BIODIVERSITY OF STAPHYLINIDS OF PUNJAB, PAKISTAN

Abstract

Rove beetles belong to the largest family (Staphylinidae) of beetles in the order Coleoptera of the Class Insecta. Because of their cosmopolitan distribution with broad latitudinal ranges, they are known to play important role as pollinators, decomposers and scavengers. The studies on their biodiversity including the species richness, distribution pattern and seasonal abundance were unknown with respect to their role in ecological system in Punjab, Pakistan. The present study is therefore, being carried out to study the biodiversity of Staphylinidae in different ecological regions of Punjab. For this purpose, collection was made from cropped area (8 localities) and forest area (3 localities) of the Punjab, Pakistan with 5 different collecting methods; pitfall trapping, flight intercept trapping, light trapping, Berlese funnel trapping and sweep netting during 2008 and 2009. Population was collected for four days after every two months from each locality during the entire collection period. Relative humidity (%), temperature (C O ) and soil moisture contents (%) were also recorded for all the localities. In the cropped areas, 1083 specimens belonging to 5 subfamilies, 15 genera and 26 species were collected and identified. Paederus fuscipes Curt. was the species with the highest population (32%) overall while Tachyporus himalyicus Bernh. was with lowest population (0.4%). It was found that some species preferred some crops, e.g., Paederus fuscipes was found only in cropped areas preferably in maize and berseem crops and Oxytellus Gr. genus was found mostly in plant and leaf debris. Astilbus mixtus Cam. was found associated with termites in the sandy areas only. High Shannon weaver index value (2.572) was found from Rahim Yar Khan and lowest value (1.82) was found from Rawalpindi during 2008. In the forest areas, mostly species were collected from Changa Manga (46.67%) during 2008 and from Muridwala (38.33%) during 2009. Some species were found missing in the forest areas like Paederus fuscipes, Astilbus mixtus etc. Association between collecting methods and localities was also determined. This association was found positive only for locality 1 (Lahore). No association was found between years and localities. Most Staphylinidae were collected through pit fall traps and least was found with FIT’S. Most Staphylinidae were collected during July-August. There was also a positive correlation between relative humidity, soil moisture contents and rove beetles. Dry soils had less rove beetles as compared to the moist soils. If the soil moisture contents will be more, there will be no space for air between the soil particles then the rove beetles will be less because of mortality due to suffocation. On the basis of coefficients of association calculated from different biotic (crops and other insects) and abiotic factors (temperature, relative humidity, soil moisture contents) that were faced by the collected species, the specimens belonging to different Staphylinidae species have been arranged into five groups with five species treated as separate on the basis of their habitat, locality, abundance and their status.