Rice Chilo suppressalis

The pheromone of the rice stem borer, Chilo suppressalis, is a mixture of two aldehydes, (Z)-ll-hexadecenal and (Z)-13-octa-decenal. Field-cage trials carried out in the Philippines at the International Rice Research Institute showed that the fully stabilised microencapsulated formulations of these aldehydes persisted for over 30 days and virtually eliminated the laying of fertile eggs during this period (6). 

Rice plant allelochemics greatly influenced behavior and physiology of striped stemborer (SSB), Chilo suppressalis (Walker), brown planthopper (BPH),... 

FIG. 1. Orientational and ovipositional responses of striped stem borer, Chilo suppressalis, moths on paper strips treated with ether extract of steam distillates of resistant (TKM6) and susceptible (Rexoro) rice varieties. 

In that period after World War II, Japan citizens also suffered from shortages of food, especially rice. So as to increase the rice production, synthetic pesticides were used extensively in Japan. For example, parathion was used to control the Asiatic rice borer, Chilo suppressalis. Unfortunately, this phosphorus insecticide was highly toxic, and a number of farmers were killed by poisoning. Another notorious pesticide was phenylmercuric acetate, which was used against rice blast disease. Because it contained mercury, the public could not accept it. 

Striped Rice Stem Borer (Chilo suppressalis) (left) and Rice LeafroUer (Cnaphalocrocis medinalis) (right). 

Pheromone component of the rice stem borer Chilo suppressalis. Mp 14-15°. Bpo.oi 127-128°. 

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