Mean Population Density Research Articles

Species composition and distribution of free-living marine nematodes in Vostok Bay, Sea of Japan

The qualitative and quantitative composition of free-living marine nematodes have been studied in Vostok Bay (Peter the Great Bay, Sea of Japan). It is found that the population density of nematodes in the bottom sediments of Vostok Bay shows an uneven distribution. The mean population density equaled 56800 ± 23400 specimens/m2. A correlation has been revealed between the population density of nematodes and the substrate type. Altogether, 85 species of nematodes have been found; they were dominated by Sabatieria palmaris, Rhabdodemania orientalis, Araeolaimus parvibulbosus, Oncholaimium paraolium, Doryolaimopsis peculiaris, and Metachromadora itoi. Six taxocenoses of nematodes were distinguished, taking into account the species dominating in the population density and using cluster analysis of the obtained data. The dominating trophic assemblage of nematodes was “scrapers.” In general, the species composition of nematodes in Vostok Bay is characterized by the relatively great similarity with that in other areas of Peter the Great Bay (Sea of Japan).

Development of ciliate community on artificial substrates associated with vertical gradients of environmental conditions in a karstic lake

The composition of ciliate communities, their abundance and biomass were studied on glass slides exposed in the epilimnion (1 m), metalimnion (9 m) and hypolimnion (18 m) in the karstic barrage Visovac Lake (SW Dinarid, Croatia). After one-month exposure periods from May 1995 to February 1996, mean ciliate biomass decreased with depth (at 1 m 54 μ g cm-2, at 9 m 37 μ g cm-2 and at 18 m 28 μ g cm-2), whereas the mean population density was relatively uniform (675 Ind. cm-2 at 1 m, 592 Ind. cm-2 at 9 m, and 678 Ind. cm-2 at 18 m). Sessile forms (peritrichs and suctorians) were dominant during all exposure periods and at all three depth layers. Omnivorous ciliates were dominant in the epilimnion, whereas in the metalimnion and hypolimnion bacterivores and carnivores were most abundant. Ciliates inhabiting artificial substrates in the epilimnion had two temporal peaks of density and biomass: in June and in October. In the deeper layers these maxima appeared one or two months later. Seasonal changes in ciliate biomass and community and trophic composition were associated with changes in thermal stratification and vertical oxygen gradients as important abiotic parameters, periphyton biomass as food source, and the tufa deposit determining the properties of substrate.

Efficacy of oral isotretinoin in the control of skin and nasal colonization by antibiotic-resistant propionibacteria in patients with acne

Skin colonization by antibiotic-resistant propionibacteria is commonplace among acne patients globally. Increasing attention is now being paid to how resistance rates might be reduced to preserve the future efficacy of antibiotics, especially erythromycin and clindamycin in acne therapy. To assess the efficacy of oral isotretinoin in the control of antibiotic-resistant propionibacteria. Acne patients (72 in the U.K., 62 in the U.S.A.) colonized with high numbers of antibiotic-resistant propionibacteria were sampled before, during and 12 weeks after oral isotretinoin therapy. Propionibacterial samples were collected from five acne-prone skin surface sites using a detergent scrub method and from the anterior nares using moistened swabs. Total and antibiotic-resistant propionibacteria were enumerated by viable counting on media with and without selective antibiotics. After 16 weeks of oral isotretinoin therapy, mean population densities of viable propionibacteria and variants resistant to erythromycin, clindamycin or tetracycline had fallen by more than 90% at all skin sites and in the nares. The sole exception was a smaller reduction in tetracycline-resistant strains on the lower back. In general, greater reductions were observed on skin than in the nares. By the end of the treatment period only three patients (all in Philadelphia) yielded no antibiotic-resistant strains from any site. Post-treatment, propionibacterial counts remained well below pretreatment levels but had begun to recover on the face and in the nares. The recovering propionibacterial population included both susceptible and resistant strains. Changes during and post-treatment at the two centres were similar but not identical. Oral isotretinoin effectively reduced skin and nasal colonization by antibiotic-resistant propionibacteria. However, viable populations of resistant isolates persisted post-treatment at multiple sites. Novel methods are required to eradicate antibiotic-resistant propionibacteria completely, especially from the nasal reservoir.

