Investigations on the life history of Nemosoma elongatum L. (Col., Ostomidae), a bark beetle predator

Abstract

To estimate the influence of N. elongatum on bark beetle (Pityogenes chalcographus), regulation information about the biology of this species is necessary. In the laboratory, embryonic development depended on temperature and averaged 12 days at alternating temperatures (25/15°C), mean duration of the postembryonic period was 58 days at this temperature. Prey consumption of the N. elongatum larvae (three instars) was ≅ 30 bark beetles (larvae, respectively, pupae) per individual. The adult longevity averaged 3–5 months and mean fecundity was 63.6 eggs per female at alternating temperature (20/10°C) and 58.4 eggs at constant temperature (22°C). The prey consumption of the N. elongatum imagines also depended on temperature. At alternating temperatures (20/10°C) the mean prey consumption was approximately one bark beetle adult per day and N. elongatum individual. Due to these data this predator species must be considered as an important and effective antagonist of Pityogenes chalcographus.

The relationships between Pityogenes chalcographus and Nemosoma elongatum in clear-cuts with different types of management

“…Each fertilised female can lay an average of 60 eggs and, on average, one larva consumes approximately 30 larvae of P. chalcographus during its development. The trapping of one fertilised female, therefore, potentially saves 1920 (only a simple mathematical construction) P. chalcographus specimens (mortality excluded), with similar figures presented by Dippel (1996). It follows that N. elongatum can significantly affect the population of P. chalcographus.…”

“…The different proportions of the Thanasimus and N. elongatum beetles trapped in pheromone traps, which can be expressed in orders, may be a consequence of the different strategies of the olfactory perception employed by the families Cleridae and Trogossitidae as pointed out by Kohnle and Vité (1984). The proportions of the trapped N. elongatum were significant and the significance of their trapped numbers might exceed the significance of the number of caught P. chalcographus (Dippel 1996).…”

Research on Parasitoids and Predators of Scolytidae – A Review

“…It is most often found associated with Pityogenes chalcographus in spruce and considered to be a very important predator of this bark beetle. The predator's biology and ecology have been investigated quite extensively (Baier 1991;Wigger 1994;Dippel 1995Dippel , 1996Dippel et al 1997). The adults are attracted by kairomonal cues and boring dust of bark beetles.…”

Nemozoma gymnosternalis sp. nov., a new anomalous species of Trogossitidae from Brazil

“…Nemozoma Latreille is a widely distributed genus with 23 described species, most of which occur from southern Brazil to southwestern Canada though six species, including the type of the genus, N. elongatum Linnaeus, are distributed in the western Palaearctic, i.e., Europe, Caucasus, Near East, and north Africa. The biology of some European species is relatively well known because they are often associated with economically important Scolytinae (e.g., Baier 1994, Dippel 1996, Mamaev 1976, Nikitsky 1974, Wigger 1996. Adults live together with larvae under the bark of deciduous and coniferous trees and shrubs where they hunt, especially for bark beetles.…”