Light emitting diode(LED)‐based trapping of the greenhouse whitefly (Trialeurodes vaporariorum)

Visual traps like yellow sticky card traps are used for monitoring and control of the greenhouse whitefly (Trialeurodes vaporariorum). However, reflected intensity (brightness) and hence, attractiveness depend on the ambient light conditions, and the colour (wavelength) might not fit with the sensitivity of whitefly photoreceptors. The use of light emitting diodes (LEDs) is a promising approach to increase the attractiveness, specificity and adaptability of visual traps. We constructed LED‐based visual traps equipped with blue and green high‐power LEDs and ultraviolet (UV) standard LEDs according to the putative spectral sensitivities of the insects' photoreceptors. In a series of small‐scale choice and no‐choice recapture experiments, the factors time of day as well as light intensity and light quality (colour) of LED traps were studied in terms of attractiveness compared to yellow traps without LEDs. Green LED traps (517 nm peak wavelength) were comparably attractive in no‐choice experiments but clearly preferred over yellow traps in all choice experiments. The time of day had a clear effect on the flight activity of the whiteflies and thereby on the trapping success. Blue LEDs (474 nm) suppressed the attractiveness of the light traps when combined with green LEDs suggesting that a yet undetected photoreceptor, sensitive for blue light, and an inhibiting interaction with the green receptor, might exist in T. vaporariorum. In choice experiments between LED traps emitting green light only or in combination with UV (368 nm), the green‐UV combination was preferred. In no‐choice night‐time experiments, UV LEDs considerably increased whitefly flight activity and efficacy of trapping. Most likely, the reason for the modifying effect of UV is the stimulating influence on flight activity. In conclusion, it seems that the use of green LEDs alone or in combination with UV LEDs could be an innovative option for improving attractiveness of visual traps.     

Phototactic behavior of Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) under visible wavelengths

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is one of the most important pests of greenhouse crops. The intensive use of chemical insecticides has resulted in insecticide resistance in T. vaporariorum and the critical level of pesticides residue in crops. It is therefore necessary to develop new control methods based on ecological pest management. The present study was designed to control greenhouse whitefly by finding and using insect repellent wavelengths. The repellent wavelength experiment was conducted by a two-way phototactic apparatus given a choice between darkness and visible wavelength spectrum from violet (380–450 nm) to red (620–750 nm). The phototactic responses of the greenhouse whitefly were then investigated in a four-way phototactic apparatus given a choice between two light regimes, light-emitting diode (LED) and sunlight. The results indicated that the lowest (69.2%) and highest (97.8%) number of whiteflies were attracted to violet and orange (590–625 nm) spectra, respectively. In addition, the present study indicated a significant attraction of T. vaporariorum adults to sunlight compared with LED. Furthermore, the eggplants grown under growth LEDs showed a significantly higher growth rate than the plants grown under sunlight. These findings suggest that this type of LED not only has positive effects on plant growth but it also has a repellent activity on T. vaporariorum adults, leading us to develop an effective behavioral control of the greenhouse whitefly.     

Visual orientation of the black fungus gnat,Bradysia difformis,explored using LEDs

Fungus gnats occur worldwide with more than 1 700 described species. They can cause serious damages on ornamentals, crop plants, and edible mushrooms, and are considered to be a serious pest in the last years. Bradysia difformisFrey (Diptera: Sciaridae) represents a common species in Europe. Usually, yellow sticky traps are used for monitoring and control in greenhouses and fluorescent tube‐based light traps are additionally applied for control in mushroom cultivation. The importance of such visual trapping measures for efficient monitoring or alternative control increases in biological and integrated plant protection. However, detailed color preferences of fungus gnats are mostly unknown. We studied the visual orientation of B. difformis with light‐emitting diodes (LEDs) in a broad range of peak wavelengths from 371 nm (ultraviolet, UV) to 619 nm (amber). We determined attractive wavelengths in consecutive choice experiments in daylight and darkness. Highest numbers of adult B. difformis were attracted to UV radiation (382 nm) followed by green‐yellow light (532–592 nm). The responses to UV and the green‐yellow range were relatively unspecific and mostly independent from intensity. Combination of UV and yellow LEDs improved trapping efficacy compared to a single UV or yellow LED trap, as well as compared to a common yellow sticky trap. When both wavelengths were compared to a black surface to increase contrasts, the black surface was preferred over yellow, but was less attractive than UV. Thus, B. difformis displays two, probably wavelength‐specific, behaviors to UV radiation and green‐yellow light, with UV being the most attractive stimulus. These behaviors might be directly related to underlying photoreceptors, suggesting dichromatic vision in B. difformis.     

