Factors affecting the allocation of paternal care in waterbugs (Belostoma flumineum Say)

Summary Male giant waterbugs (Belostoma flumineum Say) brood eggs oviposited on their dorsa by conspecific females. Laboratory observations indicate that viable egg pads are occasionally discarded before hatching. Theory predicts that such behavior should occur only if the costs incurred by brooding exceed the benefits of hatching the egg pad. We studied the effects of egg pad size, time invested in brooding, and egg viability upon the continuation of paternal care in the giant waterbug. We found that smaller egg pads are less likely to hatch than larger ones, and males appear to be less likely to discard egg pads as temporal investment increases. However, the inviability of eggs did not appear to affect the probability of an egg pad being discarded. Males of this species appear to have evolved a decision-making process involving the continuation of paternal care. Offprint requests to: K.C. Kruse     

Stakeholder Analysis of a Collaborative Watershed Management Process: A Florida Case Study1

Borisova, Tatiana, Laila Racevskis, and Jennison Kipp, 2012. Stakeholder Analysis of a Collaborative Watershed Management Process: A Florida Case Study. Journal of the American Water Resources Association (JAWRA) 48(2): 277‐296. DOI: 10.1111/j.1752-1688.2011.00615.x Abstract: This study focuses on a Florida watershed where development of a total maximum daily load (TMDL) and its implementation plan resulted in conflicts among stakeholders. The overall goal is to build a better understanding of stakeholder perceptions of water quality problems, water policy processes and decisions, and water management plan development in a region where these issues have become contentious. Findings are based on a stakeholder analysis using qualitative data collected through focus groups with agricultural producers, local governments, and environmental groups, and supplemented with additional qualitative data on the watershed management process. Stakeholder conflicts in this case study are associated with perceived flaws in the structural and procedural characteristics of the stakeholder involvement process: (1) suboptimal watershed stakeholder representation on the TMDL executive committee, (2) an inappropriate voting procedure for making TMDL decisions, (3) limitations in information sharing between regulatory agencies and watershed stakeholders, and (4) stakeholders’ doubts about whether tradeoffs associated with achieving the water quality targets were assessed adequately throughout the TMDL planning and implementation process. This study contributes to the literature on collaborative watershed management by analyzing stakeholder involvement given Florida’s unique institutional settings, where implementation of TMDL pollution abatement is mandatory.     

Male backspace availability in the giant waterbug (Belostoma flumineum Say)

Summary Following bouts of courtship and copulation, female giant waterbugs (Belostoma flumineum Say) deposit eggs on the backs of their mates. Throughout a 6– to 12-day brooding period, males display several behaviors that are vital to egg-nymph survival. Consequently, females depend on male post-copulatory behaviors for successful reproduction and the possibility exists for male backspace availability to limit female reproduction in this species. I studied seasonal trends and factors that affect male backspace availability in populations of B. flumineum in east-central Illinois (USA). Early in the spring/summer, giant waterbug populations are relatively small and a large majority (188/205=91.7%) of the males are egg-laden; males experimentally added to the population during this period quickly became encumbered. In contrast, later in the summer after young-of-the-year emerge as adults, the waterbug population density increases dramatically and fewer (670/1274\2= 52.6%) of the males are encumbered (egg-laden). Of the males that are egg-laden both early and late in the season, significantly more are completely encumbered (i.e., 100% of the dorsum egg covered) early in the spring. The adult sex ratio is generally not biased and the number of eggs/pad that completely covers a male approximates a full ovarian complement. Therefore, these factors probably do not cause male backspace to become limited. The primary factor that appears to limit male backspace availability is the ability of females to synthesize a second partial clutch in a short time, often within 1 to 4 days. Females are capable of ovipositing partial clutches on 12 males within 30 days, whereas male brooding period is temperature dependent and ranges from 6 to 13 days. Newly emerged males are capable of breeding significantly sooner than can newly emerged females, thereby creating ample oviposition substrate for the females in the population after young-of-the-year adults appear. The evolution of sex-role reversal is not well understood; however it should not evolve in waterbugs unless male backspace limits female reproduction. Such a situation appears to exist in B. flumineum early in the season but not later in the summer.