Spatial Distribution of Jack Pine Cones and Those Attacked by Insects

The middle crown and south quadrant of 6-m-tall jack pines, Pinus banksiana Lamb., produced significantly more cones than the rest of the tree. The number of cones attacked by Eucosma monitorana Heinrich was also highest in the middle crown and south quadrant. Laspeyresia toreuta (Grote) attacked the most cones in the middle crown. A positive, linear correlation existed between the number of cones attacked by inseets and cone abundanee per tree, indicating a response of the insect population to inereased food supply

Fecundity, Longevity, and Host Finding of Three Parasitoid Species of Liriomyza sativae

Liriomyza sativae is a polyphagous agromyzid leafminer and it has invaded large part of world, i.e Hemiptarsenus varicornis, Gronotoma micromorpha, and Opius dissitus. This research were conducted to investigate progeny, immature development period, longevity of female parasitoids of L. sativae, and to study female parasitoid behaviour in host finding. Host finding behaviour was observed by examining their visit frequency to the leaves that mined by leafminer larvae and healthy leaves. Results showed that H. varicornis produced more progenies (10.70 + 2.58 progenies/female), but not significantly different (P < 0.05) from progenies produced by G. micromorpha (9.90 + 3.81 progenies/female) and O. dissitus (9.60 + 3.31 progenies/female). The immature development period of G. micromorpha (25.65 + 0.38 days) was found to be longer than H. varicornis (16.14 ± 1.20 days) and O. dissitus (14.03 + 0.22 days). Significant different (P = 0.1014) of adult longevity was not found among H. varicornis (9.22 + 2.48 days), G. micromorpha (7.25 + 1.34 days), and O. dissitus (8.74 + 2.18 days). Our analyses also indicated that G. micromorpha and O. dissitus found their hosts based on the larvae mining, however, H. varicornis performed it randomly. Based on the number of progeny and longevity of adult female, all parasitoids tested may have a potential as biological control agents of leafminer, L. sativae

Identifikasi Thrips Alliorum (Priesner), Thrips Hawaiiensis (Morgan), dan Thrips Parvispinus (Karny) Berdasarkan Variasi DNA COI Mitokondria

Genus Thrips adalah genus kedua terbesar Ordo Thysanoptera yang sebagian besar anggotanya bersifat polifag dan beberapa spesies merupakan hama serius pada tanaman sayuran. Kerusakan yang ditimbulkan oleh trips dapat menyebabkan kehilangan hasil 30–50%. Thrips alliorum (Priesner), T. hawaiiensis (Morgan), dan T. parvispinus (Karny) banyak dilaporkan menjadi hama pada pertanaman terutama pertanaman hortikultura. Penggunaan karakter molekuler, seperti runutan DNA fragmen gen Cytochrome Oxydase I mitokondria (mtCOI) dapat digunakan untuk identifikasi spesies atau konfirmasi hasil identifikasi dengan menggunakan karakter morfologi. Tujuan penelitian ini adalah mengidentifikasi T. alliorum, T. hawaiiensis, dan T. parvispinus berdasarkan runutan DNA fragmen gen mtCOI. Identifikasi molekular dilakukan melalui tiga tahap, yaitu koleksi sampel dan isolasi DNA, amplifikasi DNA menggunakan polimerase chain reaction (PCR), dan analisis hasil runutan DNA. Hasil penelitian ini menunjukkan bahwa runutan DNA fragmen mtCOI T. alliorum, T. hawaiiensis, dan T. parvispinus memiliki panjang basa 678, 690, dan 668 pb yang didominasi oleh basa A dan T dengan nilai variasi nukleotida sebesar 25,18%. Identifikasi tiga spesies trips T. alliorum, T. hawaiiensis, dan T. parvispinus berdasarkan runutan DNA fragmen mtCOI menunjukkan hasil yang sama dengan identifikasi berdasarkan karakter morfologi

Karakteristik Populasi dan Serangan Penggerek Jagung Asia, Ostrinia furnacalis (Lepidoptera: Pyralidae), dan Hubungannya dengan Kehilangan Hasil

