Thesis (Ph. D. )--Washington State University, August 2006. / Includes bibliographical references (p. 215-227).

Typescript, etc.

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Vita. / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1979 C54 / Master of Science

Thesis (M.Sc. (Plant Production)) -- University of Limpopo, 2014 / In most cases the discipline plant protection is restricted to the protection of propagules, the plants and their produce in storage, while excluding the protection of processed (cooked) food from contaminants. Generally, the German cockroach (Blattella germanica L.) is a serious contaminant of processed food and had recently been viewed as a pest worthy of control in plant protection when viewing the entire value chain of agricultural commodities. Due to the nature of the pest, it is quite difficult to control using registered agrochemicals on the market. An entrepreneur in the rural areas of Limpopo Province developed bait for cockroach control, which was code named Mohlolo during efficacy trials. The use of baiting in cockroach management is currently the sought after approach in the world where cockroaches are problematic. Bait has the advantage over liquid or dust formulations because baiting requires shorter service, has shown increased efficacy, and has reduced environmental contamination. The objectives of this study were to determine whether the effect of MIB would be age related in the suppression of populations of B. germanica under laboratory conditions, and also to investigate whether MIB would reduce populations of B. germanica in residential areas. Five concurrent B. germanica age-related experiments were run in a complete randomized design. 1-d, 2-d, 3-d, 4-d, 5-d old nymphs and adult German cockroach experiments were conducted at Limpopo Agro-Food Technology Station (LATS) laboratory, (53’21,41” S/29 23o 44’19,95”E) hosted at the University of Limpopo. Each age group consisted of 10 nymphs and was put in 250 cm3 container that contained xv Mohlolo insecticide bait (MIB). One gram (1 g) of Mohlolo insecticide bait and moistened cotton wick were put at the bottom centre of the 250 cm3 containers containing nymphs based according to their respective ages. Residential experiments were conducted at UL student apartments. Two Bait containers were then placed in the kitchen, lodge, bathroom and bedroom. In the kitchen MIB containers were put behind the cooking stove and refrigerator, in the lodge the bait was placed next to the study table (because most study tables are also used during the eating time). In the bathroom the baits were put next to toilet seat and lastly in the bedroom, the bait was placed next to study table. According to the results, 100% mortality of 1-, 2-, 3-, 4-, 5-days nymphs and adult B. germanica was obtained after 7th, 2nd 3rd 3rd and 4th day, whereas LT50 values ranged from half a day to one and half (1.5) day. The study also demonstrated that B. germanica populations had high LT50 and LT100 values in residential areas compared to LT50 and LT100 values obtained in the laboratory experiments. This is probably due to the fact that residential areas that have low levels of sanitation availed the cockroaches with an opportunity to choose from many foods hence, it reduced the probability for cockroaches to feed on Mohlolo insecticide bait in the respective apartments. Results of this study showed that, Mohlolo bait toxicity and effectiveness as a control agent can reduce infestation of cockroaches in all developmental stages when applied at small quantity. Providing results of this study would provide information on resistance and tolerance of B. germanica nymphs and adult population against MIB in the xvi laboratory and residential areas. It would also provide biological information on the efficacy of MIB against the German cockroaches.

Graduation date: 1996

No description available.

Call number: LD2668 .T4 1985 S245 / Master of Science

Fleas are one of the major external parasites affecting free range chickens, causing irritation, tissue damage, blood loss and toxicosis which in turn affect quality and quantity of meat and egg production. There are many commercial insecticides available that are effective against fleas. These commercial insecticides have, however become expensive to most resourcelimited farmers and therefore unaffordable, causing farmers to seek low cost alternatives. This study was conducted to document, determine the existence of external parasites in freerange chickens and validate the alternative remedies used in controlling free-range chicken fleas by resource-limited farmers. A questionnaire survey was used to collect data on external parasites of free-range chickens and ethno-veterinary control remedies used by resourcelimited farmers to control these parasites at Amatola basin, in Eastern Cape, South Africa. Resource-limited farmers perceived that mites (79.6%), fleas (64.5%), lice (10.8%) and ticks (6.5%) were problematic parasites of chickens. To control these parasites, resource-limited farmers commonly use ash (28%) madubula (13% carbolic acid) (26.7%), Jeyes fluid (13% carbolic acid) (10%), paraffin (8.4%), used engine oil (2.8%), plants Tagetes minuta, Clutia pulchella, Calpurnia aurea (5.2%) and a few (4.2%) used commercial drugs Karbadust (Carbarly 5%) and mercaptothion 5%. About 7.5% of the respondents used neither of the remedies. To confirm the farmers’ perception on problematic external parasites of free-range chickens a diagnostic survey was conducted. Fifty free-range chickens were randomly selected and examined for external parasites. About 96% of the free-range chickens examined harboured at least one species of external parasites. Fleas (Echidnophaga gallinacea) (50.7%) were the most prevalent followed by lice, Menopon gallinae (12.4%); Menacanthus stramineus (5.3%) and Knemidocoptes mutans (0.57%). Given that Jeyes fluid, used engine oil, paraffin, C. aurea, C. pulchella and T. minuta were mainly used in controlling these parasites, it was important to determine the potential dermal irritant effects of these plants. A dermal irritant effect test was, therefore, conducted using a rat model. Forty eight rats, with parts of the backs shaven, were used to screen the materials for irritation. All the materials tested did not cause any visible skin irritation on rats (p>0.05). Regarding that ethnoveterinary materials were non irritant on rat skin in vitro repellency and contact bio-assay models were used to assess the insecticidal properties of Tagetes minuta, Calpurnia aurea, Clutia pulchella, used engine oil, paraffin and Jeyes fluid on fleas. For the in vitro bioassay T. minuta and Jeyes fluid at 100% concentration demonstrated a repellency level of 76 and 83%, respectively. Tagetes minuta was the most effective among plant materials (p<0.05). Clutia pulchella, C. aurea, used engine oil and paraffin showed insignificant repellency (p>0.05). For the contact bio-assay, C. pulchella, C. aurea and T. minuta at a concentration of 100% resulted in flea mortality of 83.5, 73.3 and 42.5%, respectively. The efficacy of Clutia pulchella compared well with that of Karbadust which had a mean mortality of 97.5%. Paraffin, used engine oil, and Jeyes fluid (19.2%) caused higher flea mortality of more than 82%. In the in vivo study 60 free-range chickens were artificially infested with fleas and test materials were topically applied on infested sites. Test materials exhibited varying flea load reduction efficacy. Used engine oil and Jeyes fluid at 76.8% concentration had a reduction efficacy of 100 and 96% after 3 days post application of test materials. These were not significantly different to that of the positive control Kabadust (carbaryl 5%). The plants C. pulchella and C aurea at 100% concentration had an efficacy of 92 and 77%, respectively. The commonly used remedies by resource-limited farmers to control fleas vary in efficacy. Some of the materials are as effective as the commercial insecticides hence they have a potential to be exploited as insecticides. Further investigations on plant compounds with insecticidal properties and their toxicity, need to be conducted before the plants are recommended for use.