Insect Sampling

10 Key excerpts on "Insect Sampling"

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  eBook - ePub

  Urban Landscape Entomology

  • David Held(Author)
  • 2019(Publication Date)
  • Academic Press

    (Publisher)

  Chapter 5

  Sampling insects and decision-making

  Abstract

  Sampling (a.k.a. scouting) is the only way to know the abundance, location, and timing of activity of insects and mites in urban landscapes. In Chapter 2 , you learned the terms density and distribution as important descriptions for populations. All sampling and eventual pest management decisions are made at the population level. Sampling techniques for pests and beneficial insects in urban landscapes are not expensive or difficult yet they are not commonly used. This may be due to several reasons; outbreaks are not as predictable as problems with annual or perennial weeds, insecticides on average are less expensive than fungicides or herbicides, and plant professionals typically do not know how to sample. In urban landscapes, insects and mites can be found above the ground, in the soil, or inside the plant (e.g., leafminers, borers). In the following sections, you will learn the common methods for sampling arthropods in the landscape and what you could do with that information once you have it. The resources section at the end of this chapter provides a list of sources for sampling equipment and links to online resources for sampling.

  Keywords

  Aesthetic injury level; Damage; Integrated pest management; Sampling; Symptoms

  Sampling (a.k.a scouting) is the only way to know the abundance, location, and timing of activity of insects and mites in urban landscapes. Chapter 2 , introduced the terms density and distribution as important descriptions for populations. All sampling and eventual pest management decisions are made at the population level. Sampling techniques for pests and beneficial insects in urban landscapes are not expensive or difficult, yet they are not commonly used. This may be due to several reasons; outbreaks are not as conspicuous as problems with annual or perennial weeds, insecticides on average are less expensive than fungicides or herbicides, and plant professionals typically do not know how to sample. In urban landscapes, insects and mites can be found above the ground, in the soil, or inside the plant (e.g., leafminers, borers). In the following sections, you will learn the common methods for sampling arthropods in the landscape (Box 5.1)

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  Integrated Management of Insects in Stored Products

  • Bhadriraju Subramanyam(Author)
  • 2018(Publication Date)
  • CRC Press

    (Publisher)

  Sampling should also be used to determine whether control measures were successful, by comparison of pre- and posttreatment counts or presence/absence of insects in the samples. However, it is important to bear in mind that after applying control measures a majority of the insects are killed, and the density and spatial structure of insects in the sampling universe may be altered. Therefore, the number of samples needed to estimate the posttreatment density reliably may be different from the number of samples needed to estimate the pretreatment density.

  XI. SUMMARY

  In most agricultural situations, sampling the entire sampling universe to determine a population attribute (mean density or proportion) is impossible or cost-prohibitive. Therefore, these population parameters are unknown. Thus, samples of a known size are removed from the sampling universe to make inferences about these population parameters. Designing a sampling program involves choosing an appropriate sample unit, determining the number of samples to use, selecting locations to be sampled, and the time of sampling. Small sample units are often more efficient than large sample units, but the costs associated with obtaining the samples are higher for the former than the latter. Sample locations should be selected to provide a representative sample. Samples must be taken frequently to detect insect populations before they reach unacceptable levels. Sampling methods that provide absolute estimates are generally needed for studying insect ecology, but for pest management less accurate estimates of insect density may be considered to reduce sampling costs. However, it is important to establish a relationship between relative density estimates and absolute pest density estimates or damage.

  Mapping the location of insects within the sampling universe is difficult, especially if the insects are mobile or active. Therefore, information from the sample units is used to describe the spatial distribution or sampling distribution of the insect populations. Fitting probability distribution functions or dispersion indices to sampling data permits development of sampling plans for estimation or decision-making in pest management (Binns and Nyrop 1992). A few sampling plans, for estimating insect density, have been developed for stored-product insects (Hagstrum et al. 1985; Hodges et al. 1985; Subramanyam and Harein 1990; Subramanyam et al. 1993). We hope researchers and pest managers working with stored-product insects will use the sampling concepts and formulas presented in this chapter to develop sampling plans for cost-effective management of insect pests. The four basic pieces of information needed to use the numerous equations presented in this chapter are the mean, variance, number of samples used to estimate the sample mean and variance, and proportion of sample units with insects. Most of the computations are easy and can be done on a hand calculator, while fitting a few models or equations to sample data may require the use of a computer. Most of the equations have been illustrated using examples based on published and unpublished stored-product Insect Sampling data. Numerous references have been provided for those interested in additional information not covered in this chapter. Sampling is an integral component of integrated pest management. The business of storing, processing, and distributing food products can be more profitable if pest management decisions are based on practical sampling programs that provide precise estimates of population density or proportion.