Colour choice behaviour in the pollen beetle Meligethes aeneus (Coleoptera: Nitidulidae)

The pollen beetle Meligethes aeneus Fabricius (Coleoptera, Nitidulidae), a pest of oilseed rape (Brassica napus), is known to respond to coloured stimuli; however, current understanding of the underlying mechanisms of colour choice in this species is limited. In the present study, physiological and behavioural experiments are conducted to determine the response of the pollen beetle to colours in the field. Spectral sensitivity is measured in 10 animals using the electroretinogram technique. Light flashes (100 ms) at varied wavelengths (340–650 nm, 10‐nm steps) and at different light intensities are applied to the eye after dark adaptation. In behavioural experiments in the field, 100 water traps of varying colours (from yellow to green to blue with varying amounts of white and black added, and with known spectral reflectance) are set out on a bare soil field in May 2008. The mean spectral sensitivity curve of M. aeneus peaks at 520 nm; however, a model template fitted to the long wavelength tail of the observed curve reveals a peak at approximately 540 nm (green). A secondary sensitivity peak is observed in the ultraviolet (UV) range (370 nm). A total of 2482 pollen beetles are captured in the coloured traps. The results show that the pollen beetles' preference for yellow over other colours can be modelled as a colour opponent mechanism (green versus blue); however, further experiments are needed to specify responses to colours with higher UV reflectance. These findings may be used to optimize trap colours for monitoring to help develop integrated pest management strategies for pollen beetle control.     

瓢虫的趋光性反应研究

以六斑月瓢虫Menochilus sexmaculata Fabricius和狭臀瓢虫Coccinella transversalis Fabricius为例,研究了瓢虫对不同光质(波长)的趋光性反应。在室内分别测定了六斑月瓢虫和狭臀瓢虫对5种发光二极管(LED)光波的趋性,以及在田间挂板(佳多)测定了瓢虫对色板的选择趋性。室内测定结果表明,瓢虫对黄色和白色LED光波的选择趋性显著高于与其它颜色;田间挂板试验表明,黄色对瓢虫的诱杀作用最强。综合分析,黄色对瓢虫有强烈的吸引作用,建议在使用黄板进行田间监测和防治时应考虑对天敌瓢虫的诱杀作用。     

Which wavelength does the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae), prefer? Electrophysiological and behavioral studies using light-emitting diodes (LEDs)

The cigarette beetle, Lasioderma serricorne (Fabricius), is an important pest insect that consumes a variety of dry foods. It is known that UV light traps attract this species. However, less attention has been paid to its preferred wavelength. First, we investigated the spectral sensitivity of the compound eye. Next, we compared the attraction efficiency of LEDs of different colors (wavelengths). Our results showed that ultraviolet (UV, 375 nm) and blue (470 nm) LEDs attracted the most cigarette beetles of both sexes, irrespective of mating or oviposition status, although the UV LED consistently tended to attract the most beetles. Although the primary sensitivity peak of the compound eye was 520 nm, the green LED (520 nm) scarcely attracted beetles. Although the reason for the difference between the peaks in spectral sensitivity and attraction of beetles awaits further studies, whether UV and/or blue LEDs is more effective as a practical light trap for controlling L. serricorne beetle is discussed in this study.     

Relevance of visual and olfactory cues for host location in the mustard leaf beetle Phaedon cochleariae

The relevance of visual and olfactory cues for host‐plant location is investigated in males and females of the oligophagous mustard leaf beetle Phaedon cochleariae Fabricius (Coleoptera: Chrysomelidae). Different objects are offered in a walking arena and the behaviour of beetles is observed. Beetles orient toward vertically or horizontally striped black and white pattern independent of stripe orientation. The results suggest that contrast facilitates orientation in the field, whereas the pattern itself may be less important for host location in dense vegetation. The response to green and yellow objects is tested to investigate discrimination abilities between young (green) and mature (yellow) leaves. Beetles prefer green over yellow independent of material (cardboard or leaves of Nasturtium officinale R. Br., Brassicaceae). Preference behaviour tested in a dual‐choice contact assay coincides with visual preferences, where adults prefer young, more nutritious leaves for feeding and oviposition. Furthermore, females discriminate between visual cues of green leaves and green cardboard, whereas males do not, indicating that females are more sensitive in colour discrimination. Differences in colour wavelength influence the choice of beetle behaviour more strongly than differences in intensity. Both sexes of P. cochleariae prefer volatiles of the host plant N. officinale, whereas only females respond to the main volatile compound 2‐phenylethyl isothiocyanate. Given a choice between visual and olfactory cues, males orientate towards the colour cues, whereas females do not show any preferences. In males, visual cues may thus override olfactory cues, whereas, in females, both are equally important, which may reflect different ecological requirements and/or physiological abilities.     

