Waxy Bloom Research Articles

Morphological Characterization and Diversity Analysis in Pea Germplasm

An experiment was conducted to identify the diverse morphological breeding lines. A total of Fifty-two germplasm lines were characterized morphologically as per DUS guidelines, and Shannon’s diversity indices (mean value=0.612) were estimated using Microsoft Excel. The results revealed that maximum variability and diversity were present in foliage color, pod intensity of green color, seed cotyledon color and plant height. Minimum variability was reported for stem anthocyanin colouration, seed testa mottling, leaf axial color and flower standard petal color. The traits of foliage waxy bloom and stipule type were present in all the genotypes. Stem anthocyanin coloration, seed testa mottling, flower standard petal color, and leaf axial color were unique traits and were reported in only a few of the genotypes. It may be concluded that these traits would be considered diverse morphological traits during the selection of lines in segregating generations for the development of pea lines /Variety.

Investigations into Determinants of Blueberry Coating Effectiveness.

Coatings have been investigated as a means of slowing weight loss and helping to preserve quality in blueberries but reported results have been inconsistent with the inadequate presentation of the impact of coatings on blueberry appearance. In this study, we compare the ability to limit weight loss, along with the effect on appearance, of several previously studied coatings for blueberries and attempt to identify reasons why coatings have not been more successful in limiting weight loss in blueberries. In a two-year study, coatings were applied either as a spray or a dip, depending on the nature of the coating, and included 1% chitosan (CH) with and without either 1% or 2% oleic acid (OA), 1% Semperfresh (SF), 2% sodium caseinate (SC), and carnauba wax (CAR). None of the coatings reduced weight loss in either year of the study and sometimes enhanced it. CH, CH + OA, CAR, and SF greatly altered the appearance of the berries by removing all or a part of the waxy bloom. SC also did this to some degree but was generally better at maintaining the natural appearance. It was found that coating application did not effectively limit weight loss through either the cuticle or stem end of the blueberries. Loss of the bloom on the blueberry surface, confirmed visually and by scanning electron microscopy, occurred during coating application, but was found to not influence coating effectiveness. Using CH + OA as an example, it was found that increasing the amount of handling during the drying process significantly increased subsequent weight loss relative to blueberries with minimal handling. This indicates that careful handling during the coating process is important for coating success.

Waxy bloom on capsules is a major determinant of early infection by gray mold (Amphobotrys ricini(N.F. Buchw.) Hennebert) in castor (Ricinus communisL.)

AbstractGray mold is a major disease of castor caused by the pathogenAmphobotrys ricini. It mainly affects the inflorescence resulting in severe yield losses. Role of qualitative characters of inflorescence (spike) and capsuleviz. spike compactness, capsule type, waxy bloom intensity on capsules (visual), capsule spine length, spine texture and spine density in predisposing castor crop to gray mold was investigated. A set of 26 castor lines differing for presence and intensity of bloom was characterized for spike and capsule characters. The lines were screened in vitro (detached spike and capsule techniques) and in vivo by raising the plants in poly house and field conditions for disease reaction. Spearman's rank correlation analysis revealed significant positive correlation (rs = >0.5;p = <0.05) between disease severity and capsule type, capsule waxy bloom, spine texture, spine length. Principal component regression analysis revealed that waxy bloom intensity is the major factor, among the evaluated, that predisposes castor lines to the fungus infection promoting disease severity. Quantification of epicuticular wax from capsules of different waxy bloom lines revealed that there was an increase in severity of infection with increase in wax quantity on capsules irrespective of nature of bloom substantiating the role of waxy bloom quantity in promoting the infection. High quantities of wax (1.50–3.00 µg/mg) were extracted from lines showing high per cent disease severity (40%–95%), and low quantities of wax (0.00–1.50 µg/mg) were extracted from lines showing low per cent disease severity (1%–40%). A disease scoring scale considering differences in waxy bloom quantity as a biochemical marker has been proposed. It may not be a replacement to phenotypic screenings but helps breeders in selecting early generation material for low disease severity when huge populations are to be screened against gray mold by choosing low waxy bloom varieties.

Silicon enhances production and quality of blueberry fruits (Vaccinium corymbosum L.)

