Characterization and distribution of esterase electromorphs in the whitefly,Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae)

Esterase profiles were examined for over 40 populations of the whitefly,Bemisia tabaci, obtained from native and cultivated plant hosts worldwide. Twelve unique electromorphs were identified from distinct populations concentrated largely in Central America, Africa, and India. One electromorph, type B, has recently been proposed as a separate species,Bemisia argentifolii, and has recently spread throughout much of the world. When considered with evidence from mating studies and the ability to induce phytotoxic disorders (squash silverleaf disorder), our data suggest that the single taxonBemisia tabaci may actually represent a species complex.     

Sublethal effects of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes) on the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) under laboratory conditions

Sublethal effects were evaluated in subsequent generations of whiteflies Bemisia tabaci (Gennadius) arising from parental generations exposed in the four nymphal stages to the fungus Beauveria bassiana (Balsamo) Vuillemin. Examples of such effects include impaired fertility, production of malformations or external variations, and reduced survival of later generations. Malformations of the head, legs, wings or abdomen were not observed in adults derived from treated nymphs, nor were negative effects observed in the fecundity and fertility of the descendants of the whiteflies treated with the fungus. However, moulting problems were observed in insects descended from B. bassiana-treated whiteflies. This is the first time that such effects have been reported, with almost 30% of imagos resulting from treated nymphs unable to detach completely from the exuvia. A gradual reduction in mortality rates between subsequent generations was observed. The importance of these results is discussed in the light of findings from other studies into the effects of entomopathogenic fungi on pest insects.     

Similarity in flight activity rhythms in coexisting species of Aleyrodidae, Bemisia tabaci and Trialeurodes abutilonea

Experiments were conducted in Arizona, USA to examine the diel patterns of flight activity of two coexisting species of whiteflies, Bemisia tabaci (Gennadius) and Trialeurodes abutilonea (Haldeman) (Aleyrodidae). Aerial populations were monitored during parts of two growing seasons using sticky traps. It was found that on most days when more than 100 whiteflies were captured, the flight activity rhythms of the two species were remarkably similar. During 13 of 14 weeks if aerial populations of one species were used to predict populations of the other, coefficients of determination were highly significant. This is in part a function of the two species having parallel patterns of pupal eclosion and teneral periods of approximately the same duration. The two species both experience 90% eclosion within 1 h of the onset of photophase and both have a teneral period slightly in excess of 4 h at 27°C. As a result populations of the two whiteflies emerge together, become flight ready, and fly at the same time. Arizona populations of these two introduced species appear to have developed certain very similar behavioral and physiological processes under conditions of a rigorous desert climate.

---

Zusammenfassung In Arizona (USA) wurden Experimente durchgeführt, um die Muster der täglichen Flugaktivität von zwei co-existierenden Aleurodidenarten, Bemisia tabaci und Trialeurodes abutilonea zu untersuchen. Mit Hilfe von Klebefallen wurden die Adult-Populationen während zweier Wachstumperioden beobachtet. Die Rhythmen der Flugaktivität während der meisten Tage, an denen mehr als 100 Weisse Fliegen gefangen wurden, waren bemerkenswert ähnlich. Die Bestimmungskoeffizienten waren deutlich signifikant in 13 von 14 Wochen, wenn die Populationen der einen Art benutzt wurde, um die Population der anderen Spezies vorherzusagen. Dies rührt zum Teil daher, dass sich beide Arten in ähnlicher Weise entwicklen. Beide schlüpfen zu 90% innerhalb von 3 Stunden nach Beginn der Photophase und beginnen bei 27°C im Mittel nach 4 Stunden und 12 Minuten zu fliegen. Daraus folgt, dass Populationen beider Arten zur selben Zeit schlüpfen, flugbereit werden und zu fliegen beginnen. Es scheint, dass die in Arizona vorhandenen Populationen dieser beiden eingeführten Arten unter dem Einfluss eines rauhen Wüstenklimas einige sehr ähnliche Verhaltensweisen und physiologische Prozesse entwickelt haben.

