Penelitian untuk mengetahui periode penutupan tanah menggunakan mulsa plastik terhadap populasi uret dan produktivitas tebu dilaksanakan di areal endemik uret di Desa Banyuputih, Situbondo pada musim tanam 2014/2015. Perlakuan terdiri atas lima penutupan mulsa plastik (1) Sebelum turun hujan (SBH), (2) Satu hari setelah turun hujan dengan curah hujan 14 mm (1 HSH), (3) Tujuh hari setelah turun hujan (7 HSH), (4) 14 hari setelah turun hujan (14 HSH), (5) 21 hari setelah turun hujan (21 HSH) dan Kontrol (tidak ditutup mulsa plastik). Penelitian menggunakan Rancangan Acak Kelompok diulang lima kali. Parameter yang diamati meliputi populasi uret dan dewasa (kumbang), persentase kerusakan tanaman, produktivitas tebu dan hablur serta data curah hujan. Hasil penelitian menunjukkan bahwa semua perlakuan penutupan mulsa plastik secara nyata dapat menekan populasi uret dan kerusakan tanaman apabila dibandingkan dengan kontrol. Perlakuan penutupan mulsa plastik satu dan tujuh hari setelah turun hujan memberikan selisih produktivitas tebu masing-masing 83 ton/ha (hablur 7,6 ton/ha) dan 96 ton/ha (hablur 7,8 ton/ha) di atas kontrol dan kedua perlakuan tersebut dapat direkomendasikan. Penelitian ini perlu ditindaklanjuti terutama untuk mengetahui efisiensi penggunaan mulsa plastik dalam pengendalian uret pada tanaman tebu di daerah endemik uret. Kata kunci: periode penutupan, mulsa plastik, pengendalian uret, populasi, produktivitas tebu ABSTRACT The period of using plastic mulch on white grubs population and productivity of sugar cane at white grubs endemic area was conducted in Banyuputih Village, Situbondo on planting season of 2014/2015. Treatment consisted of 5 plastic mulch period (1) Before raining (SBH), (2) One day after rainfall, 14 mm (1 HSH), (3) Seven days after raining (7 HSH), (4) 14 days after raining (14 HSH), (5) 21 days after raining (21 HSH) and Control (without mulching plastic). Research using Randomized Block Design was repeated 5 times. Parameters observed in white grubs and adult (beetle), percentage of plant damage, productivity of sugar cane and sugar and rainfall data. The results showed that all plastic mulch period treatments significantly reduced white grubs population and crop damage compared with controls. Treatment of plastic mulch period of one and seven days after raining provides a difference in productivity of sugar cane of 83 tons/ha (7.7 tons/ha) and 96 tons/ha (sugar 7.8 tons/ha) above the control and both treatments can be recommended. This research needs to be continued especially to find out the efficiency of using plastic mulch in endemic white grubs area.

Natural Enemies Conservation: The Role of Neem-seed Extracts for Natural Enemies Conservation Used of Cotton Insect Pest Control. Insects associated with cotton plant are numerous, as the plant bears extrafloral nectar. More than 90 species of natural enemies are reported and identified. They could manage the cotton pest, keeping the pest population is under action threshold level when their presence is considered in scouting and action threshold concept. However, most of cotton farmers are insecticide-spray-minded people who think that insecticide sprays is a must in cotton cultivation. This behavior is unfavorable for the natural enemies in building their population so they can act as an effective mortality factor for the pest. Neem seed extract (NSE) is toxic to herbivores but relatively safe for natural enemies, so that it could be used as a substitute for synthetic chemical insecticides. Therefore, NSE is recommended to be used for conserving natural enemies in cotton agro ecosystem.

Sugarcane-borers complex in Indonesia consists of a shoot borer (Scirpophaga excerptalis) and four stem borers (Chilo sacchariphagus, C. auricilius, Sesamia inferens and Tetramoera schistaceana). Control of these borers is carried out biologically through the release of egg parasitoid Trichogramma spp. There are four species of mass-produced egg parasitoids and are used in the borer control program, namely Trichogramma japonicum, T. chilonis, T. nanum, and T. minutum. During this time, to measure the level of effectiveness of egg parasitoid releases was through the level of stalk damage. The effectiveness of the release of egg parasitoid should be measured through the mortality rate of borer eggs or parasitization level by the parasitoid. The observations in sugar cane plantations with release and without release of the Trichogramma spp. showed that releases of T. japonicum and T. chilonis were not effective in causing borer egg mortality. The level of parasitization of the borers’ eggs in both plantations was not significantly different, and the parasitization of sugarcane borer eggs was observed mostly due to natural egg parasitoid species, such as Tetrastichus sp., Telenomus sp., and T. chilonis. Biological control of the sugarcane borer complex by mass release of egg parasitoid needs to be reviewed.