The effect of silicon (Si) in the nutrient solution on the fruit development of 2-year-old blueberry plants (Vaccinium corymbosum L. cv. Ventura) was studied. Si was applied to the nutrient solution at a dose of 0.0, 0.6, and 1.2 mM. The parameters of fruit, stems and leaves growth, firmness, and biomass were measured. Fertigation in conjunction with traditional spread fertilization could improve the growth and yield of highbush blueberry to find the optimal method to control decay and prolong the quality of blueberries after harvest. The blueberry fruit has a light-blue appearance because its blue-black skin is covered with a waxy bloom. This layer is easily damaged or removed during fruit harvesting and postharvest handling. Si enhances the resistance of this layer to damage. A 2-year study was done to compare the effects of silicon fertigation and silicean sand and coir fiber as substrates on growth and availability of nutrients for blueberry plants during establishment of highbush blueberry (Vaccinium corymbosum L. “Bluecrop”). The results of experiment indicated that the application of Si had better benefit on the fruit growth of blueberry plants in coir fiber, than the effect that was observed in the sand substrate. The results should improve our understanding for better preservation of postharvest quality of blueberry fruit.

KARSKY - NEW WINE HARVEST COMPLEX-RESISTANT GRAPE VARIETY WITH COLORED PULP AND JUICE

The newest Karsky grape variety, complexly stable with colored pulp and juice, was bred in Greece in 2014 by crossing the Ommonia varieties with a mixture of pollen from the EFIAGE-3 and EFIAGE-4 varieties. The duration of the production period is 146-155 days. Vigor of shoot growth is strong (2.1-3.0 m.). The yield is high. The average weight of a bunch is 180 g. It is characterized by high winter hardiness, drought resistance and increased resistance to fungal diseases. The flower is hermaphrodite. Cylindrical-conical bunch of medium density. The berry is small, round, blue-black in color with a thick waxy bloom. The skin is firm and firm. Intensely colored pulp and juice with varietal flavor. The sugar content is very high. The variety is intended for the production of intensely colored wines of various categories, high-quality juices, suitable for the production of grape vodka.

Mapping of the Waxy Bloom Gene in ‘Black Jewel’ in a Parental Linkage Map of ‘Black Jewel’ × ‘Glen Ample’ (Rubus) Interspecific Population

Black and red raspberries (Rubus occidentalis L. and Rubus idaeus L.) are the prominent members of the genus Rubus (Rosaceae family). Breeding programs coupled with the low costs of high-throughput sequencing have led to a reservoir of data that have improved our understanding of various characteristics of Rubus and facilitated the mapping of different traits. Gene B controls the waxy bloom, a clearly visible epicuticular wax on canes. The potential effects of this trait on resistance/susceptibility to cane diseases in conjunction with other morphological factors are not fully studied. Previous studies suggested that gene H, which controls cane pubescence, is closely associated with gene B. Here, we used tunable genotyping-by-sequencing technology to identify the de novo SNPs of R. occidentalis and R. idaeus using an interspecific population that segregates for the waxy bloom phenotype. We created linkage maps of both species and mapped the identified SNPs to the seven chromosomes (Ro01–Ro07) of Rubus. Importantly, we report, for the first time, the mapping of gene B to chromosome 2 of R. occidentalis using a genetic map consisting of 443 markers spanning 479.76 cM. We observed the poor transferability of R. idaeus SSRs to R. occidentalis and discrepancies in their previously reported chromosome locations.

Influence of different levels of waxy bloom intensity on gray mold disease severity in castor

It is assumed that the presence of wax on castor predispose the crop to gray mold infection in contrary to otherplant-pathogen systems, where wax acts as a protective barrier. However, there is no scientific evidence to implicate it in aiding disease development, field observations and screening of 26 genotypes with different wax levels under controlled conditions in glass house and poly house showed that genotypes with high wax intensities showed higher disease severity (~60-80%) compared to low or no wax genotypes (~1-15%) indicating the role of wax in susceptibility of castor to gray mold.

