Biogeography and Reinterpretation of the Evolution of Paternal Care Scenario in Belostomatidae (Insecta, Hemiptera)

Abstract

Aim

To estimate the origin and diversification times of the main lineages of Belostomatidae, with emphasis on the subfamilies Belostomatinae and Lethocerinae; to reconstruct the biogeographical history of the family's representatives, estimating which locations may have served as important sources of immigration and emigration events and testing whether different modes of parental care (egg-brooding vs. egg-attending) influenced dispersal rates; and to contextualise the evolution of Belostomatidae within the scenario of Cretaceous palaeoecological changes, describing the evolution of body size, egg morphology, and Belostomatidae behaviour in light of the phylogeny now dated based on total evidence.

Location

All zoogeographical regions.

Time Period

From the Jurassic to the present.

Major Taxa Studies

Family Belostomatidae (Insecta, Hemiptera, Heteroptera).

Methods

We used a total-evidence approach to estimate evolutionary divergence times and net diversification rates, and to reconstruct the biogeographical history of Belostomatidae, assessing how egg morphology and dispersal capacity co-evolved with paternal care strategies.

Results

Belostomatidae possibly emerged in the Lower Jurassic, with a significant drop in net diversification between the Palaeocene and Eocene (𝛾 = −0.23; p = 0.032), a period of declining global continental water levels. The diversification of Belostomatinae began much earlier than Lethocerinae. Biogeographical analysis indicates a South American origin, with the Eastern Palearctic as a source of emigration and the Oriental region as a sink. While speciation was mainly driven by vicariance, dispersal was strongly distance-dependent and significantly greater in Lethocerinae, influenced by their egg-attending strategy. We found no evolutionary trend toward increased body size in Lethocerinae, though their ancestors were likely large with small eggs.

Main Conclusions

We propose an initial ‘careless oviposition’ phase, followed by the independent origin of the two main paternal care strategies, with eggs showing ancestral plastron restricted to the apical chorion in Belostomatinae, expanded to cover a large part of the chorion in Lethocerinae.