Selective Bait Research Articles

Quantitative Method Development to Determine Feed Consumption Using a Dye

Although there are many methods to determine ingestion and absorption of aquafeeds, none exist that are simple, cost-effective, and quantitative and that can mark fish with a long-lasting, visible indicator. In addition to aquafeed development, selective baits are needed that can be used for aquatic invasive species removal efforts, including for Grass Carp Ctenopharyngodon idella. Bait incorporated with a pesticide would allow for selective removal of targeted species. A method to quickly assess multiple bait formulations was developed to expediate development for invasive species management. Incorporation of Sudan Black B (SBB) in aquafeeds at concentrations greater than 75 and 120 mg SBB/kg fish resulted in pigmented external soft tissues of Largemouth Bass Micropterus salmoides and Rainbow Trout Oncorhynchus mykiss, respectively, 24 h after consumption. Visual confirmation of consumption was detectable in the gastrointestinal tract at all concentrations tested (≥10 mg SBB/kg) and quantifiable by absorbance measured at 601 nm from extracted SBB in tissues at concentrations less than those required for visual pigmentation. Although SBB was detectable in multiple tissues, fin and mandible tissues yielded the greatest accuracy in estimating consumption from extracted SBB. Compared with other tissues tested, liver tissue accumulated the highest level of SBB but had the greatest variability, while muscle tissue accumulated little detectable SBB. We used the SBB analytical method to compare consumption of six novel baits that were in the initial developmental stages to produce a palatable bait formulation designed to attract Grass Carp for management control. Overwhelming preference of a rapeseed bait formulation was confirmed using SBB as a tracer of consumption in the laboratory; however, use of SBB under natural conditions may be valuable for answering additional questions. Baits incorporated with SBB allowed for the rapid, simultaneous assessment of multiple formulations and could allow for future refinement of management baits, with results available as quickly as 24–72 h after application.

Efficacy of Minimum Application of Chlorfluazuron Baiting to Control Urban Subterranean Termite Populations of Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae)

Simple SummaryThe termite baiting system has emerged as a popular option for controlling subterranean termites. The effectiveness of termite baiting depends on the foraging of the termites to encounter the bait, feed on the bait, and the horizontal transfer of residual insecticide deposits between nestmates. However, termite baiting can be costly and time consuming. Thus, this study looks to minimize the termite baiting application which leads to the total colony elimination. Overall, this study found that a termite colony population can be eliminated by selective termite baiting treatment.Termite infestations in urban areas are a serious problem because they cause negative economic effects, reduce the esthetic value of buildings, damage crops, and require household repairs. Chemical controls are the most common method used against subterranean termites, and baiting has emerged as one of the prominent control methods. The goal of this research was to determine the efficacy of termite baiting by treating one of six active termite stations (selective baiting) with chlorfluazuron baits to eradicate six populations of subterranean termites. This work shows that the placement of chlorfluazuron baits in one of the active stations was sufficient to destroy a colony that was interconnected with multiple chlorfluazuron-free stations. In general, it requires an average of 4–8 weeks for a quantity of less than 300 g of chlorfluazuron bait to remove a termite infestation at the study site.

Sustainable Termite Management Using Innovative and Selective Termite Baiting Method

In a natural ecosystem, termites play an important role as a decomposer since termite can digest cellulose. Termites can be considered as pests once they had exerted substancial economical damages, such as Coptotermes spp known to be a major termite pests. Termites will cause a serious problem when the infestation occurred in urban areas as they give negative economic effects, reducing the value aesthetic of the buildings which lead to expensive building maintenance and repair. Chemical controls are the most common method used against pests of urban forests in Malaysia. The objectives of this studies are to evaluate the effectiveness of treatment by treating one active station out of all active termite stations (selective baiting) by using chlorfluazuron termite baits. Form the result, a termite colony population can be eliminated in selective termite baiting treatment. Elimination of termite population by selective termite baiting treatment was successful with the aid of termite behavior of trophallaxis which is the sharing of the bait toxicants among the termite nest mates. This sharing of toxicant among the nest mates circulates the active ingredients throughout the colony thus eradicate the colony along the process. Regardless of how many in ground station and above ground stations, baits placement in one out of all active stations was more than enough to kill the colony as all interceptor’s station shares the same tunnelling pathways which lead to the same colony. Chlorfluazuron baits need an average 4-8.6 weeks to eliminate termite infestation at the study sites. Furthermore, this method can cut the cost on total termiticide (bait) used. Thus, time can be save the during the baiting inspections due only single station to be monitored as reduction of termite activities in one station represent the reduction of activity in other stations only if the termite are originated from the same colony

