Pest Management Recommendations Research Articles

Coffee berry borer (Coleoptera: Scolytidae) population dynamics across Hawaii Island's diverse coffee-growing landscape: optimizing location-specific pesticide applications.

A major challenge to area-wide management of coffee berry borer (Hypothenemus hampei Ferrari) (Coleoptera: Scolytidae) is understanding how a heterogeneous coffee-growing landscape affects coffee berry borer population dynamics across temporal and spatial scales. We examined coffee phenology, weather, coffee berry borer flight activity, infestation, coffee berry borer position within the fruit, and management across 14 commercial coffee farms from 2016 to 2018 on Hawaii Island to characterize variation among districts and elevations. Here we aim to determine whether the timing of pesticide applications might be optimized based on specific locations. We observed larger populations of coffee berry borer at low-elevation farms and in the Kona district compared to mid- and high-elevation farms and the Ka'u district. Temperature, relative humidity, and rainfall all differed significantly across districts and elevations. We also observed a trend of higher fruit production at low-elevation farms compared to high-elevation farms, and differences in the timing of fruit development. Infestation increased with higher pest pressure and air temperatures and reduced fruit availability early and late in the season. Lastly, the timing and number of management interventions varied among districts and elevations. Combining information on trap catch, infestation, coffee berry borer position, and plant phenology, we present an optimized pesticide spray schedule for each location and find that the number of sprays could be reduced by 33-75% in comparison to the existing integrated pest management recommendations while maintaining effective control. Implementing a coordinated area-wide approach refined by small-scale optimization will lead to improved management of coffee berry borer on individual farms and a reduction in pest pressure across the coffee-growing landscape.

Weather-Informed Recommendations for Pest and Disease Management in the Cashew Production Zone of Côte d’Ivoire

Poorly informed pest and disease management strategies can have detrimental effects on the environment, crop quality, crop yield, farmers’ income, and the overall sustainability of agriculture. For this reason, integrated pest and disease management (IPDM) draws on knowledge from various research fields to effectively manage risks of bio-aggressor outbreaks. However, many agricultural sectors of Sub-Saharan African countries lack such necessary knowledge, including the epidemiology of bio-aggressors in relation to the increased climate variability. The objective of this work is to provide weather-based guidance for the development of sustainable pest and disease control strategies in cashew cultivation areas of Côte d’Ivoire, the second most important cash crop of the country. Leveraging the bioclimatic knowledge in the literature about fungi and insects, we explored four-year hourly data (2017–2020) of 34 sites of the cashew production zone. The outputs showed potentially conducive weather events for fungi and insects throughout the entire cashew production areas, with the forest–savanna transition zone being the most critical. These outputs were used to elicit recommendations for pest and disease management in consultation with a multidisciplinary stakeholder task force. They recommended that effort for disease prevention in the forest–savanna transition zone, the new cashew production zone, should be an incrementation of the one already recommended in the north savanna. Weather-based disease monitoring, entomopathogenic-fungi-based pest control, and the promotion of early-maturing cashew genotypes are also recommended, especially in the forest–savanna transition zone.

Type of Stress Induces Differential Responses in Acer rubrum (Red Maple), but Induced Responses Have No Effect on Herbivorous Pests

Plants thrive in dynamic environments requiring adaptive strategies in response to environmental stressors. Furthermore, insect herbivores may be attracted or deterred by the expression of these traits. This study examines growth, physiological, and phytochemical adaptations of maple trees in response to stressors and how these stressors effect herbivore feeding behavior within an agricultural production system. Agricultural systems are unique because plants experience environmental stressors unique to production such as herbicide sprays and girdling. Using four environmental stressors commonly observed in agricultural production (control, mechanical defoliation, chemical defoliation, and girdling), applied to two cultivars of red maple (Acer rubrum, ‘Brandywine’ and ‘Franksred’), this study analyzed differentiation of expressed traits in a production system. Responses varied depending on cultivar and stress treatment but had no effect on insect herbivore behavior. Understanding the ecological interactions within these systems will provide information for better plant production and pest management recommendations.

