Abstract

Trombidiidae species are reported as ecto-parasites in their larval stages for the variety of acrididae, which are pests of many economic crops in the world including Pakistan. The current parasitism ratio of red mite, Eutrombidium trigonum, was studied on three host species of Hieroglyphus, which are presently destroying valued crops. It was observed that proportional survival was found to be lower in mites-parasitized specimens. Females of these three species had reduced initial and total reproduction as compared to un-parasitic species. Egg production significantly reduced to 47.23±510.23, 98.67±11.43 and 51.56±12.40 with mite’s parasitism during its entire life in these three studied species. As far as the survival of individuals is concerned, it is also significantly affected by mites’ parasitism. At present, survival of Hieroglyphus species was reported at 20.32±3.43, 42.39±8.46 and 37.25±7.93 days for male and 16.30±2.61, 35.73±10.26 and 25.63±8.40 days for females of Hieroglyphus perpolita Hieroglyphus oryzivorous and Hieroglyphus nigrorepletus respectively. Infestation was reported at 18.25% on H. oryzivorus followed by 12.86 and 12.31% on H. nigrorepletus and H. perpolita respectively. Similarly, the infestation of adults was reported to be significantly high at 15.60% for H. oryzivorus, followed by 8.89% on H. perpolita while it was reported to be significantly low at 6.53% forH. nigrorepletus. Overall, parasitism percentage was reported at 43.42% for hopper stages and 31.02% for adult individual. This study suggests that these mites could be the major controlling factors in the dynamics of natural population of Hieroglyphus species.

Key words: Eutrombidium trigonum, ectoparsite, Hieroglyphus, pest, major controlling factors.