Distribution and prevalence of nematodes ( Scutellonema bradys and Meloidogyne spp.) on marketed yam ( Dioscorea spp.) in West Africa

The distribution, population density and incidence of plant parasitic nematodes and associated damage to yam ( Dioscorea spp.) tubers obtained from market stalls in the West African countries of Benin, Burkina Faso, Côte d’Ivoire, Ghana, Mali, Nigeria and Togo was determined during the tuber storage periods in 2002 and 2003. A total of 527 yam tuber samples, exhibiting typical nematode ( Scutellonema bradys) damage symptoms, were collected and assessed for S. bradys densities. In addition 25,318 tubers on sale in markets were assessed for visual symptoms (except in Nigeria) of nematode damage ( S. bradys and Meloidogyne spp.). S. bradys was present in all countries assessed, with greatest ( P ≤ 0.05) mean population densities occurring in tubers in Benin (397 g −1), followed by Nigeria (248 g −1) and lowest in Togo (28 g −1). When analysed by agroecological zone, the greatest ( P ≤ 0.05) mean S. bradys density was observed in the mid altitude savannah (890 g −1), followed by the southern guinea savannah (488 g −1). S. bradys occurred in lower ( P ≤ 0.05) densities on Dioscorea alata (57 g −1) than other yam species, while Dioscorea rotundata was the most abundant yam species encountered. There was considerable variation in S. bradys density between cultivars within country and in some cases between countries. From some cultivars no S. bradys were recovered, even though they presented symptoms of damage. Tubers from Ghana had the greatest ( P ≤ 0.05) proportion of tubers visually affected by S. bradys (7.53%), when analysed across yam species and Mali the least (0.28%), while the highest proportion of galled tubers (due to Meloidogyne spp.) was observed in Mali (14.4%) on D. rotundata (19.6%). S. bradys infection, based on visible symptoms, was more evident on D. rotundata (3.8%) than D. alata (0.6%), although 5.18% of yams in the group comprising the unidentified yam species had the greatest mean proportion of visually affected tubers. On market stalls, D. alata (4.73%) and D. rotundata (3.35%) were most affected by visible galling due to Meloidogyne spp.

Feeding habits of feral domestic cats ( Felis catus ), wild cats ( Felis silvestris ) and their hybrids: trophic niche overlap among cat groups in Hungary

The feeding habits of feral domestic cats Felis catus (n=264), wild cats Felis silvestris (n=22) and their hybrids (n=30) were investigated in Hungary. Cat groups were identified taxonomically by morphological and molecular methods. Diet components were identified in stomach contents and faeces collected from the recta. In each cat group, abundant small mammals were dominant in the diet (relative frequency of occurrence: feral domestic cat, 61–82%, depending on regions; wild cat, 70%; hybrid, 59%). Birds were the second most important quarry (2–7%, 16% and 20%, respectively in the three cat groups), while the contribution of hares (1–2%, 5% and 3%, respectively) and other taxa was not significant. Every cat group preyed on small-sized animals (<50 g; 89–96%, 80% and 80%, respectively), terrestrial (91–98%, 84% and 86%, respectively) and wild (71–73%, 87% and 77%, respectively) prey. Standardized trophic niche breadth was typically very narrow (BA=0.07–0.16, 0.13 and 0.17, respectively). Feral domestic cats occasionally consumed household food (2–7%) and domestic animals (4–8%). This could mean that feral domestic cats have an advantage over wild cats that are food specialists. The trophic niche overlap between cat groups was high (77–88%). Food composition and feeding habits, (weight, zonation and environmental association of consumed prey) of feral domestic cats, however, was different compared to wild cats, which indicated the possibility of partial resource partitioning. The values for hybrids were between the two groups. As well as the stable presence of feral domestic cats (mean population density, D=1.34 individuals/1000 ha) based on field live-trapping, hybrids are also present (D=0.10), leading to continuous hybridization. This can threaten the population of wild cats, which are present at a low density (D=0.17).