Morphological characteristics of the leaf blade and the variety of dill morphotypes

Relevance. Common dill (Anethum graveolens L.) is an annual plant of the celery family (Apiaceae). It has alternated variously repeatedly pinnatisected simple leaves character- ized by a number of morphological features including color, presence of waxy bloom, size and density of the final segments, size and shape of the leaf blade. Leaves on different nodes of the same plant can be variable. Environment conditions of plant cultivation also affect some morphological characteristics of the leaf (inc. size of the leaf and its final segments). But, under the same conditions each variety of dill possess a certain set of morphological features that determine the variety identity. In recent years, dill varieties with new morphological features of the leaf blade have emerged, and it is important to evaluate and classify the existing morphologic diversity of the plant.Methods. Several methods are currently used to describe morphological features of dill leaves structure: developed by VIR (All-Russian Institute of Plant Genetic Resources), UPOV, the plant approbation manual, description of leafy vegetables in “Cultivated Flora” compendium. There are similarities and differences between the methods in description of characteristics and their grouping according to the extent of the characters. In this study the current methods for description of the morphological features of dill leafs were compared. The described morphological evaluation of the dill varieties was carried out at 2016–2018 in open field in the Research Institute of Vegetable Crop Breeding (LLC), in the “Gavrish-Slobodskoy” Plant Breeding Center (Pavlovskaya Sloboda, Istrinsky district, Moscow region).Results. As a result, it was revealed that the UPOV method more comprehensively describes the morphological characteristics of dill leaf blade. This method can be extended in the following direction: Establish groups according to the length of leaf, using leaf blade length without petiole: small leaf blade – 5-12 cm, medium – 12-25 cm, large – 25- 40 cm; Establish new character: a density of leaf segments (in parts of the 2nd order) and identify the following groups: thin (up to 5 segments), medium density (6-15 segments), and dense (16 or more segments) arrangement of the segments; Establish new character: segment length, grouping it according their actual length: up to 1 cm – short, from 1 to 1.5 cm – medium, and more than 1.5 cm – long leaf segments. According to the evaluated leaf morphological characteristics: size, color, presence of waxy bloom, “leaf patterns”, the dill plants are very diverse. Two dill morphotypes can be distinguished by presence or absence of waxy bloom, 3 morphotypes by the leaf shape (diamond-shaped, elongated, triangular), and 27 morphotypes – by location and size of the final leaf segments.

Structural differences arise between fruit cuticles of two apple cultivars during long term cold storage

Apple fruits are covered by hydrophobic cuticle that provides protection against desiccation, pathogens, excessive water absorption and radiation. The features of cuticle affect the quality and storability of the fruits. It was aimed to evaluate the correlation between peel ultrastructure and weight loss in fruits covered by waxy bloom (cv. Florina) and without bloom (cv. Red Rome van Well) during 4-month cold storage. SEM (scanning electron microscopy) was used for visualization of the fruit surface and fruit weight was also measured. Several studies have revealed that there may be correlation between the ultrastructure of cuticle and its water permeability. Our results confirmed this phenomenon in case of two cultivars. The weight loss per fruit surface area unit of ‘Florina’ was found significantly higher than that of ‘Red Rome van Well’. At the same time the cuticular surface of the fruits contained more micro-cracks in case of the former cultivar. These data confirmed the relationship between the density of cuticular micro-cracks and the water vapour permeability. We concluded that this feature is more significant than the amount of natural waxy bloom on fruit surface.

Waxy bloom on grape berry surface is one important factor for oviposition of European grapevine moths

Grapevine moths are severe pest insects in European viticulture. Oviposition by grapevine moths is largely influenced by several physical and chemical cues located on the surface of their host plant’s fruits. The contribution of waxy bloom layer on the berry surface for oviposition decision of two European grapevine moth species, Eupoecilia ambiguella and Lobesia botrana, was investigated. An experimental setup was developed to prove oviposition preferences of both species for certain grape varieties and developmental stages based on epicuticular wax extracts. Chemical analysis of epicuticular wax patterns of four different Vitis vinifera varieties revealed differences. However, oleanolic acid was the main component on berry surface waxes and its relative amount decreased between early and late phenological stages. Furthermore, oleanolic acid was responsible for the preference of earlier phenological stages for E. ambiguella oviposition. However, ovipositional variety preferences were triggered by minor components on the wax berry layer. While the oviposition decision of L. botrana was mainly triggered by oleanolic acid, additional cues like olfactory and haptic ones were also important. The ovipositional preferences were discussed in accordance with the results of the chemical analysis in order to elucidate the role of wax compounds for oviposition stimulation.

