Actual or ideal body weight to calculate CD34+ cell dose in patients undergoing autologous hematopoietic SCT for myeloma?

CD34+ cell dose calculations are usually based on actual body weight (ABW). We have shown that ideal body weight (IBW) may provide a better basis for this in a small population of patients with hematologic malignancies. This was studied further in 514 myeloma autografts. The CD34+ cell doses (10(6)/kg) by IBW and ABW were 1.37-39.36 (median 6.03) and 1.15-29.67 (median 4.84), respectively. IBW-based cell doses correlated slightly better with engraftment than ABW-based doses (higher r(2)): 0.5 x 10(9)/l neutrophils 0.83 versus 0.82, 1.0 x 10(9)/l neutrophils 0.78 versus 0.77, 20 x 10(9)/l platelets 0.54 versus 0.53 and 50 x 10(9)/l platelets 0.57 versus 0.55. When outliers (hematologic recovery in <8 or >16 days) were excluded, the findings were similar: 0.5 x 10(9)/l neutrophils 0.85 versus 0.84, 1.0 x 10(9)/l neutrophils 0.85 versus 0.84, 20 x 10(9)/l platelets 0.86 versus 0.85 and 50 x 10(9)/l platelets 0.85 versus 0.84. CD34+ cell doses based on IBW as well as ABW significantly affected engraftment when analyzed separately as continuous variables. However, when analyzed together, only the dose based on IBW retained significance. We conclude that calculation of CD34+ cell numbers for autotransplantation should be based on IBW.

Phase I/II trial of total lymphoid irradiation and high-dose chemotherapy with autologous stem-cell transplantation for relapsed and refractory Hodgkin's lymphoma.

BACKGROUND: The standard approach to treatment of relapsed/refractory Hodgkin's lymphoma (HL) is high-dose chemotherapy conditioning followed by autologous hematopoietic stem-cell transplantation (aHSCT). We report the results of a prospective phase I/II clinical trial of accelerated hyperfractionated total lymphoid irradiation (TLI) immediately followed by high-dose chemotherapy for relapsed/refractory HL. PATIENTS AND METHODS: Forty-eight patients underwent aHSCT with either sequential TLI/chemotherapy (n = 32) or chemotherapy-alone conditioning (n = 16), based on prior radiation exposure. The first 22 patients enrolled on trial received escalating doses of etoposide (1600-2100 mg/m(2)) with high-dose carboplatin and cyclophosphamide. RESULTS: No dose-limiting toxicity was seen and TLI/chemotherapy was well tolerated. The 5-year event-free survival (EFS) estimate for all patients was 44% with overall survival (OS) of 48%. Five-year EFS and OS for the TLI/chemotherapy group was 63% and 61%, respectively, compared with 6% and 27%, respectively, for the chemotherapy-alone group (P < 0.0001 and P = 0.04, respectively). Patients with primary induction failure HL who received TLI/chemotherapy had 5-year EFS and OS rate of 83%. The 100-day treatment-related mortality was 4.2% and two secondary cancers were seen. Significant factors predicting survival by multivariate analysis included TLI/chemotherapy conditioning and B symptoms at relapse. CONCLUSIONS: Sequential TLI/chemotherapy conditioning for relapsed/refractory HL is safe and associated with excellent long-term survival rates.

Effects of diet-age and streptomycin on virulence of Autographa californica M nucleopolyhedrovirus against the tobacco budworm.

Addition of the antibiotic streptomycin to two artificial diets routinely used in bioassays of neonate lar vae of Heliothis virescens (tobacco budworm) infected with Autographa californica M nucleopolyhedrovirus (AcMNPV) increased lethal times of the virus. After storage of diets for 3 weeks at 4 degrees C, lethal times of infected larvae were significantly slower compared to those for larvae bioassayed using diets stored for 2 weeks or less. The effect of diet-age on rate of mortality was not the result of a change in total protein content or pH of the diet, but was apparently the result of some other alteration in the quality of the diet (e.g. microbial spoilage, palatibility, and/or nutritional value unrelated to total protein). Although we did not determine why lethal times were slower in response to streptomycin concentration or diet-age, we did find that slower lethal times were correlated with slower relative growth rates (RGR) of infected larvae. In addition, RGR of infected larvae decreased as a function of increasing streptomycin concentration, diet-age, and the interaction of the two factors. These results demonstrate that it is difficult to obtain consistent and comparable bioassay results if antibiotic composition and diet-age are not controlled. We suggest a standardized diet or highly standardized procedures for a given diet be developed that permits comparison of bioassays among and within laboratories.