Seasonal cycles and persistence in an acarine predator‐prey system on cassava in Africa

AbstractWe applied time series analysis and a mechanistic predator‐prey model to long‐term data of monthly population counts of the herbivorous pest mite Mononychellus tanajoa and its introduced phytoseiid predator Typhlodromalus aripo from a cassava field in Benin, West Africa. In this approach, we determined the extent to which the main features of the observed predator‐prey fluctuations in cassava fields can be explained from biotic traits inherent to the biology of predator and prey, and the extent of the significance of abiotic factors in determining population levels. The time series analyses with cross‐correlation showed that the period of predator‐prey fluctuations coincided with the annual pattern of intense rainfall and onset of dry season. A pronounced M. tanajoa peak followed after a short lag (2 weeks) by a T. aripo peak coincided with a trough in rainfall intensity. Both the prey and predator had local and lower peaks that coincided with high rainfall intensity, but with a considerably longer lag (ca. 3 months) compared with the high peaks occurring at the onset of the dry season. Regression of log‐transformed data series (over a 7‐year period) showed that—except for the first year after predator release—M. tanajoa fluctuated around an almost time‐invariant mean population density, while T. aripo densities showed a consistent decline over the full observation period. To explain observed trends and periodic components in the data‐series of predator and prey densities, we review hypotheses that are based on (1) the annual patterns and trends in abiotic factors, (2) mechanisms endogenous to the predator‐prey system and (3) a combination of exogenous and endogenous factors.

Sampling and development of economic injury levels for Anthonomus rubi Herbst adults

Field studies were conducted in northwestern Turkey from 1998–2000 to examine population dynamics of adult strawberry blossom weevils ( Anthonomus rubi Herbst), and to establish economic injury levels based on the relationship between densities of overwintered adults and yield losses. Adult weevils were sampled weekly in untreated and insecticide-treated plots using a sweep net. Sweep net catches showed that the abundance of A. rubi adults had two peaks; the first between late-April and early-May, and the second between late-June and mid-July. Linear regression revealed a strong relationship between overwintered and new-generation adult densities. The overwintered-generation adults had generally higher mean population densities than the new-generation. A significant linear decrease was observed in strawberry yields as densities of overwintered-generation adults increased. Percentage yield losses varied between 1.64% and 13.42% among sites. Estimated economic injury levels ranged from 1.00 to 4.00 adults per sweep depending on the management scenario, control cost, control efficacy, and crop value.

Habitat associations of the endangered damselfly, Coenagrion mercuriale, in a water meadow ditch system in southern England

The damselfly Coenagrion mercuriale (Charpentier) (Odonata: Coenagrionidae) is threatened throughout Europe. It is listed on the EC Habitats and Species Directive and is the only odonate currently given priority status in the UK Biodiversity Action Plan. Information about the habitat preferences of this species is required to guide conservation and management programmes. We obtained estimates of density of mature adult C. mercuriale during an intensive mark-release-recapture study over 7.65 km of a water meadow ditch network in the Itchen Valley, Hampshire. Detailed habitat information was also collected, including a variety of physical variables, and data about the in-channel and bankside vegetation. C. mercuriale density and movement were analysed in relation to habitat variables and local population size using Generalized Linear Models. Mean adjacent population density was the single most important factor determining density. However the species was also associated with a number of habitat features, the most important of which were: a channel substrate consisting primarily of silt, wide underwater ledges (berms), in-channel emergent dicots, and bankside monocots. The presence of trees was negatively associated with damselfly density. Mean net lifetime movement was greatest from sections with low density, with smaller than average berms, and with deeper water. The causes and consequences of these findings are discussed in relation to the conservation and management of this rare species.

Fixed Precision Sampling Plans for White Apple Leafhopper (Homoptera: Cicadellidae) on Apple

Constant precision sampling plans for the white apple leafhopper, Typhlocyba pomaria McAtee, were developed so that it could be used as an indicator species for system stability as new integrated pest management programs without broad-spectrum pesticides are developed. Taylor's power law was used to model the relationship between the mean and the variance, and Green's constant precision sequential sample equation was used to develop sampling plans. Bootstrap simulations of the sampling plans showed greater precision (D = 0.25) than the desired precision (Do = 0.3), particularly at low mean population densities. We found that by adjusting the Do value in Green's equation to 0.4, we were able to reduce the average sample number by 25% and provided an average D = 0.31. The sampling plan described allows T. pomaria to be used as reasonable indicator species of agroecosystem stability in Washington apple orchards.

The synergistic effects of stochasticity and dispersal on population densities.

Using laboratory experiments, simulation models, and analytical techniques, we examined the impact of dispersal on the mean densities of patchily distributed populations. Even when dispersal leads to no net additions or removals of individuals from a population, it may nonetheless increase mean population densities if the net immigration rate is positive when populations are growing and negative when they are declining. As a model system for exploring this phenomenon, we used the yeastlike fungus Aureobasidium pullulans. In a laboratory experiment, we showed that dispersal can both ensure persistence and increase mean population densities even when dispersal among populations causes no direct addition or loss of fungal cells. From the laboratory data, we constructed a plausible model of A. pullulans dynamics among apple leaves within an orchard. This simulation model demonstrated that the effect of dispersal on mean densities is enhanced by three factors: weak density dependence of the dynamics within populations, high environmental variability affecting population growth rates, and lack of synchrony among the fluctuations of populations. Using an analytical model, we showed that the underlying mechanisms for this phenomenon are general, suggesting that a large effect of dispersal on mean population densities is possible in many natural systems.

