Sweet Corn Sentinel Monitoring for Lepidopteran Field-Evolved Resistance to Bt Toxins.

As part of an insect resistance management plan to preserve Bt transgenic technology, annual monitoring of target pests is mandated to detect susceptibility changes to Bt toxins. Currently Helicoverpa zea (Boddie) monitoring involves investigating unexpected injury in Bt crop fields and collecting larvae from non-Bt host plants for laboratory diet bioassays to determine mortality responses to diagnostic concentrations of Bt toxins. To date, this monitoring approach has not detected any significant change from the known range of baseline susceptibility to Bt toxins, yet practical field-evolved resistance in H. zea populations and numerous occurrences of unexpected injury occur in Bt crops. In this study, we implemented a network of 73 sentinel sweet corn trials, spanning 16 U.S. states and 4 Canadian provinces, for monitoring changes in H. zea susceptibility to Cry and Vip3A toxins by measuring differences in ear damage and larval infestations between isogenic pairs of non-Bt and Bt hybrids over three years. This approach can monitor susceptibility changes and regional differences in other ear-feeding lepidopteran pests. Temporal changes in the field efficacy of each toxin were evidenced by comparing our current results with earlier published studies, including baseline data for each Bt trait when first commercialized. Changes in amount of ear damage showed significant increases in H. zea resistance to Cry toxins and possibly lower susceptibility to Vip3a. Our findings demonstrate that the sentinel plot approach as an in-field screen can effectively monitor phenotypic resistance and document field-evolved resistance in target pest populations, improving resistance monitoring for Bt crops.

Crop production in the USA is frequently limited by a lack of pollinators.

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

Wild Bee Visitation Rates Exceed Pollination Thresholds in Commercial Cucurbita Agroecosystems.

Wild bees supply sufficient pollination in Cucurbita agroecosystems in certain settings; however, some growers continue to stock fields with managed pollinators due to uncertainties of temporal and spatial variation on pollination services supplied by wild bees. Here, we evaluate wild bee pollination activity in wholesale, commercial pumpkin fields over 3 yr. We identified 37 species of bees foraging in commercial pumpkin fields. Honey bees (Apis mellifera L. [Hymenoptera: Apidae]), squash bees (Eucera (Peponapis) Say, Dorchin [Hymenoptera: Apidae]), and bumble bees (Bombus spp., primarily B. impatiens Cresson [Hymenoptera: Apidae]) were the most active pollinator taxa, responsible for over 95% of all pollination visits. Preference for female flowers decreased as distance from field edge increased for several bee taxa. Visitation rates from one key pollinator was negatively affected by field size. Visitation rates for multiple taxa exhibited a curvilinear response as the growing season progressed and responded positively to increasing floral density. We synthesized existing literature to estimate minimum 'pollination thresholds' per taxa and determined that each of the most active pollinator taxa exceeded these thresholds independently. Under current conditions, renting honey bee hives may be superfluous in this system. These results can aid growers when executing pollination management strategies and further highlights the importance of monitoring and conserving wild pollinator populations.

Potential biological control of Erwinia tracheiphila by internal alimentary canal interactions in Acalymma vittatum with Pseudomonas fluorescens.

AIMS: We aim to determine if Pseudomonas fluorescens is a viable biological control for Erwinia tracheiphila within the insect vector, Acalymma vittatum. METHODS AND RESULTS: Pseudomonas fluorescens secreted fluorescein and inhibited growth of E. tracheiphila in disc diffusion assays. To determine if this antagonism was conserved within the insect vector, we performed in vivo assays by orally injecting beetles with bacterial treatments and fluorescent in situ hybridization to determine bacterial presence within the alimentary canal. CONCLUSIONS: Pseudomonas fluorescens inhibited the growth of E. tracheiphila on a nutrient-limiting medium. In situ experiments demonstrated that P. fluorescens is maintained within the alimentary canal of the beetle for at least 4 days, and co-occurred with E. tracheiphila. When beetles were first presented with Pseudomonas and then challenged with E. tracheiphila, E. tracheiphila was not recovered via FISH after 4 days. These data suggest that P. fluorescens has potential as a biological control agent to limit E. tracheiphila within the insect vector. SIGNIFICANCE AND IMPACT OF THE STUDY: This is a novel approach for controlling E. tracheiphila that has the potential to decrease reliance on insecticides, providing a safer environment for pollinators and growers.

