The life cycle energetics of Rhopaea verreauxi (Coleoptera: Scarabaeidae)

Summary

Life cycle energy budgets were constructed for the scarabaeid Rhopaea verreauxi. The acquisition and utilization of energy was most efficient in the early phases of the first larval instar; the cumulative conversion efficiencies (A _c /C _c , P _c /C _c andd P _c /A _c ) declining throughout the life cycle. The third larval instar dominated the energy budget. Production in this stage was mainly the accumulation of lipids. In terms of energetics, the reproductive effort of a female R. verreauxi was particularly high. The amount of production eliminated as exuviae was similar to that in other holometabolous insects and a negligible fraction of consumption and assimilation. The life cycle A _c /C _c of 31% for R. verreauxi was typical of nonspecialist herbivores and the life cycle P _c /A _c of 20% typical of relatively long-lived ectotherms.

It was noted that the production of methane could represent a possible loss of up to 6% of the gross energy intake. Despite this, despite the use of constant temperatures and despite the fact that R was not ‘corrected’, the cummulative energy budgets constructed were considered to be reasonably accurate representations of the dimensional changes that occur in the energy budget of an individual R. verreauxi.