English

Silver leaf whitefly (Bemisia tabaci Gennadius) (Hemiptera: Aleyrodidae) is a polyphagous winged insect pest that causes high yield losses in tomatoes and other vegetable crops globally. To combat the infestation by the silver leaf whitefly and other insects, tomato growers use cultural and synthetic chemical-based methods. However, the silver leaf whitefly continues to dominate the tomato production systems. Some of the reasons for such continued dominion by the silver leaf whitefly in tomato include among other reasons; little understanding of the mechanisms for survival of the insect pest by tomato production stakeholders which consequently results in difficulties in making appropriate pest management decisions, presence of diverse hosts, the ability of the silver leaf whitefly to develop resistance to synthetic pesticides and ineffective techniques used by tomato grower in combating the insect. Of these challenges, this review discusses the mechanisms for survival of the insect, current pest management options and recommendations for a way forward concerning the silver leaf whitefly management in Africa. © 2022 Friends Science Publishers

Efficacy and Toxicity of VarroMed® Used for Controlling Varroa destructor Infestation in Different Seasons and Geographical Areas

VarroMed® is a soft acaricide registered for honey bees on the European Union market since 2017 for Varroa control. Researchers involved were partners of different countries of the Varroa control task force of the COLOSS Association. Our goal was to evaluate performances (acaricide efficacy and toxic effects on honey bees) of VarroMed® in different climatic conditions. Our results in the tested apiaries showed an efficacy ranging from 71.2 to 89.3% in summer/autumn, and from 71.8 to 95.6% in winter. No toxic effects on bees were observed, except in one apiary, where severe cold climatic conditions played a crucial role. The treatment could be efficiently applied in broodright as well as in broodless colonies. Integrated pest management (IPM) recommendations for beekeepers are provided in order to apply the best Varroa control protocol.

An act of defiance? Measuring farmer deviation from personalised extension recommendations in Zambia

AbstractGiven the recognised role of blanket extension advice in the low uptake of productivity‐enhancing technologies among developing country farmers, personalised or site‐specific extension approaches are gaining attention. Focusing on the case of the plant clinic extension model which provides personalised crop protection services to smallholder farmers, we investigate to what extent and how accurately farmers adopt personalised extension advice, and the implications for agricultural productivity. We combine a unique database of personalised integrated pest management (IPM) recommendations provided to 420 plant clinic attendees in Zambia with survey data on the actual IPM practices implemented by these same clinic attendees. We find that more than 80% of the sample farmers deviated from the personalised IPM recommendations they received from plant clinics. Based on the degree of deviation from the personalised recommendations, we identify five categories of adopters of IPM practices and show their heterogeneous effects on maize productivity. For example, our multi‐valued treatment effect estimates suggest an 82% yield penalty for non‐adopters compared to full adopters of recommended IPM practices, while the yield gain for full adopters is more than double that of partial adopters, as well as that of those who adopted additional practices beyond what was recommended. Our findings have important implications for the promotion of personalised extension services and for the measurement of the impact of complex agricultural technologies.

New Records of Scarab Insect Pests of Cacao (Theobroma cacao L.) in the Philippines

New records of scarab pests of cacao (Theobroma cacao L.) were reported in the Philippines: the rhizotrogine chafer, Holotrichia bipunctata Brenske, 1892 (Coleoptera: Scarabaeidae: Melolonthinae: Rhizotrogini) and diplotaxine chafer Apogonia palawana Heller, 1897 (Coleoptera: Scarabaeidae: Melolonthinae: Diplotaxini). The feeding patterns of the two insect pests are characterized, and some integrated pest management recommendations were cited.

Agronomic management of industrial hemp alters foliar traits and herbivore performance

Agronomic management decisions can alter plant foliar traits, especially nutritional quality, with potential to influence plant–herbivore interactions. Herbivores balance consumption of plant tissue for nutritional gains related to growth and development while contending with plant traits that may deter herbivory or are toxic. This study evaluates the influence of management decisions on the foliar quality of industrial hemp (Cannabis sativa) and the impact on the performance of fall armyworm (Spodoptera frugiperda). We included three common management decisions in this study: fertilization rate, cultivar choice, and planting date. In a no-choice feeding trial, fall armyworm larvae were fed leaves of field-grown hemp from three different cultivars that received different rates of fertilizer and were planted on two different dates. We quantified levels of foliar nitrogen, the ratio of carbon to nitrogen, leaf mass per unit area, and concentrations of tetrahydrocannabinol and cannabidiol, and determined the influence of foliar quality on herbivore performance. Fertilization rate, cultivar, and the interactions of planting date with both fertilization rate and cultivar influenced multiple aspects of hemp foliar quality. Overall, fertilization had the largest influence on foliar quality and subsequent herbivore performance. Variation in foliar traits influenced herbivore performance. Foliar nitrogen had a positive impact on fall armyworm performance and the ratios of carbon and total cannabinoids to nitrogen had negative impacts on fall armyworm performance. Our findings show that management decisions in industrial hemp can affect plant–insect interactions through changes in foliar quality. These outcomes suggest that developing crop management recommendations for pest management will be important for a re-emerging crop like industrial hemp.