Horticultural Production Systems Influence Ground Beetle (Coleoptera: Carabidae) Distribution and Diversity in Cucurbits.

Commercial cucurbit production typically involves agriculturally intensive practices, with fields prepared using conventional tillage, plasticulture, and chemically based pest management. Conservation-based management options are limited. In this study, we consider two alternative strategies, strip tillage and the use of row covers. We compare their impact on the beneficial carabid beetle (Coleoptera: Carabidae) community in melons and squash, following conventional or organic systems, over two years. Multivariate analysis demonstrated that soil management system (strip tillage versus plasticulture) was the primary variable influencing carabid distribution; row cover was a less important factor. The response to soil management was species dependent. Some dominant species, such as Harpalus pensylvanicus DeGeer, demonstrated no preference for a particular soil treatment. For others, including the tiger beetle, Cicindela punctulata Olivier, and a slug predator, Chlaenius tricolor Dejean, activity-density was higher in strip-tillage production systems. Our analysis suggested that strip-tillage production systems support a richer, more diverse carabid community. These results demonstrate that even within intensive annual horticultural systems, production practices can play a critical role in shaping the beneficial arthropod community, potentially encouraging or limiting ecosystem services.

Modeling seasonal migration of fall armyworm moths.

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere's role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of fall armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama-Georgia and Pennsylvania-Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of fall armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥ 10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of fall armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.

Sunflower as a Potential Trap Crop of Halyomorpha halys (Hemiptera: Pentatomidae) in Pepper Fields.

The brown marmorated stink bug, Halyomorpha halys (Stål), feeds on a variety of fruits and vegetables, and is an economically important invasive hemipteran pest. Trap cropping of H. halys was examined at the Pennsylvania State University Southeast Agriculture Research and Extension Center (SEAREC) in Lancaster Co., PA, from 2012 to 2013, with sunflowers used as a trap crop to protect bell pepper. H. halys were observed frequently on sunflowers planted surrounding the pepper field, and in both years of this experiment significantly more H. halys were observed in sunflowers than peppers. Both adults and nymphs were observed with equal frequency, with higher numbers of both observed in September. A 2:1 ratio of females to males was observed throughout both years. While sunflowers were attractive to H. halys, no difference in fruit damage was observed in peppers surrounded by the sunflower trap crop versus those peppers surrounded by peppers. While sunflowers present an interesting potential trap crop for H. halys, future research is needed to clarify the feasibility of this crop protection technique.

Examining shifts in Carabidae assemblages across a forest-agriculture ecotone.

Northeastern U.S. farms are often situated adjacent to forestland due to the heterogeneous nature of the landscape. We investigated how forested areas influence Carabidae diversity within nearby crop fields by establishing transects of pitfall traps. Trapping extended across a forest-agriculture ecotone consisting of maize, an intermediate mowed grass margin, and a forest edge. Carabidae diversity was compared among the three habitats, and community and population dynamics were assessed along the transect. We used a principal response curve to examine and visualize community change across a spatial gradient. The highest levels of richness and evenness were observed in the forest community, and carabid assemblages shifted significantly across the ecotone, especially at the forest-grass interface. Despite strong ecotone effects, population distributions showed that some species were found in all three habitats and seemed to thrive at the ecotone. Based on similarity indices, carabid assemblages collected in maize adjacent to forest differed from carabid assemblages in maize not adjacent to forest. We conclude that forest carabid assemblages exhibit high degrees of dissimilarity with those found in agricultural fields and forested areas should thus be retained in agricultural landscapes to increase biodiversity at the landscape scale. However, ecotone species found at forest edges can still noticeably influence carabid community composition within neighboring agricultural fields. Further studies should determine how these shifts in carabid assemblages influence agroecosystem services in relation to ecosystem services observed in fields embedded in an agricultural matrix.

