Is parental care behavior in Belostoma species an evolutionary cause for their common sexual size dimorphism pattern?

Abstract

Current evidence suggests that sexual size dimorphism (SSD) reflects the male and female adaptation to their different reproductive roles. Belostoma and Lethocerus species, included in Belostomatidae, present different kinds of paternal care. Females of Belostoma Latreille species lay their eggs on the back of males. Males carry, aerate and protect the clutch until hatching, which is critical for offspring survival. Males of Lethocerus Mayr species exhibit some parental care behavior but do not carry the eggs. The genera are nearly related. We studied and compared the SSD patterns of B. oxyurum (Dufour), B. micantulum (Stål), B. elegans (Mayr), B. bifoveolatum Spinola, B. gestroi Montandon and Lethocerus annulipes (Herrich‐Schäffer) by means of a multivariate approach to distinguish selection targets in different components of size. Morphometric analysis revealed that SSD patterns vary among traits and that the arrangements are similar in Belostoma species, showing a common trend under resembling selective mechanisms. The widespread SSD trend in insects is that all components of body size are biased towards females, generally related to a fecundity advantage, a pattern now also detected in L. annulipes. We found in Belostoma species that the male has relatively longer middle and hind legs. We propose that SSD in hind legs biased towards males is a selective response for paternal care; they denote a brood‐adapted morphology. The middle leg enlargement may be an associated response to maintain effective locomotion.

Sexual dimorphism and intraspecific variation in wing size and shape of Tongeia fischeri (Lepidoptera: Lycaenidae)

“…in Sullivan & Miller 2007), larger wing size may indicate larger body size. fecundity (Reeve & Fairbairn 1999;Fischer & Fiedler 2000;Iglesias et al 2012). Sexual dimorphism in wing morphology of butterflies and moths appears to be driven largely by natural and sexual selection that affects males and females differently (Allen et al 2011).…”

The life cycle of the giant water bug of northwestern Patagonian wetlands: the effect of hydroperiod and temperature regime

“…Iglesias et al (2012) found that in B. bifoveolatum, and in other belostomatid species, the males have relatively longer middle and hind legs than females and provide parental care. The morphology of males allows them to maintain effective locomotion even when carrying the egg pads (Iglesias et al 2012). We observed that egg pad size varied among years at Llao Llao, but this result was not associated with variation in male morphology in either wetland.…”

“…Iglesias et al. () found that in B. bifoveolatum, and in other belostomatid species, the males have relatively longer middle and hind legs than females and provide parental care. The morphology of males allows them to maintain effective locomotion even when carrying the egg pads (Iglesias et al.…”

“…The morphology of males allows them to maintain effective locomotion even when carrying the egg pads (Iglesias et al. ). We observed that egg pad size varied among years at Llao Llao, but this result was not associated with variation in male morphology in either wetland.…”

Ecology of giant water bugs (Hemiptera: Heteroptera: Belostomatidae)

“…Other studies show that the trends of SSD depend on individual species (Iglesias et al . ; Thrasher et al . ).…”