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  Descriptive Taxonomy

  The Foundation of Biodiversity Research

  • Mark F. Watson, Chris H. C. Lyal, Colin A. Pendry(Authors)
  • 2015(Publication Date)
  • Cambridge University Press

    (Publisher)

  Both need sampling techniques, which are crucial for inventories and are the main theme of our review. Matching the huge diversity, there is a great variety of qualitative and quanti- tative collecting techniques for insects, only briefly sketched below. The actual techniques employed will depend on the scope and emphasis of the study, be it targeting specific taxa or surveying an entire ecosystem. In addition, the habitat(s), available time and resources strongly determine the method(s) of choice. Mass-collection techniques produce huge numbers of insect specimens, which have to be sorted into groups, counted, assigned to morphospecies and eventually be sent to specialists for exact determination or description (for further challenges applying a morphospecies concept, see Krell, 2004). These costly procedures are often avoided by discarding insects other than the target group, which could be a certain subfamily or larger group. Alternatively, mas- sive sampling endeavours lead to accumulation of huge and space-consuming repositories of more or less sorted insect material stored in alcohol. We present below a short synoptic overview of insect inventorying techniques, review the present state of knowledge resulting from mass-collecting techniques, present examples for non-invasive bioacoustic inventorying and outline the needs for more efficient and coordinated inventorying efforts. These include application of standard protocols to ensure both efficiency and sustainability of records and data generated. In addition, we will focus on data processing and dissemination techniques, which is another bottleneck for inventorying the huge number of insect species inhabiting our planet. FIELD METHODS FOR INVENTORYING INSECTS 191

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  Insect Sampling in Forest Ecosystems

  • Simon R. Leather(Author)
  • 2008(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  Canadian Journal of Zoology , 63 , 1306–1355. Rutledge, P.A. & Fleeger, J.W. (1988) Laboratory studies on core sampling with application to subtidal meiobenthos collection. Limnology and Oceanography , 33 , 274–280. Service, M.W. (1993) Mosquito Ecology: Field Sampling Methods. Elsevier, London. Shlyakhter, A.I. & Kammen, D.M. (1992) Sea-level rise or fall? Nature , 357 , 25. Siemann, E., Tilman, D., & Haarstad, J. (1999) Abundance, diversity and body size: patterns from a grassland arthropod community. Journal of Animal Ecology , 68 , 824–835. Sokal, R.R. & Rohlf, F.J. (1995) Biometry. W.H. Freeman, New York. Southwood, T.R.E. (1978) Ecological Methods. Chapman & Hall, London. Stewart, R.J. & Schaefer, C.H. (1983) The relationship between dipper counts and the absolute density of Culex tarsalis larvae and pupae in rice fields. Mosquito News , 43 , 129–135. Sugihara, G. (1980). Minimal community structure: an explanation of species abundance pat-terns. The American Naturalist , 116 , 770–787. Svensson, B.W. (1999) Environmental heterogeneity in space and time: patch use, recruit-ment and dynamics of a rock pool population of a gyrinid beetle. Oikos , 84 , 227–238. Taylor, J.R. (1982) An Introduction to Error Analysis. University Science Books, Sausalito, CA. 218 CHAPTER 9 Trexler, J.D., Apperson, C.S., & Schal, C. (1998) Laboratory and field evaluations of oviposition responses of Aedes albopictus and Aedes triseriatus (Diptera: Culicidae) to oak leaf infusion. Journal of Medical Entomology , 35 , 967–976. Turner, A.M. & Trexler, J.C. (1997) Sampling aquatic invertebrates from marshes: evaluating the options. Journal of the North American Benthological Society , 16 , 694–709. Vance, G.M., VanDyk, J.K., & Rowley, W.A. 1995. A device for sampling aquatic insects associated with carrion in water. Journal of Forensic Sciences , 40 , 479–482. Washino, R.K. & Hokama, Y. (1968) Quantitative sampling of aquatic insects in a shallow-water habitat.