Effects of cuticular wax on the postharvest quality of blueberry fruit

The blueberry fruit has a light-blue appearance because its blue-black skin is covered with a waxy bloom. This layer is easily damaged or removed during fruit harvesting and postharvest handling. We investigated the effects of wax removal on the postharvest quality of blueberry fruit and their possible mechanisms. The removal of natural wax on the fruit was found to accelerate the postharvest water loss and decay, reduce the sensory and nutritional qualities, and shorten the shelf-life. Wax removal decreased the activities of antioxidant enzymes and contents of antioxidants, and accelerated accumulation of ROS and lipid peroxidation, especially at the later period of storage. Moreover, the organellar membrane structure was disrupted in fruit with wax removed. These results indicate that cuticular wax plays an important role in maintaining the postharvest quality and delaying fruit senescence. The results should improve our understanding for better preservation of postharvest quality of blueberry fruit.

Genotyping-by-sequencing of waxy and glossy near-isogenic broccoli lines

Wild-type Brassica oleracea L. have matte blue-green leaves caused by an interaction between leaf pigmentation and a waxy bloom coating the surface. Glossy mutants have reduced and/or altered epicuticular wax giving the leaves a shiny green appearance and have been identified in most B. oleracea crop varieties, including cauliflower, kale, broccoli, Brussels sprouts, cabbage, and collard. The genetic basis of glossy mutants has not been studied in B. oleracea. Glossiness can confer resistance to multiple herbivores mediated by modification of herbivore feeding behavior and foraging efficiency of their predators. The USDA-ARS-U.S. Vegetable Laboratory released two pairs of near-isogenic broccoli lines (NILs) that visibly differ only for glossiness, providing ideal germplasm for the genetic study of epicuticular wax in B. oleracea. Genotyping-by-sequencing resulted in hundreds of polymorphisms between each pair of NILs. Polymorphisms were identified in or near three different wax synthesis genes suggesting the two glossy mutants were caused by alteration of different steps of the pathway.

A Review of Sooty Blotch and Flyspeck Disease in German Organic Apple Production

Sooty blotch and flyspeck (SBFS) fungi colonise the surface of a range of fruits, especially apple, without penetrating the cuticle. Economic damage results from the exclusion of severely affected fruit batches from being marketed as table apples. A study of SBFS was conducted in 2007–2012 in the two largest German apple production areas, i.e. the Lake Constance and Lower Elbe regions. The absence of this disease complex from orchards under integrated pest management in both regions in all years was explained by the collateral effects of scab and storage-rot sprays with captan and quinone-outside inhibitors (QoI) such as trifloxystrobin. However, SBFS was economically relevant in organically managed orchards, being generally more severe in Southern Germany than in the North. In both regions, Peltaster cerophilus was the most frequently isolated SBFS fungus and was chiefly responsible for crop losses. Cyphellophora sessilis, Microcyclosporella mali and Schizothyrium pomi also contributed to SBFS in some organic orchards, whereas a diversity of additional species was confined to untreated orchards. Evidence was obtained that P. cerophilus overwinters within orchards, fruit mummies being one of presumably several colonised plant organs. Infections of young apple fruits were initiated at any time following the end of flowering, and P. cerophilus was capable of causing several infection cycles per season by means of conidial inoculum. The colonisation of sheets of waxed paper by P. cerophilus indicated that this species does not require fruit leachates for growth. No further expansion of colonies was observed during cold storage; instead, P. cerophilus was gradually displaced by other fungi. Differences in the susceptibility of apple varieties to P. cerophilus were due to fruit ripening, late-maturing cultivars being most heavily colonised, and to surface properties, varieties with a waxy bloom being conspicuously less strongly colonised than others. This fungus was unable to colonise russeted fruit areas. Repeated spray treatments with lime-sulphur and potassium bicarbonate throughout the season were effective and necessary to control SBFS in organic production. This strategy threatens the fungicide-saving potential offered by scab-resistant apple varieties. Cultural measures against SBFS include summer pruning as well as the manual removal of fruit mummies in winter.