     

The status ofBemisia tabaci (Hom.: Aleyrodidae),Trialeurodes vaporariorum (Hom.: Aleyrodidae) and their natural enemies in Crete

The non «B» biotype ofBemisia tabaci (Gennadius) is recorded for the first time in Crete in 1992, in the north east and south east of the island.Trialeurodes vaporariorum (Westwood) is the predominant whitefly on plants in the north and west of the island. Three surveys of Crete were made in 1992 and 1993 for natural enemies ofB. tabaci andT. vaporariorum and resulted in the collection of 4 species ofEncarsia, (plus a number of species that are unidentifiable at this time), anEretmocerus sp. (unidentifiable at this time) and a fungal pathogen,Paecilomyces farinosus (Dickson Ex Fries) Brown &; Smith.Encarsia adrianae was identified fromT. vaporariorum; which constitutes its most westerly distribution point and a new host record respectively.B. tabaci andT. vaporariorum were found on horticultural crops, ornamentals and weeds. Populations of both whitefly species were severely depleted on field hosts throughout the island during the winter of 1992/93. Climatic constraints, competition withT. vaporariorum in otherwise suitable niches, effective natural enemies and an observed low level of polyphagy may explain the present limited distribution of the non «B» biotype ofB. tabaci in Crete.     

Population dynamics of the whitefly,Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), in Java,Indonesia, with special reference to spatio-temporal changes in the quantity of food resources

Six monitoring plots were established in the northern part of West Java, Indonesia, to clarify the factors that influence population fluctuations of the whitefly,Bemisia tabaci. Yellow sticky traps were used to monitor adult populations. To examine the relationship between the population fluctuations and the quantity of food resources, the quantity of food resources ofB. tabaci (i.e. soybean and mung bean) was also investigated routinely in each subdistrict where the experimental plot was located. The maximum number of adults per trap in each sowing season showed a similar noticeable seasonal trend in all experimental plots. Climatic factors did not have a major role to play in population fluctuations. The number of adults per trap in each experimental plot tended to increase when the quantity of food resources in each subdistrict increased. The changes of the quantity of food resources seemed to influence the population fluctuations. It is suggested that the operation of regulatory processes in population density is influenced largely by both the distance between habitat patches and the amplitude of temporal fluctuations of the quantity of food resources. An explanation for why the time lag between fluctuations of the quantity of food resources and the number of individuals ofB. tabaci occurred is discussed. Based on their flight ability and intrinsic rate of natural increase,B. tabaci is considered not to be a serious pest in the environment where the host plants are grown discontinuously in time and space.     

Development of Encarsia bimaculata (Heraty and Polaszek) (Hymenoptera: Aphelinidae) in Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) nymphs

Encarsia bimaculata was recently described from India as a potentially useful parasitoid of Bemisia tabaci. Its developmental biology was studied in the laboratory at 25–30 °C and 70–75% RH. Results showed that E. bimaculata is a solitary, arrhenotokous, heteronomous, autoparasitoid. Mated females laid eggs internally in B. tabaci nymphs that developed as primary parasitoids. Males developed as hyperparasitoids, either in females of their own species or in other primary aphelinid parasitoids. Superparasitism was common under cage conditions. Both sexes have an egg, three larval instars, prepupal, and pupal stages. Development from egg to adult took 12.70 ± 2.10 days for females and 14.48 ± 2.60 days for males. Individual B. tabaci nymphs were examined for E. bimaculata parasitization using three isozymes: esterase, malate dehydrogenase, and xanthine dehydrogenase. All three isozymes showed differential banding patterns that identified E. bimaculata parasitized or unparasitized B. tabaci nymphs.     

Global relationships of Bemisia tabaci (Hemiptera: Aleyrodidae) revealed using Bayesian analysis of mitochondrial COI DNA sequences

