The Effect of Female Quality on Male Ejaculatory Expenditure and Reproductive Success in a Praying Mantid

Abstract

Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario.

Male mate choice in a sexually cannibalistic species: male escapes from hungry females in the praying mantid Tenodera angustipennis

“…Postmating mate choice (e.g., strategic ejaculate allocation by males, and biased sperm uptake and usage by females) may also be possible, but only a little is known in mantids (Holwell et al. 2010 ; Jayaweera and Barry 2015 ).…”

Chemical signalling and context dependent polyandry in the false garden mantid Pseudomantis albofimbriata (Mantodea: Mantidae)

“…; Jayaweera et al . ), this is the first empirical evidence of such in a semi‐natural environment. In the current study, we observed multiple matings in more than 50% of trials where females attracted multiple males, and in all other trials, males lingered close to the mating female and oscillated their antennae in her direction until the end of the 2‐day observation period.…”

“…If the period of unattractiveness exceeds the time to lay the first egg sac, then polyandry is unlikely and the male is likely to attain 100% paternity within the first egg sac. The time taken by a female to lay her first egg sac depends mainly on female body condition, where good condition females lay 3–4 days after mating (Jayaweera & Barry ), moderate condition females lay 8–9 days after mating (Barry K., unpublished data) and poor condition females lay 10–13 days after mating (Jayaweera & Barry ). In the current study, females laid their first egg sac 13 days after mating, which is longer than the average refractory period.…”

“…This is more relevant if mating is particularly costly for females (Perampaladas et al . ) or single insemination is enough for sperm to fertilise all of the female's eggs (Jayaweera & Barry ). However, in the current study, females in trials with multiple males mated with a second male if they were in close visual range, making it unlikely to be a female strategy.…”