INSECT PESTS AND THEIR PREDATORS ON RICE-FISH SYSTEM

By: Sudjarwo, Herminanto, A. Agnanto, and L. Ardiyanto
Faculty of Agriculture UNSOED

ABSTRACT
A study has been carried out to know pests, natural enemies, and their control on rice planted in rice-fish system at Beji, Purwokerto. Results showed that pests in the rice-fish system were stem borers, leaf folders, case worms, gall midges, brown planthoppers, black bugs, and rats. The leaf folder on generative phase of the plants performed the highest attack intensity up to 26.6%. Predators found were spiders, the lady beetle Verania spp., and Paederus fuscipes. Verania spp. dominated its existence on rice. Positive impact of the rice-fish culture is its reduction in using chemical pesticides when compared with the monoculture rice culture .
Key words: Plant pests, predators, rice-fish system, and insecticide utilization.

GROWTH OF THE FUNGUS Beauveria bassiana VUILL. ON CORN EXTRACT MEDIUM AND ITS EFFECTIVENESS TO BROWN PLANTHOPPER

By: Endah Irmayanti, Herminanto, and Eko Pramono
Agrotechnology Study Program Faculty of Agriculture UNSOED
Email: hermin06@gmail.com

ABSTRACT
A research has been conducted to know effects of corn extract medium on sporulation and viability of the fungus B. bassiana and its effectiveness for controlling the brown planthopper Nilaparvata lugens. The results performed that propagation of the fungus B. bassiana in the liquid medium of corn extract harvested in a week produced 2.33 x 10^13 conidia/ml, whereas in the solid medium harvested in a month produced 1.15 x 10^13 conidia/ml. The viability of the fungus living in such liquid medium was greater than in the solid medium. This fungus living in the liquid medium could kill the target pest up to 52.50% at the field condition. The last nymphal instar of the pest seemed to be the most vulnerable to the entomopathogenic fungus.
Key words: Beauveria bassiana, brown planthopper

USE OF SERAI STEM ASH FOR CONTROLLING THE RICE WEEVIL Sitophilus oryzae L.

By: Herminanto
Agro Technology Study Program Faculty of Agriculture UNSOED
Po Box 125 Purwokerto 53101; e-mail: Hermin06@gmail.com

ABSTRACT
A research has been conducted by aims to know emergence of new adults, size, and attack by the rice weevil Sitophilus oryzae on various rice varieties in storage; effects of serai stem ash on mortality emergence of new adults; effects of the serai stem ash on reduction in damage and weight of rice in storage. Results performed that the pest was mostly damaging and causing high weight reduction on the local red rice. It also caused the most numerous adults and shortest emergence on such rice. The serai stem ash in higher doses increased the mortality; the LD50 was 12.05 g/100 g of rice. The high dose of it decreased number of emerged adults, damage and weight reduction in rice, and caused slow development of the pest as well.
Key words: Sitophilus oryzae, serai stem ash.
(full text is available on request)

DEVELOPMENT AND PREDATION OF Ischiodon spp. AS NATURAL ENEMY OF COWPEA APHID Aphis craccivora KOCH.

By: Herminanto
Agrotechnology Study Program Faculty of Agriculture Jenderal Soedirman University
PO Box 125 Purwokerto 53101; Telp/fax: 0281 638791;
E-mail: Hermin06@gmail.com

ABSTRACT
A research has been conducted to study development and predation of a syrphid fly Ischiodon spp. on cowpea aphid Aphis craccivora Koch. It used a randomized complete .block design. Treatments contained six prey populations. i.e.: 20, 40, 60, 80, 100, and 120 aphids. Each was replicated four times. Results performed that various aphid population densities did not influence the predatory life span. However, the body sizes varied at different treatments. Greater number of aphids as the prey tended to increase amount of consumed preys by the predator, ranging from 15.5 – 67.75 aphids per predator. The highest predation reached 80% on 40 aphid population.
Key words:Ischiodon spp, Aphis craccivora, development, and predation.
(full text is available on request)