubense TR4 and F. oxysporum f. sp. cubense non TR4, respectively.  Analysis using universal primer ITS4/ITS5 identified 7 isolates of F. solani, 1 isolate of F. verticillioides, and 2 isolates non Fusarium.  Infection of F. oxysporum f. sp. cubense TR4 and non-TR4 were found mostly in pseudo stems, whereas F. solani and F. verticillioides dominantly colonized banana corm. Pathogenicity test showed that F. oxysporum f. sp. cubense TR4 and non-TR4 caused necrosis on corm of cv. Ambon Kuning.  Similar necrosis symptom was also observed on infection of F. solani but with less severity.

Abstract. Fanani Z. M., Rauf A, Maryana N, Nurmansyah A, Hindayana D. 2019. Geographic distribution of the invasive mealybug Phenacoccus manihoti and its introduced parasitoid Anagyrus lopezi in parts of Indonesia. Biodiversitas 20: 3751-3757. Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), is an invasive pest detected for the first time in Indonesia in 2010. An exotic parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced and released in 2014 to control the pest. Study was conducted with the objective to determine the geographic distribution of P. manihoti and spread of A. lopezi. Field surveys were conducted on cassava fields in various locations in Lampung, Java, and Nusa Tenggara. Our studies showed that P. manihoti was found to be widely distributed in Lampung, Banten, West Java, Central Java, East Java, West Nusa Tenggara and East Nusa Tenggara. In each location visited, symptoms of P. manihoti infestation as indicated by internode distortion and bunchy top were prominent. Three years following release, parasitoid A. lopezi has established and spread into several cassava growing areas, except East Nusa Tenggara. Parasitism rates varied from 1.50% in West Nusa Tenggara up to 59.18% in East Java. Logistic regression revealed that probability of severe damage by the cassava mealybug was significantly (P<0.05) increased with the increasing abundance of ants.

Salah satu hama penting pada tanaman cabai adalah Thrips parvispinus Karny (Thysanoptera: Thripidae). Keberadaannya terdeteksi mulai dari dataran rendah sampai dataran tinggi. Penelitian ini bertujuan untuk mengetahui keragaman morfologi T. parvispinus pada tiga ketinggian tempat yang berbeda yakni:  Cirebon (<30 mdpl), Bogor (300-400 mdpl), dan Cianjur (>1200 mdpl). Pada masing-masing lokasi dikoleksi 60 ekor trips betina dan kemudian diawetkan dalam preparat mikroskop dengan media Hoyer. Karakter morfologi T. parvispinus yang diamati adalah ukuran panjang tubuh, lebar kepala, lebar toraks, panjang sayap, dan warna tubuh. Perbedaan karakter morfologi tubuh trips pada ketiga ketinggian tempat dianalisis menggunakan sidik ragam dan uji kisaran berganda Duncan. Korelasi antara ketinggian tempat dan perubahan warna tubuh trips dianalisis dengan uji khi kuadrat. Hasil penelitian menunjukkan bahwa panjang tubuh, lebar toraks, dan panjang sayap trips yang berasal dari dataran tinggi lebih panjang daripada dataran sedang dan rendah. Ketiga karakter morfologi tersebut menunjukkan perbedaan yang nyata antara dataran sedang dan dataran rendah dengan dataran tinggi, kecuali karakter lebar kepala. Perubahan warna kepala, toraks, dan abdomen berkorelasi dengan ketinggian tempat.

Penelitian tentang keanekaragaman dan kelimpahan musuh alami Bemisia tabaci di pertanaman cabai merah telah dilakukan di Kecamatan Pakem, Kabupaten Sleman, DIY selama musim kemarau Mei-Oktober 2009. Penelitian bertujuan untuk mempelajari keanekaragaman dan kelimpahan spesies parasitoid dan predator dari B. tabaci.   Pengambilan sampel spesies parasitoid dan predator dilakukan dengan menggunakan nampan kuning, jaring serangga, pengamatan langsung pada tajuk tanaman, dan pengumpulan nimfa-nimfa B. tabaci. Keanekaragaman serangga dihitung menggunakan indeks keanekaragaman Shannon dan sebaran. Spesies predator yang ditemukan di pertanaman cabai merah adalah Harmonia octomaculata (Fabricius), Menochilus sexmaculata (Fabricius), Scymnus sp., Micraspis inops Mulsant, Coccinella sp., (Coleoptera: Coccinellidae), Paederus fuscipes Curtis (Coleoptera: Staphylinidae), Orius sp. (Hemiptera: Anthocoridae), Linyphiidae (Araneae), dan Syrphidae (Diptera). Parasitoid Eretmocerus sp. (Hy-menoptera: Aphelinidae) ditemukan memarasit nimfa-nimfa B. tabaci mempunyai potensi yang baik untuk mengendalikan nimfa B. tabaci di pertanaman cabai merah.

Modelling on Rice Blast Disease Severity in Subang DistrictBlast disease (Pyricularia oryzae) is a major diseases of rice in Indonesia. Research related to modelling of  blast disease severity is limited. Therefore, this study aimed to design a statistical model on rice blast disease infestation on the rice paddy and to asses a correlation between the disease severity and infected seed level. The models were constructed based on multiple linier regression analyses. The study was conducted by observing the disease severity, collecting information about cultivation technique and weather conditions. The result of regression analysis showed severity modeling on influencing factors is Y = -67.17 + 5.51X1 – 10.54X2 + 13.26X3 + 8.51X4 + 2.29X5 + 1.32X6 + 8.47X7 + 0.31X8 + 4.53X9 (p-value <0.0001, R2 = 0.85). Nitrogen application and plant ages had significant effect on disease severity. The addition of N fertilizer increased the severity of blast disease by 8.47%. Increasing the daily life of plants increases the disease severity by 0.31%. The correlation (r) of pathogen infection after harvesting was strongly influenced by infection before planting with correlation value of 0.78. This means that the severity of seed disease after harvesting is influenced by 78% infection of pathogenic seed before planting. The result of regression analysis showed Y = 5.98 + 2.41X (p-value = 0.0076, R2 = 0.61). An increase of 1% pathogens carried by seed before planting will be increasing disease severity by 2.41% after harvesting. The results of this study can be used as a reference in preparing preventive control measure and reduce the risk of pathogen carried by seeds that act as a source of initial inoculum.