Artificial infestation method for causing dead hearts in rice plant for screening purpose against Yellow rice stem borer Scirpophaga incertulas | Pheromone Resources

Artificial infestation method for causing dead hearts in rice plant for screening purpose against Yellow rice stem  borer  Scirpophaga incertulas 

The neonate larvae were inoculated on the outer most leaf sheath ( which should be yellowing due to senescence and not dried) after its slight loosening (Plate 1). After inoculation of the required number of  neonate larvae (Plate 2) the leaf sheath was folded at the dewlap position to avoid escape of the inoculated larvae. 

An efficient technique for screening rice germplasms against yellow stem borer, Scirpophaga incertulas Walker (Lepidoptera: Pyralidae)  has been developed. Three methods viz., inoculation of the target insect, with egg mass in closed conditions –with wind breaks or egg mass with out wind breaks or by direct inoculation of neonate larvae, were compared  and the resulted in a wide variations in creation of white ear heads.  There was only  34.8%  creation of WEH due to egg mass inoculation (based on the number of eggs inoculated), with out wind breaks followed by 32.7% WEH due to inoculation of neonate larvae at the centre of the plot under field conditions. The incidence, based on hills/unit area, it was  2.89% creation of WEH in both egg mass inoculation with wind breaks and inoculation with neonate larvae with out wind breaks. The  intensity, when it was calculated based on the total number of tillers/unit area, a maximum of 0.58% of WEH was created   at  both egg mass inoculation with wind breaks and inoculation of neonate larvae with out wind breaks. In the net house experiments, when 4, 2 and 1 larvae per tiller was inoculated recorded to be  96% DH created at both 2 and 4 larvae/tiller.  At 1 larva per tiller it was only 40% DH in the cv. Ramaboita. While, it was  maximum of 96% DH at 4 larvae/ tiller and 80% at 2 larvae/tiller in the cv.TN1. The  survival of larval when 1,2,3 and 4 larvae/tiller was inoculated, it was 92% survival at 3 and 4 larvae/tiller was 84% survival at 2 larvae per tiller. The method of inoculating 2 neonate larvae found  to be efficient as compared to the other methods.

Ref: Nandagopal V., Prakash, A., Rao, J. and Singh, N.K.2010. Efficient technique for artificial infestation of rice yellow stem borer, Scirpophaga incertulas for screening of rice germplasms. Journal of Applied Zoologist Researches 21(2): 91-96.

This method was successfully employed in screening against the sugarcane internode borer Chilo  sacchariphagus   indicus

Pl.contact :veeraswaminandagopal76@gmail.com

Ref: V.Nandagopal,  T. Kumarasami and M.Balasubaramanian.1984. A  technique for  artificial   infestation  of sugarcane   internode  borer   Chilo  sacchariphagus   indicus  (K).  Sugarcane   Tecnologist    Association India.48:179-181.

This method should work for  artificial infestation for screening in  Sorhgum,bajra etc.