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CHAPTER 1 - Introduction to the Neuroptera: what are they and how do they operate?
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- By T.R. New
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
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- 04 May 2010
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- 07 June 2001, pp 3-5
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Summary
INTRODUCTION
Neuroptera (also known as Planipennia), the lacewings, antlions, and their allies, are one of the smaller and more primitive orders of holometabolous insects. About 6000 species are known. They are commonly linked with the Megaloptera (alderflies, dobsonflies) and Raphidioptera (snakeflies) in the superorder Neuropteroidea (or Neuropterida), and are of world-wide occurrence, although many taxa are more restricted and some are characteristic faunal elements of particular regions. Neuroptera have a long evolutionary record, and there are many fossils from the Permian and Jurassic which are referable clearly to this order (Carpenter, 1992), mainly on details of the complex wing venation which gives lacewings their common name. Most are terrestrial, although a few (such as the specialised Sisyridae, the spongeflies, whose larvae are predators of freshwater sponges, and Nevrorthidae) frequent freshwater environments. Adults and larvae of most families are predatory, and the main interest of the order to many entomologists is that which forms the major theme of this book – that some lacewings can be of considerable value as manipulable predators for use in biological control programmes. This brief introduction is a broader survey of the Neuroptera, to facilitate a more general perspective of the order. Thus, whereas this book is about members of only three families (Coniopterygidae, Hemerobiidae, Chrysopidae with the last by far predominant), up to 18 Recent families are recognised, and a number of others are extinct. The phylogenetic relationships between some of these are still debated.
CHAPTER 17 - Lacewings, biological control, and conservation
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- By T.R. New
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
- Published online:
- 04 May 2010
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- 07 June 2001, pp 380-384
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Summary
INTRODUCTION
Release of non-specific predatory insects into a new area implies responsibilities associated with a ‘duty of care’ for the receiving environment and, from the conservationist's viewpoint, is not always an exercise to be undertaken lightly, despite the seeming urgency of biological control measures against pest arthropods. The twin contexts that are relevant to introductions of lacewings are (1) release of species which are exotic to the areas where they are released (that is, as classical biological control agents, species not present previously in the region of introduction, for which the above precautions may be particularly important) and (2) native species whose populations are enhanced by releases from commercial stocks, or by use of attractants to concentrate field populations in more limited areas. Both approaches are usually part of IPM programmes undertaken with the overall aim of seeking more cost-efficient pest control with the economic and environmental benefits of reduced pesticide use.
Incorporation of predators into such strategies is increasingly undertaken with the aims of short-term gain and longer-term environmental safety. Nevertheless, it is pertinent here to recapitulate some of the responsibilities and concerns that such operations raise, and to emphasise the need to monitor introductions effectively to help improve further the application technologies and quality of the results obtained.
Many such releases are indeed undertaken with due regard to ‘acceptable risk’, but clear definition of those risks is itself a complex matter. Increasingly, such risks are being dealt with by a combination of regulations, protocols, and guidelines involving some degree of consensus of scientific and regulatory participants.
CHAPTER 18 - Micromus tasmaniae: a key predator on aphids on field crops on Australasia?
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
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- 04 May 2010
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- 07 June 2001, pp 388-394
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Summary
INTRODUCTION
The Australian Hemerobiidae are largely endemic, with many of the 34 recorded species (New, 1988) not known elsewhere. Micromus tasmaniae (Walker) is by far the most abundant and widespread hemerobiid in Australia and New Zealand (where it is presumed indigenous, though possibly originating from Australia: Wise, 1992), and has attracted attention as the most frequent lacewing on low vegetation, including common occurrence on a variety of field crops. Its predominance is evident in several surveys noted below, and as New Zealand lacks native Chrysopidae on crops, it has attracted attention there as the lacewing occurring in agricultural systems. It is, likewise, often abundant in Australia. For example, in suction trap catches near Melbourne, Victoria, over three years it comprised 3847/4080 (94.3%) of all Hemerobiidae (New, 1984). Most other Australian hemerobiids are relatively scarce in such collections, and only Drepanacra binocula (Newman) is otherwise likely to be familiar, even to many entomologists. That species also occurs in New Zealand, and like the other New Zealand Micromus species, M. bifasciatus Tillyard, is relatively scarce and not regarded as a significant component of the crop fauna.
BIOLOGY
The two common Australasian hemerobiid species differ considerably in biology.Drepanacra binocula is predominantly arboreal and is a relatively specialised feeder on Psylloidea, whereas Micromus tasmaniae is a more generalised polyphagous feeder on arthropods of low vegetation, though it occurs also on shrubs and trees. The early stages were described by New & Boros (1984).