Optimization of air protection expenditures on municipal scale

The application of air protection methods and technologies involves considerable investment and maintenance costs. Thus, to reduce overall expenditures an economic calculation of air pollution control, should be applied. This problem is connected in special way with areas of great population of inhabitants with spatially uneven density, where energetic, technological and domestic emission sources are located. Such calculations are preferred to be used on the town and municipal scale. The maximized ecological effect might be calculated from aggregate mean annual ambient concentration and population density distribution. Aggregate concentration reflects concentrations of all emitted pollutants, being taken into account. As an example, the optimization for Bytom ‐ an industrial town regarded as one of the most heavily polluted in Europe ‐ was carried out due to its energy production facilities. Alternative fuels were taken into consideration. It demonstrates that expenditures of a relatively small percentage of overall energy production costs can make a substantial improvement to the ambient air condition.

RESONANCE INFLATES CARRYING CAPACITY IN PROTIST POPULATIONS WITH PERIODIC RESOURCE PULSES

Resonance is an interaction between extrinsic environmental variability and intrinsic population processes that can raise population mean density or amplify environmental fluctuations in systems with periodic environmental fluctuations. This study empirically demonstrates significant effects on population dynamics from resonance and describes the conditions under which they occur. In a laboratory microcosm experiment with the ciliate protist Colpidium striatum, resources were periodically alternated between high and low concentrations at different frequencies. Resonance raised the mean population density of rapidly fluctuating treatments by 21% compared to a constant control run at the average nutrient concentration, and eventually approximated the mean density of the highest nutrient control. The resonant resource perturbations occurred on a time scale intermediate to the reproduction and starvation rates of the organisms. It is likely that metabolic nonlinearities in these reproductive and starvation responses interacted with the periodic resources fluctuations of intermediate frequency to produce the population boost through the cumulative storage of resources in the cells of the protists. The populations also showed a frequency threshold effect in the translation of environmental variability into population variability. The patterns of population abundance and variability observed in this experiment indicate that resonance between intrinsic and extrinsic processes may be an important factor to consider in population dynamics.

Role of Salicylic Acid in "Pseudomonas aeruginosa" Strain IE-6S+-Mediated Induction of Systemic Resistance against "Meloidogyne javanica" in Tomato

Root colonization by certain non-pathogenic bacteria can induce systemic resistance to pathogen infections in plants. In a split-root assay with tomato plants, we investigated which determinants of the rhizobacterium Pseudomonas aeruginosa IE-6S+ were important for induction of resistance to the root-knot nematode Meloidogyne javanica. P. aeruginosa IE-6S+ produced 3.9±1.1 µg ml-1 salicylic acid (SA) in a liquid casamino acid medium under laboratory conditions. The bacterial inoculant induced resistance equivalent to the application of 10 mM synthetic SA. However, SA at this concentration did not produce significant mortality of M. javanica juveniles in vitro. Soil iron (2.4 mM FeCl3·6H2O) did not markedly alter the resistance that P. aeruginosa IE-6S+ induced in tomato roots, which suggested that P. aeruginosa IE-6S+ activity was not iron-regulated. However, the resistance reaction was greatly enhanced when IE-6S+ and SA were co-inoculated with 0.5% Tween-20. While IE-6S+ colonized the tomato rhizosphere at 6.38 log cfu per g fresh weight of root during the first 3 days after inoculation, the bacterial populations declined steadily, reaching a mean population density of 4.73 log cfu g-1 fresh weight of root at 21 days. The bacterium was not isolated from the unbacterized half of the split root system.

BREEDING, FORAGING, AND VOCAL BEHAVIOR OF THE WHITE-THROATED JACAMAR (BRACHYGALBA ALBOGULARIS)

We studied White-throated Jacamars (Brachygalba albogularis) at Manu National Park, Peru, finding a mean population density of 0.8 groups per km of suitable streamside habitat, and taking the first recordings of its song. Observations at nests provided the first evidence of cooperative breeding in the genus Brachygalba, as well as information on foraging tactics, prey selection, and provisioning behavior.

