International Journal of Pure and Applied Zoology

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Elm Bark Beetle Population Dynamics and its Attack Density in Relation to Host Tree Diameter, Maternal Gallery Length and Oviposition in the Elm Nursery Stands

Elm bark beetle Scolytus kashmirensis is a key pest on Ulmus villosa in the social forestry ecosystem of Kashmir. The population dynamics, effects of attack density on the gallery length and oviposition and importance of log diameter on emergence of the beetle pest were determined in the present study. The results showed that seasonal fluctuation in population of immature scolytids correlated with adult population. The seasonal peaks in population density of immature scolytids and adults have a direct influence on one another. The adult beetles arrived in April up to June with peak period during the first ten days of May (2.20 ± 0.78 SD per 0.2 m2 area). The second arrival period started from July and extended up to September with peak period during the last ten days of July (3.40 ± 0.51 SD per 0.2 m2 area). The logs infested by parent beetles (of partial 2nd generation) during April to May (2013) started producing adults of 1st generation from July onwards with peak period during the first ten days of July (11.90 ± 2.02 per 0.2 m2 area). The logs infested by beetles from July to September (2013) did not show any emergence and the 2nd generation adults emerged from April of the following year which continued up to June with peak period during the middle of May (8.50 ± 2.32 SD per 0.2 m2 area). The results of attack density on gallery length and oviposition showed a significant positive correlation between the variables. In our study, we also evaluated relationship between log diameter and emergence of beetles. In addition, the optimal attack densities and influence of log diameter on beetle population are discussed.

Author(s): Abdul A Buhroo and Abdul Lateef Khanday*