CHAPTER 2 - Introduction to the systematics and distribution of Coniopterygidae, Hemerobiidae, and Chrysopidae used in pest management
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- By T.R. New
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
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- 04 May 2010
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- 07 June 2001, pp 6-28
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Summary
INTRODUCTION
Not altogether coincidentally, the three families of Neuroptera discussed in this book are those on which most biological and taxonomic information and understanding is available. They are the most widespread, predominant, and diverse families in the northern temperate regions, where the foundations of early knowledge on the order were laid, and the use of lacewings in pest control was pioneered. All are more widespread, and all have recently been subject to comprehensive global review and reappraisal, so that much of the early scattered information has been brought together, reevaluated and synthesised, keys to generic level produced, and some constructive comment on their diversity, evolution, and biogeography is feasible. However, biological information on most species, and many genera in other parts of the world, is not available or is fragmentary. Although some inferences can be made from the species already studied, the considerable biological variability within each family suggests that extrapolation from the few well-studied species in each should be cautious. Likewise, despite the impetus provided by recent overviews, many new species await discovery and description, and the minefields of over-simplified treatment of complex species groups are exemplified well in the following chapter on Chrysoperla, a single genus of Chrysopidae (Henry et al., this volume).
This chapter is a broad introduction to the systematics and biogeography of the Coniopterygidae, Hemerobiidae, and Chrysopidae, to provide a perspective for the remainder of this book, and to help readers appreciate the complexity of the groups considered – as well as the opportunities they may furnish for study and manipulation in the future.
CHAPTER 15 - Sampling and studying lacewings in crops
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
- Published online:
- 04 May 2010
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- 07 June 2001, pp 351-356
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Summary
INTRODUCTION
Neuenschwander (1984) emphasised that much sampling and monitoring of lacewing populations in the past has not been strictly quantitative, but has involved collections to determine presence/absence and gross inferences on the relative abundance of various species on a crop or in an assemblage in an area or defined environment.
Nevertheless, for many purposes there is need for field assessments based on quantitative appraisal based on adequate, replicable sampling protocols, and continued monitoring to determine population sizes, changes in species abundance, phenological traits, and responses to change. Neuenschwander's account of such approaches and the techniques employed remains valid and applicable, and forms the basis for the discussion which follows. However, in the intervening years, the need for improved sampling to establish predictive capability has become more widespread in IPM, and the wisdom of monitoring the establishment, influences, and spread of biological control agents consolidated.
As in any sampling programme, the scale of operation and the precise questions being asked must determine the sampling regime and the intensity of sampling needed. ‘Sampling effort’ reflects both the duration and intensity of sampling. At the extremes, a single brief collection period may be all that is needed to confirm the presence of a given lacewing species on a crop whilst, at the other, continuous or interval sampling using a variety of techniques over an extended period (of one or more growing seasons or years) may be necessary to reveal population trends, phenology, and the relative abundance of the members of a complex of natural enemies, or the establishment of a newly introduced biological control agent.
CHAPTER 19 - Preliminary notes on Mallada signatus (Chrysopidae) as a predator in field crops in Australia
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- By P.A. Horne, T.R. New, D. Papacek
- Edited by P. K. McEwen, Cardiff University, T. R. New, La Trobe University, Victoria, A. E. Whittington, National Museums of Scotland
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- Book:
- Lacewings in the Crop Environment
- Published online:
- 04 May 2010
- Print publication:
- 07 June 2001, pp 395-397
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Summary
INTRODUCTION
The manipulative use of Chrysopidae as biological control agents in Australia is in its infancy. The family is well represented, with slightly more than 50 species described (New, 1996), but many of these are recorded only infrequently in Australia and occur almost entirely in forests and other naturally vegetated habitats. Many are also limited in their distribution within Australia. The species encountered most frequently in southern Australia are Apertochrysa edwardsi (Banks), Mallada innotatus (Walker), M. signatus (Schneider), and Plesiochrysa ramburi (Schneider). Indeed, a survey of Chrysopidae on native Acacia trees over three years in Victoria yielded only three species (A. edwardsi, M. signatus, P. ramburi), with A. edwardsi by far the most abundant (New, 1983). However, this species is predominantly arboreal, and has not been reported commonly on field crops. Apertochrysa edwardsi is Bassian, the two Mallada species are widespread in Australia, and P. ramburi occurs over much of the western Pacific region, where its larvae have been reported from many crops. The larvae of all these species were described by Boros (1984), but many details of their biology have not been clarified, and there are few records of their prey or feeding activity. However, they are clearly the most likely candidates among Australian Chrysopidae for investigation for their potential in biological control.
This note considers the potential for one of these common species, M. signatus, as a species currently attracting considerable attention as a polyphagous predator on pests of field crops.
ROLE IN BIOLOGICAL CONTROL
In eastern Australia, Mallada signatus is commonly found only in small numbers on field crops.