IgE reactivity against a cross-reactive allergen in crustacea and mollusca: evidence for tropomyosin as the common allergen.

BACKGROUND: Although cross-reactivity between mollusks and other crustaceans in shrimp-sensitive subjects has been reported, the mechanism of this allergenic cross-reactivity has not been studied in detail. OBJECTIVE: To investigate this cross-reactivity in vitro, we have taken advantage of a complementary DNA that expresses tropomyosin, the immunodominant shrimp allergen. METHODS: Serum IgE from nine patients with known anaphylaxis to shrimp and five normal volunteers were analyzed by immunoblotting against 13 distinct crustaceans and mollusks. As additional antigens, muscle preparations were isolated from grasshopper, cockroach, fruit fly, chicken, and mouse. RESULTS: Sera from all patients, but not control subjects, reacted specifically with a 38 kd protein in all crustaceans and mollusks studied. In addition, 8 of 9 sera from patients, but from none of the normal control subjects, recognized proteins of various other molecular weights among the mollusk extracts studied. The 38 kd protein was identified as tropomyosin and was shown to share immunodominant epitopes among all species of crustaceans and mollusks tested by specific absorption studies. Moreover, sera from all nine subjects with shrimp allergy demonstrated IgE reactivities against grasshopper, cockroach, and fruit fly but not chicken or murine muscle. CONCLUSION: The allergic epitopes on tropomyosin are conserved among invertebrates including not only shellfish but also insects. This latter observation suggests that persons sensitive to shrimp should undergo further study for potential cross-reactive inhalant or ingested insect sensitivity.

Exogenous jasmonates simulate insect wounding in tomato plants (Lycopersicon esculentum) in the laboratory and field.

Wounding increases the levels and activities of several defense-related proteins in the foliage of the tomato plant,Lycopersicon esculentum Mill. Evidence indicates that two of these responses, the systemic increases in polyphenol oxidase and proteinase inhibitors, are regulated by an octadecanoid-based signalling pathway which includes the wound hormone, jasmonic acid. It is not known whether other responses to wounding are also regulated by this same signalling pathway. In this paper, we show that application of jasmonates (jasmonic acid or its volatile derivative, methyl jasmonate) in low concentrations to foliage of young tomato plants induced, in a dose-dependent manner, the same protein responses-polyphenol oxidase, proteinase inhibitors, lipoxygenase, and peroxidase-as doesHelicoverpa zea Boddie feeding. Application of jasmonic acid to a single leaflet of four-leaf tomato plants induced these four proteins in a spatial pattern nearly identical to that produced by localized feeding ofH. zea. Exogenous jasmonic acid also decreased suitability of foliage for the beet armyworm,Spodoptera exigua Hubner in the laboratory. Based on these results, we conducted an experiment to measure the effects of jasmonic acid spray under field conditions. We provide the first evidence that jasmonic acid spray on field plants induces production of chemical defenses above the levels found in unsprayed controls. Exogenous jasmonic acid sprayed on plants in agricultural plots increased levels of polyphenol oxidase and proteinase inhibitors. Because application of jasmonic acid induces these defensive compounds at low concentrations in a manner similar to natural wounding, it may prove to be a useful tool for stimulating plant resistance to insects in the field.

Production of polyhedra of the Autographa californica nuclear polyhedrosis virus using the Sf21 and Tn5B1-4 cell lines and comparison with host-derived polyhedra by bioassay.

