Duration of the Development Stages of Rhizophagus grandis Gyll. (Coleoptera, Monotomidae) in Laboratory Rearing on Picea orientalis Logs in Turkey

Abstract

In this study, the duration of the development stages of Rhizophagus grandis Gyll. (Coleoptera, Monotomidae) in "log-breeding" method in laboratory conditions was investigated. Rearing studies were carried out in R. grandis Biological Control Laboratory of Macka Forestry Enterprises throughout 28th of April and 4th of July 2009, under the conditions of 22.5°C±2 constant temperature, 72±5% proportional humidity in perpetual darkness. The first prepupae emergence was observed within 31 days at the earliest and 38 days at the latest following introduction of maternal R. grandis mature couples to the logs. Total elapsed time for feeding by maternal R. grandis before copulation, their copulation and depositing eggs, embryo development of the eggs and completion of larval stages were 34.5±2.7 days on the average. On rearing logs, depending on the number of obtained R. grandis prepupae, the time elapsed between the dates of the first and the last prepupae emergence was minimum 1 day and maximum 29 days. Prepupae emergence have lasted 14.8 days (3-29 days) on the average. A positive linear correlation was found between the quantity of R. grandis prepupa and prepupae emergence periods. As the number of prepupae increases, the duration of prepupae emergence gets longer (r=13.75, p<o.003). In an average of 67.7±2.7 (61-71 days) days following the introduction of maternal R. grandis to the logs, 94.7% of the new R. grandis adults were obtained.