A. K. Singh ¹, R. K. S. Tomar ²

Affiliations
1 Indira Gandhi Agricultural University, All India Coordinated Project on Spices, Regional Agricultural Research Station, Raigarh 496001, Chhattisgarh, IN
2 Indira Gandhi Agricultural University, Regional Agricultural Research Station, Boirdadar, Raigarh 496001, Chhattisgarh, IN

Abstract

Use of neem cake at 1kg + 100 gm of Trichoderma harzianum in 3kg FYM mixed for 7 days applied to soil before planting and watering regularly gave maximum yield (13.45t ha^-1) and minimum disease incidence (5.5%), next best treatment was seed treatment with hot water 51°C + 100gm T. harzianum + 1Kg neem cake at sowing time gave disease incidence (6.75%) and yield (12.03t ha^-1) both of treatments are statistically at par as regards in disease incidence and yield. The results showed that these safer management tools against diseases in ginger crop gave better protection and pesticide residue free rhizome because of its use as direct consumption without any processing.

Keywords

Bio-Intensive, Pythium , Rhizome Rot, Trichoderma harzianum.

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Madhulika Srivastava ¹, A. K. Singh ²

Affiliations
1 Division of Entomology, Indian Agricultural Research Institute, New Delhi 110012, IN
2 Department of Zoology, Delhi University, New Delhi 110008, IN

Abstract

Chemical signals play an important role in communication between different organisms determining the ecological balance between host plants, insect pests and their natural enemies. Some organic acids present in host insects and plants influence host habitat location and host location by insect natural enemies. Kairomonal response of Trichogramma chilonis Ishii to seven organic acids, viz., triacontanoic, docosanoic, octocosanoic, tricosanoic, pentadecanoic, heptacosanoic and hexacosanoic acids, was studied by laboratory bioassay. Among the acids tested, triacontanoic acid elicited the highest response from T. chilonis, followed by docosanoic and octocosanoic acids. Triacantonic acid at 10 ppm concentration and docosanoic acid at 20 ppm concentration could be used successfully in IPM programmes for enhancing the activity of T. chilonis in different agroecosystems.

Keywords

Kairomone, Organic Acid, Trichogramma chilonis.

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Gautam Sudhida ¹, A. K. Singh ¹, R. D. Gautam ²

Affiliations
1 Insect Behaviour Laboratory, Department of Zoology, University of Delhi, New Delhi 110005, IN
2 Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110012, IN

Abstract

Life tables of two chrysopid predators, viz., Chrysoperla sp. (carnea-group) and Mallada desjardinsi (Navas) on the invasive mealybug, Phenacoccus solenopsis (also reported as P. solani), were prepared in the laboratory to determine the efficacy of the predators as biocontrol agents of the pest. The rate of mortality (qx) during 0-7 days age interval was higher in Chrysoperla sp. (carnea-group) (0.28) than in M. desjardinsi (0.22) while it was reverse during 70-77 days age interval when reared on P. solenopsis. In fact, qx was higher in M. desjardinsi (2.50) than in Chrysoperla sp. (carnea-group) (0.00). The rate of multiplication per day was 0.1159 and 0.1414 females/female for Chrysoperla sp. (carnea-group) and M. desjardinsi, respectively. The intrinsic rate of increase (rm) was found to be 0.11 for both the predators. Chrysoperla sp. (carnea-group) population multiplied 62.80 times in a generation time of 35.72 days on the mealybug, whereas M. desjardinsi multiplied 67.12 times in a time period of 29.75 days. Life table assays help in estimating the total number of the natural enemies to be released in biological control programmes. This study would be of paramount importance in estimating the total number of the natural enemies to be released in biological control programmes against the mealybug, which is exotic.

Keywords

Green Lacewing, Chrysoperla Sp. (Carnea-Group), Mallada desjardinsi, Phenacoccus solenopsis, Life Table, Fecundity Table, Intrinsic Growth Rate.

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Madhulika Srivastava ¹, A. K. Singh ²

Affiliations
1 Indian Agricultural Research Institute, New Delhi 110 012, IN
2 Central Agroforestry Research Institute, Jhansi (U.P), IN

Abstract

Adaptation to climatic conditions (more importantly the temperature) of an area play a decisive role in influencing the parasitoid efficiency in controlling pests. Besides, the optimal conditions for inundative release of parasitoid e.g. Trichogramma, may also depend on strain. A strain of Trichogramma chilonis tolerant to high temperature was developed in the Biological control laboratory of IARI (PUSA), New Delhi and effect of temperature was studied on parasitoid efficiency. The biological traits viz., fecundity, emergence, survivability (male&female) and female populations were studied at 25, 27, 29, and 31ºC. The fecundity and emergence were recorded highest at 27 ºC. An increase of 107.23% (fecundity), 184.50% (emergence) and 15.65% (female survival) was observed from base to 35th generation, while male survival and female population decreased by 8.2 and 1.2%, respectively. The survival of immature stages of tolerant strain of Trichogramma proved their ability to withstand the temperature.

Keywords

Emergence, Fecundity, Parasitoid, Longevity, Trichogramma, Sex Ratio.

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Madhulika Srivastava ¹, A. V. N. Paul ¹, Prem Dureja ², A. K. Singh ³

Affiliations
1 Division of Entomology, IARI, New Delhi, 110012, IN
2 Division of Agricultural Chemicals, IARI, New Delhi, 110012, IN
3 Department of Zoology, Delhi University, Delhi, 110007, IN

Abstract

Kairomones emanating from males and females of three different host insects, viz., Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae) and Chilo auricilius (Dudgeon) (Crambidae: Lepidoptera) that tend to influence the parasitic potential of Trichogramma chilonis Ishii was studied. Whole body extracts of male and female moths were analysed separately by gas liquid chromatography for determining their hydrocarbon profile, which showed the presence of straight chain saturated hydrocarbons ranging from C₉ to C₅₀, Different host insects showed variation in number and concentration of these chemicals, which were responsible for influencing parasitoid activity and parasitism. The concentration of these hydrocarbons ranged from 4 ppm to 1215280 ppm. The foraging activity of the parasitoid as indicated by parasitoid activity index (PAI) was highest (14.63) in S. exigua female body extract at highest concentration (60, 0000 ppm). Per cent mean parasitism rates recorded for S. litura male and S. exigua male and female body extract were significantly different from that for the body extract of C. auricilius. Both kairomonal interactions observed in the male body extract of S. litura could be due to the presence of appreciably very high amounts of favourable hydrocarbons docosane and heneicosane and comparatively high amount of octosane and pentaeosane as compared to its female body extract. Similarly, female body extract of S. exigua also showed comparatively higher amounts of favourable hydrocarbons tricosane, docosane, pentacosane, heneicosane and hexacosane as compared to its male body extract. Based on the hydrocarbon profile of body washings of males and females of the three host insects and quantity of favourable and unfavourable hydrocarbons present in individual extract body, it may be coneluded that heneicosane and hexacosane exerted significantly higher level of kairomonal effect on the parasitoid as compared to other hydrocarbons. The response elicited by the male extract body of S. litura was significantly higher, whereas the body extract of male C. auricilius elicited the least response from T. chilonis. These favourable hydrocarbons at the appropriate concentration of body extract of spent adults of S. litura males and S. exigua females could be used for enhancing parasitization by T. chilonis.

Keywords

Chilo auricilius, Host Body Extract, Kairomones, Spodoptera exigua, S. litura, Trichogramma chilonis.

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