Phytophthora palmivora EM SOLOS DE POMARES DE MAMOEIRO NO SUL DA BAHIA

The root rot of papaya caused by Phytophthora palmivora has contributed for the increase of the production costs in Brazil mainly in Bahia State. Seeking to diagnose the infestation level of areas cultiveted with papaya in the Extreme South of Bahia, samplings were performed in 33 commercial orchards of papaya, cultivated with the varieties Formosa, Golden and Sunrise Solo randomly selected in the municipalities of Eunapolis, Porto Seguro, Teixeira de Freitas, Mucuri, Prado, Nova Vicosa, Alcobaca and Santa Cruz de Cabralia. The soil samples (five) were collected in a depth of 0-20 cm, composed each one for three sub-samples, randomly obtained in each area. The simple samples were homogenized, mixed to obtain a composed sample of each the five collected points of the orchard. The composed samples were placed in polyethylene bags and properly labeled. At the Laboratory of Phytophthora at CEPEC/CEPLAC, two methodologies were used to isolate the pathogen from soil samples: dilution plates with selective medium (PARPH) and soil baits with disks (1cm) of green papaya fruits. Phytophthora palmivora was detected in 31 of the 33 orchards evaluated. There were no significant differences for the pathogen incidence in relation to the papaya varieties planted in the orchards. Phytophyhora. palmivora was detected in the orchads of all eight municipalities, attesting its wide distribution in southern Bahia State

Comparison of the relative efficacy of an insect baiting method and selective media for diversity studies of Metarhizium species in the soil

ABSTRACTMetarhizium are a commonly occurring group of entomopathogenic fungi normally found in soil. The most common methods to assess the diversity of Metarhizium species in soil are (i) the use of selective media and (ii) insect baiting using Galleria mellonella larvae. We compared the recovery efficiency from soil of four common species of Metarhizium (Metarhizium anisopliae, Metarhizium pingshaense, Metarhizium brunneum and Metarhizium robertsii) using these two methods. Firstly, we compared the number of colony forming units (CFU) produced in vitro when grown on two selective media, one containing chloramphenicol, thiabendazole and cycloheximidethe (CTC) and one based on the fungicide dodine (n-dodecylguanidine acetate) (DOD). Secondly, we artificially inoculated natural/non-sterile soil with the four fungal species at a rate of 2×102 and 2×103 conidia g−1of soil, baited with G. mellonella, and processed for evaluation using the selective media. The in vitro results showed that the greatest number of CFUs were recorded for M. brunneum. In contrast, when inoculated into soil, more G. mellonella larvae became infected by M. anisopliae. Finally, when using selective media, most CFUs recovered were for M. robertsii. The importance of our results in selecting a method to study the natural occurrence of Metarhizium in soil are discussed.

Prey composition modulates exposure risk to anticoagulant rodenticides in a sentinel predator, the barn owl

Worldwide, small rodents are main prey items for many mammalian and avian predators. Some rodent species have pest potential and are managed with anticoagulant rodenticides (ARs). ARs are consumed by target and non-target small mammals and can lead to secondary exposure of predators. The development of appropriate risk mitigation strategies is important and requires detailed knowledge of AR residue pathways. From July 2011 to October 2013 we collected 2397 regurgitated barn owl (Tyto alba) pellets to analyze diet composition of owls on livestock farms in western Germany. 256 of them were fresh pellets that were collected during brodifacoum baiting. Fresh pellets and 742 liver samples of small mammals that were trapped during baiting in the same area were analyzed for residues of ARs. We calculated exposure risk of barn owls to ARs by comparing seasonal diet composition of owls with AR residue patterns in prey species. Risk was highest in autumn, when barn owls increasingly preyed on Apodemus that regularly showed AR residues, sometimes at high concentrations. The major prey species (Microtus spp.) that was consumed most frequently in summer had less potential to contribute to secondary poisoning of owls. There was no effect of AR application on prey composition. We rarely detected ARs in pellets (2 of 256 samples) but 13% of 38 prey individuals in barn owl nests were AR positive and substantiated the expected pathway. AR residues were present in 55% of 11 barn owl carcasses. Fluctuation in non-target small mammal abundance and differences in AR residue exposure patterns in prey species drives exposure risk for barn owls and probably other predators of small mammals. Exposure risk could be minimized through spatial and temporal adaption of AR applications (avoiding long baiting and non-target hot spots at farms) and through selective bait access for target animals.