Biological control of infection of blueberry flowers caused by Monilinia vaccinii-corymbosi

Abstract Monilinia vaccinii-corymbosi , the fungus that causes mummy berry disease, infects open blueberry flowers via the stigma–style pathway, followed by internal colonization and subsequent mummification of the developing fruit. The potential for use of the commercial biocontrol products Serenade ( Bacillus subtilis QRD137) and BlightBan ( Pseudomonas fluorescens A506) to suppress floral infection in this pathosystem was investigated. B. subtilis exhibited marked antibiosis against the pathogen in vitro, reducing radial growth rates of M. vaccinii-corymbosi to less than one-half of those of the untreated control after 1 week of co-culture on potato-dextrose agar ( P =0.0029). In contrast, P. fluorescens did not reduce fungal growth compared with the untreated control ( P =0.3182). When Serenade was applied to stigmatic surfaces of detached blueberry flowers in the laboratory, population densities of B. subtilis , determined by dilution-plating, were variable 1 and 2 days after application, followed by a consistent drop in bacterial numbers after 3 and 4 days. In contrast, population densities of P. fluorescens increased exponentially 1 and 2 days after application of BlightBan and remained constant thereafter. The greatest mean population densities observed were 1.6 × 10 5 and 1.5 × 10 5 colony-forming units per stigma for B. subtilis and P. fluorescens , respectively. In a separate experiment, conidia of M. vaccinii-corymbosi were applied to detached flowers 24 h before or after application of the biocontrol products to flower stigmas. Serenade significantly reduced the number and growth rates of hyphae penetrating the stylar canal to less than one-fifth of those measured in the untreated control, whereas fungal suppression following application of BlightBan was less pronounced. Reductions in fungal growth rate in flowers treated with B. subtilis isolated from Serenade and reformulated by freeze-drying in skim milk were intermediate between the untreated control and the Serenade treatment, suggesting that part of the observed activity of Serenade was due to the formulation of that product. The results of these experiments identify Serenade as a promising candidate for further testing against mummy berry disease.

Distribution and Virulence Phenotypes of Heterodera glycines in Missouri.

The soybean cyst nematode, Heterodera glycines, is the most economically important pathogen of soybean in Missouri. Knowledge of the nematode's distribution and ability to adapt to resistant varieties is important for determining crop losses and establishing research priorities. No previous surveys of Missouri have provided reliable population density and phenotypic diversity data; therefore, we conducted a random survey to obtain both. Two samples from each of 200 fields were collected; 392 samples were processed for extractions of cysts and eggs. Two hundred and forty seven (63%) of the samples had detectable cyst nematode populations, which ranged from 15 to 149,700 eggs per 250 cm3 of soil. The lowest average population densities were observed in the east-central region of Missouri (2,260 eggs per 250 cm3 of soil), and the highest were observed in the northeast (9,238 eggs per 250 cm3 of soil), but among the eight regions sampled, mean population densities did not differ significantly. These population densities were potentially responsible for losses worth over $58 million in 1999 in Missouri. Race tests were conducted on populations from 183 samples. In order of frequency, races 3, 1, and 2 accounted for 86% of H. glycines populations. Nearly 60% of the populations were virulent (able to produce females) on plant introduction (PI) 88788, which is the source of resistance for most H. glycines-resistant cultivars. More than a third of the populations were virulent on cv. Peking, another common resistance source. Very few populations were virulent on PI 90763 or PI 437654, suggesting that these sources of resistance should be exploited more frequently.

Abundance of Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) neonates falling to the soil under tree canopies in Florida citrus groves.

The purpose of these experiments was to estimate the number and distribution of Diaprepes abbreviatus (L.) neonate larvae dropping from the canopy of infested citrus trees. The number of neonates was monitored in the field using passive funnel traps in two simultaneous experiments and a separate experiment for an additional year. In one experiment, traps were placed from trunk to dripline in the cardinal directions under each of five trees (132 traps total). In a second experiment, eight traps were placed under each tree in the cardinal directions, one trap 30 cm from the trunk and one trap 30 cm from the dripline/direction for 25 trees (200 traps total). Larvae were collected weekly for 50 wk in conical tubes containing ethylene glycol as a preservative. Traps closer to the tree trunk captured more larvae than traps nearer the dripline. The area under the tree canopy was positively correlated with the total estimated number of larvae captured per tree. The estimated number of total larvae/tree over the course of our experiments ranged from 955 to 7,290. The highest number of neonate larvae observed in 1 wk was 67 +/- 6/m2. There was an inverse relationship between the number of traps beneath a tree and the number of trees that needed to be sampled to estimate mean population density with a given precision. However, there was a direct relationship between number of traps/tree and the total number of traps needed for a given precision. This passive technique could be used to quantify the destructive larval stage and to assess D. abbreviatus management strategies.