Ultraviolet and violet light: attractive orientation cues for the Indian meal moth, Plodia interpunctella

The Indian meal moth (IMM), Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), engages in long-distance or foraging flights in the twilight hours of the scotophase when blue light dominates the irradiance spectrum of the sky. We tested the hypothesis that IMM uses wavelengths of visible blue/violet light as orientation cues that trigger phototactic responses. In four-choice laboratory experiments, blue light (400–475 nm) was significantly more effective than green (475–600 nm), orange (575–700 nm), or red (590–800 nm) light in attracting males and mated females. In subsequent experiments that tested light emitting diodes (LEDs) emitting peak wavelengths in the blue/violet-light range, the 405-nm 'violet' LED was significantly more effective than the 435-, 450-, or 470-nm 'blue' LED in attracting males as well as virgin and mated females. In electroretinogram recordings, the 405-nm wavelength elicited significantly stronger receptor potentials from female and male eyes than the 350-nm (UV) wavelength, and in a behavioral experiment it significantly enhanced the known attractiveness of UV light. Equal attraction of IMMs to 405-nm LEDs at 600–700 µW/cm² with or without UV light, and significantly stronger attraction to a 405-nm LED than to a 350-nm LED at maximum light intensities, suggest that the deployment of violet instead of UV light could become one of several management tactics for control of IMMs.     

Blue excitable green emitting Ce3+ doped CaS phosphor for w‐LEDs

CaS:Ce³⁺ is an efficient green‐emitting (535 nm) phosphor, excitable with blue light (450–470 nm) and was synthesized via a solid‐state reaction method by heating under a reducing atmosphere. The luminescent properties, photoluminescent (PL) excitation and emission of the phosphor were analyzed by spectrofluorophotometry. The excitation and emission peaks of the CaS:Ce³⁺ phosphor lay in the visible region, which made them relevant for light‐emitting diode (LED) application for the generation of white light. Judd‐Oflet parameters were calculated and revealed that green light emitted upon blue illumination. The prepared phosphor had strong blue absorption at 470 nm and a broad green emission band range from 490–590 nm with the peak at 537 nm. The characteristics of the CaS:Ce³⁺ phosphor make it suitable for use as a wavelength tunable green emitting phosphor for three band white LEDs pumped by a blue LED (470 nm). The Commission International de l'Eclairage co‐ordinates were calculated by a spectrophotometric method using the spectral energy distribution (0.304, 0.526) and confirm the green emission. The potential application of this phosphor is as a phosphor‐converted white light‐emitting diode. Copyright © 2015 John Wiley & Sons, Ltd.     

Field Evaluation of Different Wavelengths Light-Emitting Diodes as Attractants for Adult Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae)

In recent years, light traps with light-emitting diodes (LEDs) have been widely used in integrated pest management. The spiralling whitefly, Aleurodicus dispersus Russell, a highly invasive pest which causes heavy damage to fruit trees and ornamental plants, exhibits positive phototaxis, and light trap is the most appropriate tool for monitoring. We evaluated the use of LEDs as an inexpensive light source and examined the relationship between the captured number and the population density of adult A. dispersus in the field. We found that the violet (405 nm) LED traps captured the most adults of A. dispersus, and the captured numbers were significantly higher than those of blue (460 nm), green (520 nm), yellow (570 nm), and red (650 nm) LED traps. The adults of A. dispersus captured by light traps equipped with violet LEDs and smeared with liquid paraffin had a significant positive correlation with the population density of adult A. dispersus in a guava orchard, with a correlation coefficient of 0.828. In general, the light traps with 15 violet LED bulbs hung into 550-mL plastic bottles and smeared with liquid paraffin were the portable devices for attraction of adult A. dispersus. The results have potential use for improving the efficiency of light traps at attracting and trapping the adult spiralling whitefly.     

