Informatics Publishing Limited

G. Karunakar ¹, S. Easwaramoorthy ², H. David ²

Affiliations
1 Maduranthakam Co-op, Sugar Mills Ltd., Padalam 603 308, Kancheepuram Dist., Tamil Nadu, IN
2 Section of Entomology, Sugarcane Breeding Institute, Coimbatore 641007, Tamil Nadu, IN

Abstract

Steinernema feltiae Filipjev, S. glaseri Steiner and Heterorhabitis indica (Poinar, Karunakar, David) developed and reproduced in sugarcane shoot borer, Chilo infuscatellus Snellen and Chilo sacchariphagus indicus (Kapur) larvae infected with granuloviruses (GV). The mean percent infectivity of the three nematode species showed no significant difference among the diseased and healthy larvae of both shoot and internode borers. The multiplication of dauer juveniles was significantly higher in healthy larvae of C. infuscatellus and C. sacchariphagus indicus compared to GV infected larvae.

Keywords

Granuloviruses, Heterorhabditis indica, Interactive Effects, Steinernema feltiae, S. glaseri.

Full Text

   

G. Karunakar ¹, S. Easwaramoorthy ¹, H. David ¹

Affiliations
1 Section of Entomology, Sugarcane Breeding Institute, Coimbatore 641007, Tamil Nadu, IN

Abstract

Among the five different temperatures tested for storage of infective juveniles (Ijs). survival of Steinernema feltiae Filipjev and S. glaseri Steiner was higher at 7.5°C, while the survival of Heterorhabditis indica (Poinar, Karunakar and David) was higher at 10°C. All the three species of nematodes showed higher percentage of survival when stored at 250 IJs per ml compared to 500 and 1000 Us per ml. A negative correlation was observed between duration of storage and per cent survival in S. feltiae (r = -0.9831**). S. glaseri (r = -0.9847**) and H. indica (r = -0.9437**). Based on the results of the study, the best combination of temperature, population density and duration of storage for the entomopathogenic nematodes was 7.5°C, 250 IJs perml and 120 days, respectively for S. feltiae, 7.5°C, 250 IJs per ml and 90 days for S. glaseri and 10°C, 250 IJs per ml and 90 days for H. indica.

Keywords

Heterorhabditis indica, Population Density, Steinernema feltiae, S. glaseri, Storage.

Full Text

   

P. Sivasankaran ¹, S. Easwaramoorthy ¹, H. David ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore 641 007, Tamil Nadu, IN

Abstract

Among the five different temperature conditions tested; radial growth, biomass production and sporulation were greater at 25°C foHowed by 30 and 20De. Similarly susceptibility of third instar shoot borer (Chilo infuscatellus Snellen) larvae to fungal infection was higher when the larvae were held at 25°C after treatment. Among the 5 relative humidity (RH) levels tested at 25°C, the radial growth of the fungus was maximum at 90 per cent RH, whereas biomass production and sporulation were greater at 100 per cent RH. Higher mortality of borer larvae occurred at 100 and 90 per cent RH levels and the susceptibility decreased as the RH increased.

Keywords

Beauveria nr. bassiana, Chilo infuscatellus, Relative Humidity, Temperature.

Full Text

   

S. Easwaramoorthy ¹, H. David ¹, N. K. Kurup ¹, G. Santhalakshmi ¹

Affiliations
1 Division of Crop Protection, Sugarcane Breeding Institute, Coimbatore - 641 007, IN

Abstract

Surveys conducted in three states of southern peninsular India revealed the occurrence of 57 species of spiders belonging to 13 families of Araneae in the sugarcane ecosystem. Of these, only two species viz., Hippasa greenalliae BlackwaH (Lycosidae) and Cyrtophora cicatrosa Stoliczka (Araneidae) were abundant, while six species were less abundant and 49 species were rare in occurrence. The spiders were found to colonize the sugarcane crop 40·45 days after planting. The population of the wolf spider H.greenalliae which comprised more than 70% of the total population increased with age of the crop upto 180 days. There was no significant variation in the population of H.greenalliae in sugarcane cropped field and adjacent fallow land. The orbweaver spider C.cicatrosa started colonizing the crop 100 days after planting of the crop and its population increased upto 240 days. Population of H.greenalliae and that of all the species had negative association with maximum temperature and rainfall and positive association with relative humidity. A reverse trend was noticed in C.cicatrosa. Soil and foliar application of insecticides recommended for the suppression of shoot borer, Chilo infuscatelius Snellen in the early stage of the crop growth did not exert any significant influence on the colonization of spiders. Among the five insecticides tested as foliar sprays at six month old crop, quinalphos, monocrotophos and endosulfan significantly reduced the spider population.

Keywords

Sugarcane Ecosystem, Spiders, Hippasa greenalliae, Cyrtophora cicatrosa.