Evaluation of Monitoring Traps for <I>Drosophila suzukii</I> (Diptera: Drosophilidae) in North America

Drosophila suzukii Matsumura (Diptera: Drosophilidae), a recent invasive pest of small and stone fruits, has been detected in more than half of the U.S. states, and in Canada, Mexico, and Europe. Upon discovery, several different trap designs were recommended for monitoring. This study compared the trap designs across seven states/provinces in North America and nine crop types. Between May and November 2011, we compared a clear cup with 10 side holes (clear); a commercial trap with two side holes (commercial); a Rubbermaid container with mesh lid and rain tent (Haviland), and with 10 side holes and no tent (modified Haviland); a red cup with 10 side holes (red); and a white container with mesh lid and rain tent (Van Steenwyk). Although fly catches among traps varied per site, overall, the Haviland trap caught the most D. suzukii, followed by the red, Van Steenwyk, and clear trap. The modified Haviland and commercial trap had low captures. Among five crop types in Oregon, a clear cup with mesh sides (Dreves) also was tested and caught the most flies. Traps with greater entry areas, found in mesh traps, caught more flies than traps with smaller entry areas. In terms of sensitivity and selectivity, traps that caught more flies likewise caught flies earlier, and all traps caught 26-31% D. suzukii out of the total Drosophila captured. Future trap improvements should incorporate more entry points and focus on selective baits to improve efficiency and selectivity with regard to the seasonal behavior of D. suzukii.

Quantitative proteomics profiling of the poly(ADP-ribose)-related response to genotoxic stress

Upon DNA damage induction, DNA-dependent poly(ADP-ribose) polymerases (PARPs) synthesize an anionic poly(ADP-ribose) (pADPr) scaffold to which several proteins bind with the subsequent formation of pADPr-associated multiprotein complexes. We have used a combination of affinity-purification methods and proteomics approaches to isolate these complexes and assess protein dynamics with respect to pADPr metabolism. As a first approach, we developed a substrate trapping strategy by which we demonstrate that a catalytically inactive Poly(ADP-ribose) glycohydrolase (PARG) mutant can act as a physiologically selective bait for the isolation of specific pADPr-binding proteins through its macrodomain-like domain. In addition to antibody-mediated affinity-purification methods, we used a pADPr macrodomain affinity resin to recover pADPr-binding proteins and their complexes. Second, we designed a time course experiment to explore the changes in the composition of pADPr-containing multiprotein complexes in response to alkylating DNA damage-mediated PARP activation. Spectral count clustering based on GeLC-MS/MS analysis was complemented with further analyses using high precision quantitative proteomics through isobaric tag for relative and absolute quantitation (iTRAQ)- and Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics. Here, we present a valuable resource in the interpretation of systems biology of the DNA damage response network in the context of poly(ADP-ribosyl)ation and provide a basis for subsequent investigations of pADPr-binding protein candidates.

Physical and behavioural abilities of commensal rodents related to the design of selective rodenticide bait stations

Design of selective bait stations to deliver rodenticide bait is often proposed for management of non-target animal access, but much of the information on the behavioural and physical capabilities of rodents relative to station access has not been readily available or is based on unpublished, informal observations or anecdotes repeated for many years. We studied the climbing and jumping abilities of Polynesian Rats (Rattus exulans), Norway Rats (R. norvegicus), Roof Rats (R. rattus), and House Mice (Mus musculus), focused on applications for eradication of these invasive rodents from island ecosystems in the Pacific where a variety of important non-target animals occur. The maximum jumping heights achieved by the three rat species was 40 cm; House Mice jumped a maximum of 25 cm. The minimum diameter holes through which these species could pass were 40 mm (Norway Rats), 35 mm (Roof Rats), 30 mm (Polynesian Rats), and 13 mm (House Mice). Our findings establish threshold differences for these species for transiting access openings or jumping to platforms to obtain food. In areas where endangered birds or other animals occur, such information could be used in designing selective stations so as to prevent unnecessary poisoning.