Both wild-type and recombinant baculoviruses are becoming more attractive for the control of insect pests. Thus, there is an increased incentive to address and resolve logistical problems associated with large-scale production of these viruses. In this study, we have compared the potential of two insect cell lines, Tn5B1-4 and Sf21, for the production of polyhedra and compared the efficacy of both cell culture-derived and host-derived viruses by bioassay. The efficacy of both wild-type AcMNPV and AcAaIT, a recombinant baculovirus expressing an insect-specific scorpion toxin, were compared. Yields of polyhedra from Tn5B1-4 were sixfold higher than those from the cell line Sf21. Morphological analysis of polyhedra derived from cell culture showed greater variability in size relative to host-derived polyhedra. The maximum size of cell culture-derived polyhedra was over 1.5 times larger than that of insect-derived polyhedra. The efficacy of AcMNPV and AcAaIT derived from cell culture, or from amplification in larvae of Trichoplusia ni or Heliothis virescens, was compared by bioassay in H. virescens. There was a significant difference between the slopes for lethal time data for host-derived and cell culture-derived wild-type virus. Mortality occurred at a faster rate following infection with host-derived virus. No significant difference was seen for the recombinant virus AcAaIT. Lethal doses of cell- and host-derived polyhedra were not significantly different. The reasons for and implications of this for pest control are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential induction of tomato foliar proteins by arthropod herbivores.

The effects of mechanical and chemical damage and three types of biotic damage on the activities of four foliar proteins of the tomato plant (Lycopersicon esculentum Mill var. Castlemart) were assayed. Proteinase inhibitor, polyphenol oxidase, peroxidase, and lipoxygenase activities were assayed in damaged leaflets and compared with activities in undamaged leaflets. These proteins are putative plant defenses in tomato. Differential induction of these proteins by the various damage-treatments was demonstrated, such that different subsets of the four proteins were induced by different types of damage. This study clearly demonstrates the ability of plants to respond differentially to different types of damage. Possible mechanisms for this differential induction and the implications of differential induction for plant defense are discussed.

Potential role of lipoxygenases in defense against insect herbivory.

The potential role of the plant enzyme lipoxygenase in host resistance against the corn earwormHelicoverpa zea was examined. Lipoxygenase is present in most of the common host plants ofH. zea, with highest activity in the leguminous hosts such as soybean and redbean. Treatment of dietary proteins with linoleic acid and lipoxygenase significantly reduced the nutritive quality of soybean protein and soy foliar protein. Larval growth was reduced from 24 to 63% depending upon treatment. Feeding byH. zea on soybean plants caused damage-induced increases in foliar lipoxygenase and lipid peroxidation products. Larvae feeding on previously wounded plant tissue demonstrated decreased growth rates compared to larvae feeding on unwounded tissue. Midgut epithelium from larvae feeding on wounded tissues showed evidence of oxidative damage as indicated by significant increases in lipid peroxidation products and losses in free primary amines. The potential role of oxidative and nutritional stress as a plant defensive response to herbivory is discussed.

Avoidance of antinutritive plant defense: Role of midgut pH in Colorado potato beetle.

The fate of the tomato foliar phenolic, chlorogenic acid, in the digestive systems of Colorado potato beetleLeptinotarsa decemlineata (Coleoptera: Chrysomelidae) andHelicoverpa tea (Lepidoptera: Noctuidae) is compared. In larvalH. zea and other lepidopteran species previously examined, approximately 35-50% of the ingested chlorogenic acid was oxidized in the digestive system by foliar phenolic oxidases (i.e., polyphenol oxidase and peroxidase) from the tomato plant. The oxidized form of chlorogenic acid, chlorogenoquinone, is a potent alkylator of dietary protein and can exert a strong antinutritive effect upon larvae through chemical degradation of essential amino acids. In contrast, inL. decemlineata less than 4% of the ingested dose of chlorogenic acid was bound to protein. In vitro experiments to determine the influence of pH on covalent binding of chlorogenic acid to protein showed that 30-45% less chlorogenic acid bound to protein at pHs representative of the beetle midgut (pH 5.5-6.5) than at a pH representing the lepidopteran midgut (pH 8.5). At an acidic pH, considerably more of the alkylatable functional groups of amino acids (-NH2, -SH) are in the nonreactive, protonated state. Hence, polyphenol oxidases are unlikely to have significant antinutritive effects against the Colorado potato beetle and may not be a useful biochemical source of resistance against this insect. The influence of feeding by larval Colorado potato beetle on foliar polyphenol oxidase activity in tomato foliage and its possible significance to interspecific competition is also considered.

Protective action of midgut catalase in lepidopteran larvae against oxidative plant defenses.