Pest Management Needs and Limitations for Corn Earworm (Lepidoptera: Noctuidae), an Emergent Key Pest of Hemp in the United States

Abstract Corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), has emerged as an injurious insect pest to hemp, Cannabis sativa L., a crop newly reintroduced to the United States. Growing hemp presents a potential alternative economic opportunity for farmers but can be challenging with a market that is unstable and just developing. One of the most notable production challenges is managing corn earworm, an insect pest that is particularly damaging when it feeds on flower buds produced in cannabinoid varieties, creating extensive bud tunneling and wounds that allow entry of pathogens that can aid development and presence of bud rot. Damage to seeds is of lesser concern in hemp cultivars grown for grain and minimal risk is associated with hemp grown for fiber. Our ability to research hemp has only recently been allowed as production was largely suspended following World War II and, as such, there has been limited opportunity to develop information for empirically-based pest management recommendations. Further complicating development of integrated pest management (IPM) strategies are regulatory challenges associated with providing registration support to add hemp to pesticide labels, as it was not formally recognized as a crop by U.S. regulatory agencies until late 2019. Research needs and challenges to develop effective IPM programs for corn earworm on hemp are discussed here.

Farmers’ Knowledge of Integrated Pest Management of Cotton Crop in Some Villages of Ismailia Governorate

The aim of this research was to determine knowledge level of the farmers concerned the integrated pest management recommendations (IPM) of cotton at Ismailia Governorate. In addition to determine the correlation relationship between knowledge degree of the farmers and the studied variables. Furthmore, determine the information sources of the (IPM) . Consequently, identification of the most important problems facing cotton growers in the research area . This research was conducted in Ismailia on a sample of 302 respondents with a percentage of 22% of the whole farmers of country Data were collected through which a personal interview guided by a questionnaire during the months of March of 2020, and the data were quantitatively processed and statistically analyzed using the tabular presentation with frequency, percentages, and arithmetic mean , And the simple correlation coefficient. The most important results were: - The general level of knowledge of the surveyed farmer was low regarding with their knowledge about the integrated management methods, it reaches 48.4% of the respondents. - Farmers of knowledge degree was average regarding both of application of Agricultural duration and agricultural Practices that reaches to 51.8% besides the use of mechanical control which found to be 59%, On the contrary, farmers knowledge level regarding was use of legislative control was low as it reached 40% likewise the chemical control that found to be 42.8% of the respondents. - It was found that there was a correlation a significant between the Farmers’ Technical Knowledge of (IPM) on Cotton Crop and the age variable of the surveyed farmer (-.147*) however,this relationship goes direct at a significant level (0.01) for the surveyed farmer according to : The degree of regular education, years of experiences of (IPM) and the rate of visit of the IPM experts which found to be 0.232 ** , 0.287 ** and 0.211 **, respectively . - The most reliable information sources of IPM were : family, neighbors and friends, director of the agricultural administration, director of the extension center, and local leaders with a percentage of 96%, 83%, 70%, 58%, respectively . - The most important problems facing farmers in the field of using (IPM) of Cotton were: the low price of the cotton quintal, high labor costs, high costs of weeds control, high prices of insecticides and chemical fertilizers beside the equal prices of cotton among farmers regardless of their rank with percentage of 88.7%, 82.8%, 77.2% and 73.5%, respectively.

