Southern pine beetle frontalis

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). 

It is the intent of this paper to explore the various control tactics that are being suggested in the management of bark beetles in the forest system with specific attention given to the potential impact on the predator population. Similar arguments could be extended to other bark beetle mortality agents such as the parasite community. Primary examples and control tactics discussed will be drawn from our experience with the southern pine beetle, I). frontalis, a major pest in the southeastern U.S., along with other bark beetles in North America. 

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... 

Recently in 2005, we synthesized 10 g of (+)-endo-brevicomin, the minor component of the pheromone of the male southern pine beetle, Dmdroctonus frontalis [22-24]. We used lipase AK in this synthesis to desymmetrize the prochiral diol. Dr. B. T. Sullivan at the U.S. Forest Service is currently studying the practicality of the pheromone traps with a mixture of (+)-endo-brevicomin, frontaKn and a-pinene. 

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

CgHnOj, Mr 142.20 oil, bp. 99-100 C (15.99 kPa), [a]o -55.5 (diethyl ether). F. is one of the aggregation pheromones of bark beetles of the genus Dendroc-tonus. This attractant is used to promote an effective colonization of a tree first chosen as nesting site by one insect by controlling an optimal ratio of the sexes. Males of D. brevicomis have pure (lS)-(-)-F., the pheromone of D. frontalis (Southern Pine Beetle) is an... 

Southern pine beetle and Western pine beetle Dendroctanus frontalis snd Dondroclonus biwicomis)... 

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). 

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. 

Southern pine beetles, Dendroctonua frontalis, were assayed for susceptibility to 16 terpenoids from pine oleoresin (15). The LDcq of d-limonene was 0.47 pg/insect, while i-limonene was slightly less toxic (0.55 /lig/insect), as was myrcene (0.62 /jg/insect). The most toxic chemical tested was limonene dioxide (0.24 /ig/insect), indicating that oxidation of limonene may be an activation process (15). 

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. 

Some species incorporate host compounds into the pheromone blend, such as myrcene with D. brevicomis. Vite et al. (1972) distinguished between species like D. brevicomis and D. frontalis (southern pine beetle) which apparently contain pheromone in their hindguts when they emerge and release it on contact... 

Frontalin, a pheromone of the southern pine beetle D. frontalis, has been synthesized using a procedure that is likely to find general use in the synthesis of 1,3-dioxolans (Scheme 46). 1,3-Dioxans are conveniently available from a wide... 

Payne and Dickens (357) have described a technique to elucidate the specificity of the receptor system of the southern pine beetle, D. frontalis. The technique employs the differential adaptation of the antennal olfactory receptors to various test compounds either the single unit recording technique or the electroantennogram (EAG) technique is used. It is designed to determine whether different compounds are recognized by the same receptor site and is based on the exposure of the antennal preparation to one compound until the site is completely adapted, followed by exposure to a test compound. It is claimed that failure to show a response to a test compound after adaptation to another indicates that all the chemorecognition sites for the test compound are occupied by the first compound. As it had been shown that the receptors for both bicyclic ketals and host terpenes respond with equal intensites (358), Dickens and Payne (321) calculated the percent of the acceptors (receptor sites) capable of interacting with the various compounds tested. 

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). 

Renwick (S6S) reported on the activity of a number of frontalin analogs in field tests on D. frontalis, the Southern pine beetle. The only analog which showed any additive activity was 5,7-dimethyl-6,8-dioxabicyclo [3.2.1] octane when presented together with frontalin and a-pinene. The 5,7-dimethyl substitution pattern is the same as the 5-methyl-7-ethyl substitution pattern of exo- and encfo-brevicomin. Renwick (363) noted this and also pointed out that while brevicomin is an active component of the attractant of D. brevicomis, it is inactive or suppresses response in D. frontalis. It has since been established that (—)-frontalin is the active enantiomer in this species (46). 

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