Population Dynamics of Sugarcane Moth Borers in Indonesian Cane Fields

We conducted monthly monitoring of lepidopterous moth borers in four sugarcane fields in Java, Indonesia, from May 2009 to May 2011. Fields sampled belonged to Pesantren Baru, Jombang Baru, Gondang Baru and Subang sugar factories. Three main moth borer species were found to inflict damage to sugarcane plantations in all regions, and these are the stalk borers Chilo sacchariphagus (Bojer) and Chilo auricilius Dudgeon and the top borer Scirpophaga excerptalis (Walker). Tetramoera (Eucosma) schistaceana (Snellen) was also encountered but only caused minor damage. Borer populations increased with plant age and reached a peak around January – May in most cases, with the onset of rainfall triggering population rise. All borers coexisted in the same plant with no evidence of competition between the two stalk borers (C. sacchariphagus and C. auricilius) over their specific feeding location (internode) or between the two stalk borers and the top borer (S. excerptalis) over the same plant. This suggests that an infestation by one species does not make the plant less desirable to be colonised by another. Parasitism rates by natural enemies were very low which reflects the challenges facing biological control efforts in Java. Knowledge generated through this project will improve our understanding of borer dynamics in South East Asia and will enhance our preparedness for potential introduction by any of these pests into Australia

Yield and Quality of Ratoon Sugarcane Are Improved by Applying Potassium under Irrigation to Potassium Deficient Soils

The current study was carried out at the experimental farm of Rana Sugars Ltd., Buttar Seviyan, Amritsar, Punjab, India, to identify methods to improve the yield and quality of ratoon sugarcane in potassium-deficient soils. The treatments comprised two levels of irrigation, resulting in plants which either received sufficient water (I1) or were water-stressed (I2), and four rates of potassium (K) application: 0 (K1), 40 (K2), 80 (K3) and 120 (K4) kg K2O ha−1. The results showed that the irrigation levels did not influence crop parameters significantly, although all parameters presented higher values for I1-treated plots. Compared to the K1 (i.e., 0 kg ha−1 K fertiliser applied) treatment, the K2, K3 and K4 treatments yielded 11.16, 37.9 and 40.7%, respectively, higher millable canes and 1.25, 5.62 and 13.13% more nodes per plant, respectively. At 280 days after harvest of the first (plant) crop, the I1 treatment provided ratoons which were up to 15.58% higher than those obtained with the I2 treatment, with cane girths up to 7.69% wider and yields up to 7.29% higher than those observed with the I2 treatment. While the number of nodes per plant did not differ significantly between treatments, there were significant differences in other parameters. Quality parameters (with the exception of extraction percentage) were significantly enhanced by the K3 treatment. The benefit-to-cost ratio (B/C) was higher for the I1 treatment than for the I2, due to a reduced productivity associated with the I2 treatment. At both irrigation levels, the K3 treatment resulted in the highest quality parameters. K1-, K2- and K4-treated plots presented more instances of insect infestations than plots receiving the K3 treatment. Relative to the K3 plots, infestation by the early shoot borer (Chilo infuscatellus) was 18.2, 6.0 and 12.2% higher, respectively, in plots that underwent the K1, K2 and K4 treatments, while infestation by the top borer (Scirpophaga excerptalis) was 21.2, 9.21 and 14.0% higher, and that by the stalk borer (Chilo auricilius) was 10.7, 0 and 8.10% higher. Not all infestation differences between treatments were significant. Our research demonstrates that growing sugarcane in potassium-deficient soils with applications of 80 kg K2O ha−1 under irrigation should be recommended to increase yield and quality while minimising insect infestation and to implement sustainable ratoon sugarcane production.

