Insect pests in tropical forestry

Abstract

Since the publication of the first edition of this book in 2001, there have been several significant developments in forestry and forest entomology in the tropics that warranted inclusion in a second edition. One is the emergence of new pest species associated either with the expansion of plantation forestry into new regions or marginal areas, or a gradual adaptation by indigenous species to exotic hosts or the rapid spread of new invasives. The South American carpenterworm, Chilecomadia valdiviana, in Chile, and the South African goat moth, Coryphodema tristis, are examples of emerging indigenous pests associated with the establishment and expansion of exotic Eucalyptus spp. plantations in these countries. The blue gum chalcid, Leptocybe invasa, and the erythrina gall wasp, Quadrastichus erythrinae, are recent examples of the rapid worldwide spread of an invasive insect, similar to that which occurred for the leucaena psyllid, Heteropsylla cubana, in the 1980s and 1990s. The biology, ecology and impact of these, and many additional pest species, are discussed in an expanded Chapter 5.Another development has been the growing awareness of the 'true' global impact of forest invasive species as losses have been better quantified. Damage worldwide has been estimated at several billion US dollars per year, even without taking into account the loss of non-market value, which may well exceed that figure. This has prompted a range of international responses, including the formation of networks and surveillance programmes to provide early warning of incursions of forest invasives and the development of international standards for phytosanitary measures, such as that for wood packaging material, as discussed in Chapter 9. The global increase in self-help schemes such as plant clinics and field schools is also discussed. A range of new technologies has enhanced the accuracy and efficiency of forest health surveys over the past decade. These include the use of geographic information system-global positioning system interface tools and handheld computers to assist navigation and data collection in the field, and the application of digital, remotely sensed imagery to detect and classify damaged forest canopies. There have also been significant advances in the use of semiochemicals, including pheromones, for the detection and monitoring of forest pests and for controlling pest populations by means of mass trapping, lure and kill, lure and infect and mating disruption.One of the fundamental principles underlying this book is that the prevention of problems is far better than attempts at cures. The book is not in any way designed to be a manual of pest management. Instead, it presents concepts and examples of tropical forest viii Preface insects, their ecology, impact and control approaches where appropriate, and we hope that individual readers will make the connection between the generalities in the book and their own situation, socio-economic position and appropriate technologies. Some situations or examples have been revisited...