<p>Program pengembangan tebu saat ini diarahkan ke lahan kering yang memiliki ketersediaan air dan kesuburan tanah terbatas.  Kondisi lahan kering dapa menjadi pembatas produktvitas tebu.  Penambahan biomassa ke lahan dapat meningkatkan kesuburan dan populasi arthropoda tanah/detrivora.  Penelitian penambahan biomassa <em>Crotalaria juncea </em> pada lahan kering  dilaksanakan di Kebun Percobaan Asembagus, Situbondo mulai bulan Januari–Juli 2015. Tujuan penelitian adalah untuk menganalisa pengaruh penambahan biomassa pada lahan kering terhadap diversitas arthropoda tanah dan pengaruhnya terhadap produksi tebu. Perlakuan terdiri atas lahan dengan penambahan biomassa (serasah tebu dan pupuk hijau <em>C</em><em>. juncea</em>) dan lahan yang tanpa penambahan biomassa.  Pengamatan kelimpahan arthropoda tanah dan tingkat diversitas dilakukan dengan pemasangan <em>pitfall trap</em>s dan <em>yellow</em><em> pan traps</em><em>.</em><em> </em>Hasil penelitian menunjukkan bahwa Collembola dan Hymenoptera merupakan arthropoda tanah yang dominan. Indeks diversitas arhropoda tanah pada lahan dengan penambahan biomassa lebih tinggi (0,82–0,84) dibandingkan pada lahan tanpa penambahan biomassa (0,75–0,79). Penambahan biomassa pada tahun pertama dapat meningkatkan kandungan C Organik tanah dari 0,76 menjadi 1,06, dan meningkatkan kandungan N dari 0,03 menjadi 0,11, serta meningkatkan produksi tebu dari 70,4 ton/ha menjadi 101,4 ton/ha. Untuk memperbaiki kondisi ekosistem lahan kering diperlukan penambahan biomassa secara terus menerus.</p><p><strong>Effect of Biomass Addition in Dry Land to Diversity of Soil Arthropods and Productivity of Sugarcane</strong></p><p>The current sugarcane development program is directed to dry lands that have limited water availability and soil fertility, thereby limiting the productivity of sugarcane.  In order to restore soil fertility and reduce the evaporation of groundwater, addition of biomass in the form of trash (dried leaves) of sugarcane as well as the addition of green manure (<em>Clotalaria juncea</em>) is needed.  Biomass addition to the land could increase soil fertility and the population of soil arthropods/detrivores.  The experiment was conducted on dry land at Asembagus Experimental Station, Situbondo from January 2015–July 2015.  The purpose of this research was to analyze the effect of biomass addition to the diversity of soil arthropods and sugarcane productivity.  Treatments consisted of land with the addition of biomass (sugarcane/sugarcane and green manure <em>C. juncea</em>) and control.  Observation of the abundance of soil arthropods and diversity level was done by setting pitfall traps and yellow pan traps, observation was done monthly.  The results showed that the order of Collembola and Hymenoptera were dominant arthropods. The diversity index of ground arhropods on the land with biomass increments was higher (0.82–0.84) than that in the land without biomass addition (0.75–0.79).  The addition of biomass in the first year succeeded in increasing the organic C content of soil from 0.62 to 1.06 and increasing the production of sugar cane from 70.4 tons/ha to 101.4 tons/ha.  In order to improve the ecosystems condition, it is required the addition of biomass continuously.</p>

ABSTRAKEvaluasi keberhasilan dan efektivitas pengendalian hayati menggunakan Trichogramma spp. untuk mengendalikan penggerek pucuk dan batang tebu belum pernah dilakukan secara intensif. Penelitian ini bertujuan untuk mengevaluasi teknik pengendalian kompleks penggerek tebu dengan pelepasan Trichogramma spp. Evaluasi dilakukan dengan pendekatan pengujian keragaan parasitoid telur melalui penghitungan laju reproduksi dan kemampuan parasitisasi parasitoid pada telur Corcyra cephalonica (Stainton), telur inang yang biasa digunakan dalam produksi massal Trichogramma spp. Observasi lapangan dilakukan untuk mengetahui tingkat parasitisasi telur penggerek pucuk dan batang tebu pada pertanaman tebu dengan dan tanpa pelepasan Trichogramma spp. Observasi ini dilakukan dengan mengumpulkan telur penggerek pucuk dan penggerek batang tebu dari kedua lahan tersebut dan diamati tingkat parasitisasinya. Hasil evaluasi menunjukkan bahwa pelepasan Trichogramma chilonis Ishii atau Trichogramma japonicum Ashmead tidak efektif memarasit telur S. excerptalis atau Chilo spp. Parasitisasi 100% telur S. excerptalis dan 77% telur Chilo spp. disebabkan oleh Telenomus sp. Keragaan T. japonicum yang dilepas menunjukkan kebugaran yang rendah. Oleh karena itu, pelepasan Trichogramma spp. untuk mengendalikan kompleks penggerek tebu di Indonesia perlu dipertimbangkan lagi dengan mempertimbangkan spesies parasitoid yang dilepas dan teknik pelepasannya untuk memperoleh pengendalian hayati yang sukses. Kata kunci: Chilo sp., Telenomus, Trichogramma, Scirpophaga excerptalis ABSTRACTThe success and effectiveness evaluation of Trichogramma releases for controlling sugarcane top borer (Scirpophaga excerptalis (Walker)) and stalk borers (Chilo spp.) have not been intensively evaluated. This research was aimed to evaluate the control technique of sugarcane borer complex by releasing Trichogramma spp. The evaluation approach was performance tests of the parasitoid fitness through determination of reproductive rate and parasitism capacity of the parasitoids. Field observations were also done to obtain the borers' egg parasitism level in Trichogramma released and unreleased sugarcane fields. The observation was done by collecting the borers' eggs in such fields and egg parasitism level was recorded. Results showed that releases of Trichogramma chilonis Ishii or Trichogramma japonicum Ashmead were not effectively caused egg parasitism on S. excerptalis or Chilo spp. A hundred % parasitism of S. excerptalis eggs and