Trends in Vertebrate Pesticide Use and New Developments: New Zealand Initiatives and International Implications

Author(s): Eason, Charles; Murphy, Elaine; Ogilvie, Shaun; Blackie, Helen; Ross, James; Kavermann, Mathew; Sam, Shona; Statham, Mick; Statham, Helen; Lapidge, Steven; Humphrys, Simon; Henderson, Ray; MacMorran, Duncan; Gibson, Troy; Gregory, Neville; Harrison, Joanne; Giles, Gregory; Sammut, Ivan; Jansen, Paul; Conole, Daniel; Rennison, David; Brimble, Margaret | Abstract: In New Zealand, sodium fluoroacetate (1080) has been used for vertebrate pest control for several decades. Since the 1990s, some 1080 users have switched to brodifacoum for possum and rodent control because of its ready availability and ease of use. An awareness that field use of brodifacoum results in persistent residues provides the impetus to develop alternatives and provide new tools and greater flexibility. Looking to the future, we seek toxins which increasingly combine “low-residue” characteristics with humaneness, and more selective bait and delivery systems enabling better and more acceptable control of possums, wallabies, mustelids, rodents, feral cats, and rabbits. Experience gained in the 1990s with the introduction of cholecalciferol (Feracol®) and a cyanide pellet (Feratox®), which both kill possums without secondary poisoning, underpins the extension in 2009 of the Feratox® registration to include introduced Dama wallabies. To date, zinc phosphide has not been registered in NZ, despite its field use in Australia and the U.S. and low secondary poisoning risk compared with 1080. Research and registration dossiers are being assessed in 2009-10 for zinc phosphide containing products for possum and rodent control. Registration documents are also being prepared for a combination of cholecalciferol and coumatetralyl to provide a slow-acting alternative to brodifacoum for the field control of possums, rodents, and rabbits with low risk of bio-accumulation. Anticipated timelines for product availability are 2010 (zinc phosphide) and 2011-13 (cholecalciferol and coumatetralyl). Our intention now is to move beyond these conventional rodenticides and develop new vertebrate pesticides. For example, we are pursuing the registration of para-aminopropiophenone (PAPP) for humane control of stoats and feral cats, and a series of related novel toxins and other compounds that target the red blood cell for other pest species including rodents. PAPP products should be available in 2010, subject to registration approvals. New research initiatives in 2010 will increasingly result in a shift in focus to the development of novel rodenticides aided by new international research collaborations.

Combining affinity purification by ADP-ribose-binding macro domains with mass spectrometry to define the mammalian ADP-ribosyl proteome

Mono-ADP-ribosylation is a reversible posttranslational modification that modulates the function of target proteins. The enzymes that catalyze this reaction in mammalian cells are either bacterial pathogenic toxins or endogenous cellular ADP-ribosyltransferases. For the latter, both the enzymes and their targets have largely remained elusive, mainly due to the lack of specific techniques to study this reaction. The recent discovery of the macro domain, a protein module that interacts selectively with ADP-ribose, prompted us to investigate whether this interaction can be extended to the identification of ADP-ribosylated proteins. Here, we report that macro domains can indeed be used as selective baits for high-affinity purification of mono-ADP-ribosylated proteins, which can then be identified by mass spectrometry. Using this approach, we have identified a series of cellular targets of ADP-ribosylation reactions catalyzed by cellular ADP-ribosyltransferases and toxins. These proteins include most of the known targets of ADP-ribosylation, indicating the validity of this method, and a large number of other proteins, which now need to be individually validated. This represents an important step toward the discovery of new ADP-ribosyltransferase targets and an understanding of the physiological role and the pharmacological potential of this protein modification.