The purposes of the study were to determine: 1) the distribution of egg groups, larvae, boring holes\ud of Asian corn borer, Ostrinia furnacalis (Lepidoptera: Pyralidae); and the relationship between plant damage\ud and yield loss. The study was conducted in Desa Cihideung Ilir, Kecamatan Ciampea, Kabupaten Bogor, the\ud Province of West Java. Corn seeds cv. Bisma were manually planted with a planting space of 40 x 70 cm. Egg\ud density was observed on 52, 58, and 75 days after planting. At harvest, stem samples were taken to determine the\ud number and position of boring holes and percentage of tunnel length to stem length. Our results showed that\ud 99.5% of the egg groups was found on the lower surface of the leaves and the rest was found on the upper surface\ud of the leaves. Approximately 54% of the egg groups found were located on 6th to 9th leaves. Similarly, the boring\ud tunnels were mostly present on the 6th to 10th leaves. The relationship between the number of boring holes and the\ud length of boring tunnels followed a sigmoidal curve model. The length of boring tunnels on the 6th to 10th stem\ud segments significantly affected the dry weight of grains. Percentage of boring tunnels up to 8%, >8 to 28%, >28\ud to 45%, and >45% expressed tolerance, linearity, disensity, and impunity phases, respectively

Kutu Putih Singkong, Phenacoccus Manihoti Matile-ferrero (Hemiptera: Pseudococcidae): Persebaran Geografi Di Pulau Jawa Dan Rintisan Pengendalian Hayati

Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae): Geographic distribution in Java and initiation of biological control. Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Psedococcidae), is a recently introduced pest in Indonesia. Parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was imported to control the pest. Studies were conducted to determine geographic distribution of P. manihoti throughout Java, and to evaluate the potential of the parasitoid as a biological control agent. Geographic distribution of the pest was determined through field survey, whereas evaluation of the parasitoid was studied through cage experiment and field release. Our survey revealed that the cassava mealybug has spread throughout Java. Heavy infestations caused shortened and distorted stems, complete defoliation, and stunted growth. In cages containing only mealybugs, all cassava plants (100%) died after two months. Whereas in cages containing both mealybugs and three pairs of parasitoid, rate of parasitization was 25% and plant mortality 20%. Parasitoids released in the field were able to survive, reproduce, and establish under Bogor climatic condition. These might indicate that parasitoid A. lopezi is a potential natural enemy to be used in biological control program of the cassava mealybug

Ritme Aktivitas Penerbangan Harian Tetragonula Laeviceps (Smith) (Hymenoptera: Apidae) di Bogor

Tetragonula laeviceps (Smith) adalah salah satu spesies lebah tak bersengat yang paling umum dijumpai di Indonesia. Namun demikian, tidak banyak publikasi tersedia tentang ritme aktivitas penerbangan T. laeviceps. Penelitian ini bertujuan mengkaji aktivitas penerbangan T. laeviceps dalam kaitannya dengan waktu harian dan berbagai unsur cuaca. Tiga koloni diamati setiap jam selama 5 menit dari pukul 06:00 hingga 18:00 WIB. Pengamatan meliputi banyaknya T. laeviceps yang keluar sarang, masuk sarang, membawa polen, membawa resin, dan membuang sampah. Hasil penelitian menunjukkan bahwa aktivitas penerbangan berbeda nyata (P &lt; 0,001) di antara jam-jam pengamatan. Secara umum, preferensi waktu (akrofase) aktivitas penerbangan terjadi pada pukul 11:00–12:00 WIB. Banyaknya T. laeviceps yang keluar dan masuk sarang berkorelasi positif (sedang) dengan suhu udara dan intensitas cahaya, tetapi berkorelasi negatif (sedang) dengan kelembapan relatif

Laju Enkapsulasi Parasitoid Anagyrus Lopezi (De Santis) (Hymenoptera: Encyrtidae) oleh Kutu Putih Singkong Phenacoccus Manihoti Matile-Ferrero (Hemiptera: Pseudococcidae)

Parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) didatangkan ke Indonesia pada awal tahun 2014 untuk mengendalikan kutu putih singkong, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). Penelitian bertujuan mempelajari laju enkapsulasi parasitoid A. lopezi oleh berbagai instar P. manihoti. Pengamatan laju enkapsulasi dilakukan dengan memaparkan seekor parasitoid betina yang telah kawin pada kutu putih nimfa-1, -2, -3, dan imago didalam tabung mika selama 24 jam. Kutu putih kemudian dibedah dan diamati banyaknya telur parasitoid yang diletakkan serta yang terenkapsulasi. Hasil penelitian menunjukkan laju enkapsulasi agregat paling tinggi dilakukan oleh imago, yaitu 8,4%, diikuti oleh nimfa-3 (5,8%), nimfa-2 (3,1%), dan nimfa-1 (1,1%). Laju enkapsulasi efektif oleh imago 2,0%, sedangkan oleh nimfa sekitar 1,0%. Laju enkapsulasi yang rendah ini diyakini tidak akan mengurangi keefektifan parasitoid A. lopezi dalam pengendalian hayati kutu putih singkong P. manihoti di Indonesia