Use of plant clinic advice among farmers in Ethiopia: implications for sustainable pest management service

This study examined the use of crop health advices that farmers received at village-based plant clinics and their determinants in Ethiopia. Data were collected from 210 randomly selected plant clinic users from three districts of Ethiopia, and analysed using descriptive statistics and a binary logistic regression model. Plant clinic users were smallholders with an average landholding of 0.8 ha, predominantly male, with a mean age of 46 years. Most recommendations for pest management were a combination of monitoring, cultural practices and pesticides, in line with Integrated Pest Management (IPM) principles. About 64% and 34% of the clinic users fully or partially, respectively, applied the recommendations. After visiting plant clinics, farmers demonstrated improved knowledge and practices in using pesticides, although no significant difference was observed between the types of pesticides they used. Stability of plant doctors, distance to plant clinics, and education significantly and positively influenced the use of plant clinic advice, whereas age was negatively associated. The findings suggest that plant clinics provide relevant and practical advice that address plant health problems of farmers. Thus, such project-based intervention should be fully integrated into regular programmes to ensure their sustainability.

Sustainable Pest Management through Improved Advice in Agricultural Extension

This 5-year study addresses how improved quality of agricultural extension may lead to more sustainable pest management. We studied 112 agricultural extension workers trained as plant doctors under the Plantwise program in China. They run 70 plant clinics in Beijing, Guangxi, and Sichuan provinces. We analysed 47,156 recommendations issued by these plant doctors to 13,051 different growers between 2012 and 2017, and this for 250 different plant health problems on 91 crops. We also interviewed growers who had taken queries to plant clinics. On average, 86% of plant doctors provided comprehensive integrated pest management recommendations to the growers, with a 16% improvement in comprehensiveness over years. This most often included advice of synthetic pesticides (66%) with its frequency not much changing with time. In contrast, as a likely result of Plantwise interventions and China’s pesticide reduction policies, recommendations for biological control increased from 2% to 42%, pest monitoring by 8%, and cultural control by 11%. Recommendations of problematic plant protection agents as listed in the Montreal Protocol, Stockholm or Rotterdam convention, or as highly toxic under WHO’s toxicity classification were already rare in 2013 (1.9%) and nearly phased out by 2017 (0.2%). About 92% of growers implemented the advice, suggesting that agricultural extension services may contribute to changes in agricultural practices at scale. Further investment in such agricultural extension services may be warranted instead of phasing them out.

Evaluating the current integrated pest management recommendations in Canada for carrot weevil (Coleoptera: Curculionidae) and carrot rust fly (Diptera: Psilidae)

AbstractThe primary insect pests in Canadian carrot production are carrot rust fly (Psila rosae (Fabricius); Diptera: Psilidae) and carrot weevil (Listronotus oregonensis (LeConte); Coleoptera: Curculionidae). An integrated pest management programme for these pests exists in Québec and Ontario, where most Canadian carrot (Daucus carota subsp. sativus (Hoffmann) Schübler and Martens; Apiaceae) production occurs. As current carrot insect integrated pest management recommendations are decades old, laboratory and field trials were performed to evaluate the carrot insect integrated pest management recommendations. Carrot weevil populations were evaluated in the laboratory for resistance to the primary product used for control, phosmet. Ontario carrot weevils exhibited negligible mortality when exposed to phosmet compared with > 80% mortality in a susceptible strain. Using data from a carrot integrated pest management programme, weather data was correlated with monitoring and damage data of both pests from historical records. Increased carrot weevil captures were weakly related to increased damage. Carrot weevil damage was reduced by following integrated pest management recommendations in one of three trials. No strong relationship between weather and carrot rust fly captures was identified, suggesting the degree day model for carrot rust fly activity needs revision. In field trials, carrot rust fly damage was negligible despite integrated pest management recommendations for insecticide applications. Future research should include improving carrot weevil monitoring and control and increasing the carrot rust fly action threshold to optimise insecticide applications.

Oviposition preference, larval distribution and impact of the swede midge, Contarinia nasturtii, on growth and yield of canola

The swede midge (Contarinia nasturtii) has become a significant economic pest of canola (Brassica napus L.) in Ontario and an emergent pest in the Prairie provinces. Determining yield impacts of swede midge damage and the growth stage(s) at which canola is most vulnerable or attractive to swede midge will contribute to the development of pest management recommendations throughout the growth of the crop. In four experiments, canola plants were exposed to specific densities of adult swede midge and measures of oviposition, damage and yield were collected. There was a significant positive relationship between female density and total oviposition per plant with a very high capacity for larval numbers on canola; up to ~ 4000. Given a choice of four growth stages, approximately 85% of oviposition occurred on seven-leaf and early bud canola. Given no choice, the high total oviposition on 3-leaf and flowering stages suggests that swede midge will oviposit on less favorable canola growth stages, if no others are present. Damage sustained on primary racemes remained relatively constant over time. However, damage ratings on secondary and tertiary racemes decreased over time in the highest treatment densities, suggesting compensation by the plant. All yield measures, except seed weight per pod, significantly decreased with increasing female density on primary and/or secondary racemes. A density of ~ 0.6 females per plant resulted in 10% reductions in the number of pods and seed weight produced on primary racemes. These results support recommendations for insecticide applications at, or just prior to, the early bud stage.