Chemical Alternatives to Malathion for Controlling <I>Ceratitis capitata</I> (Diptera: Tephritidae), and Their Side Effects on Natural Enemies in Spanish Citrus Orchards

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most important fruit pests worldwide. Mediterranean fruit fly control in Spain has been based on organophosphate sprays, especially malathion, mixed with protein baits. However, this insecticide has recently been excluded from annex 1 of the Directive 91/414 CEE, which lists authorized active ingredients for pest control in the European Union. This article reports on the efficacy of four alternative baited insecticides on Mediterranean fruit fly and their side effects on three natural enemies [Cryptolaemus montrouzieri (Mulsant), Neoseiulus californicus (McGregor), and Aphidius colemani (Viereck)] relevant for pest control in citrus agroecosystems. A high Mediterranean fruit fly mortality was obtained for all baited insecticides (phosmet and spinosad) except lambdacyhalothrin, which caused the lowest mortality and showed a novel disabling effect on surviving Mediterranean fruit fly adults. Spinosad proved to be the most selective bait treatment for C. montrouzieri and N. californicus, whereas for A. colemani the most selective bait was phosmet and lambda-cyhalothrin. These findings would contribute to a sustainable chemical control of C. capitata populations under an integrated pest management system in Spanish citrus orchards.

Eradication of Phytophthora ramorum and Other Pathogens from Potting Medium or Soil by Treatment with Aerated Steam or Fumigation with Metam Sodium

Phytophthora ramorum survived in potting media infested with sporangia or chlamydospores, allowing the pathogen to remain undetected while disseminated geographically. Chlamydospores or oospores of P. ramorum, Pythium irregulare, Thielaviopsis basicola, and Cylindrocladium scoparium produced in vermiculite culture were used to infest potting media. Infested media in plastic plug flats were treated with aerated steam mixtures from 45 to 70 °C for 30 min. In a second experiment, infested media were fumigated in polyethylene bags with a concentration series of metam sodium ranging from 0.25 to 1.0 mL·L−1. Survival of the pathogens was determined by selective baiting or direct plating the infested media on PARP selective medium. Assays indicated that all pathogens in the infested potting media were killed by aerated steam heat treatments of 50 °C or higher. Metam sodium concentrations of 1.0 mL·L−1 of medium or greater also eradicated all pathogens from the potting medium and soil. These results show that aerated steam treatment or fumigation with metam sodium can effectively sanitize soil-less potting media infested with P. ramorum or other soilborne pathogens, as well as P. ramorum-infested soil beneath infected plant containers. In addition, steam treatments to 70 °C did not melt plastic plug trays.

A field experiment on selective baiting and bait preferences of pest mustelids (Mustela spp.)

We tested whether a new automated bait dispenser, the Scentinel®, could be programmed to deliver non-toxic bait selectively only to animals of specified dimensions (>400 g body weight and <110 mm body diameter, the size of a ferret or a mink). We tested whether wild ferrets would discriminate between two types of bait (egg/oil and homogenised brain tissue). We set 24 Scentinels in 12 randomised pairs for 11 weeks on a 2400-ha area of pastoral farmland in New Zealand. Of 1559 visits by small animals, 198 were by ferrets (c. 28 individuals). The Scentinels correctly delivered 895 baits to visitors weighing >400 g, and no baits to 543 visitors of <400 g. The mean body weight of live ferrets recorded by Scentinels was not significantly different from that of 34 carcasses collected from the same area by professional trappers. Of the 145 baits dispensed to ferrets, egg/oil bait was significantly more often eaten. We conclude that the Scentinel can reliably deliver bait to specified sizes of animals and deny it to others. It can also facilitate extensive bait preference tests on unrestrained wild pests.

Prerequisites for oral immunization of free-ranging raccoons (Procyon lotor) with a recombinant rabies virus vaccine: study site ecology and bait system development.