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a species complex that is one of the most devastating agricultural pests worldwide and affects a broad range of food, fiber and ornamental crops. Unfortunately, using parsimony and neighbor joining methods, global phylogenetic relationships of the major races/biotypes of B. tabaci remain unresolved. Aside from the limitations of these methods, phylogenetic analyses have been limited to only small subsets of the global collection of B. tabaci, and thus limited taxon sampling has confounded the analyses. To improve our understanding of global B. tabaci phylogenetic relationships, a Bayesian phylogenetic technique was utilized to elucidate the relationships among all COI DNA sequence data available in GenBank for B. tabaci worldwide (366 specimens). As a result, the first well-resolved phylogeny for the B. tabaci species complex was produced showing 12 major well-resolved (0.70 posterior probability or above) genetic groups: B. tabaci (Mediterranean/Asia Minor/Africa), B. tabaci (Mediterranean), B. tabaci (Indian Ocean), B. tabaci (sub-Saharan Africa silverleafing), B. tabaci (Asia I), B. tabaci (Australia), B. tabaci (China), B. tabaci (Asia II), B. tabaci (Italy), B. tabaci (New World), B. tabaci (sub-Saharan Africa non-silverleafing) and B. tabaci (Uganda sweet potato). Further analysis of this phylogeny shows a close relationship of the New World B. tabaci with Asian biotypes, and characteristics of the major sub-Saharan Africa non-silverleafing clade strongly supports an African origin of B. tabaci due to its position at the base of the global phylogeny, and the diversity of well-resolved sub-clades within this group. Bayesian re-analyses of B. tabaci ITS, COI, and a combined dataset from a previous study resulted in seven major well-resolved races with high posterior probabilities, also showing the utility of the Bayesian method. Relationships of the 12 major B. tabaci genetic groups are discussed herein.     

Parasitoids attackingBemisia tabaci [Hom.: Aleyrodidae] in Eastern Africa

BioControl - Parasitoids ofBemisia tabaci were collected in Kenya, Malawi and Zimbabwe. The 2 principal species encountered wereEretmocerus mundus andEncarsia sublutea. Rates of parasitism varied,...     

国内烟粉虱B生物型的分布及其控制措施研究

收集了国内 15个省 2 6个不同地区的烟粉虱种群 ,根据有关报道合成了一个随即引物H16 ,对不同地区的烟粉虱DNA进行了RAPD -PCR扩增 ,根据扩增结果分析了不同烟粉虱种群的生物型。结果表明 ,在以上不同省市和地区中 ,北京、山东等 11个省 19个地区都有烟粉虱B型的分布。以烟粉虱B型为防治对象 ,比较了使用高效氯氰菊酯、高效大功臣 2种化学农药 ,和应用桨角蚜小蜂、粉虱座壳孢 2种寄生性天敌 ,对黄瓜上烟粉虱种群的控制效果 ,结果表明在一个世代内 ,喷施高效大功臣 (10 0 0× ,1次 ) ,喷施粉虱座壳孢 (5× 10 6 个孢子 /ml,2次 ) ,和释放桨角蚜小蜂 (3头雌蜂 /株 ,2次 ) ,对烟粉虱种群的控制作用分别达到 78.2 1%、95 .74 %和 5 7.5 8% ,三者都可以对烟粉虱起到较好的防治效果。     

Induction of the activities of antioxidative enzymes and the levels of malondialdehyde in cucumber seedlings as a consequence of Bemisia tabaci (Hemiptera: Aleyrodidae) infestation

The activities of antioxidative enzymes and the concentration of malondialdehyde were assayed in cucumber leaves (Cucumis sativus L.) 0, 6, 12, 24, 48, 72, and 96 h after the cucumber seedlings were infested by Bemisia tabaci (Gennadius). The results indicated that the activities of antioxidative enzymes were increased after herbivore infestation, including superoxide dismutase (SOD), and peroxidase (POD), and the levels of malondialdehyde (MDA), which is a product of membrane lipid peroxidation in the leaves. The enzymes and MDA showed peaks of different activity levels at 24 and 48 h after the infestation. SOD activity reached the highest peak, 10.4% higher than control, at 24 h, POD activity reached the highest peak, 213.2% higher than control, at 6 h, catalase (CAT) activity was not statistically significant compared with the control, and MDA content reached the highest peak, 59.9% higher than control, at 48 h. The results suggested that the enhanced activities of antioxidative enzymes and MDA content may contribute to bioprotection of cucumber plants against B. tabaci infestation. Handling editor: Henryk Czosnek     

Floating row covers and pyriproxyfen help control silverleaf whitefly Bemisia tabaci (Gennadius) Biotype B (Homoptera: Aleyrodidae) in zucchini