Variation and covariation in survival, dispersal, and population size in barn owls Tyto alba

Summary Population dynamics are the result of variation in survival, recruitment, emigration and immigration rates. Covariation between these demographic rates critically affects the dynamics and magnitude of fluctuations in population size. Such covariation can arise by environmental factors affecting several rates in similar ways. Also demographic processes, such as the source–sink and the balanced dispersal process, are expected to lead to covariation between demographic rates. Here, we study variation and covariation in survival, emigration, immigration, and the size of a Swiss barn owl (Tyto alba) population, and examine the factors associated with this variation. For practical reasons, survival and emigration are often confounded in studies of natural populations. We overcome this problem by jointly analysing live‐recapture and dead‐recovery data using recently developed statistical methods. Mortality, emigration, the number of known immigrants, and population size were positively correlated over time. Neither the source–sink nor the balanced dispersal process is expected to lead to this pattern. Survival was lower for juveniles than adults (mean 17% vs. 72%), and highly variable across years in both age classes. Snow cover, mean annual temperature and population density accounted for 32–47% of the variation in survival of juveniles and adults. Emigration was higher for juveniles than for adults, and adults emigrated more often when the population size was higher. Our results showed that local population dynamics were affected by density dependence and the stochastic environmental factors snow cover and temperature. Rather than lending support to one of the two dispersal hypotheses, the patterns of correlation between survival, dispersal, and population size suggest strong fluctuations in environmental conditions that influence the dynamics of barn owl populations at a larger spatial scale.

Seasonal Variations in the bacterial population in an activated sludge system

Diminishing groundwater sources and a growing need of municipal water in arid countries like Saudi Arabia underline the need for an increase in the reuse of treated wastewater. Treatment of wastewater must be reliable and must be subject to monitoring to ensure the public health, safety, and environmental protection. A one-year study was conducted at the Al-Khobar wastewater treatment plant to investigate the effect of seasonal variations of temperature and flow rate on the fate of indicator microorganisms. The raw sewage, secondary effluent, and chlorinated effluent were analyzed for the detection and enumeration of four standard microorganismic indicators: standard plate count, total coliform, fecal coliform, and Clostridium perfringens on a weekly basis. It was found that the microbial populations present in the wastewater are very much sensitive to the wastewater temperature and, to some extent, on the wastewater flowrate. The t-test analysis performed on mean population densities of the indicator microorganisms studied shows higher microbial populations during summer than in winter. The insight gained from this study may be applied to other similar treatment plants operating in this region.Key words: Clostridium perfringens, indicator microorganism, wastewater reuse, seasonal variations, wastewater treatment.

Empirical binomial sampling plans: model calibration and testing using Williams’ method III for generalized linear models with overdispersion

Binomial sampling plans that use presence/absence data for estimating pest population density are commonly used in cropprotection when counting individual pest units is not cost effective. These plans are often based on the empirical relationship between the proportion of presences, p, and a count-based estimate of the mean population density, \(\tilde \mu \), given by \(\ln \left\{ { - \ln (1 - p)} \right\} = \alpha _0 + \alpha _1 ln(\tilde \mu )\), which is typically fitted as a simple linear regression. However, correctly incorporating all of (i) binomial sampling errors, (ii) biological errors (i.e., overdispersion), and (iii) errors in variables is not possible using linear regression. Here, model calibration and testing is carried out using William’s method III for fitting a binomial generalized linear model with overdispersion (GLMw) in order to handle (i) and (ii), and simulation is used to study the effect of using the sample estimate of μ as the predictor variable. Calculation of the operating characteristics function of the decision rule for an action threshold of p 0 is compared for linear and GLMw models, with the former shown to substantially underestimate the probability of correct decisions and overestimate the probability of incorrect decisions. A binomial sampling plan for populations of the leaf beetle Chrysophtharta bimaculata, a defoliator of Eucalyptusnitens plantations, is used to demonstrate the methods.