Effectiveness of portable solar-powered light-emitting diode insect trap: Experimental investigation in a groundnut field

Pest control is a major challenging component in agricultural and horticultural crops. Recently, the light-emitting diode (LED) trap driven by solar energy is a growing eco-friendly technology in pest control. The study was aimed to design, fabricate and investigate the effectiveness of a portable solar-powered LED trap for monitoring insect pests. The trap is compressed into a photovoltaic panel, battery, LED array, solar rectifier, insect collection tray, and PVC legs. Four different coloured LEDs viz., ultraviolet (UV)-405 nm, blue-470 nm, green-525 nm and red-630 nm were studied. The study was conducted in a groundnut field during the autumn season for 15 days. The results showed that the UV LED trap captured significantly more insects than the blue, green, and red LED traps except for Helicoverpa armigera. The average attraction of Spodoptera litura, Aproaerema modicella, Amsacta albistriga, Scirtothrips dorsalis, Aphis craccivora, and Empoasca kerri population to UV LED trap was 77.17 ± 18.89, 64.67 ± 12.91, 39 ± 16.80, 43.33 ± 18.30, 38.33 ± 17.08 and 33.17 ± 10.94, respectively. The red LED trap captured the least number of insects; however, the attraction of A. albistriga to the red LED was higher than the blue and green LED traps. Arcsine transformation (AT) was applied to transform experimental trap efficiency. UV LED trap had a significantly higher AT value than other LED traps. Overall mean AT values for UV, green, blue, and red LED traps were 34.98, 31.06, 29.87 and 22.87, respectively. The proposed portable solar-assisted LED trap could be a promising and effective pest control tool in areas where inconsistent electricity supply.     

Spectral preference and temporal modulation of photic orientation by Colorado potato beetle on a servosphere

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is a diurnal insect that strongly relies on visual cues to guide its walk. In the present study, we investigated the orientation behavior of non‐diapausing walking CPB in response to emissive colors produced by light emitting diodes (LEDs) in a dual choice arena adapted to a servosphere, where the only illumination available came from the photo‐stimuli. Our results demonstrate that CPB show positive phototactic behavior when stimulated with different wavelengths of light; they preferred to orient towards white (420–775 nm), ultraviolet (UV) (351 nm), blue (472 nm), green (570 nm), yellow (585 nm), orange (590 nm), and red (660 nm) over darkness when both alternatives were offered, but no orientation responses were elicited by infrared (940 nm). Both males and females preferred yellow and green over other colors, but did not show any particular preference between them, thus correlating with their preference for wavelengths reflected by vegetation. Sexual differences were noted in that male CPB preferred white over either red or UV, whereas female CPB did not show any preferences when offered these colors. Female CPB preferred UV and blue over red, whereas males showed no preferences when these colors were offered. Colorado potato beetles turned at higher angles and performed more tortuous walks in complete darkness and when infrared vs. darkness were offered compared with the rest of the colored lights. Both sexes preferred continuous over pulsed yellow light. Colorado potato beetles subjected to pulsed yellow light showed a temporal alteration of their walking performance by walking less, slower, and turning at a higher rate. The results are discussed with regard to the role of color in the CPB attraction to host plants and conspecifics as well as the role of intermittent photic stimuli in their orientation behavior. The information provided here provides a basis for the improvement of trapping devices for detection and survey of incipient or invasive CPB, and development of alternate control strategies for this important pest of potatoes and other solanaceous crops.     

Attractive Effects of American Serpentine Leafminer, Liriomyza trifolii (Burgess), to Light-Emitting Diodes

Phototactic responses of Liriomyza trifolii adults to six different light-emitting diodes (LEDs) were investigated, and their responses were compared to that using a luring lamp (BLB) under laboratory conditions. Based on the attraction rate under optimal light conditions, the green LED (520?±?5 nm) showed the highest attraction rate (99.7 %), followed by the yellow LED (590?±?5 nm, 96.1 %), the red LED (625?±?10 nm, 91.4 %), the blue LED (470?±?10 nm, 91.2 %), the UV LED (365 nm, 71.0 %), and the IR LED (730 nm, 5.6 %). Moreover, the green LED was approximately 1.4 times more attractive than BLB (71.1 %) to L. trifolii adults. These results suggest that the green LED was the most useful for monitoring of L. trifolii adults under optimal conditions.     

