Herbivore-Induced Rice Volatiles Attract and Affect the Predation Ability of the Wolf Spiders, Pirata subpiraticus and Pardosa pseudoannulata

Spiders are important natural enemies of rice pests. Studying the effects of herbivore-induced rice volatiles on spider attraction and predation ability may lead to safer methods for pest prevention and control. In this study, four-arm olfactometer, predation ability experiment, and field trapping experiment were used to evaluate the effects of herbivore-induced rice volatiles on Pirata subpiraticus Bösenberg et Strand (Araneae: Lycosidae) and Pardosa pseudoannulata Bösenberg et Strand (Araneae: Lycosidae). The 0.5 μg/μL linalool concentration was attractive, and also shortened the predation latency in male P. subpiraticus and female P. pseudoannulata. The 0.5 μg/μL linalool concentration increased the daily predation capacity of female P. pseudoannulata. Male P. pseudoannulata were attracted to 1.0 g/L methyl salicylate, which also shortened their predation latency. In field experiments, methyl salicylate and linalool were effective for trapping spiders. Herbivore-induced rice volatiles attract rice field spiders and affect their predatory ability. These results suggest that herbivore-induced rice volatiles can be used to attract spiders and provide improved control of rice pests.

Efektivitas Cyhalofop-butyl Mengendalikan Gulma pada Budidaya Padi Sawah Tabela

High competition in the early growth phase will suppress growth and reduce rice yields. Presence of weeds in the rice field ecosystem needs to be controlled. Weed control with herbicides is more effective than other controls. This study aims to determine the effectiveness of the herbicide Cyhalofop-butyl in controlling weeds in the cultivation of direct seeds rice cultivation. The research was conducted in Sekaran village, Wonosari sub-district, Klaten district, Central Java. The method used was randomized block with seven treatments and four replications. The treatment consisted of a dose of the herbicide Cyhalofop-butyl 100 g.L^-1with levels: (50, 75, 100, 125, 150, and 175 L.ha^-1), mechanical weeding and control (no weeding). The results showed that Cyhalofop-butyl at a dose of 50–175 L.ha^-1 was effective in controlling the weeds of <em>Echinochloa crus-galli, Leptochloa chinensis</em> and other weeds at 3 weeks after application up to 6 weeks after application, without causing phytotoxicity effect on rice plants, herbicide Cyhalofop-butyl does not affect the growth and production of rice but reduces competition between weeds and rice plans. Herbicide Cyhalofop-butyl applied at a dose of 50 - 175 L.ha^-1provide rice grain yield of 10,25 - 11,50 kg per plot.

Host Diversity of Beauveria bassiana (Balsamo) Vuillemin in Rice Field in Bolaang Mongondow Regency

Beauveria bassiana can attack a variety of hosts and their virulence can vary at each host and location. Exploration of the diversity of hosts B. bassiana from local isolates needs to be done as initial information that can explain the ability of B. bassiana in infecting insects. Sampling locations were selected in three district, each district selected three stations and each station consisted of 10 plots. The location of sampling is determined by the purposive random sampling method. Each station was made a plot measuring 1m x 1m and distributed randomly. Every insect infected with B. bassiana was taken and taken to a laboratory for identification. The results showed that there were five insects that hosted B. bassiana, namely Nilaparvata lugens, Scotinophara coarctata, Leptocorisa oratorius, Nezara viridula and Paraeucosmetus pallicornis. The highest host diversity index was found in North Dumoga with a value of 1.47. The highest abundance index was found in N. lugens host in East Dumoga with a value of 43%. The highest density was found in the host N. lugens in Central Dumoga with a value of 1.93 ind / m2. There were indications of differences in virulence of the B. bassiana local isolates that were influenced by the spesies of host and location Keywords: Beauveria bassiana, diversity, Bolaang Mogondow Regency, diversity and abundance indices

FIRST REPORT ON THE FEEDING BEHAVIOR OF EARLESS MONITOR, LANTHANOTUS BORNEENSIS AND ITS PREDATION ON RICE FIELD FROG, FEJERVARYA LIMNOCHARIS IN A CAPTIVE ENVIRONMENT

Being endemic to Borneo, the Earless monitor, Lanthanotus borneensis (Steindachner, 1878) is rarely found in its habitats due to its cryptic behavior. We provide care for confiscated animals in the Reptile House of Museum Zoologicum Bogoriense (MZB) in Cibinong, West Java, Indonesia since 2014. Little is known on its natural prey but from scattered descriptive reports. This study is aimed at documenting the feeding behavior of ten captive Earless monitors and events of predation on frogs. We set up two experiments, one with meat of Rice Field Frog, Fejervarya limnocharis, and the other with live frog of the same species. Our recorded observations ran for four weeks for the frog meat feeding experiment and followed by the frog predation experiment. Our results showed that lizards constantly accepted frog meat. Lizards tended to feed before sunset for a short period of time on the muddy soil surface, although a few individuals inconsistently fed under water. The average body mass for these lizards increased by 4.29 g and average SVL by 0.45 cm. We recorded predation on frogs in three out of ten individuals observed during this study. If F. limnocharis is confirmed to occur in the natural habitats of L. borneensis, it is possible that this frog species is among the natural prey for Earless monitors. Further studies on its natural diets should be conducted to gain in-depth knowledge essential for generating effective captive husbandry for this nationally protected species in Indonesia.

Impacts of Rice Field Winter Planting on Soil Organic Carbon and Carbon Management Index

To tackle with the problem of prevailing farmland abandonment in winter, 5 treatments includes Chinese milk vetch-double cropping rice (CRR), rape-double cropping rice (RRR), garlic-double cropping rice (GRR), winter crop multiple cropping rotation (ROT), winter fallow control (WRR) were set up. By measuring soil total organic carbon, active organic carbon and its components and calculating the soil carbon pool management index in 0~15 cm and 15~30 cm soil layers in the early and late rice ripening stage. The effects of different winter planting patterns on the changes of soil organic carbon and carbon pool management index were discussed. In order to provide theoretical basis for the optimization and adjustment of winter planting pattern of double cropping rice field in the middle reaches of Yangtze River. The results showed that soil total organic carbon, active organic carbon and its components in different winter cropping patterns were increased, and ROT and CRR treatments were more beneficial to the accumulation of soil total organic carbon, active organic carbon and its components as well as the improvement of soil carbon pool management index, which should be preferred in the adjustment of cropping patterns.