Abstract  In zucchini, the use of row covers until flowering and the insect growth regulator (IGR) pyriproxyfen are effective methods of reducing the number of insects, especially silverleaf whitefly ( Bemisia tabaci (Gennadius) Biotype B), on plants. We compared floating row covers (FRCs) up until flowering with silverleaf whitefly (SLW) introduced (FRC + SLW), or not introduced (FRC-only), or with introduction of SLW in open plots (SLW-only), or with introduction of SLW in open plots with IGR (SLW + IGR). FRC increased temperature and humidity compared with the uncovered treatments. Average fruit weight was less ( P  < 0.01) for the FRC + SLW treatment compared with the other treatments and the percentage of marketable fruit was less for the FRC + SLW than for the other three treatments. This result indicates that the use of either row covers or IGR controls whiteflies, reduces fruit damage and increases the size, weight, and quality of fruit, and may also control other sap-sucking insects. However, if SLW are already present on plants, the use of FRC may reduce predation and favour build up of SLW. Thus, FRC and IGR, if used judiciously, may provide an effective alternative to broad-spectrum pesticides in small-scale cucurbit production.     

Evaluation of the local population of Eretmocerus mundus (Hymenoptera: Aphelinidae) for biological control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in greenhouse peppers in Argentina

Bemisia tabaci biotype B is a key pest in pepper crops in Argentina. The parasitoid Eretmocerus mundus is frequently found parasitizing this whitefly in greenhouses without pesticide applications. The present studies were carried out with the objective of evaluating control obtained with different rate and number of parasitoid releases under experimental conditions. Release rate: cages with pepper pots were positioned in an experimental greenhouse and randomly assigned to the release rate treatments (0, 1 and 3 pairs of E. mundus/plant/week with a total of three introductions). Number of releases: similar cages were assigned to the number of parasitoid introduction treatments (0, 1, 2 and 3) with the best release rate obtained in the previous trial. In both assays whitefly (adults and nymphs) and parasitoid (parasitized nymphs) population sizes in each cage were monitored weekly for a period of 10 weeks. Results suggested that the introduction of 2 E. mundus/plant/week was enough to suppress host population compared to control treatment (peaks of 7.75 adults and 58.75 nymphs/cage and 643.75 adults and 1598 nymphs/cage, respectively) (p < 0.05), with 85% of parasitism. E. mundus had to be introduced three times to achieve the best pest control (peaks of 1.17 adults and 20.33 nymphs/cage vs. 55.67 adults and 75 nymphs/cage in control treatment) with 84% of parasitism (p < 0.05). These results were then validated in a pepper crop under experimental greenhouse conditions. Whitefly population was lower in those greenhouses where E. mundus was released compared to control greenhouses (0.15 adults and 0.71 nymphs/4 leaves and 0.73 adults and 1.64 nymphs/4 leaves, respectively), with a peak of 54% of parasitism (p < 0.05). We concluded that good suppression of B. tabaci could be achieved using E. mundus under spring conditions in Argentina.     

Variation between laboratory populations in the performance of the parasitoid Encarsia formosa on two host species, Bemisia tabaci and Trialeurodes vaporariorum

We tested the hypothesis that populations of the parthenogenetic parasitic wasp Encarsia formosa Gahan (Hymenoptera: Aphelinidae) differed in their ability to use two different host species, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae). Of the three wasp populations tested, two populations had been reared for many generations on B. tabaci and one population had been reared for many years on T. vaporariorum. Performance was measured by the number of whitefly nymphs that were successfully parasitized by individual wasps, and performance on either host was measured in separate experiments. There was variation between wasp populations in their performance on the host B. tabaci, with one wasp population reared for many years on this host performing considerably better than the other two populations. There were no significant differences between populations in their use of the preferred host, T. vaporariorum. The experiments were conducted in such a way that we could distinguish heritable differences between populations from environmentally-induced conditioning differences due to the immediate host from which an individual wasp enclosed. In either experiment there were no significant effects of conditioning, although there was a trend within each population for wasps conditioned on T. vaporariorum to have higher performance than those conditioned on B. tabaci. Thirdly, we conducted a selection experiment, initiated with wasps from a single population historically reared on T. vaporariorum, to measure the effect of laboratory rearing on different hosts for 17 generations. We did not see any difference in the performance of wasps on B. tabaci after this period of rearing on either of the two hosts. In summary, populations of E. formosa do differ in their relative performance on B. tabaci. The one population that was tested further did not show any response to selection by rearing, but the ability to respond to selection on performance may not be equal for all populations. The possibility that wasp populations have differential performance on particular hosts may affect the use of this species as a biological control agent.     

