Kairomonal effect of acetone extracts of groundnut on foraging activities of Trichogramma chilonis (Ishii) and Chrysoperla zastrowi sillemi (Esben-Peterson)

Abstract

The present study concentration (1% = 10000 ppm) of the acetone extracts of various plant parts of groundnut were prepared to determine the specific acetone extract of the groundnut plant part(s) to optimizing the foraging behavior of Trichogramma chilonis Ishii and Chrysoperla zastrowi sillemi (Esben-Peterson). Laboratory bioassay with acetone extracts of young leaves, old leaves, flowers and stems of groundnut plant with T. chilonis and C. zastrowi sillemi revealed their kairomonal activities under in vitro condition. Treating irradiated eggs of Corcyra cephalonica Stainton with acetone extract of flowers of groundnut recorded the parasitization of 16.97 per cent by T. chilonis on third day after inoculation which increased from 56.87 to 73.14 per cent on fifth and seventh day after inoculation and they were 6.33, 19.77 and 25.64 per cent when the eggs were treated with acetone alone on third, fifth and seventh days after inoculation, respectively. Maximum emergence (66.11%) was observed with acetone extract of flowers followed by acetone extract of young leaves (49.82%). The highest predation by C. zastrowi sillemi on acetone extract of flowers treated eggs of C. cephalonica was recorded (69.97%) whereas it was 26.94 per cent in acetone treated eggs. Key words: Chrysoperla zastrowi sillemi, Corcyra cephalonica, Groundnut, Kairomone, Trichogramma chilonis.In nature, tritrophic interactions of host plant, host insects and their natural enemies are mediated by a complex array of stimuli, of which the role of semiochemicals is commendable. Among the parasitoids used in augmentative releases, Trichogramma chilonis is widely used in the Indian subcontinent and is responsible for the large scale mortality of a variety of lepidopterans occurring in diversified ecosystems (Padmavathi and Paul, 1997).The generalist predator, Chrysoperla zastrowi sillemi is considered as an important predator in different crop eco-systems. Due to heavy dependency of natural enemies on info-chemicals for optimal performance as biological control agents in IPM strategies identification of the chemical nature of these cues is vital. Various studies have proved these cues are mainly hydrocarbons in nature (Mathur et al., 2012). These saturated long chain hydrocarbons that are present on the surface of host plants and host insects have been reported to elicit synomonal and kairomonal responses in Trichogramma spp. Grenier et al. (1993).Similarly, plant surfaces serve many purposes, like permitting controlled release of volatiles that may deter the pests or attract natural enemies and pollinators. Higher alkanes are known to be one of the main components of cuticular waxes of plant leaves and extracts. In order to evaluate the role of kairomones released by plant on foraging activities by T. chilonis and C. zastrowi sillemi, laboratory bioassay were conducted with the acetone extracts (1% or 10000 ppm) of various parts of groundnut plant to demonstrate the kairomonal interaction among the parasitoid, predator and the host.Laboratory s...

Kairomone and Synomone Mediating Cowpea Aphid, Aphis Craccivora Location by some Natural Enemies

“…In the present study, using gas chromatography/mass spectrometry, the major volatile components in the ethanol extract of A.craccivora were identified (GC/MS) belong to saturated hydrocarbon compounds (undecane, dodecane, tridecane, tetradecane, nonadecane, pentadecane, hexadecane, heneicosane, heptadecane, docosane and tricosane). It known that hydrocarbons are commonly involved in insect communication (Chapman, 1998).Also, in the present study results coupled with those by Padmavathi and Paul, (1997), Srivastava et al, (2008), Maruthadurai et al, (2011) and Parthiban et al, (2015a and2015b) that Several hydrocarbon components (heneicosane, tricosane, tridecane pentacosane, docosane; nonacosane, hexacosane, undecane, and hexadecenoic acids) of the whole-body extracts of some insect species significantly exerted higher level of kairomonal effect on some parasitoids and predators. Shonouda et al, (1998) indicate the presence of saturated hydrocarbons, ranging from docosane to octacosane based on gas chromatography-mass spectrometry analysis of Aphis fabae extracts.…”

Interaction between Certain Natural Enemies and some Stored-Grain Insect Pests

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Enhancing biocontrol potential of Trichogramma chilonis against borer pests of wheat and chickpea

“… 53 , 54 The efficacy of HIPVs in the attraction of herbivores’ natural enemies has been mostly studied under laboratory conditions. 24 , 25 , 26 , 27 , 28 , 29 Less numerous experiments were conducted under semi-field conditions with crude kairomone formulations; however, suitable formulations having the capacity for a slow steady release of kairomones to improve the attraction of herbivores’ natural enemies against potential pests of crops are lacking. 30 , 32 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 …”

“… 14 , 22 , 23 , 21 The influence of kairomones on parasitoids’ foraging activities was examined in laboratory conditions. 24 , 25 , 26 , 27 , 28 , 29 …”