Colour‐based foraging diverges after multiple generations under different light environments

When the environment changes, sensory systems can adapt plastically or evolve genetically to the new surroundings, and traits and behaviours reliant on these sensory systems may also change, leading to altered evolutionary trajectories. We tested for differences in colour‐based foraging preferences of guppies (Poecilia reticulata) that lived for 6–10 generations under each of three light environments (green, lilac or control) to determine whether evolution under different light environments alters visually based behaviour. When tested in a common light environment, we found differences in pecking behaviour between treatments that were likely due to changes in the visual system. Pecking behaviour towards green stimuli was consistent across light treatments, possibly reflecting the importance of detecting green algae in the wild. The blue stimulus was only pecked at by fish from the control environments. Behaviour towards long wavelength stimuli varied, possibly due to the polymorphic nature of the long wavelength opsins. These results are consistent with one component of sensory drive but do not allow us to conclude whether these differences are due to plastic or evolved responses.     

Experimentally comparing the attractiveness of domestic lights to insects: Do LEDs attract fewer insects than conventional light types?

LED lighting is predicted to constitute 70% of the outdoor and residential lighting markets by 2020. While the use of LEDs promotes energy and cost savings relative to traditional lighting technologies, little is known about the effects these broad‐spectrum “white” lights will have on wildlife, human health, animal welfare, and disease transmission. We conducted field experiments to compare the relative attractiveness of four commercially available “domestic” lights, one traditional (tungsten filament) and three modern (compact fluorescent, “cool‐white” LED and “warm‐white” LED), to aerial insects, particularly Diptera. We found that LEDs attracted significantly fewer insects than other light sources, but found no significant difference in attraction between the “cool‐” and “warm‐white” LEDs. Fewer flies were attracted to LEDs than alternate light sources, including fewer Culicoides midges (Diptera: Ceratopogonidae). Use of LEDs has the potential to mitigate disturbances to wildlife and occurrences of insect‐borne diseases relative to competing lighting technologies. However, we discuss the risks associated with broad‐spectrum lighting and net increases in lighting resulting from reduced costs of LED technology.     

Acquisition of Tomato yellow leaf curl virus enhances attraction of Bemisia tabaci to green light emitting diodes

The light sensitivity of insects varies in response to different wavelengths of light. The change of light responses of vector insects plays an important role in the method of transmission and propagation of plant viruses. Here, we investigated whether the light attraction behaviors of whiteflies are altered by virus acquisition. Firstly, the light attraction rates of whiteflies were determined using LED light bulbs exhibiting different wavelengths in the visible and UV spectra. Whiteflies, Bemisia tabaci and Trialeurodes vaporariorum, were mostly attracted to green LEDs (526 nm). The attraction rate to green LED light was higher in B. tabaci than in T. vaporariorum, whereas it did not significantly differ between the B- and Q-biotypes of B. tabaci. Secondly, we investigated whether or not the green light attraction behavior of B. tabaci is influenced by the acquisition of Tomato yellow leaf curl virus (TYLCV). The attraction rate to green LED light was 2.5–3 times higher in TYLCV-infected whiteflies than in TYLCV-free whiteflies. However, this difference disappeared when the distance from the light source was greater than 0.5 m. Our results show that B. tabaci favors green light and its attraction is highly enhanced by the acquisition of the plant virus, TYLCV.     

The photokinesis of oriental fruit flies,Bactrocera dorsalis,to LED lights of various wavelengths

The oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), is an invasive pest of orchards around the world, particularly in Asian countries such as China. Light traps offer a potential means for pest monitoring and management. This study aimed to evaluate the sensitivity of the fly to light and investigate the impact of monochromatic light in the sensitivity spectrum on B. dorsalis. Six light wavelengths in LEDs – green (522 nm), yellow (596 nm), blue (450 nm), red (633 nm), purple (440 nm), and white (compound light) – were adapted to test responses of 5‐, 10‐, and 20‐day‐old B. dorsalis adults kept in laboratory conditions. We also tested the effects of green and red lights on pupal development and adults’ life activities. The results indicated a phototaxis preference rank in B. dorsalis adults to monochromatic LEDs with, in decreasing order, green, yellow, purple, blue, and red. Moreover, positive phototaxis significantly increased with age. Male adults are more sensitive than female adults to test lights, mainly at the age of 10 and 20 days. Emergence rates of pupae exposed to 12 and 24 h green light daily were 42 and 67%, respectively, whereas controls held in red light emerged at 33 and 37%, respectively. Furthermore, body weight, female fecundity, and mortality of B. dorsalis in night‐time exposure of green light (from 21:00 to 09:00 hours; during daytime flies were illuminated by white LED light) were significantly higher than in red‐light test groups and dark controls. In conclusion, B. dorsalis displayed preference toward green light, and fly age and gender seemed to significantly impact the phototactic behavior. Green LED light exposure during nighttime remarkably improved the emergence rates of B. dorsalis, and it enhanced growth, development, and ovipositing peak period, but decreased adult lifespan. This research lays a foundation for the development of new trap models, e.g., with green sticky cards or green light, for monitoring and control of B. dorsalis in the field.     