A model baiting system suitable for the delivery of an oral rabies vaccine to free-ranging raccoons (Procyon lotor) was developed and tested on barrier islands in South Carolina (USA). Features of barrier island physiography and ecology were studied relative to selective bait deployment and site biosecurity. Capture-mark-recapture data were obtained from 228 raccoons. Raccoon density estimates, using a modified census assessment technique, were one raccoon per 1.8 to 2.7 ha. Mean (+/- SE) and range home area estimates of radio-collared raccoons were 84 (+/- 15.6) ha (27 to 176 ha) by a minimum convex polygon method and 138 (+/- 22.8) ha (43 to 241 ha), by a harmonic mean transformation method. Habitat utilization determinations of radio-collared raccoons were conducted to identify study areas to potentially maximize selectivity of bait towards raccoons and to reduce the absolute number of baits deployed. Island raccoons showed a habitat preference for maritime forest, maritime shrub and marsh areas. Additionally, there was no evidence of inter-island or mainland exchange of ear-tagged or radio-collared raccoons. A disease and mortality survey was conducted to identify baseline pathology and incidental lesions in the target raccoon population, prior to actual vaccination initiation. Thirty-eight percent of 30 clinically suspect raccoons sampled had intracytoplasmic eosinophilic inclusions diagnostic of canine distemper; no other lesions suggestive of viral etiologies were found. Serological surveys for raccoon poxvirus and rabies virus antibodies were negative. Antibody titers to canine adenovirus 1 and 2 indicated a moderate level of exposure (approximately 10 to 16%) in the raccoon population. Overall, 93 to 100% of placebo baits were consistently disturbed by 7 days post-bait deployment, and bait acceptance rates by raccoons ranged from 49 to 85%, by using a modular systems approach to select the optimum combination of bait attractant, biomarker, matrix, density, and distribution. These results suggest that a large proportion (up to 85%) of a free-ranging island raccoon population can be selectively and safely targeted, marked and monitored utilizing a proposed oral bait delivery system for recombinant or other rabies vaccines.

HABITAT CHARACTERISTICS AND GRASSHOPPER COMMUNITY DYNAMICS ON MIXED-GRASS RANGELAND

AbstractA study was conducted in Butte County of western South Dakota to determine the relationships between habitat characteristics and spatial and temporal changes in community structure of grasshoppers on mixed-grass rangeland. Detrended correspondence analysis (DCA) of 29 undisturbed grasshopper communities and correlation analysis of DCA axis values and habitat variables denned specific spatial gradients underlying the community structure of grasshoppers. Results indicated that grasshopper communities changed along a primary gradient of percentage of coverage of grasses, particularlyBuchloe dactyloides(Nutt.) Engelm., and a secondary gradient of percentage composition of clay and sand in the soil.DCA of 24 grasshopper communities sampled in 1986 and 1987, multiple regression analysis, and factor analysis were used to determine the relationships between specific habitat characteristics and changes in communities of grasshoppers treated with either a nonselective insecticidal spray (malathion) or a selective insecticidal bait (bran bait with carbaryl). Results indicated that between-year change in community composition, or the difference between post-treatment communities in 1986 and 1987, was positively correlated with percentage of coverage of total grasses and forbs. Community malleability, defined as the tendency of a community to return to its predisturbed state, was greater in habitats with high coverages ofAgropyron smithiiRydb. andCarexspp., low coverage ofBouteloua gracilis(H.B.K.) Lag. ex Steud., and low species richness of grasses. Our results emphasize the importance of habitat characteristics in structuring undisturbed grasshopper communities and in community change after perturbation with insecticides.

Acceptance of Wheat Bran Bait by Species of Rangeland Grasshoppers

The experimental design is described for a 8500-ha pilot management test of wheat bran bait containing insecticide, Nosema locustae Canning, or both, for control of a complex of rangeland grasshoppers. One objective was to determine which species accepted the bait. Field plots were treated by aircraft with 0.56, 1.12, or 1.68 kg or 1.96% carbaryl-treated flaky wheat bran bait/ha. Acceptance of bait varied greatly within 28 observed species of grasshoppers. All major pest species except Amphitornus coloradus (Thomas) and Camnula pellucida (Scudder) were susceptible. In general, species of Acridinae and Gomphocerinae (slant-faced grasshoppers) suffered slightly greater mortality than species of Melanoplinae (spur-throated grasshoppers), while Oedipodinae (banded-wing grasshoppers) were affected least. Such differences could be exploited in a management program based primarily on judicious use of selective bait.

Improved methods for use in studies onPhytophtohora cinnamomiRands and otherPhytophthoraspecies

A satisfactory method was devised for obtaining large numbers of active zoospores of Phytophthora cinnamomi Rands. Aerial mycelium from cultures grown on a pea agar medium is placed in non-sterile soil extracts for periods of up to 48 hours. This method has proved more consistent and provided larger numbers of zoospores than other methods tried. Seedlings of blue lupin (Lupinus angustifolius L.) have proved to be a very convenient host plant for infection studies with P. cinnamomi. Blue lupin seedlings used as a selective bait were more efficient than the apple technique in soil isolation tests for P. cinnamomi and were also found suitable for isolation of several other species of Phytophihora.