Catalase activity was detected in the midgut tissues and regurgitate of several lepidopteran pests of the tomato plant. Greatest activity in the midgut was detected in larvalHelicoverpa zea, followed bySpodoptera exigua, Manduca sexta, andHeliothis virescens. We present evidence that catalase, in addition to removing toxic hydrogen peroxide, may inhibit the oxidation of plant phenolics mediated by plant peroxidases. Small amounts of larval regurgitate significantly inhibited foliar peroxidase activity via removal of hydrogen peroxide. Treatment of foliage with purified catalase nearly eliminated peroxidase activity and was superior as a larval food source compared to untreated foliage. Tomato foliar peroxidases oxidize an array of endogenous compounds including caffeic acid, chlorogenic acid, rutin, coumaric acid, cinnamic acid, and guaiacol. The oxidized forms of these compounds are potent alkylators of dietary and/or cellular nucleophiles (e.g., thiol and amino functions of proteins, peptides, and amines). When tomato foliar protein was pretreated with peroxidase and chlorogenic acid and incorporated in artificial diet, larval growth was reduced compared to larvae fed untreated protein. Thus, the diminution of peroxidase activity and removal of hydrogen peroxide by catalase may represent an important adaptation to leaf-feeding. The secretion of catalase in salivary fluid during insect feeding is also suggested to be a potential mechanism for reducing hydrogen peroxide formation as an elicitor of inducible plant defenses.

Reassessment of the role of gut alkalinity and detergency in insect herbivory.

Previously it was reported that significant amounts of the tomato phenolic, chlorogenic acid, were oxidized in the digestive system of generalist feedersSpodoplera exigua andHelicoverpa zea. The covalent binding of the oxidized phenolic (i.e., quinone) to dietary protein exerts a strong antinutritive effect against larvae. In this study, we examined the fate of ingested chlorogenic acid in larvalManduca sexta, a leaf-feeding specialist of solanaceous plants. Significant amounts of chlorogenic acid were bound to excreted protein byM. sexta when larvae fed on tomato foliage. However, in the case ofM. sexta we suggest that the strong alkalinity and detergency of the midgut may minimize the antinutritive effects of oxidized phenolics. The solubility of tomato leaf protein is significantly greater at pH 9.7, representative of the midgut ofM. sexta, than at pH 8.0, representative of the midguts ofH. zea and S. exigua. We suggest that this increase in solubility would compensate for any loss in bioavailability of essential amino acids caused by the covalent binding of chlorogenic acid to amino acids. Furthermore, lysolecithin, a surfactant likely to contribute to the detergent properties of the midgut fluid, was shown to enhance protein solubility as well as inhibit polyphenol oxidase activity. The adaptive significance of gut alkalinity and detergency is discussed.

Plant defenses: Chlorogenic acid and polyphenol oxidase enhance toxicity ofBacillus thuringiensis subsp.kurstaki toHeliothis zea.

Two chemicals implicated in resistance of the tomato plant, chlorogenic acid and polyphenol oxidase, are known to form orthoquinones in damaged plant tissue. Orthoquinones have been reported to alkylate -NH2 and -SH groups of proteins and amino acids, altering solubility, digestibility, and, for some pathogenic viruses, infectivity. Here we explore effects of quinone alkylation on toxicity of an important microbial insecticide,Bacillus thuringiensis subsp.kurstaki (BTk), to larvalHeliothis zea. BTk incubated with these phytochemicals and fed to larvae was more toxic than untreated BTk. Similar but less dramatic results arose when BTk was incubated with polyphenol oxidase alone. Digestibility experiments suggest that alkylation enhanced the solubilization and/or proteolysis of crystal protein in vivo. Implications of our results for compatibility of BTk with host-plant resistance and biological control are discussed.

Inactivation of baculovirus by quinones formed in insect-damaged plant tissues.

The infectivity of the nuclear polyhedrosis virus, HzSNPV toHeliothis zea was significantly reduced when viral occlusion bodies were exposed to the plant phenolic chlorogenic acid in the presence of polyphenol oxidase. Chlorogenic acid is rapidly oxidized to the ortho-quinone, chlorogenoquinone, by foliar polyphenol oxidases of the tomato plant, Lycopersicon esculentum, when foliage is damaged during feeding by larvalH. zea.Our results indicate that chlorogenoquinone, a powerful oxidizing agent, covalently binds to the occlusion bodies of HzSNPV and significantly reduces their digestibility and solubility under alkaline conditions. This binding is proposed to interfere with the infection process by impairing the release of infective virions in the midgut.

Toxins in chrysomelid beetles Possible evolutionary sequence from de novo synthesis to derivation from food-plant chemicals.

