Spermatophore feeding and mating behaviour in praying mantids (Mantodea: Liturgusidae)

Functional morphology of the praying mantis male genitalia (Insecta: Mantodea)

Male genitalia in praying mantids are highly complex, but we know little of how they function. I combined the micro-computed tomography of a copulating pair of the European mantis (Mantis religiosa) with public videos of copulation in various species of Mantodea and an analysis of literature. The function of each major element is reviewed. Copulation is divided into three phases: opening, anchoring and deposition. The opening is achieved by pulling the female subgenital plate with the male apical process. Multiple cases of female cooperation or resistance were observed and one case of coercion by the male. In species with the reduced apical process, female cooperation is mandatory. The male subgenital plate may participate in the opening as an integral part of the genitalia. After the opening, the conformation of the genitalia drastically changes, revealing activity of the genital papilla. Tight grasp on female genitalia is maintained solely by the clamp on the right phallomere, despite the overall complexity and predictions of sexual conflict theory. Other prominent elements show rhythmic motions, but their functions are not entirely clear and evidently involve spermatophore deposition, female stimulation or rival sperm removal. The opening and anchoring are similar in Mantodea and Blattodea, but achieved with non-homologous elements.

Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis

Models of the evolution of sexual cannibalism argue that males may offset the cost of cannibalism if components of the male body are directly allocated to the eggs that they fertilize. We tested this idea in the praying mantid Tenodera sinensis Males and females were fed differently radiolabelled crickets and allowed to mate. Half of the pairs progressed to sexual cannibalism and we prevented cannibalism in the other half. We assess the relative allocation of both male-derived somatic materials and ejaculate materials into the eggs and soma of the female. Our results show that male somatic investment contributes to production of offspring. The eggs and reproductive tissues of cannibalistic females contained significantly more male-derived amino acids than those of non-cannibalistic females, and there was an increase in the number of eggs produced subsequent to sexual cannibalism. Sexual cannibalism thus increases male material investment in offspring. We also show that males provide substantial investment via the ejaculate, with males passing about 25% of their radiolabelled amino acids to females via the ejaculate even in the absence of cannibalism.

The Functional Significance of Chiral Genitalia: Patterns of Asymmetry, Functional Morphology and Mating Success in the Praying Mantis Ciulfina baldersoni

Genital asymmetry is relatively common and widespread throughout the animal kingdom. The functional significance of genital asymmetry is however, poorly understood for most species. Male praying mantids of the genus Ciulfina are remarkable in possessing complex and directionally asymmetric genital phallomeres in some species, and chirally dimorphic/antisymmetric genitalia in others. Here we explore the chiral dimorphism in male genitalia of Ciulfina baldersoni which appear to exhibit genital antisymmetry. We test whether genital orientation influences mating success, copulation duration and the attachment duration of spermatophores. Additionally we investigate genital interactions between male and females using x-ray micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Lastly we assess whether genital asymmetry is associated with non-genital morphological asymmetry of a range of traits. Our results highlight the complex functional morphology of genitalia in this praying mantis species and yet demonstrate no functional difference between dextral and sinistral morphs other than the direction of attachment with both morphs enjoying equal levels of mating success. Chiral morphs also did not strongly associate with any other forms of asymmetry. We therefore conclude that genital chirality in Ciulfina baldersoni is a likely case of antisymmetry with no functional significance to genital orientation, and is likely to be selectively neutral.

Low mate encounter rate increases male risk taking in a sexually cannibalistic praying mantis

Male praying mantises are forced into the ultimate trade-off of mating versus complete loss of future reproduction if they fall prey to a female. The balance of this trade-off will depend both on (1) the level of predatory risk imposed by females and (2) the frequency of mating opportunities for males. We report the results of a set of experiments that examine the effects of these two variables on male risk-taking behavior and the frequency of sexual cannibalism in the praying mantis Tenodera sinensis. We experimentally altered the rate at which males encountered females and measured male approach and courtship behavior under conditions of high and low risk of being attacked by females. We show that male risk taking depends on prior access to females. Males with restricted access to females showed greater risk-taking behavior. When males were given daily female encounters, they responded to greater female-imposed risk by slowing their rate of approach and remained a greater distance from a potential mate. In contrast, males without recent access to mates were greater risk-takers; they approached females more rapidly and to closer proximity, regardless of risk. In a second experiment, we altered male encounter rate with females and measured rates of sexual cannibalism when paired with hungry or well-fed females. Greater risk-taking behavior by males with low mate encounter rates resulted in high rates of sexual cannibalism when these males were paired with hungry females.

Microsatellite markers for the praying mantid Ciulfina rentzi (Liturgusidae)

Nine polymorphic microsatellite loci were characterized from an enrichment library of the Australian praying mantid Ciulfina rentzi, a group with a unique reproductive morphology and behaviour. The number of alleles per locus ranged from three to 16 and heterozygosity from 0.24 to 0.94. These markers are the first microsatellites developed for any praying mantid. They will be useful for paternity analysis and for population genetic studies in the Wet Tropics World Heritage Region of Australia.

Internal reproductive anatomy of the praying mantid Ciulfina klassi (Mantodea: Liturgusidae)

Using light and scanning electron microscopy, the internal male and female reproductive anatomy of the praying mantid Ciulfina klassi is identified and described. This is the first detailed study to investigate the internal reproductive morphology of any Mantodea. The female structures identified were (1) paired ovaries with primitive panoistic type ovarioles, (2) a single blind-ended spermatheca with secretory gland cells and surrounding layer of striated muscle, and (3) female accessory glands associated with the production of the ootheca (the egg casing). The male structures identified were (1) paired multi-tubular testes, in which different stages of spermatogenesis were observed, (2) tubular vasa deferentia, (3) seminal vesicles, (4) male accessory glands and (5) a single muscular ejaculatory duct. Knowledge of basic reproductive morphology can be used to infer function and so provide key information for future research into reproductive behavior and physiology in the Mantodea.