CD22 ligation inhibits downstream B cell receptor signaling and Ca(2+) flux upon activation.

OBJECTIVE: CD22 is a surface molecule exclusively expressed on B cells that regulates adhesion and B cell receptor (BCR) signaling as an inhibitory coreceptor of the BCR. Central downstream signaling molecules that are activated upon BCR engagement include spleen tyrosine kinase (Syk) and, subsequently, phospholipase Cγ2 (PLCγ2), which results in calcium (Ca(2+)) mobilization. The humanized anti-CD22 monoclonal antibody epratuzumab is currently being tested in clinical trials. This study was undertaken to determine the potential mechanism by which this drug regulates B cell activation. METHODS: Purified B cells were preincubated with epratuzumab, and the colocalization of CD22 and CD79α, without BCR engagement, was assessed by confocal microscopy. The phosphorylation of Syk (Y348, Y352) and PLCγ2 (Y759) as well as the Ca(2+) flux in the cells were analyzed by flow cytometry upon stimulation of the BCR and/or Toll-like receptor 9 (TLR-9). The influence of CD22 ligation on BCR signaling was assessed by pretreating the cells with epratuzumab or F(ab')(2) fragment of epratuzumab, in comparison with control cells (medium alone or isotype-matched IgG1). RESULTS: Epratuzumab induced colocalization of CD22 and components of the BCR independent of BCR engagement, and also reduced intracellular Ca(2+) mobilization and diminished the phosphorylation of Syk and PLCγ2 after BCR stimulation in vitro. Inhibition of kinase phosphorylation was demonstrated in both CD27- and CD27+ B cells, and this appeared to be independent of Fc receptor signaling. Preactivation of the cells via the stimulation of TLR-9 did not circumvent the inhibitory effect of epratuzumab on BCR signaling. CONCLUSION: These findings are consistent with the concept of targeting CD22 to raise the threshold of BCR activation, which could offer therapeutic benefit in patients with autoimmune diseases.

Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers.

Transgenic maize engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become widely adopted in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million hectares, constituting 63% of the U.S. crop. Using statistical analysis of per capita growth rate estimates, we found that areawide suppression of the primary pest Ostrinia nubilalis (European corn borer) is associated with Bt maize use. Cumulative benefits over 14 years are an estimated $3.2 billion for maize growers in Illinois, Minnesota, and Wisconsin, with more than $2.4 billion of this total accruing to non-Bt maize growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion for non-Bt maize growers. These results affirm theoretical predictions of pest population suppression and highlight economic incentives for growers to maintain non-Bt maize refugia for sustainable insect resistance management.

Conventional and seed-based insect management strategies similarly influence nontarget coleopteran communities in maize.

Seed-based pest management tools, such as transgenes and seed treatments, are emerging as viable alternatives to conventional insecticide applications in numerous crops, and often occur as coupled technologies. Seed-based technologies have been readily adopted in maize, for which ecological studies are needed to examine effects to farmland biodiversity. We compared the response of nontarget coleopteran communities in Cry1Ab/c sweet corn and Cry3Bb field corn to conventional pyrethroid applications and a control. Of particular interest was the Cry3Bb field corn, which was coupled with a neonicotinoid seed treatment and was not rotated across years. A functionally diverse subset of the coleopteran community, consisting of three families (Carabidae, Chrysomelidae, and Nitidulidae) and 9,525 specimens, was identified to species. We compared coleopteran diversity and dynamics using rarefaction and ordination techniques. There were no differences in species richness among treatments; however, higher activity densities were more common in the control. In the nonrotated field corn, principal response curves showed a consistent pattern of treatment communities deviating from the control communities over time, whereas crop rotation in the sweet corn negated treatment effects. Treatment effects could not be detected when beetles were grouped based on functional roles. Results indicate that neonicotinoid seed-based treatments may have effects on some nontarget coleopterans, but these effects are similar to conventional pyrethroid applications.

