title: Life table and predatory efficiency of Stethorus gilvifrons (Coleoptera: Coccinellidae), an important predator of the red spider mite, Oligonychus coffeae (Acari: Tetranychidae), infesting tea.
abstract: The ladybird beetle, Stethorus gilvifrons, is a major predator of the red spider mite, Oligonychus coffeae, infesting tea. Biology, life table and predatory efficiency of S. gilvifrons were studied under laboratory conditions. Its average developmental period from egg to adult emergence was 19.2 days. After a mean pre-oviposition period of 5.3 days, each female laid an average of 149.3 eggs. Adult females lived for 117.3 days and males for 41.5 days. The life table of the beetle was characterized by an intrinsic rate of increase (r) of 0.066 day(-1), net reproductive rate (R (0)) of 72.2 eggs/female, gross reproduction rate (Sigmam ( x )) of 82.3 eggs/female, generation time (T) of 64.9 days, doubling time of 10.5 days and finite rate of increase (lambda) of 1.07 day(-1). Population dynamics of S. gilvifrons and its prey, O. coffeae, was monitored by sampling 25 tea leaves from each experimental block grown under the prevailing field conditions. Populations of S. gilvifrons reached a peak during January to March and had low incidence during June to November. Peaks in the populations of S. gilvifrons coincided with the abundance of O. coffeae in tea fields. Weather factors such as low temperature, high humidity and heavy rainfall adversely affected the populations of S. gilvifrons. The predatory efficiency of S. gilvifrons increased during the growth of larval instars. An adult female consumed 205.0 eggs, 92.2 larvae, 81.8 nymphs and 52.4 adult mites per day.
authors.affiliation: Division of Entomology, UPASI Tea Research Foundation, Tea Research Institute, Nirar Dam BPO, Valparai, Coimbatore District, Tamil Nadu 642127, India. insectakperumalsamy@gmail.com
authors.forename: Kandasamy
authors.initials: K
authors.lastname: Perumalsamy
authors.forename: Rajagopal
authors.initials: R
authors.lastname: Selvasundaram
authors.forename: Amsalingam
authors.initials: A
authors.lastname: Roobakkumar
authors.forename: Vattakandy Jasin
authors.initials: VJ
authors.lastname: Rahman
authors.forename: Narayanannair
authors.initials: N
authors.lastname: Muraleedharan
mesh_terms: D000818:Animals; D028241:Camellia sinensis / Q000469:parasitology*; D001517:Coleoptera / Q000502:physiology*; D005260:Female; D007814:Larva; D015993:Life Tables; D008297:Male; D008925:Mites / Q000502:physiology*; D009758:Nymph; D010063:Ovum; D010572:Pest Control, Biological; D011235:Predatory Behavior / Q000502:physiology*
references.citation: Pak J Biol Sci. 2007 Dec 15;10(24):4563-6
references.pmid: 19093534