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  Handbook of Sampling Methods for Arthropods in Agriculture

  • Larry P. Pedigo, G. David Buntin, Larry P. Pedigo, G. David Buntin(Authors)
  • 2020(Publication Date)
  • CRC Press

    (Publisher)

  4

  As part of an overall IPM strategy, sampling techniques should be compatible with the objective of the decision maker. For example, if the management situation calls for a binary decision on whether or not to apply a prophylactic suppression tactic, then the sampling technique must provide discrete predictive data within the appropriate time horizon to accommodate the decision. If, however, the situation calls for continuous monitoring to assess population growth and development, then the sampling technique(s) must account for population dynamics and host susceptibility in order to make effective curative control decisions.5 The design and use of arthropod sampling techniques, therefore, helps to enable IPM by providing a means by which to make informed decisions. In addition, because the cost of sampling is integral to the cost (and hence, feasibility) of IPM, every effort should be made to develop a high level of efficiency with the design and use of the technique(s). Otherwise, sampling and subsequent curative control decision making will prove to be a less desirable management alternative, resulting in either overuse or underuse of suppression tactics.6

  Inasmuch as the challenge of establishing an effective IPM strategy largely is a challenge of developing an effective and efficient sampling technique, the objective of this chapter is to review several basic techniques currently employed for the surveillance and sampling of arthropods. Primary categories include: techniques for surface and above-ground arthropods, techniques for soil arthropods, and techniques for indirect assessment of arthropods. Although reference to, or review of, all adaptations to these primary sampling techniques is not pragmatic, representative examples for categories are provided for illustrative purposes.

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  Sterile Insect Technique

  Principles And Practice In Area-Wide Integrated Pest Management

  • Victor A. Dyck, Jorge Hendrichs, A.S. Robinson, Victor A. Dyck, Jorge Hendrichs, A.S. Robinson(Authors)
  • 2021(Publication Date)
  • CRC Press

    (Publisher)

  Thus, he used a type II error with level β, the convention used by Kuno (1991) and Yamamura and Sugimoto (1995). Sampling Methods. Different sampling methods, that sample different portions of a population, are often applied in area-wide integrated pest management (AW-IPM) programmes (Vreysen, this volume). Insects with free-living immature stages will usually require sampling methods different from those applicable to mature individuals, and hungry insects may be attracted to lures that are different from those that attract sexually active or ovipositing individuals (Jang et al. 1999). Traps that minimize the capture of sterile males, and instead capture mainly females, are a special advantage in the case of male-only sterile releases (Katsoyannos et al. 1999). In attempting to sample a sparse (or perhaps non-existent) population, careful planning is needed to ensure that all portions of the population receive attention. If there are portions of a population that cannot be trapped or sampled otherwise, then, before applying the probability models to them, sufficient time must be given for them to become responsive to a trap. Given the propensity of insects to congregate in certain areas, detection trapping needs to be done throughout the assessment area that will eventually be designated “pest free”. Any information about the location of aggregated insects, times of greatest activity, and relative efficiency of various trap types and other sampling methods should be utilized to improve the chances of detecting insects that are at very low densities. In addition, to cover all life stages and physiological states, all effective trap types and other sampling methods should be utilized. Detectability. Insect detectability (σ) can be estimated using a variety of methods (Thompson 2002); one method uses mark-recapture techniques (Shelly et al. 2010; Itô et al., this volume). Before an eradication programme commences, this should be done for each trap type used

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  Insect Ecology

  • Upadhyay, Shadanan(Authors)
  • 2018(Publication Date)
  • Biotech

    (Publisher)

  Instead of conclusions based on presence-absence data, probabilities that convey the likelihood a species will occupy a given area are more preferred because these models include an estimate of confidence in the likelihood of the species being present/absent. Additionally, they are also more valuable than data collected based on simple presence or absence because models based on probability allow the formation of spatial maps that indicates how likely a species is to be found in a particular area. Similar areas can then be compared to see how likely it is that a species will occur there also; this leads to a relationship between habitat suitability and species occurrence. In considering the distribution of an insect, and particularly that of an introduced form, it is usually customary to include within the area of distribution every place at which a single specimen has ever been collected. The distribution so defined may be termed the systematic or absolute distribution. The success is due to 2 outstanding features in insect: 1. Tendency to increase 2. Subsequent dispersal Of the various factors responsible for insect distribution, the major are climate (as insects are poikilothermous), availability of food and evolutionary This ebook is exclusively for this university only. Cannot be resold/distributed. history of the place. In nature three groups of insects are found: 1. Tropical insects with a death point of 10-15°C 2. Temperate insects with a death point of 0°C 3. Boreal(Artic) with a death point between -20°C to -30°C Insects are also called as: 1. Eurythermal-insects having wide range of temperature tolerance. 2. Stenothermal-narrow range of temperature tolerance. Within the absolute distribution there is a much smaller region in which the insect causes damage to crops, and becomes of economic. This inner area, within which all outbreaks have occurred, maybe called the area of economic distribution.