Carabidae population dynamics and temporal partitioning: response to coupled neonicotinoid-transgenic technologies in maize.

Insecticidal Bt crops and seed treatments represent additional pest management tools for growers, prompting ecological studies comparing their impact on farm system inputs and effects to nontarget organisms compared with conventional practices. Using high taxonomic and temporal resolution, we contrast the dominance structure of carabids and dynamics of the most abundant species in maize (both sweet and field corn) agroecosystems using pest management tactics determined by the purchase of seed and application of pyrethroid insecticides. In the seed-based treatments, sweet corn contained Cry1Ab/c proteins, whereas field corn contained the coupled technology of Cry3Bb1 proteins for control of corn rootworm and neonicotinoid seed treatments aimed at secondary soil-borne pests. The insecticide treatments involved foliar pyrethroids in sweet corn and at-planting pyrethroids in field corn. The carabid community, comprised of 49 species, was dominated by four species, Scarites quadriceps Chaudoir, Poecilus chalcites Say, Pterostichus melanarius Illiger, and Harpalus pensylvanicus DeGeer, that each occupied a distinct temporal niche during the growing season. Two species, Pt. melanarius and H. pensylvanicus, exhibited differences between treatments over time. Only H. pensylvanicus had consistent results in both years, in which activity densities in field corn were significantly higher in the control in July and/or August. These results, along with laboratory bioassays, led us to hypothesize that lower adult captures resulted from decrease in prey availability or exposure of H. pensylvanicus larvae to soil-directed insecticides-either the neonicotinoid seed treatment in the transgenic field corn or an at-planting soil insecticide in the conventional field corn.

Transmission efficiency of Cucumber mosaic virus by aphids associated with virus epidemics in snap bean.

Cucumber mosaic virus (CMV) is a major component of the virus complex that has become more pronounced in snap bean in the midwestern and northeastern United States since 2001. Multiple-vector-transfer tests were done to estimate the CMV transmission efficiencies (p) of the main aphid species identified in commercial snap bean fields in New York and Pennsylvania. The four most efficient vectors (p > 0.05) were Aphis gossypii, A. glycines, Acyrthosiphon pisum, and Therioaphis trifolii, which were all significant species in the migratory aphid populations in snap bean. Moderately efficient vectors (0.01 < p < 0.04) were A. spiraecola, A. craccivora, Macrosiphum euphorbiae, and Rhopalosiphum maidis. Poor vectors (p < 0.01) included A. fabae, Nearctaphis bakeri, and Myzus persicae. Only one species, Sitobion avenae, failed to transmit CMV in replicated tests. Estimates of p were consistent between different clones of the same aphid species and among three different field isolates of CMV tested. Single-vector-transfer test results for a subset of the species supported those obtained via the multiple-vector-transfer approach. Our results are consistent with the notion that A. glycines is a major vector of recent CMV epidemics in snap bean, but that species is only one of several that are involved.

Transgenes sustain epigeal insect biodiversity in diversified vegetable farm systems.

Many ecological studies have focused on the effects of transgenes in field crops, but few have considered multiple transgenes in diversified vegetable systems. We compared the epigeal, or soil surface-dwelling, communities of Coleoptera and Formicidae between transgenic and isoline vegetable systems consisting of sweet corn, potato, and acorn squash, with transgenic cultivars expressing Cry1(A)b, Cry3, or viral coat proteins. Vegetables were grown in replicated split plots over 2 yr with integrated pest management (IPM) standards defining insecticide use patterns. More than 77.6% of 11,925 insects from 1,512 pitfall traps were identified to species, and activity density was used to compare dominance distribution, species richness, and community composition. Measures of epigeal biodiversity were always equal in transgenic vegetables, which required fewer insecticide applications than their near isolines. There were no differences in species richness between transgenic and isoline treatments at the farm system and individual crop level. Dominance distributions were also similar between transgenic and isoline farming systems. Crop type, and not genotype, had a significant influence on Carabidae and Staphylinidae community composition in the first year, but there were no treatment effects in the second year, possibly because of homogenizing effects of crop rotations. Communities were more influenced by crop type, and possibly crop rotation, than by genotype. The heterogeneity of crops and rotations in diversified vegetable farms seems to aid in preserving epigeal biodiversity, which may be supplemented by reductions in insecticide use associated with transgenic cultivars.