Full Text

   

S. Easwaramoorthy ¹, H. David ¹, K. Subadra Bai ¹

Affiliations
1 Division of Crop Protection Sugarcane Breeding Institute, Coimbatore - 641 007, IN

Abstract

Toxicity of seven insecticides viz.,carbosulfan, dimethoate, malathion, monocrotophos, cypermethrin, decamethrin and fenvalerate each at three concentrations were tested for their relative toxicity to Adelencyrtus mayurai (Subba Rao), the principal parasitoid of sugarcane scale insect, Melanaspis glomerata (Green), by exposing the adults to the treated surface. At recommended concenrratfori, both fenvalerate (31.3% mortality) and deltamethrin (49.9%) proved to be less toxic to the adult parasitoids. Malathion caused 93.0 % mortality, while the other insecticides inflicted cent per cent mortality. The mortality increased with increase in the concentation of the insecticides and decreased with increase in time lag between treatment with insecticide and exposure of the parasitoid to the treated surface.

Keywords

Adelencyrtus mayurai, Parasitoid, Melanaspis glomerata, Insecticide Susceptibility.

Full Text

   

G. Karunakar ¹, H. David ², George O. Poinar ³

Affiliations
1 Kallakurichi Co-op. Sugar Mills Ltd, Vadamathur Village, Kanji, IN
2 Sugarcane Breeding Institute, Coimbatore, 641 007, IN
3 University of California, Berkeley, California - 94720, US

Abstract

The life cycle of Heterorhabditis indicus Poinar, Karunakar & David, 1992 closely resembles that of other heterorhabditids. It has two cycles - a hermaphroditic cycle, one with an oviparous generation with a complete set of four juvenile stages and another amphimictic generation with four juvenile stages. These hermaphroditic and oviparous generations are completed in 11-12 days in Galleria mellonella (L.) (Gallerriidae:Lepldoptera)at 24°C.

Keywords

Heterornabditis indicus, Biology, Galleria mellonella.

Full Text

   

G. Karunakar ¹, H. David ¹, S. Easwaramoorthy ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore - 641 007, IN

Abstract

Steinernema carpocapsae (Welser), S. glaseri (Steiner) and Heterorhabditis indicus (Polnar, Karunakar and David) at an Inoculum level of 40 infective juveniles (IJ) per Illrva caused 97.5 - 100 per cent mortality of Chilo Sacchariphagus indicus (Kapur) larvae and the morfality decreased with decrease in dosage levels. There was no significant difference in the mortality caused by the three species of nematodes. The multiplilcation of infective juveniles (IJ) per unit body weight of the host was higher in H. indicus than in S. capcapsae and S. glaseri. The dosage level of 20 IJ/larva yielded significantly high nematode multiplication in S. glaseri (37,335.8 IJ/larva) and H. indicus (2,10,283.3 IJ/larva) while S. carpocapsae multiplied to the maximum at a dosage of 10 IJ/larva (1,35,894.3 IJ).

Keywords

Dosage-Mortality, Multiplication, Steinernema glaseri, S. carpocapsae, Heterorhabditis indicus, Chilo sacchariphagus indicus.

Full Text

   

H. David ¹, S. Easwaramoorthy ¹, N. K. Kurup ¹, M. Shanmugasundaram ¹, G. Santhalakshmi ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore 641 007, IN

Abstract

Attempts were made to simplify the culturing technique of the Tachinid parasitold, Sturmiopsis inferens Tns. The results showed that removal of chorion ensheathing the parasltold maggots before inoculation on host larva did not increase the per cent parasitisation significantly and this time consuming step in the breeding technique may be dropped. Modified King's technique in which maggots are suspended in 0.15% agar agar and allowed to find the host larva on their own was as effective as that of hand inoculation of individual host larva with parasitic maggots (Scaramuzza's technique). Both these modifications in the breeding technique enabled mass production of the parasite at reasonabte cost.

Keywords

Sturmiopsis inferens, Mass Culturing.

Full Text

   

P. Sivasankaran ¹, S. Easwaramoorthy ¹, H. David ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore - 641 007, IN

Abstract

Second and third Instar larvae of the shoot borer Chilo infuscatellus Snell., were more susceptible (51.47 to 65.2 %) to the fungus, Beauveria nr. bassiana even at a low dosage (10⁵ or 10⁶ spores/ml), At 10⁷ spores/ml, the mortality observed was 68.53-75.93 %. Mortality of the larvae decreased with increase in larval age or decrease in the concentration of the fungus. The fungus took less time to cause mortality in second instar larvae and the incubation period Increased with Increase in the age of the larvae or decrease in the dosage. All the six species of phytophagous insects tested Viz., Chilo sacchariphagus indicus (Kapur), C. partellus Swinhoe, Scirpophaga excerptalis Walker, Sesamia inferens Walker, Heliothis arniigera Hubner and Spodoptera litura Fabricius were susceptible to the fungal Infection. The mean mortailty of third Instar larvae varied from 50.0 to 65.0 per cent in the different species. The fungus was not infective to Sturmiopsis inferens Tns. the principal larval parasite of the shoot borer.

Keywords

Beauveria nr. bassiana, Chilo infuscatellus, Pathogenicity, Host Range.

Full Text