SUGAR CANE INTERNATIONAL, JANUARY-FEBRUARY 2010, VOL. 28, NO. 1 30 www.agra-net.com/sugarcane Introduction Age has been identified as a major determinant of various life history attributes in living organisms.They constantly strive against the con- straints of environmental conditions and food resource availability in order to achieve a balance between early and late-age fitness traits for their survival. During this process, their physiology is under continu- ous stress and the nature of balancing trade-off varies with age, which is expressed as age-specific variations in various life and reproductive attributes. Eventually a deteriorating state, i.e. senescence is achieved which ultimately leads to death (Mangel, 2002; Srivastava and Omkar, 2004; Pervez et al. , 2004 Singh, 2005; Omkar et al. , 2006). Aging is a deteriorative process brought about by the changes from maturity to senescence resulting in an increasing loss of vigour and persistent decline in fitness components (Comfort, 1960;Alatalo et al. , 1986;Arking, 1991; Price and Hansen, 1998). It is phylogenetical- ly persistent, though against Darwin’s theory of natural selection (being degenerative yet adaptive), and characterized as the composite result of a gene-environment interaction, regulated by stress, meta- bolic factors and reproduction (Finch, 1990).Throughout phylogenies, reproductively active individuals are known to age more rapidly, as reflected by deterioration patterns of different fitness components and decreasing longevity, explained as reproductive costs (Rose, 1984; Partridge 1986;Van Voorhies, 1992; Simmons & Bradley, 1997) and trade-offs (Dixon & Kundu, 1997; Dixon, 2000). However, knowledge of the course of the impact of reproductive costs (or aging pattern) is still obscure except for that on mortality rates (Medawar, 1957). Aging patterns, being the outcome of inherent life-history trade offs and physiological condition of organisms (Kokko,1998) can,however, also be interpreted in a number of other ways (e.g. declining fecundi- ty, egg viability, etc.). The brown lacewing, Micromus igorotus Bank (Neuroptera: Hemerobiidae) is an effective predator of the sugarcane woolly aphid, Ceratovacuna lanigera Zehntner (Kulkarani et al. , 2006,Tripathi et al. , 2008; Singh, 2008; Singh and Tripathi, 2009; Singh et al. , 2009). Adults and larvae of the brown lacewing are predators of a wide range of aphid species including some, which are serious agricultural pests. It preferentially feeds on the aphid, C. lanigera leading to high growth, development and reproductive output (Singh et al. , 2009).The age-spe- cific fecundity, and natality based demographic parameters of M. igoro- tus, on this aphid has also been studied (Singh et al. , 2009).The high val- ues of fecundity, egg viability, net reproductive rate and intrinsic rate of increase allow efficient mass-rearing of M. igorotus in the laborato- ry and suggest the possible successful establishment of this predator in habitats containing C. lanigera infestations.This further strengthens the possibility of it being utilized as a sugarcane woolly aphid biocon- trol agent. However, studies dealing with effect of paternal age on var- ious life attributes are still required for the better understanding of the effects of aging on them. Unlike maternal age, the effects of pater- nal age in insects have not been extensively studied.Fox et al. (1995a) reported effect of age on paternal investment in Callasobruchus macu- latus. They found that male age had a major effect on ejaculate size with 2-day-old males producing larger ejaculates than younger or older ones. Egg viability was found to be influenced by male-age in ladybird beetles, Coccinella septempunctata (Srivastava and Omkar, 2004) and Propylea dissecta (Pervez et al. , 2004; Mishra and Omkar, 2004). In view of the lack of information on effect of paternal age on reproductive attributes viz. pre-oviposition period, oviposition period, fecundity,percentage egg viability and reproductive rate of M. igorotus, the present study was designed. Knowledge of the effects of male age on reproductive attributes may prove to be useful in developing mass rearing procedures.This will improve the use of M. igorotus in sugar- Effects of male age on reproductive response of Micromus igorotus Bank (Neuroptera: Hamerobiidae), a predator of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner (Hemiptera: Aphididae) by S. K. Singh, 2,* Omkar, 2 G. Mishra 2 and G. M. Tripathi 1 1 Indian Institute of Sugarcane Research, Lucknow-226 002, India 2 Ladybird Research Laboratory, Department of Zoology, University of Lucknow, Lucknow-226 007, India * Corresponding author: satyendra_55@hotmail.com ABSTRACT This study was designed to understand the influence of male age on reproductive parameters of Micromus igoro- tus Bank (Neuroptera: Hamerobiidae). Males of M. igorotus did not mate till they were 6-days-old. The age of males when mated was found to significantly influence pre-oviposition, oviposition, post-oviposition periods, fecundity, percent egg viability and reproductive rates. The highest percent egg viability was seen in eggs from females mated with 20-day-old M. igorotus males (92.48±1.23%). Also, egg production was highest in females mated with 20 day-old males, after which aging processes probably caused a decline. Results of this study could be utilized in optimizing mating age of this predator in mass rearing operations, and possibly help in the mass multiplication for biocontrol programmes of C. lanigera. Keywords: paternal age, Micromus igorotus, Ceratovacuna lanigera, biological control, aging.