Spatial and temporal dynamics of predation of robber flies (Insecta: Diptera: Asilidae) on insect fauna across the dry deciduous forest landscape

Abstract : 

The stability of the landscape depends on the prey predator’s relationship on that ecosystem. So, our present model of two most abundant asilid predator and their predation dynamics in response to varied diversity of different prey groups is the main aim of the present study. P. femoralis and M. aurata found to predate upon nine insect orders and Arenae (spiders). It revealed that slightly better prey capturing frequency of P. femoralis (0.68, p<0.05) in comparison to M. aurata (0.67, p<0.05). Sperman’s rank correlation study further confirmed maximum prey capturing efficacy of P. femoralis in comparison to M. aurata as evident from maximum positive values of correlation (41) and positive slopes (6) at p<0.05. Present study also established pre-monsoon as most preferred season to influence maximum predation dynamics of these asilid predators in comparison to other season as their feeding activities increased by 2.3-4 folds in case of P. femoralis and 1.5-1.9 folds in case of M. aurata respectively. It may also seem to be due to most of the insect orders (Diptera-21; Hymenoptera-11; Hemiptera- 10; Coleoptera-9) available in greater abundance during pre-monsoon, thus affecting predatory activities of asilid fauna ultimately. Different vegetation pattern in two different forest patch (dense vegetation patch with large forest undergrowth vs. thin vegetation without forest undergrowth) influenced predatory dynamics of two asilid species from 25 to 44 in case of P. femoralis and from 18 to 31 in case of M. aurata. Present study also indicated that differences in diet among the habitats can be attributed to differences in the abundance of the dipterans, and other abundant prey groups rather than to the co-existence of two distinct robber fly populations in prey preference. From the best of the knowledge, it will probably require long term and more detailed field studies under conditions of spatially and temporally variable prey community composition and relative abundance at much broader range to better understand trophic interactions and predatory dynamics of theses model asilid fauna at finer level

Keyword : 

Prey preference, predation, capture efficiency, robber flies, dry deciduous forest

Author(s) : , A. Naskar, A. Maity, S. Homechaudhuri, D. Banerjee
Downloads : 29

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