To Spray or Not to Spray: A Decision Analysis of Coffee Berry Borer in Hawaii.

Integrated pest management strategies were adopted to combat the coffee berry borer (CBB) after its arrival in Hawaii in 2010. A decision tree framework is used to model the CBB integrated pest management recommendations, for potential use by growers and to assist in developing and evaluating management strategies and policies. The model focuses on pesticide spraying (spray/no spray) as the most significant pest management decision within each period over the entire crop season. The main result from the analysis suggests the most important parameter to maximize net benefit is to ensure a low initial infestation level. A second result looks at the impact of a subsidy for the cost of pesticides and shows a typical farmer receives a positive net benefit of $947.17. Sensitivity analysis of parameters checks the robustness of the model and further confirms the importance of a low initial infestation level vis-a-vis any level of subsidy. The use of a decision tree is shown to be an effective method for understanding integrated pest management strategies and solutions.

Susceptibility ofSpodoptera frugiperda(Lepidoptera: Noctuidae) Field Populations to the Cry1FBacillus thuringiensisInsecticidal Protein

The fall armyworm, Spodoptera frugiperda (Smith & Abbot) (Lepidoptera: Noctuidae), is a polyphagous insect pest affecting multiple crops. Fall armyworm in corn is managed with insecticides and corn hybrids expressing insecticidal proteins derived from Bacillus thuringiensis Berliner (Bt). The early detection of insect resistance is important for making appropriate management decisions and for implementing integrated pest management and insect resistance management recommendations. The objective of this study was to estimate susceptibility of fall armyworm populations to the Cry1F Bt insecticidal protein, emphasizing collections from locations where fall armyworm overwinters in the U.S. Fall armyworm neonates were exposed to artificial diet treated with increasing Cry1F concentrations, and mortality and growth inhibition were evaluated after 7 d. Differences in Cry1F susceptibility between the most susceptible and the most tolerant field populations were 2- and 6-fold for 2012 and 2013, respectively. These results are consistent with other susceptibility studies of Bt toxicity in other species although reduced susceptibility in one population collected from Florida may suggest resistance development.

English

Effective extension services are essential to provide farmers with skills and knowledge to manage pests and diseases. These services are provided by government agencies, non-governmental organisations, community based organisations as well as various actors in the private sector. Plantwise aims to help farmers lose less of their crops to pests and diseases, through among other strategies, the establishment of networks of plant clinics. Farmers visit these clinics and explain their plant health problems to plant doctors, who are mostly extension agents trained to provide diagnosis and give recommendations for pest management. However, plant doctors need diagnostic support in order to provide accurate diagnosis especially when faced with new pests. This study was carried out in Kenya to establish the diagnostic support available to plant doctors in the country and provide suggestions for improvement. A total of 133 plant doctors were interviewed and plant clinic data in the Plantwise online management system (POMS) database reviewed to find out how often plant doctors indicated the intention to send samples to a diagnostic lab as a follow up action. Plant doctors interviewed were aware of diagnostic services, and 65% indicated an intention to send samples for diagnosis. Thirty per cent of those interviewed had sent samples to a diagnostic centre, and feedback generally took several days with feedback not received in 27% of the cases, suggesting a need to improve coordination between research and extension. Plant doctors using tablet computers had better access to diagnostic support from their peers through their social online network. Key words: Extension service, plant clinic, diagnostic service, plant doctor, plantwise.

Pesticide Chemical Research in Toxicology: Lessons from Nature.

