P. N. Ganga Visalakshy, K. P. Jayanth, Sanjay Kumar Ghosh, MG Chaudhary,
Abstract Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), a biological control agent of Parthenium hysterophorus L. (Asteraceae), was feeding on leaves of Helianthus annuus in India, raising concerns of its host range. Based on the age grading technique, it was shown that the majority of Z. bicolorata on sunflower plants at any time were reproductively immature. This establishes that Z. bicolorata does not pose any risk to sunflower in India.
Tópico(s): Essential Oils and Antimicrobial Activity
2008 - Taylor & Francis | Biocontrol Science and Technology
K. P. Jayanth, P. N. Ganga Visalakshy,
ABSTRACT The introduced Mexican beetle, Zygogramma bicolorata Pallister (Chrysomelidae), has brought about large scale defoliation of the noxious weed Parthenium hysterophorus L. (Asteraceae) in Bangalore and surrounding areas. Studies carried out over a period of two years in two uncultivated parthenium infested horticultural fields showed that defoliation by the beetle can cause up to 99.5% decline in weed density, provided the soil is left undisturbed. Forty different species of plants, formerly ...
Tópico(s): Biological Control of Invasive Species
1996 - Taylor & Francis | Biological Agriculture & Horticulture
K. P. Jayanth, P. N. Ganga Visalakshy,
Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) of Mexican origin, released in Bangalore in 1984, was observed defoliating Parthenium hysterophorus L. (Asteraceae) in 1988, and had dispersed over 50 000 km2 by 1992. The insect appears to have potential in reducing weed density in those parts of India having moderate weather conditions.
Tópico(s): Chemical synthesis and alkaloids
1994 - Taylor & Francis | Biocontrol Science and Technology
P. N. Ganga Visalakshy, K. P. Jayanth,
Observations under field conditions in Bangalore showed that release of Neochetina eichhorniae and N. bruchi (Coleoptera: Curculionidae) brought about successful control of the water hyacinth in water bodies where the plants were free-floating. However, in situations where the plants were partly anchored, suppression of the weed was achieved only 8 years after insect release. Studies carried out under glasshouse conditions, in which plants with free-floating and silt-covered roots were exposed to ...
Tópico(s): Biological Control of Invasive Species
1996 - Taylor & Francis | Biocontrol Science and Technology
K. P. Jayanth, P. N. Ganga Visalakshy, Malvika Chaudhary, Sunil K. Ghosh,
Freshly emerged adults of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), introduced for biological control trials against the noxious weed Parthenium hysterophorus , were seen to feed and lay eggs on sunflower leaves under confined conditions in the laboratory. The time taken for initiation of feeding was found to be positively correlated with adult age, while survival after feeding on the crop was negatively correlated. However, adults that had fed on sunflower even for 1 day on P. hysterophorus ...
Tópico(s): Biological Control of Invasive Species
1998 - Taylor & Francis | Biocontrol Science and Technology
Gopalakrishna K. Pillai, P. N. Ganga Visalakshy, A. Krishnamoorthy, M. Mani,
The efficiency of the native parasitoid, Encarsia transvena Timberlake for the management of greenhouse whitefly, Bemisia tabaci (Gennadius) was studied in cages and a greenhouse in India. Parasitism by Enc. transvena of B. tabaci on Lycopersicon esculentum L. (tomato), Solanum melongena L. (eggplant) and Nicotiana tabacum L. (tobacco) was evaluated in cages to compare the utility of each species as potential banker plants. B. tabaci populations were consistently present on all three host plant species ...
Tópico(s): Plant and animal studies
2013 - Taylor & Francis | Biocontrol Science and Technology
M. Mani, P. N. Ganga Visalakshy, A. Krishnamoorthy, R. Venugopalan,
Abstract The soft green scale Coccus viridis (Green) (Homoptera: Coccidae) has become a major pest of sapota, Manilkara achras (Mill.) Forberg in India. A field study was conducted on the population dynamics of soft green scale Coccus viridis (Green) for 2 years (2004–2006) on sapota at the Indian Institute of Horticultural Research (IIHR) farm, Bangalore, India. The population of green scale declined from 30.72 per leaf in May 2004 to 1.62 per leaf in March 2006. Two coccinellid predators Chilocorus ...
Tópico(s): Silkworms and Sericulture Research
2008 - Taylor & Francis | Biocontrol Science and Technology
Soumya Kallekkattil, P. N. Ganga Visalakshy, A. Krishnamoorthy, S. J. Kavitha, K. Gopalakrishna Pillai,
The relative suitability of five instars of Diaphania indica (Saunders) (Lepidoptera: Pyralidae) as a substrate for the development of a larval parasitoid, Apanteles stantoni Ashmead (Hymenoptera: Braconidae), was investigated. Maximum parasitism (22.25 ± 1.21%) under laboratory conditions was observed in the early larval instars. The highest parasitoid emergence was recorded from the second (86.07 ± 0.70%) and third (98.93 ± 0.72%) instar larvae of D. indica, and that from the first larvae was 71.43 ± 1.18%. ...
Tópico(s): Insect Pest Control Strategies
2017 - Taylor & Francis | Biocontrol Science and Technology
The water hyacinth weevil, Neochetina eichhorniae, is an effective biological control agent of the aquatic weed Eichorniae crassipes. The adults under field conditions have degenerated indirect flight muscles that explains their inability to fly. A study on the factors initiating flight muscle development in adults was carried out. Among the various abiotic factors studied, density of weevils per plant and high temperature in presence of food initiated and accelerated flight muscle development. ...
Tópico(s): Biological Control of Invasive Species
2004 - Taylor & Francis | Biocontrol Science and Technology