How Guilds Build Success; Aspects of Temporal Resource Partitioning in a Warm, Temperate Climate Assemblage of Dung Beetles (Coleoptera: Scarabaeidae).

Succession in local dung beetle assemblages influences their delivery of ecological functions in natural and modified environments globally. Short-term changes in dung beetle (Coleoptera: Scarabaeidae) species richness, abundance, and biomass were investigated in standardized dung pads in northern, coastal Turkey. For mean tunneling guild abundance, dung deposition time, dung exposure period, and their interaction were significant, and for mean dung dwelling guild abundance, dung exposure period was significant, as was the interaction with dung deposition time, which collectively evidenced temporal resource partitioning, based principally on differences in diel activity. Succession was highly compressed, with maximum abundance at 12 h and maximum species richness at 24 h. A large ball roller and small- to medium-sized tunnelers dominated different periods in the first 24 h but were superseded by dwellers. Regression analysis demonstrated a significant, positive relationship between species richness and the evenness of abundance for both dung deposition times. Correlation analysis generally showed strong, positive correlations between tunneling species, low correlations between tunneling and dwelling species, and low correlations between dwelling species. Niche partitioning based on size difference appears to have acted on the environmental filtering of tunneling species along the temporal gradient of declining moisture, thereby limiting the number of abundant, concurrent species. The aggregation of tunneling species provided opportunities for the less competitive dwelling species to occupy less densely populated zones termed probability refuges. The network of strong, positive habitat' correlations between tunneling species may indicate that their collective functionality is vulnerable to loss of efficiency if species are lost.

Temporal Resource Partitioning and Interspecific Correlations in a Warm, Temperate Climate Assemblage of Dung Beetles (Coleoptera: Scarabaeidae).

Guilds of dung dwelling and tunneling dung beetles coexist in local assemblages in warm temperate regions, despite the tendency of dwellers to be inferior competitors. A field experiment on the Black Sea coast of Turkey examined the role of temporal resource partitioning in their coexistence. Standardized dung pads deposited at 4 h intervals through a 24 h period in summer were collected 12, 24, or 48 h later. Adults from 10 tunneling and seven dung dwelling species were collected. The tunnelers contributed a high proportion of both total abundance and biomass. There was a significant effect of dung deposition time and exposure period on mean tunneler abundance. Mean tunneler abundance was nearly seven times higher in dung deposited at 06:00 than at 18:00. The dwellers reduced the potential for competitive interactions with tunnelers by relatively uniform dispersal across the six dung deposition times. The distinctly different dung use patterns by dwellers and tunnelers demonstrated temporal resource partitioning. Interspecific correlation coefficients were also determined because interspecific relationships are at the core of resource partitioning. Total tunneler and dweller abundances were not correlated. Overall, there were strong positive correlations between tunneling species and low correlations between tunneling and dwelling species, and between dwelling species. The five most abundant tunnelers, from two tribes and three genera, were strongly positively correlated. There were substantial size differences among the four most abundant tunnelers that probably facilitate their coexistence.

The effects of Pseudomonas putida biotype B on Tetranychus urticae (Acari: Tetranychidae).

This study investigated Pseudomonas putida biotype B as a potential biological control agent of Tetranychus urticae. The bacteria were isolated from greenhouse soil from Carsamba, Turkey. The experiment was carried out in a completely randomized plot design under laboratory conditions. For this purpose, spraying and dipping applications of a suspension of P. putida biotype B (10(8)-10(9) colony forming units/ml) were applied to newly emerged, copulated females. Dead mite and egg counts were started on the 3rd day after treatments, and observations were continued daily until all the mites had died and egg hatching had finished. Both types of bacterial application significantly reduced total egg numbers and egg hatching, compared to their respective controls. Bacterial spraying was significantly more effective than dipping-the spray application demonstrated 100% efficacy and resulted in the fewest viable eggs. The results of this study indicated that P. putida biotype B has a strong efficacy in causing mortality in T. urticae.