Insect Borers

Another potential pest of timbers in maritime situations is the wood-boring weevil Pselactus spadix that can excavate galleries in the inter-tidal and splash zones of wharf timbers. The larvae are believed to be the primary tunnellers, 

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Most wood species are subject to some form of biological attack, a hazard not encountered by most other constructional materials. Fungal decay and attack by termites and other insect borers and marine borers are the main problems. The heartwood of many timber species and the sapwood of most species can be impregnated with wood preservatives to prevent these problems. 

The main hazard to timber is biological attack. In milder climates this is mainly rot due to fungal infections together with insect borers. In hot... 

An interesting industry that has developed out of the necessity for preserving wood is now the second largest wood-related industry. Preservation against fiingi, insects, borers, and mildew is accomplished by using one of three important types of preservatives. The first type is creosotes, which are mixtures of aromatic hydrocarbons with organic acids and bases. 

Solomon, J. D. (1995). Guide to insect borers of North American broadleaf trees and shrubs. Agricultural Handbook 706, Washington, DC US Department of Agriculture, Forest Service. 

Preservative-. Any pesticide substance that, for a reasonable length of time, will prevent the action of wood-destroying fungi, insect borers, and similar destructive agents when the wood has been properly coated or impregnated with it. Normally an arsenic derivative. Chromated Copper Arsenate (CCA) is an example. 

Fungi are broadly associated microbial pathogens of insects. Beauveria bassiana is extensively used as a microbial insecticide in China and Eastern Europe, especially for the control of the com borer Ostrinia spp. However, fungi have had no significant development as microbial insecticides in the United States. 

The best protection for wood against the attack of decay fungi, insects, or marine borers is obtained by applying preservatives under pressure before installation (61,62). Both oil-type preservatives, such as creosote or petroleum solutions of pentachlorophenol, and waterborne preservatives, such as copper-chrome arsenate and ammoniacal-copper arsenate, are used when wood is to be in direct contact with the ground or in the marine environments. 

The situation with some forms of biological deterioration is somewhat different. Where the agent is macrobiological, as in the case of rodents, insects, and marine borers, the attack is physical in nature, such as by gnawing or boring. The attack is not at the atomic or molecular level. Any breaking of molecular bonds such as in polymer chain shortening is thus accidental. The attack may be said to be at the material s structural level, not the polymer molecule level. 

The insect s choice of food may be governed to a considerable extent, as ours is, by attractants and repellents. In many instances, the actual insecticidal action of plant extractives may be due primarily to an artificially high level of application, while, in fact, the parent plants are only repellent in the field. This repellency may appear to be resistance on the part of the plant, and the chemistry of such resistance factors has begun to receive much-needed attention. For example, Smissman and his coworkers have examined the chemical basis for the inherited resistance of some strains of corn to attack by the European corn borer. 6-Methoxybenzoxazolinone (X) was isolated (2, SO) and shown to be one of the principal resistance factors, and a number of synthetic analogs were found to... 

It is expected that taxonomically related species which have developed from a common ancestor also exhibit similarity at the pheromone level. An interesting typical representative can be observed in the family Tortricidae. This family includes a multitude of agricultural pest insects such as leaf-rollers and fruit-borers, whose sex pheromones have been exhaustively investigated [33]. Among the four subfamilies in Tortricidae, Tortricinae and Olethreutinae are the major two,... 

Chlorpyrifos inhibits substrate-borne reception and emission of sex pheromone in Tri-chogramma brassicae, an entomophagus insect massively used as a biological control agent of com borers, among survivors of an LC20 dose. Inhibition was probably due to nervous system effects and was not specific to pheromone communication (Delpuech et al. 1998). 

The sugar cane borer, Diatraea saccharalis, is the most serious sugar cane insect pest in Louisiana. Ryania and cryolite (sodium fluoaluminate) were dusted on 65,000 acres in 1953 at a total cost of 600,000. Borers in other areas are controlled to a certain extent by natural or introduced parasites. Puerto Rico estimates an annual loss of 2,500,000 from borers. Serious losses are incurred in other areas, but no chemical controls have been adopted. 

Other insects are of local importance including various beetles, grubs, the lesser cornstalk borer, and several vectors of virus diseases. The latter might be controlled by systemic insecticides. 

No successful experiments are known to have been conducted in the United States in the control of these insects by means of insecticides. Grist (10), reporting on the work of Van der Laan, indicates the possibility of control of the white stem borer (Scirpophaga innotata) in Indonesia by spraying seed beds with 0.04% DDT emulsion. 

Contamination of crops and products with ochratoxin A and related metabolites is not as directly associated with a particular fungus as is the case with the aflatoxins. Ochratoxin A is also likely to occur with other mycotoxins, such as citrinin and penicillic acid or patulin. In addition, it is not certain whether ochratoxin A contamination is only a storage problem or perhaps a dual field and storage problem. In cases such as coffee crops, the use of insecticides might help to control insect activity and consequently fungal infection. Coffee-berry borers are a major insect pest which can act as vectors to carry fungal spores, resulting in crop infection and ochratoxin accumulation. 

Acetyl derivatives of the BayUs-Hillman adducts on treatment with Zn in saturated aq. NH4CI solution under reflux has also been utilized as a method for the preparation of chiral insect ph eromones dominicalure 1 and dominicalure 11 of the lesser grain borer Rhyz pertha dominica. 

Minnesota, Iowa, and Illinois (9). As indicated by its common name, the hop-vine borer had been found in close association with hop (Humulus lupulus) plants. Wild hops, found from the east coast of the U.S. to the Rocky Mountains, presumably served as the primary host for the Insect in North America (10) for the last 100-150 years or longer. 

Because of their similar life cycles, habits, damage to corn, and apparent resistance to conventional corn rootworm insecticides, we could expect both the PSB and HBV to increase their densities and/or range throughout the Midwest much as the PSB has (9,12). These concerns are evident in the 1985 establishment of a multistate regional research effort entitled "Impact of integrated crop management practices on European corn borer and related stalk boring insects". 

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