Pesticide researchers are students of nature, and each new compound and mechanism turns a page in the ever-expanding encyclopedia of life. Pesticides are both probes to learn about life processes and tools for pest management to facilitate food production and enhance health. In contrast to some household and industrial chemicals, pesticides are assumed to be hazardous to health and the environment until proven otherwise. About a thousand current pesticides working by more than 100 different mechanisms have helped understand many processes and coupled events. Pesticide chemical research is a major source of toxicology information on new natural products, novel targets or modes of action, resistance mechanisms, xenobiotic metabolism, selective toxicity, safety evaluations, and recommendations for safe and effective pest management. Target binding site models help define the effect of substituent changes and predict modifications for enhanced potency and safety and circumvention of resistance. The contribution of pesticide chemical research in toxicology is illustrated here with two each of the newer or most important insecticides, herbicides, and fungicides. The insecticides are imidacloprid and chlorantraniliprole acting on the nicotinic acetylcholine receptor and the ryanodine receptor Ca2+ channel, respectively. The herbicides are glyphosate that inhibits aromatic amino acid biosynthesis and mesotrione that prevents plastoquinone and carotenoid formation. The fungicides are azoxystrobin inhibiting the Qo site of the cytochrome bc1 complex and prothioconazole inhibiting the 14α-demethylase in ergosterol biosynthesis. The two target sites involved for each type of pesticide account for 27-40% of worldwide sales for all insecticides, herbicides, and fungicides. In each case, selection for resistance involving a single amino acid change in the binding site or detoxifying enzyme circumvents the pesticide chemists's structure optimization and guarantees survival of the pest and a continuing job for the design chemist. These lessons from nature are a continuing part of pest management and maintaining human and environmental health.

Integrated Pest Management Practices Reduce Insecticide Applications, Preserve Beneficial Insects, and Decrease Pesticide Residues in Flue-Cured Tobacco Production.

Integrated pest management (IPM) recommendations, including scouting and economic thresholds (ETs), are available for North Carolina flue-cured tobacco growers, although ETs for key pests have not been updated in several decades. Moreover, reported IPM adoption rates by flue-cured tobacco growers remain low, at < 40%, according to NC cooperative extension surveys conducted during the last four years. Previous research has suggested that timing insecticide treatments using currently available ETs can reduce the average number of applications to two or fewer per season. We conducted field-scale trials at nine commercial tobacco farms, three in 2104 and six in 2015, to quantify inputs associated with current scouting recommendations, to determine if current ETs were able to reduce insecticide applications as compared to grower standard practices, and to assess the impacts of reduced insecticide applications on end of season yield and pesticide residues. Two fields were identified at each farm and were scouted weekly for insects. One field was only treated with insecticides if pests reached ET (IPM), while the other field was managed per grower discretion (Grower Standard). IPM fields received an average of two fewer insecticide applications without compromising yield. More insecticide applications resulted in higher pesticide residues in cured leaf samples from Grower Standard fields than those from IPM fields. Reductions in insecticides and management intensity also resulted in larger beneficial insect populations in IPM fields.

Preconditioning of the generalist herbivore Trialeurodes vaporariorum to greenhouse monocultures and its subsequent performance on wild polycultures

AbstractGeneralist herbivores can face many challenges when choosing their host plant. This can be particularly difficult if their choice and performance are affected by host experience. Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is an invasive generalist herbivore, which has established in year‐round greenhouses at northern latitudes where it cannot overwinter outdoors. It mainly uses crops such as cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.), and ornamentals as host plants. However, every summer the insect escapes greenhouses and is exposed to natural vegetation. We evaluated the performance of T. vaporariorum on diverse vegetation outside greenhouses after prolonged experience of greenhouse crops. First, we surveyed the vegetation near infested greenhouses. Development success of the insect differed among wild hosts. We identified five new hosts among 12 plant species that bore pupae and were thus considered suitable as the insect's host plants. Members of the Urticaceae and Onagraceae were the most preferred and frequently inhabited by all insect life stages. The highest abundance of insects occurred in plots with low plant species richness, independent of plant family in these habitats. We then studied experimentally the impact of 1 year of preconditioning to one of three common greenhouse crops, cucumber, tomato, or poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch), on the performance of the preconditioned adults and their progeny on four wild plants. Adults from tomato and poinsettia preferred the novel host species over the species to which they were preconditioned. The whitefly population preconditioned to cucumber was the most fecund on all offered hosts. We conclude that generalist herbivores can have large variation in performance, despite polyphagy, on novel hosts as shown by the variable abundance of T. vaporariorum pupae among outdoor hosts. Furthermore, performance of whiteflies on natural vegetation was affected by experience on greenhouse crops. Based on our observations, we provide insights and recommendations for pest management.