Influence of age at mating on the reproductive performance of Parthenium beetle, Zygogramma bicolorata (Coleoptera: Chrysomelidae)

Abstract

Age-specific mating incidence, sexual maturation and effect of age at mating on reproductive performance of the Parthenium beetle, Zygogramma bicolorata Pallister, was studied. Based on 50% mating incidence the calculated age of sexual maturation of males and females was 10.5 and 11.1 days, respectively, which was not statistically significant. However, on the basis of age at first mating, that is, sexual maturity, females matured 2 days earlier than males. Fecundity, pre-oviposition, oviposition and post-oviposition period and female longevity appear to be influenced by female age at mating with reproductive performance peaking at 30 days. On the other hand, egg viability was influenced by male age and was highest when males mated at the age of 40 days. To summarise, egg production and timing of egg deposition was female age-dependent, whereas egg fertility was male age-dependent. It was also observed that females mated at a later age and laid a higher number of eggs immediately after mating than did earlier mated females. This was ostensibly in a bid to increase fitness by maximizing reproductive output in the reduced life span available. This is the first investigation on the effect of age of females at mating on reproduction in this beetle.

Operational sex ratio and paternal age sway mating and reproductive performance inMenochilus sexmaculatus(Coleoptera: Coccinellidae)

“…The early commencement of mating in the presence of potential male competitors has also been reported in previous studies (Krupa and Sih 1993;Jormalainen et al 1994;Dick and Elwood 1996;Clutton-Brock et al 1997). Among age groups, the delay in commencement of mating by old individuals may be attributed to the female assessment of male quality followed by mating avoidance with older males (Bonduriansky and Brassil 2002;Jones and Elgar 2004;Beck and Promislow 2007;Omkar et al 2010). The decreased mating performance of old males has also been reported in other Coccinellidae species (Bista and Omkar 2015).…”

Age dependent mate choice influences reproductive and progeny attributes in aphidophagous ladybird beetles (Coleoptera: Coccinellidae)

“…Associations between mating behaviour and the reproductive and progeny attributes of C. septempunctata (r 2 -values ≥ 0.50 have Pvalues < 0.05 and indicate strong associations between the parameters; while r 2 -values < 0.50 have P-values ≥ 0.05 and indicate weak associations between the parameters). & Brassil, 2002;Beck & Promislow, 2007;Omkar et al, 2010). In contrast, there are studies that report a high female preference for old males (Proulx et al, 2002;Avent et al, 2008).…”

“…As the studies on age-specific mating incidences in ladybirds (see Srivastava & Omkar, 2004;Omkar & Pervez, 2005;Omkar et al, 2010;Omkar & Singh, 2010) indicate that middleaged mates have the highest fecundity and egg viability, and their offspring develop fastest; we hypothesized that: (i) under choice-test conditions, middle aged males / females would prefer middle aged partners rather than young and old partners, and (ii) middle aged partners would be more likely to mate, and their reproductive attributes and the development and survival of their offspring would be better than that of young and old partners.…”

“…Despite the many studies on many insect species, age based mate choice has not been studied in ladybird beetles (Coleoptera: Coccinellidae), the commonest insect predators of agricultural pests. Although, many attempts have been made in the past to decipher age-specific mating incidences in ladybirds and their effects on reproduction and fitness of their progeny (Arnqvist & Nilsson, 2000;Srivastava & Omkar, 2004;Omkar & Pervez, 2005;Omkar et al, 2010;Omkar & Singh, 2010), the question of how mate age influences mate choice and mating behaviour in ladybirds is still unanswered. The present study explores the effects of age on mate choice, mating behaviour, reproduction and offspring development and survival in two aphidophagous ladybirds, Coccinella septempunctata L. and Coccinella transversalis Fab.…”

Ageing and mating status affect food utilization efficiencies and assimilation of macronutrients in adults of Parthenium beetle, Zygogramma bicolorata Pallister

“…Ageing not only reduces the physiological integrity of structures and functions in insects (López‐Otín et al, 2013) but also affects the distribution of triglycerides, proteins and glucose in their body (Baumann & Chen, 1968; Butterworth & Bodenstein, 1968) and, consequently, their reproductive output. Studies assessing reproductive output in the Parthenium beetle, Zygogramma bicolorata Pallister have revealed that females that mate at an early or middle age have higher fecundity, longer oviposition periods and maximum life span than the females that mate at a later age (Omkar et al, 2010; Patel, Bhusal, et al, 2020). The offspring of such females also develop faster and survive longer than those of old females (Pandey & Omkar, 2013).…”