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One of the means whereby an insect recognises a plant is "by detecting secondary plant compounds. Some such compounds are phagostimulatory but many act as feeding deterrents. The extent to which these deterrents are toxic was investigated in this thesis using Locusta migratoria, an oligophagous species which feeds mainly on grasses and thereby avoids many secondary plant compounds and Schistocerca gregaria, a polyphagous species which feeds on many plants deterrent to Locusta. Toxicity tests revealed that single injections of azadirachtin, allyl isothiocyanate, tomatine and nicotine into the haemolymph were significantly more toxic to Locusta than to Schistocerca. Sinigrin, umbelliferone and salicin were non-toxic in the short term to both species. Overall there was a significant positive correlation between the deterrency of the compounds to the insects and their toxicity. Tolerance was greater following cannulation of the compounds into the gut where only allyl isothiocyanate and nicotine were toxic to Locusta, and Schistocerca was unaffected by all the test compounds. Sinigrin is more deterrent to Locusta than to Schistocerca yet in the short term was non-toxic to both species. Long term feeding studies, in which the formulation of the test compound was shown to affect its toxicity, demonstrated however that Locusta was more susceptible to sinigrin than Schistocerca. Nicotine, which followed the overall pattern of being more deterrent and toxic to Locusta than to Schistocerca, was shown to be excreted from the haemolymph and voided from the gat more efficiently in Schistocerca. The target organs of Schistocerca were also less permeable to nicotine than those of Locusta. These factors, together with the ability of Schistocerca to induce its mixed-function oxidase system are suggested as the reasons for its greater tolerance to nicotine compared to Locusta . Azadirachtin is 1000 times more deterrent to Schistocerca than to Locusta, yet was more toxic to Locusta. Azadirachtin was shown to decrease body growth and increase the instar length in both species of insect. This effect is associated with a lack of feeding which could be caused by a direct toxic action to the gat as suggested by histological evidence. Gut contractions in Locusta were reduced 'in vitro' after application of azadirachtin. The inductive effect of azadirachtin on the mixed-function oxidase levels was greater in Schistocerca than Locusta. It is concluded that Locusta is physiologically less able to deal with secondary plant compounds than Schistocerca as a result of having evolved from a polyphagous to a graminivorous feeding strategy.

An estimated 250,000 loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles are taken each year as incidental catch by the pelagic long-line fishing industry. Various gear and bait modifications as well as time/area closures to fishing, enacted to reduce anthropogenic impacts on sea turtles, have been ineffective or incompatible with regional fishery interests. Chemosensory and auditory deterrents have yielded little benefit thus far in repelling sea turtles from long-lines. The fact that sea turtles are highly visual animals has precipitated studies of the efficacy of using shark shapes to repulse them from long-lines. Previous shark-shape studies yielded promising results, but their design lacked statistical rigor. The present study examined the response of 42 captive-reared loggerhead sea turtles (Caretta caretta) to a shark-shape model at the NOAA Sea Turtle Facility in Galveston, TX. To measure repulsive effect, time taken to consume squid bait beneath the shark model was compared to that for controls in which loggerheads were offered squid beneath a spherical object or a bare squid (i.e., no object control) in a captive setting. Additional responses compared among these three treatments were time spent near treatment, number of breaths taken, approaches to the treatment, and avoidance behaviors displayed (e.g., turning carapace toward treatment). Loggerheads exhibited anti-predator behavior toward the shark model, taking significantly more time to consume squid bait beneath the shark model than for the other two treatments. Turtles also spent significantly more time opposite the tank from the shark model, approached it less often, and exhibited more carapace turns to the model. Some avoidance of the spherical control object also was observed, but was not as pronounced as that displayed toward the shark model. While a repulsive effect of the shark model was resolved during the aforementioned trials, application of such models to reducing long-line fishery bycatch would require further research to identify a plausible application; numerous shapes attached to long-line hooks would be very cumbersome. However, it may be plausible to develop a “boy’s day kite” shark model that would unfurl and “fly” underwater, and could possibly be clipped to buoy float lines.

Southern flying squirrels (SFS; Glaucomys volans) are known kleptoparasites on the endangered red-cockaded woodpecker’s (RCW; Picoides borealis) cavities and cost land managers time and money to control and the ecology of SFS in habitats managed for RCWs is poorly understood. This study is designed to obtain a better understanding of the general ecology of SFSs surrounding RCW habitat and provide possible non-lethal deterrent methods to prevent harmful interactions between SFSs and RCWs. Spatially-explicit capture-recapture showed generally higher SFS densities and habitat associations outside of RCW cluster partitions. Stable isotope analysis of SFS diets across Mississippi and Alabama revealed a narrow dietary breath relative to food items, thus habitat management may still be viable option to control SFSs. Lastly, investigation of odor deterrents resulted in the greatest avoidance of cavities containing gray rat snake (Pantherophis spiloides) feces and warrants further investigation.

Yes / This report supports the second in a series of briefings on Trident to be published during 2007 and 2008 as part of the Bradford Disarmamenet Research Centre's programme on Nuclear-Armed Britain: A Critical Examination of Trident Modernisation, Implications and Accountability.

Yes / This briefing paper is the first in a series to published through 2007 and 2008 as part of the Bradford Disarmament Research Centre¿s programme on ¿Nuclear-armed Britain: A Critical Examination of Trident Modernisation, Implications and Accountability¿. The programme has been generously funded by the Joseph Rowntree Charitable Trust. / Joseph Rowntree Charitable Trust

Yes / This briefing paper is the third in a series to be published during 2007 and 2008 as part of the Bradford Disarmament Research Centre¿s programme on Nuclear-Armed Britain: A Critical Examination of Trident Modernisation, Implications and Accountability. / Joseph Rowntree Charitable Trust

Yes

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