Southern pine beetle Dendroctonus

R=OH). With less polar chloride substituents, however, the RhuA dia-stereoselectivity is reduced and a considerable fraction of the FucA configurated product (40%) is also formed. Interestingly, alkaline cyclization in the latter occurs with an inverse preference to furnish 177, which contains the enantiomeric bicyclic [3.2.1] structure shared by the FruA product 175 as well as by (S)-( — )-frontalin 178, the aggregation pheromone of the southern pine beetle Dendroctonus frontalis. 

Is of serious concern. The role of chemical communication, in relation to proposed control tactics, of predators and bark beetles will be discussed. Emphasis will be on Thanaslmus dublus (F.) (Coleoptera Clerldae) and Medetera blstrlata Parent (Dlptera Dollchopodldae) which are primary predators of the southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera Scolytidae). 

Grosman D. M. (1996) Southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera Scolytidae) quantitative analysis of chiral semiochemicals. PhD thesis. Viginia Polytechnical Institute. 

What are some examples of these attractants (Figure 1) For mate finding, the insect-produced pheromones are the primary examples. However, environmental factors may also play an important role in the effectiveness of attractants. In the southern pine beetle, Dendroctonus frontalis. alpha-pinene released from an attacked tree is necessary along with the endogenously produced frontalin in order to attract males for mating (14). 

Frontalin (98, Figure 4.49) is the active component of the aggregation pheromone of the southern pine beetle (Dendroctonus frontalis), the western pine beetle (Dendroctonus brevicomis) and the Douglas-fir beetle (Dendroctonuspseudotsugae). Mori s 1975 synthesis of the enantiomers of frontalin via enantiomer separation (optical resolution) of an intermediate87 enabled their bioassay, and only (lS,5/ )-98 was bioactive as the pheromone component of D. brevicomis.32 A recent study on female D. frontalis revealed its (15, 5/C)-98 to be of about 91% ee.88... 

S.5R)-hrontalin -e Southern pine beetle (Dendroctonus frontalis) A Grubbs Olefin methatesis". Baker s yeasi1. 1I54J" 1168 h... 

This hypothesis is unvalidated at present, because these case studies employed different methods, are not replicated across genera, variability in natural enemies numbers is complex, and we caimot adequately separate cause and effect. Also, ratios of predators to prey are highly plastic within systems,and predation and competition are not independent owing to dilution effects. We also lack information on its applicability to other systems. Predaceous checkered beetles cause greater proportionate mortality to mountain pine beetle, Dendroctonus ponderosae Hopkins during endemic than eruptive conditions, which is consistent with our model, but not validating without information on the pre-attack chemistry of killed trees. Likewise, predation of southern pine beetle, Dendroctonus frontalis... 

COOK, S.P., HAfN, F.P., Defensive mechanisms of loblolly and shortleaf pine against attack by southern pine beetle, Dendroctonus frontalis Zimmerman, and its fungal associate, Ceratocystis minor (Hedgecock) Hunt, J. Chem. Ecol, 1986, 12, 1397-1406. 

SCHOWALTER, T.D., COULSON, R.N., CROSSLEY, D.A., Role of southern pine beetle Dendroctonus frontalis Zimmermann (Coleoptera, Scolytidae) and fire... 

Frontalin (139) is known to be the aggregation pheromone of the southern pine beetle Dendroctonus frontalis. The biologically active form of this com-... 

One of the most destructive pests in pinewoods in the south-east of the USA is the Southern pine beetle Dendroctonus frontalis Zimmermann), and in western North America the Mountain pine beetle Dendroctonusponderosae) (Fig. 8.83). 

The sex attractant of the female Western pine beetle (Dendroctonus brevicotnis) is the enantiomerically pure (lR,5S,7H)-(+)-exo-brevicomin. The (-)-enan-tiomer is not biologically active. In contrast, the pheromone component (lR,5S,7S)-(+)-eMdo-Brevicomin caused variable responses in the Southern pine beetle (Dendroctonus frontalisZiiameimann). [202]... 

A number of different stresses can elicit inducible compounds important in insect interactions with plants. Some of these compounds appear to attract insects to a plant in distress, such as the southern pine beetle, Dendroctonus frontalis, to Pinus spp. Other compounds appear to prevent attack [22]. Ozone decreases soybean resistance to insect herbivory and overrides induced resistance [Lin, H.C. Kogan, M. Endress, A.G., Environ. Ento. 1990, in press.]. This might be due to a diversion of phenolics into coumestrol instead of more toxic compounds such as glyceollin. 

Payne, T. L., Hart, E. R., Edson, L. J., McCarty, F. A., Billings, F. M. and Coster, J. E. (1976) Olfactometer for assay of behavioral chemicals for the southern pine beetle, Dendroctonus frontalis (Coleoptera Scolytidae). J. Chem. EcoL, 2, 411-9. 

Aggregation of the southern pine beetle, Dendroctonus frontalis. .. on loblolly pine (Pinus taeda) under beetle attack was not disrupted by aerial application of frontalure, which is a mixture of the attractant pheromone frontalin (195) and the host terpene a-pinene (230). Instead, aerial saturation with the pheromone in a heavily beetle-infested pine forest resulted in a rapid increase in the aggregation of beetles on pine trees undergoing attack (549). In this experiment, a ten hectare section of pine forest including 1.6 hectares of a D. frontalis infestation was treated twice by aircraft with rice seed soaked with frontalure. This formulation released virtually all of the frontalure within 24 hr (45 g/ hectare for the first application and 450 g/hectare for the second). 

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