In the Chrysomelinae, it appears that de novo synthesis of chemicals for defense is the primitive state, and the sequestration of plant chemicals for defense the derived state. The derived state evolved through both the morphological and biochemical preadaptiveness of the homologous defensive glands. In the adults, we discuss one unique case of sequestration in exocrine defensive glands of host-plant pyrrolizidine alkaloids byOreina cacaliae. However, hypericin is not sequestered either in the glands or elsewhere in the body ofChrysolina spp. feeding onHypericum, which contradicts an earlier claim. In the larvae, we examine in more detail how the phenolglucoside salicin can be used as the precursor of the salicylaldehyde present in the defensive secretion ofPhratora vitellinae andChrysomela spp. with minimal changes in the biochemical mechanisms involved in the biosynthesis of iridoid monoterpenes in related species.

Differential effect of tomatine and its alleviation by cholesterol on larval growth and efficiency of food utilization inHeliothis zea andSpodoptera exigua.

The effect of tomatine on larval growth ofHeliothis zea andSpodoptera exigua was assessed by rearing larvae on diets with different concentrations of the chemical added. When reared from neonates, linear dose-response relationships were obtained for both species, withS. exigua being three times more sensitive to tomatine thanH. zea. Tomatine toxicity was completely alleviated inH. zea by the addition of equimolar cholesterol into the diet; however, inS. exigua some toxicity was maintained. Larvae ofS. exigua that were started on control diet were insensitive to tomatine after five days; larvae started on diet with an EC50 of tomatine and then switched to control diet after five days failed to recover from toxicosis. Larval growth ofH. zea, on the other hand, was affected both at the neonate and third-instar stage, but normal growth resumed when the larvae were transferred to control diet. Tomatine had little or no affect on food consumption, assimilation, or dietary utilization of the food by third-instar larvae ofS. exigua, except at a concentration 10 times the EC50. In contrast, the efficiency of food utilization ofH. zea larvae decreased with increasing tomatine concentrations. Assimilation of the food tended to increase, although not significantly, as tomatine levels increased. Food consumption ofH. zea larvae also increased when the tomatine concentration was greater than an EC50. The addition of equimolar cholesterol to diets with an EC50 of tomatine restored weight gain and nutritional indices values to control values. These results are related to the utility of using tomatine in host-plant resistance programs.

Activation of plant foliar oxidases by insect feeding reduces nutritive quality of foliage for noctuid herbivores.

The foliage and fruit of the tomato plantLycopersicon esculentum contains polyphenol oxidases (PPO) and peroxidases (POD) that are compartmentally separated from orthodihydroxyphenolic substrates in situ. However, when leaf tissue is damaged by insect feeding, the enzyme and phenolic substrates come in contact, resulting in the rapid oxidation of phenolics to orthoquinones. When the tomato fruitwormHeliothis zea or the beet army-wormSpodoptera exigua feed on tomato foliage, a substantial amount of the ingested chlorogenic acid is oxidized to chlorogenoquinone by PPO in the insect gut. Additionally, the digestive enzymes of the fruitworm have the potential to further activate foliar oxidase activity in the gut. Chlorogenoquinone is a highly reactive electrophilic molecule that readily binds cova-lently to nucleophilic groups of amino acids and proteins. In particular, the -SH and -NH2 groups of amino acids are susceptible to binding or alkylation. In experiments with tomato foliage, the relative growth rate of the fruitworm was negatively correlated with PPO activity. As the tomato plant matures, foliar PPO activity may increase nearly 10-fold while the growth rate of the fruitworm is severely depressed. In tomato fruit, the levels of PPO are highest in small immature fruit but are essentially negligible in mature fruit. The growth rate of larvae on fruit was also negatively correlated with PPO activity, with the fastest larval growth rate occurring when larvae fed on mature fruit. The reduction in larval growth is proposed to result from the alkylation of amino acids/protein byo-quinones, and the subsequent reduction in the nutritive quality of foliage. This alkylation reduces the digestibility of dietary protein and the bioavailability of amino acids. We believe that this mechanism of digestibility reduction may be extrapolatable to other plant-insect systems because of the ubiquitous cooccurrence of PPO and phenolic substrates among vascular plant species.

Interaction of nuclear polyhedrosis virus with catechols: Potential incompatibility for host-plant resistance against noctuid larvae.