Responses of the blister beetle Hycleus apicicornis to visual stimuli

Insect attraction to host plants may be partly mediated by visual stimuli. In the present study, the responses of adult Hycleus apicicornis (Guér.) (Coleoptera: Meloidae) to plant models of different colours, different combinations of two colours, or three hues of blue of different shapes are compared. Single‐colour models comprised the colours sky blue, bright green, yellow, red, white and black. Sky blue (reflecting light in the 440–500 nm region) is the most attractive, followed by white, which reflects light over a broader range (400–700 nm). On landing on sky blue targets, beetles exhibit feeding behaviour immediately. When different hues of blue (of different shapes) are compared, sky blue is preferred over turquoise, followed by dark blue, indicating that H. apicicornis is more attracted to lighter hues of blue than to darker ones. No significant differences are found between the three shapes (circle, square and triangle) tested, suggesting that reflectance associated with colour could be a more important visual cue than shape for host location by H. apicicornis. The preference of H. apicicornis for sky blue can be exploited in designing an attractive trap for its management.     

Temporal response and attraction of Diaphorina citri to visual stimuli

As the vector of the global disease of citrus greening or huanglongbing, Asian citrus pysllids, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are the greatest threat to the worldwide citrus industry. Critical to management of D. citri and huanglongbing is optimization of surveillance methodologies. Although phytophagous insects may find host plants by multimodal cues, some appear to primarily use visual cues. In this study, we examined the behavior of Asian citrus psyllids toward light from light‐emitting diodes (LEDs) in the insect visible spectrum. The periodicity of attraction of psyllids to visual cues was evaluated in the field (yellow sticky traps) and laboratory (multi‐colored LEDs) with a strong peak of activity during the afternoon in both the field and the laboratory (both 14:00 to 18:00 hours). In laboratory evaluations of psyllids to differently colored LEDs, strongest attraction was to LEDs emitting ultraviolet (390 nm), green (525 nm), and yellow (590 nm) light. Male and female psyllids did not differ significantly in their responses to visual cues. These findings provide the basis for formulating better traps that reflect UV and yellow light and potentially incorporate UV LEDs for monitoring psyllids and a better understanding of Asian citrus psyllid visual behavior.     

Attraction of Trialeurodes vaporariorum and Bemisia argentifolii to eggplant, and its potential as a trap crop for whitefly management on greenhouse poinsettia

Trap cropping, though promising, has had little evaluation in greenhouses. This study evaluated eggplant, Solanum melongena L. (Solanaceae), as a trap crop for two whitefly species, Trialeurodes vaporariorum (Westwood) and Bemisia argentifolii Bellows & Perring (both Hemiptera: Aleyrodidae), on greenhouse poinsettia, Euphorbia pulcherrima Willd. ex Koltz (Euphorbiaceae). Because the two whitefly species co‐occur in greenhouses, a common trap crop for both whiteflies is desirable. When adults were provided a choice between eggplant and poinsettia in a cage, 60% of B. argentifolii and 98% of T. vaporariorum were observed on eggplant after 3 days. However, when adults were given eggplant after first settling on poinsettia, only 38% of B. argentifolii were later found on eggplant, whereas 95% of T. vaporariorum moved to eggplant. In a greenhouse experiment, eggplant did not affect either the spatial distribution or density of adult B. argentifolii on poinsettias. In contrast, eggplant changed the spatial distribution of T. vaporariorum within 3 days by attracting and retaining the adults. However, the attractiveness of eggplant did not result in a reduced number of T. vaporariorum on poinsettias compared with poinsettias in monoculture. Adult T. vaporariorum mortality was high on poinsettias and this likely caused adult density on poinsettias in monoculture to decrease as fast as that under trap cropping. A simulation model was developed to examine how adult whitefly mortality on poinsettia influences trap cropping effectiveness. When whitefly mortality was high, simulated densities were similar to the experimental data. This reveals an unexpected factor, pest mortality on the main crop, that can influence the relative effectiveness of trap cropping. Our results indicate that eggplant will not work unilaterally as a trap crop for B. argentifolii. For T. vaporariorum, attraction to eggplant might be useful as a trap crop system when whitefly mortality on the main crop is not high.