Hylobius abietis

Using trimethylsilyl triflate, a one-pot reaction of acetoxyallylation and O-silylation of nitrones, gave silylated hydroxylamines (673). Enantiomers of the naturally occurring alkaloid dihydropinidine, potential antifeedants against the pine weevil Hylobius abietis, were prepared by diastereoselective, dimethylzinc mediated addition of pinacolyl 2-propenylboronate to (/ )- and to (S )-2-methyl tetrahydropyridine-A-oxide, obtained from D-alanine and L-alanine, respectively (Scheme 2.190) (674). 

The enantiomeric composition of monoterpene hydrocarbons in conifers and the receptor neuron discrimination of a -pinene and limonene enantiomers in the pine weevil Hylobius abietis) have been described [106]. The authors stated that one olfactory receptor neuron in the pine weevil showed a strong response to a -pinene. A markedly better response to (4-) than to (-)-a -pinene was elicited. Another olfactory receptor neuron responded strongly to limonene. This neuron responded more strongly to (-) than to (+)-limonene [106]. 

WIBE, A., MUSTAPARTA, H, Encoding of plant odours by receptor neurons in the pine weevil (Hylobius abietis) studied by linked gas chromatography-electrophysiology, J. Comp. Physiol A, 1996,179, 331-344. 

ROTEN, 0. O., Behavioural responses by the pine weevil Hylobius abietis to conifer produced odorants detected by the receptor neurones, 2003, Master Thesis at NTNU, Trondheim. 

Hylobius abietis Oarge pine weevil) Pine, spruce Exposure to limonene vapors High limonene concentrations show signs of poisoning within a few hours. 

Hylobius abietis (large pine weevil) Pine Exposure to limonene vapors Low limonene levels do not affect feeding activity. 

Mustaparta, H. (1975) Responses of single olfactory cells in the pine weevil Hylobius abietis L. (Col Curculionidae). J. comp. Physiol., 97, 271-90. 

Havukkula, I. (1980) Klinokinetic and klinotactic humidity reactions of beetles Hylobius abietis and Tenebrio molitor. Physiol. Ent., 5, 133-40. 

Periodically occuring exothermic peaks (Figure 10) in power-time curves of pupae of the mealworm T. molitor and the wax moth G. mellonella could be traced to muscular activities which act as tracheal ventilation, accelerate the hemolymph circulation and support the heartbeat [100]. In these two insects they amounted to only 1 % of the total heat output during pupal metamorphosis and could be neglected. In contrast to these observations the same authors found significantly increased heat flows during ventilation in the Colorado beetle Leptinotarsa decemlineata and the weevil Hylobius abietis with contributions of 12 to 18 % [101,102]. Endothermic peaks which were also observed in the calorimeter curves resulted from water vapour liberated with CO2 [101,102]. 

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