Two major orthodihydroxy phenolics ofLycopersicon esculentum, rutin and chlorogenic acid, have previously been identified as potential sources of host-plant resistance against the tomato fruitwormHeliothis zea. We report here the possible incompatibility of these chemically based resistance factors with viral control ofH, zea. We have found that both rutin and chlorogenic acid significantly inhibited the infectivity of nuclear polyhedrosis viruses. Chlorogenic acid, when added to tissue culture medium containing TN-368 ovarian cells, inhibited the infectivity of a multiply embedded virus (AcMNPV) by over 86%. Rutin or chlorogenic acid, when fed toH. zea, inhibited the infectivity of a singly embedded nuclear polyhedrosis virus (HzSNPV), with the greatest degree of inhibition occurring at low doses of viral inoculum. Additionally, the ingestion of these phytochemicals significantly prolonged the survival time of virally infectedH. zea larvae. These results suggest that the effectiveness of nuclear polyhedrosis viruses in controllingH. zea populations may be adversely affected by varieties ofL. esculentum with significant levels (eg. 3.5 µmol/g wet weight) of rutin or chlorogenic acid.

Plant and fungal cell wall fragments activate expression of proteinase inhibitor genes for plant defense.

Plant and fungal cell wall fragments produced by enzymic degradation during pest attacks are hypothesized to be activators of a universal recognition system for locally and systemically activating genes which control the synthesis of plant defense chemicals such as the antibiotic phytoalexins and antinutritive proteinase inhibitors. Proteinase inhibitor cDNAs have been prepared from wound-induced mRNAs, isolated, and characterized. The cDNAs have been utilized to quantify specific proteinase inhibitor mRNAs in leaves following wounding or simulated insect attacks. The cDNAs have also been utilized as hybridization probes to isolate and characterize proteinase inhibitor genes from tomato and potato genomic DNA. Proteinase inhibitor proteins have been induced in tomato leaves by chewing insects and shown to be highly correlated with a systemically mediated reduction in the nutritional quality of the leaves toward the larval noctuidSpodoptera exigua. Thus, the wound-induced proteinase inhibitors, whose genes in tomato leaves can be activated by wounding, insect attacks, and plant and fungal cell wall fragments, can significantly decrease the quality of the leaves for such herbivorous insects. This inducible set of biochemical reactions leading to the de novo biosynthesis of proteinase inhibitors is, therefore, considered to be a potentially important defense of plant leaves that should be considered both in developing general theories on insect-plant interactions and in selecting insect-resistant crop varieties.

Alleviation of α-tomatine-induced toxicity to the parasitoid,Hyposoter exiguae, by phytosterols in the diet of the host,Heliothis zea.

The solitary, endoparasitic ichneumonid,Hyposoter exiguae (Viereck) is a parasitoid of the tomato fruitworm,Heliothis zea (Boddie). However, the parasitoid is deleteriously affected by the tomato glycoalkaloid, α-tomatine, ingested from hosts (H. zea) fed on artificial diets or semipurified extracts of tomato plants that contained α-tomatine. α-Tomatine causes prolonged larval development; disruption or prevention of pupal eclosion; deformation of antennal, abdominal, and genital structures; and reduction in adult weight and longevity of the parasitoid. These toxic effects are exacerbated when the dietary dose of α-tomatine is increased from 12 µmol to 20 µmol/g dry wt of diet. However, the toxicity of α-tomatine is attenuated in parasitoids reared from hosts fed on artificial diets that contain equimolar or supramolar amounts of 3ß-OH-sterols admixed with α-tomatine. Further, the toxicity of extracts from the foliage of different cultivars of tomatoes toH. exiguae is contingent upon the composite levels of α-tomatine and total phytosterol (free and esterified). Cultivars with a low total sterol-tomatine ratio are more toxic toH. exiguae. The possible mode of action of α-tomatine toxicity toH. exiguae by disruption of sterol metabolism is discussed.

Tomatine and parasitic wasps: potential incompatibility of plant antibiosis with biological control.

alpha-Tomatine, an alkaloid in tomato plants, is toxic to an endoparasite of a major lepidopterous pest of tomatoes. The parasite acquires the alkaloid from its host after the host ingests the alkaloid. This form of interaction creates a potential dilemma to controlling herbivorous pests through chemical antibiosis in plants.