The role of pheromones, kairomones, and allomones in the host selection and colonization behavior of bark beetles

Cascade Processes of Metallo Carbenoids

Insect pheromones—an overview of biosynthesis and endocrine regulation

Application of Intramolecular Carbenoid Reactions in Organic Synthesis

The purview of chemical ecology and the recent criticisms of improper application of theory to bark beetle phenomena is briefly discussed. Seven levels of research in chemical ecology are presented as well as their relationship to research on bark beetles. The biology and chemical ecology of several pest bark beetles from North America and Europe are discussed in regard to host tree selection theories of random landing on trees or attraction to semiochemicals. The diversity and similarities of pheromone components among species are presented in relation to their biosynthesis from host tree precursors and in relation to the ecological implications of de novo or precursor syntheses. Individual variation in biosynthesis of, response to, and release of pheromones is discussed. Olfactory perception of semiochemicals at both the electrophysiological and behavioral levels is presented. Orientation to semiochemicals during walking and flying is discussed with reference to the significance of dose-response curves for determining a compound's functionality in short- or long-range communication. The regulation of attack density, termination of the aggregation, mechanisms of attack spacing, and recognition of host suitability are presented in the context of an individual's avoidance of intra- and interspecific competition. Finally, a brief summary of topics where our understanding of the chemical ecology of bark beetles and their associates is poorly known is presented.

Chemical ecology of bark beetles

Die La rven der Aleoehara-Arten leben, soweit bekannt , raubparas i t i sch in Pupar i en cyclor rhapher Dipteren. ObwohI Superparas i t i smus vo rkommt , entwickel t sich s te ts nur eine der in das F l iegenpupar ium e ingedrungenen Aleochara-Eil a rven ektoparas i t i sch an der F l iegenpuppe [t, 2]. Von den bet A. bilineata und A. curtula beobach te t en Konkur renze rscheinungen ist eine so auffallend, dab sie mi t der leicht zug/inglichen A. curtula als Paras i t und Calliphora erythrocephata Ms Wir t un t e r such t wurde. Das Ph~Lnomen: Von der Pr im~rlarve wird bet Einfachparas i t i e rung (pro Versuchsrbhrchen t P u p a r i u m ill Normalpos i t ion in Erde + 1 l~ilarve, ]Befallskontrolle nach 12 h) die Eingangs6ffnung s te ts in e inem Vorzugsbereich ven t ra l am I l in t e rende des Pupa r iums genagt [3]. Se tz t m a n zu dem gleichen Pupa r ium innerhalb einer Zei t spanne yon t 2 7 2 h nach ]Befallskontrol le eine weitere Ei larve (Sekund~rlarve), so dr ingt diese in der Regel n ich t im Vorzugsbere ich ein (Fig. I a).

Inhibition ofDendroctonus frontalis response to frontalin by isomers of brevicomin

Oxidation products of terpenes identified from Dendroctonus and Ips bark beetles

3-Methyl-2-cyclohexen-1-ol isolated from Dendroctonus.

2-Phenylethanol isolated from bark beetles

N a c h e iner Vor re in igung der Droge m i t Pe t ro l~ the r wurde e r sch6pfend m i t A~her exgrahier t . Dabe i g ingen ein grol3er Toil des Q u e r c e t m s u n d S pu ren des Glykos idgemisches u n d fas t das g e s a m t e K~mpfe ro l in L6sung . W u r d e n n u n die vo rhe r m i t A the r e x t r a h i e r t e n Schalen noch m i t Methano l ex t rah ie r t , so ze ig ten sich in der Me thano l I6sung haup t s~ch l i eh Glykoside neben k le inen Mengen yon Querce t in n n d SpureI1 yon KXmpferol. Das Glykos idgemisch lie3 sich au f Pap ie r S & S 2043 a in vier Glykos ide t renl len, u n d zwar in Spireosid m i t d e m R t -Wer t 0,57 ulld drei andere m i t den R f -W er t en 0,25, 0,35 n n d 0,47. Es wa ren noch wei tere Fleeke zu e rkennen , deren I d e n t i t g t n i ch t fes tges te l l t wurde. Als L a u f m i t t e l d ien te das

J. P. Vité

Papers

Inhibition ofDendroctonus frontalis response to frontalin by isomers of brevicomin

Oxidation products of terpenes identified from Dendroctonus and Ips bark beetles

3-Methyl-2-cyclohexen-1-ol isolated from Dendroctonus.

2-Phenylethanol isolated from bark beetles

Detection of a volatile compound in hindguts of male Ips confusus (Le Conte) (Coleoptera: Scolytidae).