Bio-intensive management of internode borer (Chilo sacchariphagus indicus Kapur) and stalk borer (Chilo auricilius Dudgeon)

parasitoid, Trichogramma chilonis, larval parasitiod, Cotesia flavipes and pupal parasitoid, Tetrastichus howardi against sugarcane internode and stalk borer in RBD with a plot size of 72sq.m. The incidence of internode borer ranged from 2.34 to 4.91% in treated plot as compared to control (7.87%) in August, however during October incidence ranged from 2.14 to 6.86%.At harvest, minimum incidence of internode borer (5.62%) was observed in T. chilonis followed by C. flavipes (7.52%) released plots. The released parasitoids are more active in the field for its parasitisation and multiplication which result a reduction in the incidence of INB in released plots where as beyond October the prevailing low temperature, appeared to be non-conductive for its mating and field parasitisation. The incidence of stalk borer during August and October was low (1.03- 5.54%). At harvest minimum incidence (5.55%) was observed in C. flavipes followed by T. howardi release plots (10.92%) as against 17.24% in control. Removal of dry leaves and late shoots was observed to reduce the damage by migratory borer larvae in August and October. The results indicates that parasitoids (egg, larva and pupal) play a significant role in the management of INB and SB to check the spread and lowering the incidence of this pests. It is suggested that a working of these parasitoids can be exploited in programmes for management of sugarcane stalk and internode borer.

Effect of different artificial diets on the adults biological attributes of sugarcane stalk borer, Chilo auricilius Dudgeon and evaluation of their costs

An experiment was conducted to evaluate the effect of different artificial diets on the adult’s biological attributes of sugarcane stalk borer (Chilo auricilius Dudgeon) and their costs. Considering the mean values of first and second generation the maximum adult emergence (80.66 and 79.25), longer adult longevity (4.29 and 4.28), highest fecundity (233.45 and 225.98) and viability of egg (216.25 and 208.74) was recorded on diets A and C. Also the sex-ratio on diets A (M:F::1:1.16) and C (M:F::1:1) favoured the emergence of more number of females thanmales during development. On the basis of the economics also the artificial diets D, C and A (Rs. 48.62, Rs. 48.32, Rs. 103.43, respectively) were found relatively cheaper than the natural food (Rs 166.67). Thus, the overall performance of C. auricilius on diets A and C was found comparatively better than the other diets examined. Therefore, it can be used as an alternate diet other than natural diet E (sugarcane) for the mass rearing of C. auricilius in the laboratory.

Uji Daya Parasitasi Trichogramma australicum Gir. (Hymenoptera : Trichogrammatidae) Terhadap Telur Corcyra cephalonica Staint (Lepidoptera : Pyralidae) Dan Telur Chilo aurilicius Dudg (Lepidoptera : Pyralidae) Di Laboratorium

Penelitian mengenai daya parasitasi Trichogramma australicum Gir. terhadap inang alami dan inang pengganti ini bertujuan untuk mengetahui apakah T. australicum setelah bertahun-tahun dipelihara dengan menggunakan inang pengganti masih mampu memarasiti inang alaminya secara efektif. Penelitian menggunakan Rancangan Acak Lengkap dengan lima kali ulangan. Perlakuan adalah pemarasitan telur penggerek batang tebu Chilo auricilius Dudg dan telur ngengat beras Corcyra cephalonica Staint. Perhitungan data dengan parameter jumlah pemarasitan, penetasan parasitoid, dan kemampuan pemarasitan per individu parasitoid betina. Pemeliharaan T. australicum dengan menggunakan inang pengganti tidak mempengaruhi kemampuan pemarasitan terhadap inang alaminya. Parasitoid T. australicum masih memiliki potensi besar untuk digunakan sebagai agen pengendali hayati penggerek batang tebu, khususnya penggerek batang tebu berkilat C. auricilius. Rata-rata pemarasitan T. australicum terhadap telur C. cephalonica dan telur C. auricilius masing-masing sebesar 96.14% dan 95.0%. Penetasan parasitoid dari telur C. cephalonica dan telur C. auricilius masing-masing sebesar 97.13% dan 96.21%. Daya parasitasi per individu parasitoid betina terhadap telur C. cephalonica dan telur C. auricilius masing-masing sebesar 4.80 dan 4.75. Hasil analisis statistik terhadap semua uji menunjukkan tidak ada beda nyata antara kedua perlakuan. Key word : daya parasitasi, Trichogramma australicum Gir. Chilo auricilius Dudg, Corcyra cephalonica Staint