Effects of temperature and photoperiod upon adult eclosion of the sweetpotato whitefly, Bemisia tabaci

A series of experiments were conducted to characterize patterns of eclosion by Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) to their adult stage and to determine how these patterns are influenced by certain environmental parameters. Under a constant temperature of 29.5±0.6°C and a photoperiod of 14:10LD, 90% of the adults emerged from their pupal cases between 0600 and 0930 h (with lights on occurring at 0600 h). Few emerged during hours of darkness. The peak time of adult emergence was delayed when temperatures were fluctuated. Under a series of constant temperatures, a significant inverse correlation was found between the time of median emergence (i.e., eclosion of 50% of the total number of adults) and temperature (P<0.001). No emergence was observed at temperatures below 17±0.3°C. Emergence patterns persisted under conditions of continuous light and continuous darkness, suggesting the presence of a circadian system.

---

Zusammenfassung Um das Verständnis über den Lebenslauf von Bemisia tabaci zu ergänzen, wurde eine Serie von Experimenten durchgeführt, deren Zweck die Charakterisierung des Ausschlüpfvorgangs in das Endstadium war und die Feststellung, wie dieser Vorgang von gewissen Umweltparametern beeinflusst wird. Bei einer konstanten Temperatur von 29.5±0.6°C und einem Beleuchtungszyklus von 14: 10 LD (Licht/Dunkelheit) schlüpften 90% der Ausgewachsenen zwischen 0600 Uhr and 0930 Uhr (ab 0600 Uhr mit Licht) aus ihren Puppenhüllen aus. Wenig Ausschlüpfen geschah während der unbeleuchteten Stunden. Der Höhepunkt des Ausschlüpfens wurde bei wechselnden Temperaturen verschoben. Bei einer Serie von gleichbleibenden Temperaturen wurde eine bedeutende inverse Korrelation zwischen der medianen Ausschlüpfzeit (d.h. 50% der gesamten Ausgewachsenen schlüpften aus) und der Temperatur festgestellt (P<0.001). Kein Ausschlüpfen wurde beobachtet bei Temperaturen unter 17°C. Das Ausschlüpfschema war gleichbleibend bei dauerndem Licht oder dauernder Dunkelheit, was auf das Vorhandensein eines circadianen Systems hinweist.

     

Pyriproxyfen controls silverleaf whitefly, Bemisia tabaci (Gennadius), biotype B (Homoptera: Aleyrodidae) (SLW) better than buprofezin in bitter melons Momordica charantia L. (Cucurbitaceae)

To improve compatibility between chemical and biological controls, the use of selective insecticides such as insect growth regulators (IGRs) is crucial. In cucurbits, the use of pyriproxyfen (an IGR) has been shown by others to be an effective method of reducing the number of sap-sucking insects, especially silverleaf whitefly, Bemisia tabaci (Gennadius) Biotype B (SLW). Therefore, we compared pyriproxyfen and buprofezin (an IGR) with that of no treatment (control) in a bitter melon crop for the control of populations of SLW and for their effects on fruit production. Pyriproxyfen controlled SLW and tended to have heavier fruits than the control treatment and reduced the abundance of nymphs and exuvia. Buprofezin showed no evidence in controlling SLW compared with the pyriproxyfen and control treatments. Neither pyriproxyfen nor buprofezin had any effect on the number of harvested fruit or overall fruit yield, but the average weight per fruit was higher than the control treatment. Pyriproxyfen was effective in controlling whitefly populations in bitter melons, and both pyriproxyfen and buprofezin may have the potential to increase yield. Their longer-term use may increase predation by natural enemies as they are species-specific and could favour build up of natural enemies of SLW. Thus, the judicious use of pyriproxyfen may provide an effective alternative to broad-spectrum insecticides in small-scale cucurbit production.     