Coccinellids, aphids, and pollen in diversified vegetable fields with transgenic and isoline cultivars.

The influence of concurrent introduction of three transgenic vegetable cultivars on seasonal dynamics of coccinellids and their food, aphids and pollen, was examined within diversified farm systems practicing insect pest management in northeastern US agroecosystems. The transgenic cultivars used included sweet corn, potato, and winter squash, expressing Cry1(A)b, Cry3A, and plant viral coat proteins that target Lepidoptera, Coleoptera, and aphid-transmitted viruses, respectively. Transgenic systems reduced insecticides by 25%. Weekly differences in coccinellid density between transgenic and isoline crops were rare and transitory, governed by timing of at-planting or foliar insecticide use patterns; however cumulative frequencies for three of the six coccinellid species differed between transgenic and isoline crops. At a multicrop, farm systems level, seasonal dynamics of the coccinellids and aphids tracked dynamics in the sweet corn, which far surpassed the other crops in abundance of coccinellids and pollen, and harbored consistently higher aphid densities. Although these results warrant further study, the patterns suggest that diversified transgenic vegetable crops under current commercial management demonstrated transitory conservation of coccinellids, and that integration with selective insecticides or other IPM tactics could increase this potential.

Aphid (Hemiptera: Aphididae) species composition and potential aphid vectors of plum pox virus in Pennsylvania peach orchards.

Plum pox, an invasive disease recently identified in Pennsylvania stone fruit orchards, is caused by the aphid-transmitted Plum pox virus (genus Potyvirus, family Potyviridae, PPV). To identify potential vectors, we described the aphid species communities and the seasonal dynamics of the dominant aphid species within Pennsylvania peach orchards. Aphids were trapped weekly in 2002 and 2003 from mid-April through mid-November within two central Pennsylvania orchards by using yellow and green water pan traps. In total, 42 aphid species were identified from both orchards over 2 yr. Within orchards, actual species richness ranged from 24 to 30 species. The Abundance Based Coverage Estimator predicted species richness to range from 30 to 36 species, indicating that trap catches were identifying most aphid species expected to occur in the orchard. Three species, Rhopalosiphum maidis (Fitch), Aphis spiraecola Patch, and Myzus persicae (Sulzer), were consistently dominant across locations and years. Orchard-trapped populations of these three species peaked in a similar chronological sequence each year. As expected, trap color influenced the total number and distribution of the predominate species collected. However, the same dominant species occurred in both yellow and green traps. Based on the seasonal population dynamics reported here and on published vector efficacy studies, the most probable significant PPV vector was identified as A. spiraecola. If the PPV pathogen escapes current quarantine or if subsequent reintroductions of PPV occur, these data will be useful for developing plum pox management strategies.

Spodoptera frugiperda pheromone lures to avoid nontarget captures of Leucania phragmatidicola.

We confirmed that commercial three- or four-component Spodoptera frugiperda (J.E. Smith) pheromone lures had a high nontarget capture rate for Leucania phragmatidicola Guenée, which compromised monitoring efforts in the northeastern United States. We compiled taxonomic features to distinguish L. phragmatidicola from S. frugiperda, and we compared five new lures. S. frugiperda catch specificity was improved by removing (Z)-11-hexadecen-1-ol acetate (Z11-16:Ac), which attracted L. phragmatidicola. Four lures tracked late-season S. frugiperda immigration, but two of these lures also tracked a bivoltine L. phragmatidicola flight with a second generation coincident with S. frugiperda immigration, and one lure attracted the first, but not the second, generation of L. phragmatidicola. In both low- and high-moth flight conditions, two-component lures had low L. phragmatidicola captures (0.5-1.4%), and although lures with more pheromonal components captured more S. frugiperda, they also had a high percentage of capture of L. phragmatidicola (38-48%). We conclude that although two-component lures captured fewer S. frugiperda, their similar temporal pattern, along with the lower level of L. phragmatidicola, makes them useful for development for monitoring programs in the northeastern United States.

