Insects And Humans

unchanged for a considerable time so that the fiber and nutrients are unavailable to maintain 735

soil fertility and texture. Rank herbage grows around each dung pat, and this is not normally eaten by cattle. Thus, at any time, dung pats render a significant proportion (estimated at about 20%) of all pasture potentially unusable (Waterhouse, 1974). Although Australia has more than 320 indigenous species of dung beetles, almost all of these use only the dung of native marsupials, especially kangaroos, wallabies, and wombats, and, furthermore, are restricted to forest and woodland habitats. Only a few species of the native Onthophagus have adapted to using cattle dung (Waterhouse and Sands, 2001).

In 1963, it was decided to initiate a program of biological control of dung, and in 1967, after extensive research, various species of tropical southern African dung beetles were released in northern Australia. These species had been carefully selected from regions climatically similar to northern Australia and because they were known to be effective processors of the dung of large native ruminants. The results were spectacular, the beetles rapidly multiplied and spread over wide distances, while simultaneously achieving complete or partial disposal of dung for much of the year (Waterhouse, 1974). Over the next 15 years, about 50 additional species of dung beetles, plus a few species of histerid beetles that prey on fly eggs, larvae, and puparia, were imported not only from southern Africa but also from southern Europe and Asia, each having features appropriate to a particular region of Australia. Of the 50-odd species released, 25 dung beetles and 3 histerids have established breeding populations in the field, though numbers (and effectiveness of dung processing) may be highly varied according to the species, locality, season, and weather conditions (Waterhouse and Sands, 2001). All of the species established in northern regions are common in all except the winter months, and through the summer almost complete dispersal of dung occurs. Further, there is some evidence that such intense activity results in a regional suppression of buffalo fly numbers.

In the cooler southeast and southwest of Australia the introduced species are most active in the summer and autumn months when their dung dispersal may substantially reduce bush fly abundance. However, their activity is generally low in winter and spring, the latter being the period in southwestern Australia when massive populations of bush flies develop (Doube et al., 1991). Thus, in 1989, three spring-active species were imported from Spain; one of these, Bubas bison, established itself quickly though populations of the other two species took longer to increase because of their complex breeding behavior (Creagh, 1993).

In terms of dung disposal, the Australian dung beetle project has been a major success, saving farmers the costs of harrowing, accelerating the release of nutrients into the soil, and reducing the availability of fly breeding sites. No comprehensive study of the impact of the introduced beetles on the pest fly problem has been undertaken. However, Waterhouse and Sands (2001) provide examples to show that the beetles may significantly reduce fly populations at a local level, especially when rainfall, which prolongs the beetles' breeding activity, is favorable. A compounding factor in any attempt to estimate the beetles' impact is the ease with which the flies are carried on wind currents from regions where they have bred successfully. This tends to mask local effects of dung beetle activity on fly numbers. In all probability the dung beetle system will become but one component of an integrated program for fly population management, with other strategies being used when fly populations peak.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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