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  Insect Predators and Pest Management

  • Patil, Vaishali J(Authors)
  • 2021(Publication Date)
  • Daya Publishing House

    (Publisher)

  Chapter 3 Survey and Surveillance Insect population sampling specially the sampling of insect pests is one of the most useful task in pest management. Sampling of insect is dependent on specialized habits and habitats of the insects. Moreover, sampling of insects with specialized habits such as predators, requires basic knowledge of biology of preys and predators being sampled and techniques often have to be devised for each situation. The predators are usually specific for one or closely related group of insect species. During the larval and adult period predators are restricted to and dependant on an individual of the prey species and thus their reproductive rates are also dependant upon the availability of these preys. In other words, the sampling of predators is the sampling of the predator’s prey. For studying life table statistics the survey of species and successive estimates of the number of insects per unit of land area are necessary. Nearly all other studies of population dynamics of field condition needs survey and surveillance. In general, the survey and surveillance of preys and predators have an immense value in the pest management strategies and will add to knowledge of predator behaviour in relation to the reproduction, population and occurrence of the pest and the crops in the region. For execution and efficient management of pest, study of population dynamics in relation to ecological factors is essential. The validity of such studies is area specific and no such work have so far been reported in and around Kolhapur district. Hence, the present study was made on the predators, Menochilus sexmaculatus (Fabricious), Tiger beetle, Eudema angulatum Horn and praying mantid Hierodula bipapilla S-A. The above three predators are potential biocontrol agents of several agricultural pests in Kolhapur district. Kolhapur is situated in Western Maharashtra ( Fig. 1 ) and is characterized by This ebook is exclusively for this university only.

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  Lepidoptera and Conservation

  • T. R. New(Author)
  • 2013(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  Substantial areas can be inspected, with outcomes linked to habitat category. Correlative records of changes in abundance and distribution of British butterflies, largely from transect walk data (Asher et al. 2001), constitute the most influential compilation of data on any insect fauna. The same procedure is suitable for diurnal moths (Groenendijk & van der Meulen 2004). As Pollard and Yates emphasised, the basic needs for any monitoring or wider survey method are that it is rapid and easy to use in ways that are well defined, standardised and minimise errors, and the approach provides sound information on representation of species and population sizes, so that repetition may reveal trends of change. Transect walk approaches usually confine information to those insects recorded within a (defined) few metres of the transect line. However, if detection at greater distances is straightforward and unambiguous, ‘distance sampling’ may also be relevant to help in assessing densities and population sizes. The method (discussed by Haddad et al. 2008) assumes that the transects are placed randomly with respect to the target Lepidoptera, in turn assuming a uniform density distribution about the transect. Detection at the centre of the transect is then certain, and detection elsewhere is a decreasing function of distance from the central transect line. Conditions for use in estimating population numbers include (1) uniform habitats; (2) high visibility, so that targets are not obscured by dense vegetation or uneven terrain; (3) random transects do not damage habitats, such as by trampling or other disturbance, in contrast to the more usual employment of predetermined regular paths for conventional Pollard walks; and (4) the insects occur in sufficiently large numbers to estimate detection functions. Use of this sampling approach for the conspicuous Regal fritillary butterfly (Speyeria idalia) (Powell et al. 2007, Chapter 13, p

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  Essential Environmental Science

  Methods and Techniques

  • Simon Watts(Author)
  • 2003(Publication Date)
  • Routledge

    (Publisher)

  This is a technique that can only be employed during the breeding season. It is used to establish breeding densities and habitat utilisation by component species. The technique usually involves walking defined boundaries such as field margins, or operating within a defined grid system, and recording male song and any observed interaction between two males of the same species. It is a time-consuming technique requiring a high degree of field craft, and is most commonly employed to establish the territories of rare species and linking this information to the quality and distribution of specific habitats.

  The above summary is a broad indication of the many techniques available to census birds. Bird census techniques and the analysis of data from those techniques have been examined elsewhere (Bibby et al., 1992). As a rule of thumb we would suggest that, although the techniques are simple, the accuracy of your census is heavily dependent upon the ability to correctly identify birds, mainly from their song. Unless you are accomplished in this area, the value of this type of study is limited.

  8.4c Invertebrate sampling techniques

  Sampling invertebrates, terrestrial and aquatic, is often time-consuming, both in terms of the techniques employed and in the subsequent identification and analysis of the samples generated. Under the right conditions, surveys will produce many individuals, hence you are encouraged to select an appropriate survey method and site which together will meet the aims of your particular study. Most often you will aim to produce a list of species representative of the habitat or vegetation type under consideration or to concentrate on indicator or notable species. Due to seasonal and time constraints, to attempt to provide a full species list for your site is impossible. Included here is advice regarding where, what and when to sample terrestrial invertebrates. This advice can be applied to aquatic surveys as well, but they are specifically dealt with in the next section. There is some good guidance on invertebrate site surveys (Brookes, 1993).

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