Arrestment responses ofEretmocerus species andEncarsia deserti (Hymenoptera: Aphelinidae) toBemisia tabaci honeydew

The responses of Eretmocerussp. and Encarsia deserti(Gerling & Rivnay), parasitoids of Bemisia tabaci(Gennadius) to host secretions were investigated. Upon contact with honeydew excreted from the host, the parasitoids' walking speed decreased, whereas the rate of angular turning increased (the walking speed of Eretmocerussp. and Encarsia desertidecreased from 2.0 to 0.8 and from 0.8 to 0.3 mm/s, respectively, and the respective angular turning rates increased from 123.3 to 489.6 and from 267.9 to 979.2 deg/cm). Moreover, the wasps generally turned back toward the secretion as soon as they lost contact with it. This induced arrestment responses resulted in increased searching time by the parasitoids. Laboratory bioassays were conducted in which paper disks in petri dishes containing different amounts of honeydew, equivalent to the secretions of 1, 5, or 50 larvae, were offered to female wasps. The wasps responded by arrestment even to honeydew produced by a single larva. While the response of Eretmocerussp. was quantity dependent, being more intense at higher amounts of honeydew, that of E. desertiwas of equal intensity at all honeydew quantities assayed.     

三种粉虱触角、口针及跗节感受器的超微结构观察

对烟粉虱Bemisia tabaci、温室白粉虱Trialeurodes vaporariorum和禾粉虱Aleurocybotus indicus3种粉虱的触角、口针及跗节感受器的超微结构进行了观察。利用扫描电镜观察了烟粉虱、温室白粉虱和禾粉虱3种粉虱触角、口针及跗节化学感受器的类型和分布,进行了比较。3种粉虱触角上都有刚毛感受器、锥形感受器2种感受器和微毛,烟粉虱触角还有钟形感受器和腔锥感受器;温室白粉虱和禾粉虱触角均没有发现钟形感受器;3种粉虱的口针和跗节上均只有刚毛感受器和微毛,且形态结构相似。     

Establishment of papaya banker plant system for parasitoid, Encarsia sophia (Hymenoptera: Aphilidae) against Bemisia tabaci (Hemiptera: Aleyrodidae) in greenhouse tomato production

The silverleaf whitefly, Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae), is a key pest of tomato (Solanum lycopersicum L.) and other vegetable crops worldwide. To combat this pest, a non-crop banker plant system was evaluated that employs a parasitoid, Encarsia sophia (Girault & Dodd) (Hymenoptera: Aphelinidae) with whitefly, Trialeurodes variabilis (Quaintance) (Hemiptera: Aleyrodidae), as an alternative host for rearing and dispersal of the parasitoid to the target pest. (a) Multi-choice and no-choice greenhouse experiments were conducted to determine host specificity of T. variabilis to papaya (Carica papaya L.) and three vegetable crops including tomato, green bean (Phaseolus vulgaris L.), and cabbage (Brassica oleracea L.). The result showed that papaya was an excellent non-crop banker plant for supporting the non-pest alternative host, T. variabilis, whose adults had a strong specificity to papaya plants for feeding and oviposition in both multi-choice and no-choice tests. (b) The dispersal ability of E. sophia was investigated from papaya banker plants to tomato and green bean plants infested with B. tabaci, as well as to papaya control plants infested with T. variabilis; and (c) the percent parasitism by E. sophia on T. variabilis reared on papaya plants and on B. tabaci infested on tomato plants was also evaluated. These data proved that E. sophia was able to disperse at least 14.5 m away from papaya plants to target tomato, bean or papaya control plants within 48–96 h. Furthermore, E. sophia was a strong parasitoid of both T. variabilis and B. tabaci. There was no significant difference in percent parasitism by E. sophia on T. variabilis (36.2–47.4%) infested on papaya plants or B. tabaci (29–45.9%) on tomato plants. Thus, a novel banker plant system for the potential management of B. tabaci was established using papaya as a non-crop banker plant to support a non-pest alternative host, T. variabilis for maintaining the parasitoid to control B. tabaci. The established banker plant system should provide growers with a new option for long-term control of B. tabaci in greenhouse vegetable production. Ongoing studies on the papaya banker plant system are being performed in commercial greenhouses.