Beetle attack

FIGURE 12 18 Relationship between degree of oxidant injury to ponderosa pines and bark-beetle attack (left) and numbers of trees killed by western pine beetle, mountain pine beetle, and the two species together (right). Reprinted with permission from Stark and Cobb. ... 

Silvicultural Treatments. Preventive silviculture should be practiced (16) to promote individual tree resistance to bark beetle attack by (1) favoring the most resistant species ... 

Kohnle U., Densbom S., Duhme D. and Vite J. P. (1992a) Bark beetle attack on host logs reduced by spraying with repellents. J. Appl. Ent. 114, 83-90. 

There is also the possibility that pollutants alter susceptibility of the plant to pathogens (36) or insect attack. Of the latter there is the decreased resistance of ponderosa pine to bark beetle attack caused by ambient oxidant exposure (37). The investigations of others with respect to the effects of fluoride on ponderosa pine indicated that although foliar injury was associated with increased resin exudation pressure, which could be interpreted as an increased capacity of the tree to overcome bark beetle attack, degree of insect infestation was not associated with amount of foliar injury (38). As more is known about pheromones, the botanical investigation of the secondary products of metabolism, such as terpenes and phenolics, may become more important in investigating the mode of action of pollutants in the entire plant. The switch to alternate pathways, while resulting in the same products, may reduce the intermediates needed in biosynthesis and thereby affect the plants resistance to disease or attractiveness to insects. 

White fir is a formidable competitor in mixed conifer stands because heavy litter, brush, and ground cover favor it more than pines (14). In northeastern California, a conversion of a 50 50 ponderosa pine-white fir pole stand to nearly 100% fir was described as a result of extensive mortality of pine from bark beetle attack. 

Bark tunneled. Cause Elm bark beetles. These Ao", dark reddish brown beetles attack weakened elm trees and serve as vectors of Dutch elm disease. The adult beetles bore small holes through the bark and lay eggs in... 

Commercial Products BTK Bactur, Bactospeine, Caterpillar Attack, Caterpillar Killer, Dipel, Javelin, Larvo-Bt, SOK-Bt, Thuri-cide. Worm Rnder BTI Bactimos, Mosquito Attack. Teknar, Vectobac B LSD Colorado Potato Beetle Attack, M-One Appetite stimulants Entice, Wheast... 

Aggregation pheromones of spruce bark beetles, e.g., from the genus tps, were widely studied in order to fight back their destructive actions in the forests of Canada and Scandinavia. They tend to be simple metabolites of terpenes, present in the resin of the trees they live on, but a rather complicated system of chemical communication has evolved. A great amount of research was necessary to clarify the complicated systems of chemical communication within and between the species, and some points of interest are described here. The bark beetle attack from the genus Ips starts with a few males. If the tree is suitable for them, the pioneer beetles secrete pheromones... 

A wool-like fiber, sp gr 1.18. Softens at about 175". Flammability similar to cotton and viscose, fnsol in acetone, methylene chloride. Good resistance to sunlight, clothes-moth and carpet-beetle attack, and mildew moderate resistance to 10% H2S04 at 100" for hrs, and to 0.5% caustic soda at 43 for 7 days. Shrinks about 1% when immersed in boiling water for 3 minutes. Difficult to dye. Relatively resistant to pilling. 

Furniture beetles attack well-seasoned wood, but require openings or fissures in the surface for oviposition of eggs. Finished surfaces, even sandpapered surfaces, discourage oviposition. Transverse surfaces, such as the feet of legs and drawer backs, offer excellent ovipositional sites, however. 

FRANCESCHI, V.R., KROKENE, P., KREKLING, T., CHRISTIANSEN, E., Phloem parenchyma cells are involved in local and distant defense responses to fungal inoculation or bark beetle attack in Norway spruce (Pinaceae)., Amer. J. Bot., 2000,87,314-326. 

Pine resins may be divided into volatile (usually mono- and sesqui-terpenoid) and non-volatile (diterpenoid) and phenolic components e.g., lignin and its precursors). The two components are thought to act differently on invading beetles the volatiles are chemical toxins, whereas the non-volatiles are more of a physical barrier. Phloem and oleo-resin compositions differ among tree species, " and some components can be induced by beetle attacks. " Predominant resin monoterpenes in various hosts include A3-carene, limonene, and P-pinene in ponderosa pine A3-carene, limonene, and P-phellandrene in Jeffrey pine and a-pinene and A3-carene in pinyon pine P. edulis) , 48,52,53 jj. 

LORIO, JR.P.L., HODGES, J.D., Tree water status affects induced southern pine beetle attack and brood production, USDA FS South. For. Exper. Stn. Res. Pap. SOUS, 1977. 

GEISZLER, D.R., GARA, R.I., Mountain pine beetle attack dynamics in lodgepole pine. Forest, Wildlife and Range Experiment Station, University of Idaho USDA Forest Service, Forest Insect and Disease Research/Theory and Practice of Mountain Pine Beetle Management in Lodgepole Pine Forests Symposium, pp. 182-187. 

Conifers exhibit resistance to bark beetle attack and fungal invasion because of an Induced synthesis and flow of secondary resin which contains high levels of volatile monoterpenes. Monoterpene olefin synthases (geranyl pyrophosphate cyclases) were found in higher levels in fungus-infected lodgepole pine seedlings than in uninfected controls. 

The role of monoterpene enantiomers In Imparting differential conifer resistance to bark beetle attack has received little attention because of the difficulties In... 

Diterpenoids are C20 compound formed of four C5 units. Basic diterpenes are mostly non-volatile compounds found from plant resins (e.g., in the Coniferae) and latex (e.g., in the Euphorbiaceae). In conifer resin abietic acid and other diterpene carboxylic acids are solids mixed with essential oils when formed in resin ducts. The viscosity and flow of resin is controlled by the proportion of essential oils, which are composed of monoterpenes and sesquiterpenes. When these oily substances evaporate, resin acids crystallize and form a soUd protective layer on the damage site. Bark beetle attack induces resin flow on conifer bark (Fig. 94.3). 

Lombardero MJ, Ayres MP, Ayres BD (2006) Effects of fire and mechanical wounding on Pinus resinosa resin defenses, beetle attacks, and pathogens. Forest Ecol Manag 225(l-3) 349-358. doi 10.1016/J.Foreco.2006.01.010... 

Figure 5.6 (a) The total emission of monoterpenes from mature (bars) and young Poplar leaves (filled circles) determined from PTR-MS measurements, (b) The percentage of the two principal monoterpenes, (E)-(i-ocimene and llnalool (determined using CC-MS) emitted for day 0 (no insect attack) and for days 1, 4 and 7 after beetle attack. In (c), the rates ofisoprene emission and photosynthesis and the stomatal conductance are provided for mature leaves. Reproduced with permission from [256]. Copyright 2009, Blackwell Publishing Ltd. 

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). 

Hicke, J A. and J. C. Jenkins, Mapping lodgepole pine stand structure susceptibility to mountain pine beetle attack across the western United States. For. Ecol. Manage. 255 1536-1547, 2008. 

Fettig, C. J., D. M. Grosman, and A. S. Munson, Advances in insecticide tools and tactics for protecting conifers from bark beetle attack in the western United States, pp. 472-492, In Insecticides—Development of Safer and More Effective Technologies, Trdan, S. (ed.). InTech, Rijeka, Croatia, 2013. 

Kegley, S. et al., A test of verbenone to protect individnal whitebark pine from mountain pine beetle attack USDA Eor. Serv. EHP Rep. 03-09, 2003. 

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