Plant pests exert serious effects on food production due to which the global crop yields are reduced by ~20-40 percent per year, as estimated by the food and agricultural organization (fao). hence to meet the world’s food needs, loses of food due to crop pests must be reduced. herein the silicon dioxide based mems devices are covalently functionalized for robust and efficient reversible optical sensing of the female sex pheromones of the pests like helicoverpa armigera, scirpophaga incertulas for the first time in literature. the relative sensitivity of the functionalized mems devices is improved by the variation in functionalization protocols that increased the number of amine functionalities on each anchor site. the functionalized devices are also capable of selectively measuring the concentration of this pheromone at the femtogram level which is much below the concentration of pheromone found at the time of pest infestation in an agricultural field. experiments are also performed with the functionalized mems devices in a confined region in the presence of male and female pests and tomato plants (s. lycopersicum) which directly mimics the environmental conditions. again the reversible use of the functionalized devices in any season under ambient conditions, photochemical and thermal stability of the devices and absolutely trouble free transportation of these pheromone nanosensors heightens their potentials for commercial use. overall, a novel and unique approach is reported herein for the selective and reversible sensing of female sex pheromones of certain hazardous pests which may be efficiently and economically carried forward from the research laboratory to the agricultural field. (please refer to the chapter 7a, page no. xiii of the attached thesis synopsis of parikshit moitra and attached picture1) in a separate case, olive oil is getting more preference than other vegetable oils due to the growing health concern among people, globally. but olive fruit pests cause serious economic damage to olive oil orchards which needs careful monitoring and applying the remedies at proper time before pest infestation. herein the successful use of the first known covalently functionalized β-cyclodextrinylated mems devices is demonstrated for the selective detection of female sex pheromone of olive fruit pest, bactocera oleae. the selectivity of this pheromone nanosensor is determined, where the specificity towards the olive pheromone arises primarily due to the presence of β-cyclodextrin moieties over the surface of the mems devices. the relative sensitivity of the mems devices is further elevated towards the olive pheromone by increasing the number of available β-cyclodextrin moieties over the mems devices. the detection limit is found to be 0.297 femtogram of pheromone mass captured by the cantilevers which is much below than the concentration of olive pheromone found at the time of pest infestation in olive orchards. next the zinc oxide surfaces are functionalized and fabricated inter-digitated circuits on top of it for easier deployment of the devices in the agricultural field. here the sensing mechanism employs the increase in resistance with the increased mass of pheromone attachment and the observed reversible usability of these devices make them commercially potent. overall, it is the first report of selective nanosensor for female sex pheromone of the olive pest which can be directly transported from the laboratory to the agricultural field in near future to determine the presence of olive pest prior infestation and then necessary actions can be taken as and when necessary in a confined region of alerted pest attack. (please refer to the chapter 7b, page no. xiv of the attached thesis synopsis of parikshit moitra and attached picture2)