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M.Sc. / Members of the Suborder Microchiroptera consume large numbers of insects. When large enough numbers of these bats are present in agricultural areas, the need for insecticides can be reduced significantly. The ZZ2 Tomato Farms in Mooketsi and the Secrabje Farm in Waterpoort, in the Limpopo Province were chosen as study sites. Although ZZ2 focuses on the production of tomatoes, both farms produce a variety of vegetables and fruit. These farms were chosen because the management of both have shown a commitment to conservation and attempt to minimise their impact on the environment. Bat species indigenous to the study areas were captured by means of mist nets for identification purposes. Basic morphological data of captured specimens were collected and recorded. Their roosting behaviour and preferences were studied by visiting diurnal roosts in the two study sites. Microclimatic measurements were taken in roosts occupied by Chaerephon pumilus, Mops condylurus and Taedarida aegyptiaca. Microclimatic measurements were also done in bat houses designed for the housing of bats in agricultural areas. Results suggest that other factors, additional to temperature and relative humidity, contribute to the success and probability of bat house occupancy by bats. Existing roosts in man-made structures such as roofs, can successfully be enhanced to stimulate increase in colony size. Bat activities were determined in agricultural areas and adjacent natural habitats by means of recordings of the echolocation calls of the different bat Families. These were compared to the occurrence of nocturnal flying insect orders that were captured in light traps at the same localities. Of the bat species studied, a positive correlation between increased bat activity and higher number of insects, including pest species, was found. It seems as if the Molossidae has the greatest potential to be utilised in the control of insect pests of agricultural areas in the Limpopo of the bat species studied. A holistic approach favouring insectivorous bats on farms is recommended. This can be done i.a. through the conservation of abundant areas of natural vegetation adjacent to the agricultural areas which would provide foraging for bats during winter, periods of drought or when the lands lie fallow. The excessive and injudicious use of insecticides, which has a negative effect on bats, counteracts the beneficial and cheap alternative of natural insect pest control provided by insectivorous bats.

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False codling moth is a known pest of economic importance to many cultivated crops in South Africa and Africa south of the Sahara, and is particularly severe on citrus. If the fruit is infested just before harvest the chances of detecting signs of infestation are very low. As a result, the risk of packaging infested fruit and exporting them as healthy fruit is high. It is therefore a priority to develop a post-harvest technique for detection of False codling moth in citrus fruit at different levels of infestation in order to reduce phytosanitary risk. Compounds released and detected were indicative of infestation and were not insect produced but naturally produced fruit volatiles emitted at higher levels as a result of the insect within the fruit. Five major volatile compounds of interest were released by the infested oranges. These major volatile compounds include D-limonene, 3,7-dimethyl-1,3,6-octatriene, (E)-4,8-dimethyl-1,3,7-nonatriene, caryophyllene and naphthalene. Limonene was one of the most abundant volatile compounds released by the infested citrus fruit. Naphthalene, which is possibly produced due to larval feeding and development within the fruit maintained higher concentrations than controls throughout the infestation within the fruit. Naphthalene would be a good indicator of False codling moth infestation, however, not primarily for early infestation detection. A significantly higher concentration of D-limonene, 3,7-dimethyl-1,3,6-octatriene, (E)-4,8-dimethyl-1,3,7-nonatriene and naphthalene was detected using the SEP over the SPME technique. The application of an SPME procedure and the utilization of this method for detection of volatiles present in the headspace of intact infested fruit are evaluated and the possible volatile compounds diagnostic of Thaumatotibia leucotreta infestation of orange fruit and differences in volatile compound response in different orange varieties is discussed.

Soybean accounts from more than half of the acres dedicated to row crop production in the mid-south, leading to a wide planting window from late-March through mid-July. Studies were conducted in 2013 and 2014 evaluating seven planting dates of soybean, and their impact on agronomics. As planting was delayed, plant heights significantly increased, increasing the potential for lodging. Canopy closure significantly decreased as planting was delayed, leaving soybean more vulnerable to caterpillar pests. Yield potential also significantly decreased as planting was delayed. Season long surveys of insect pests and their arthropod natural enemies were conducted from 2013 to 2014 in small plot studies, and in large plot studies from 2015 to 2016 across multiple planting dates. The most common insect pests encountered in both studies were bean leaf beetles, the stink bug complex, and soybean looper. The most common natural enemies encountered were lady beetles, spiders, and the assassin bug complex. In general, insect pests densities increased as planting was delayed, whereas natural enemies were higher in earlier plantings or had no change throughout the planting windows. With the increased difficulty of controlling some caterpillar pests such as soybean looper, new control tactics need to be evaluated. A simulated Bt treatment was evaluated against a threshold, bug only, and untreated control across multiple plantings in 2013 and 2014. The simulated Bt treatment yielded significantly higher than the untreated control at plantings from early-June through mid-July. These were the only plantings that reached action threshold for soybean looper. The simulated Bt and threshold treatments were not significantly different from one another. In 2015 and 2016, a simulated Bt treatment plus threshold was evaluated in a late planting situation. The simulated Bt plus threshold treatment yielded significantly higher than the untreated control at the early-June and early-July plantings. Also in 2015 and 2016, the simulated Bt treatment was evaluated against a grower check on producer fields at 23 locations. The simulated Bt treatment resulted in significantly higher soybean yields than the grower check.

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