Population dynamics, biology and management of mealybug, phenacoccus solenopsis tinsley (Hemiptera: pseudococcidae) on okra
| dc.contributor.advisor | Mani Chellappan | |
| dc.contributor.author | Anusree Padmanabhan, P S | |
| dc.contributor.author | KAU | |
| dc.date.accessioned | 2020-02-11T10:59:35Z | |
| dc.date.available | 2020-02-11T10:59:35Z | |
| dc.date.issued | 2017 | |
| dc.description | PG | en_US |
| dc.description.abstract | Cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a highly polyphagous pest that infest more than 154 species of plants mostly belonging to Asteraceae, Malvaceae, Solanaceae, Amaranthaceae, and Euphorbiaceae. It causes severe damage to crops grown under both protected as well as open field conditions. Use of broad spectrum synthetic insecticides to manage the mealybug is a restricted option owing to concerns about residue, interference with natural enemies etc. Hence, it is necessary to study the host range, biology and to develop alternative ecofriendly strategies for the management of the mealybug. The study entitled “Population dynamics, biology and management of mealybug P. solenopsis Tinsley (Hemiptera: Pseudococcidae) on okra” was undertaken at the AINPAO (All India Network Project on Agricultural Ornithology) laboratory, Dept. of Agrl. Entomology, College of Horticulture, Vellanikkara during March 2016 – May 2017. The objectives of the study were to study the population dynamics, biology and management of P. solenopsis and characterization of its endosymbionts. To document the host range and natural enemies of P. solenopsis, purposive survey was conducted in Thrissur district. P. solenopsis was recorded on more than 40 plants, the majority of which belonged to the families viz., Asteraceae, Malvaceae, Solanaceae and Amaranthaceae. As the population of mealybug on okra fields was negligible during survey, study on population dynamics was carried out on major host plants recorded viz., Sida acuta Burm.f., Abutilon indicum (Link) Sweet, Hibiscus rosa-sinensis L.and Amaranthus viridis L. Population of mealybug was found to be high during summer (March 2016 to July 2016) and winter seasons (November 2016 to February 2017). Natural enemies recorded included a predator [Spalgis epius (Westwood)] and four parasitoids [Aenasius arizonensis (Girault), Anicetus sp., Myiocnema comperei Ashmead and Prochiloneurus spp.]. Molecular characterization of mealybug was done to confirm the species identity prior to studies on biology. Mass culturing of mealybug was done on potato sprouts. The mealybugs reproduced through ovo-viviparity and parthenogenesis. Life cycle of female mealybug consisted of three nymphal instars and an adult stage, whereas that of male mealybug consisted of an additional pupal stage along with three nymphal instars. The mean duration of first and second nymphal instars was 4.27 and 6.67 days. The average third nymphal instar duration was 4.8 days. Mean pupal period in male mealybug was 6.8 days. Adult female lived for an average of 38.75 days with pre-oviposition, oviposition and post-oviposition period of 5, 11.5 and 0.5 days respectively. Adult male lived for only an average of 1.7 days. Adult female deposited an average of 171 crawlers with a female to male sex ratio of 1: 0.03. Number of antennal segments varied among each instars. The first and second instar nymphs had six antennal segments, while the third instar nymphs and adult stage possessed seven and nine antennal segments, respectively. Study on damage assessment on okra by P. solenopsis showed that second and third instar nymphs produce profuse crinkling and yield loss in okra. Apot culture experiment was conducted to evaluate the efficacy of entomopathogenic fungi viz., Paecilomyces lilacinus (Thom) Samson and Lecanicillium lecanii (Zimm.) Zare& Gams each at three different concentrations of 1 × 107, 1 × 108 and 1 × 109 spores ml-1, along with two botanicals viz., NSKE @ 5% and neem oil soap @ 2 %, chemical insecticides viz., buprofezin 250 g a.i. ha-1 and thiamethoxam 25 g a.i. ha-1 with an untreated control. Thiamethoxam recorded the highest mortality of 75.94 per cent seven days after treatment followed by buprofezin and NSKE with mean mortality of 37.02 and 26.52 per cent, respectively. Entomopathogenic fungi, L. lecanii at 1×108spores ml-1(21.89%) was on par with P. lilacinus at 1 × 107 spore ml-1 (20.72%). The mortality of mealybug increased with time lapse after spray application. On the 14th day, highest mortality of 83.54 per cent was recorded in the treatment NSKE which was on par with thiamethoxam (81.74%). P. lilacinus at 1 × 109spores ml-1 and L. lecanii at 1 × 108 spores ml-1 were found to be the best treatments among entomopathogenic fungi. Analysis of gut microbiota showed the presence of endosymbiotic bacteria belonging 63 families which constituted 189 species. The major species identified were Candidatus Tremblaya princeps, Klebsiella sp., Pantoea agglomerans (Ewing and Fife) and Wigglesworthia glossinidia Aksoy. Many of the endosymbiotic bacteria are attributed in the survival of insects against toxicants. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810142896 | |
| dc.keywords | Okra, Thiamethoxam, P. solenopsis(Phenacoccus), Entomopathogenic fungi, Profenofos, Mealybug, Parasitoid | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 80 | en_US |
| dc.publisher | Department of Agricultural Entomology, College of Horticulture, Vellanikkara | en_US |
| dc.sub | Agricultural Entomology | en_US |
| dc.subject | null | en_US |
| dc.theme | management of mealybug on okra | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Population dynamics, biology and management of mealybug, phenacoccus solenopsis tinsley (Hemiptera: pseudococcidae) on okra | en_US |
| dc.type | Thesis | en_US |