Efficacy of the Aegean Wall Lizard (Podarcis Erhardii) as a Potential Biological Control Agent in Mediterranean Agroecosystems

aegean wall lizard;Podarcis erhardii;agroecosystem;School for Environment and Sustainability

Lisiecki, ChelseaPerfecto, Ivette ;

University of Michigan

关键词: aegean wall lizard;    Podarcis erhardii;    agroecosystem;    School for Environment and Sustainability;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/148803/Lisiecki_Chelsea_Thesis%20%281%29.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Given agriculture’s outsized proportion of global land use, food production systems must be examined fortheir role in conservation during this era of anthropogenic global change. Central to this objective isinvestigating opportunities where goals of food security and biodiversity preservation are complimentaryrather than incongruent. Biological control of herbivorous pests by natural enemies is one such area offocus, where accruing evidence suggests landscape complexity fosters functional diversity of predatorswho offer free pest control services. Despite being widespread generalist predators, reptiles haveinfrequently been considered for their role in suppressing invertebrate populations. In this study, weinvestigated an insular population of the common Mediterranean lacertid, Podarcis erhardii (Aegean walllizard), for its impact on invertebrate communities and herbivory damage through field enclosureexperiments. We further studied P. erhardii’s functional response to known agricultural pests in alaboratory setting. Our field results revealed a significant negative interaction effect between lizardinclusion and time on the abundance of ground-dwelling arthropods sized 2-5 mm (! = -0.017, SE =0.006, p = 0.006), and a marginally significant negative effect of lizard inclusion on arthropods > 5 mm(! = -0.303, SE = 0.153, p = 0.052), irrespective of time. We detected no effect of lizards on theabundance of airborne arthropods or prey < 2 mm. However, our functional response trials revealedlizards’ capacity to consume copious amounts of small prey when naturally aggregated, as well as largeamounts of prey biomass relative to predator body size. We found no influence of lizard inclusion onherbivory damage, potentially a result of intraguild predation by lizards on large predatory arthropods andsmall sample size. Our study illustrates the capacity of lizards to suppress large or naturally clumpedground-dwelling prey, especially later in the growing season when resources become scarce. We arguethat biocontrol services are best realized when P. erhardii is among a diverse assemblage of predators, inorder to maximize control of herbivorous insects over appropriate spatiotemporal scales. Accordingly, werecommend future studies involve long-term investigation of food web level interactions, including trait-mediatedeffects.