Potential of entomopathogenic nematodes for biological control of Acalymma vittatum (Coleoptera: Chrysomelidae) in cucumbers grown in conventional and organic soil management systems.

Acalymma vittatum (F.) is the primary insect pest of fresh-market cucumber and melon crops in much of the eastern United States because of their herbivory and interactions with several diseases, most notably bacterial wilt. A study was conducted to determine how soil management affects viability and infectivity of an entomopathogenic nematode that may be used for the control of A. vittatum. Dose-mortality curves under laboratory conditions suggested several Steinernema spp. as potential biocontrol agents. Field injections combined with soil bioassays showed that Steinernema riobravis Cabanillas, Poinar & Raulston (Rhabditus: Steinernematidae) longevity exceeded A. vittatum immature development time in both conventional and organic soil management systems. Mean root length densities of cucumbers increased in both soil management systems with the inclusion of nematodes. Soil management alone also influenced A. vittatum larval survivorship, with higher survival rates in the organic compared with the conventional soil management system. A 50% reduction in A. vittatum larval survival rates in both soil management systems, as determined by adult A. vittatum emergence, demonstrated the potential of incorporation of entomopathogenic nematodes for integrated pest management of diabroticites in commercial cucumber production.

Spatio-temporal dynamics of resident and immigrating populations of Carcinops pumilio (Coleoptera: Histeridae) in high-rise poultry facilities.

The histerid beetle Carcinops pumilio (Erichson) is an important natural predator of the house fly, Musca domestica L., in accumulated poultry house manure. We examined the spatio-temporal dynamics of establishing adult C. pumilio in high-rise poultry facilities using conventional and geostatistical approaches. The growth curves of resident and immigrating populations followed logistic and exponential equations, respectively, and their rates of establishment were statistically the same. Frequency distributions for both populations were strongly positively skewed, and approximately 53% of sampling intervals were significantly modeled by the negative binomial. Taylor's power law indicated both populations to be aggregated, and gave excellent least squares regression fits to both populations. Correlograms, a geostatistical tool, suggested little local spatial structure (e.g., 2nd order effects) for either population. The resident population was 'randomly' aggregated: beetles were clustered around randomly distributed aggregations of house fly immatures. The immigrating population exhibited significant spatial trends (e.g., 1st order effects) consistently seen at all sampling intervals. C. pumilio spatial structure was represented primarily by this spatial trend; thus, immigration of C. pumilio may have been either a singular event in time, or initiating at 1 or multiple times from a singular location.

Sampling in Precision IPM: When the Objective Is a Map.

ABSTRACT Measuring and understanding spatial variation of pests is a fundamental component of population dynamics. The resulting maps can drive spatially variable pest management, which we define as precision integrated pest management (IPM). Precision IPM has the potential to reduce insecticide use and slow the rate of resistance development because of the creation of temporally dynamic refuges. This approach to IPM requires sampling in which the objective is to measure spatial variation and map pest density or pressure. Interpolation of spatially referenced data is reviewed, and the influence of sampling design is suggested to be critical to the mapped visualization. Spatial sampling created problems with poor precision and small sample sizes that were partially alleviated with choosing sampling units based on their geostatistical properties, adopting global positioning system technology, and mapping local means. Mapping the probability of exceeding a threshold with indicator kriging is discussed as a decision-making tool for precision IPM. The different types of sampling patterns to deploy are discussed relative to the pest mapping objective.