Effects of delayed mating on reproductive output of female oriental beetle Anomala orientalis (Coleoptera: Scarabaeidae)

Abstract

1 Although management of the oriental beetle Anomala orientalis (Waterhouse) by mating disruption shows promise across a range of agricultural systems, relatively little is known about aspects of the reproductive biology of this species relevant to its management. We studied the effects of delayed mating on several aspects of the oviposition behaviour and biology of the oriental beetle using females mated in the laboratory at 4 -13 days posteclosion. 2 Females exhibited a gradual decline in fecundity with increased age at mating that was largely a function of a decline in duration of the oviposition period, as well as lower female fertility: females mated at 11 days were less likely to lay any fertile eggs. However, egg fertility did not vary with female age at mating. 3 Because mating delay did not affect longevity, females mated at older ages experienced decreased oviposition periods; however, females laid more eggs per day with increased age at mating, which partially offset shorter oviposition periods. 4 A mating delay of ³ 6 days relative to females mated within the first day of reaching sexual maturity resulted in an approximately 35 -50% lower mean fecundity. 5 These results suggest that, for mating disruption to be a successful management tool for the oriental beetle, mating must be prevented rather than delayed. We compare the findings of the present study with the published research on delayed mating in moths and discuss the importance of these results in relation to management of the oriental beetle using female sex pheromones.

Biology and management of the redheaded pasture cockchaferAdoryphorus couloni(Burmeister) (Scarabaeidae: Dynastinae) in Australia: a review of current knowledge

“…Although mating disruption had no effect on A. orientalis fecundity or egg fertility, it did impact on the number of eggs laid because it reduced the time available for oviposition (Wenninger & Averill 2006). However, the antennal morphology of A. couloni (McQuillan & Semmens 1990) and its mating behaviour suggest that pheromones are of little importance in attraction.…”

Effect of Increased Male and Female Age at Mating on the Reproductive Performance of <I>Cnaphalocrocis medinalis</I> (Crambidae: Lepidoptera)

“…The majority of studies investigating delayed mating have paired females of various ages with males of a single, optimal age (Wenninger andAverill 2006, Stelinski andGut 2009). The effect of male age on egg number has been addressed in only a few studies, and this interaction of male and female age has received little attention (Stelinski and Gut 2009).…”

“…In the current study, we used moths 3 d after emergence as a standard for experiments, and examined the effect of increased age at mating for 5, 7 and 9 d after emergence on the percentage of mating, egg number, hatchability, duration of the preoviposition period, and longevity of C. medinalis. Most studies have evaluated the effect of delayed mating by pairing Lepidoptera of the same age (Wenninger andAverill 2006, Stelinski andGut 2009). Such studies could not compare whether one sex was more severely affected by delayed mating.…”

“…The effectiveness of mating disruption in preventing mating can, however, vary with pest biology, crop type, and methodology of pheromone application (Miller et al 2006, Witzgall et al 2010. In some situations, mating disruption does not completely inhibit mating because some males may eventually Þnd females if given enough time (Torres-Vila et al 2002, Wenninger andAverill 2006). Nevertheless, several laboratory studies have shown that delayed mating can have a signiÞcantly negative effect on the reproductive performance of lepidopteran pests by decreasing female readiness to mate, and reducing the number of eggs laid and the hatchability (Torres-Vila et al 2002, Michereff et al 2004, Fitzpatrick 2006.…”

Weather factors affecting the male mate-locating tactics of the small copper butterfly (Lepidoptera: Lycaenidae)

“…A low population density would prolong the time from when females become receptive to when they mate, which results in female sperm limitation and may account for why population density influences mate-locating tactics (Wickman & Rutowski, 1999;Kokko & Wong, 2007). In Lepidoptera females generally suffer the cost of a decline in fecundity when mating is delayed (Wenninger & Averill, 2006). Therefore, at low population densities, which commonly results in delayed mating, active matesearching by females and waiting by males would be favoured.…”