Development of fruit quality traits and comparison of the fruit structure of two Vaccinium corymbosum (L.) cultivars

Given their flavour values and high antioxidant content, highbush blueberry fruits are increasingly appreciated by consumers, and the area of cultivation of the species is constantly growing. Mature fruits of various cultivars differ in many quantitative morphological and sensory traits. The structure of the fruits of two Vaccinium corymbosum cultivars ‘Earliblue’ and ‘Patriot’ was compared in three developmental stages using light microscopy and scanning electron microscopy. Special attention was paid to the initiation and rate of development of the most important traits associated with the fruit quality, in particular those that have an impact on fruit firmness and shelf life. It was found that the analysed cultivars were characterised by a varied rate of fruit development, and initiation of many quality traits in fruit micromorphology and anatomy took place in an early stage of development (hypanthium stage). The mature fruits of ‘Patriot’ exhibited a smaller size of the picking scar and higher firmness; they were also larger and heavier than ‘Earliblue’. In turn, the ‘Earliblue’ fruits had a thicker skin and a greater number of stone cells. Moreover, the fruits of both cultivars were characterised by presence of a small number of stomata and shallow microcracks as well as waxy bloom, which had a similar form in both cultivars, and by similar distribution of various forms of tannin and anthocyanin deposits. Cellular structure of fruits has an impact on the firmness and shelf life of blueberries.

Life History, Diagnosis, and Parasitoids of Zale phaeograpta (Lepidoptera: Erebidae)

Abstract Lepidopteran erebid Zale phaeograpta (Hampson) has recently been found feeding on blackberry leaves (Rubus sp., cultivar “Tupi”) in two sites of Michoacan, Mexico. The life cycle and several life parameters of this insect, including parasitism, were examined in the laboratory. The egg, larva (seven instars), prepupa, pupa, and adult stages lasted 4.1, 35.9, 3.1, 14.5, and 29.1 d, respectively. Eggs are turquoise blue. The prolegs of first-instar larvae have an enlarged dark area that runs laterally. From second instar onwards, a whitish longitudinal dorsal band is observed along the entire body. Third-instar larvae wear a pair of dorsal protuberances in abdominal segment VIII. The fourth- and fifth-instar larvae are cream-colored, whereas sixth instars are entirely creamy. Pupa is covered with a waxy bloom. The apical margin of the forewings in males has two silvery bands, whereas in females, a dark band is present. Female and male pupae had the same weight (0.5 g) and measured 2.21 and 2.25 cm, respectively. The adult sex ratio of females to males was 1.1:1. The cumulative number of eggs laid by female during her lifetime was 281, with preoviposition and oviposition periods of 9.9 and 7.3 d, respectively. Maximum oviposition occurred 3.9 d after the start of oviposition (87.7 eggs per female). Larvae of Z. phaeograpta were parasitized by Microplitis sp. (Braconidae) (33%) and a currently unidentified Ichneumonidae species (9%), and pupae were parasitized by Brachymeria comitator (Walker) and another unidentified Brachymeria sp. (Chalcididae).

Phenotypic diversity in sorghum landraces from Kenya

Characterisation of the available Kenyan sorghum genetic diversity is important for understanding the dynamics of the genetic resources and for improving and sustaining sorghum productivity. The aim of this study was to assess the extent and structure of diversity in sorghum landraces from Kenya. Phenotypic data were used to assess diversity in 148 sorghum accessions collected from Western, Turkana, Coast and Eastern regions of Kenya. The accessions were phenotyped using qualitative and quantitative morphological characters. Most of the accessions were high yielding as revealed by the means of panicle branches (43), panicle length (21cm), and grain weight (1.5g). Majority of the sorghums were late maturing and tall as shown by the mean number of days to 50% flowering (88 days), number of leaves and nodes. Turkana and coast sorghums had similarities in maturity, height and panicle length. The number of panicle branches had the highest Broad-sense heritability (0.957). Majority of the sorghumshad dull green midrib (49.55%), no basal tillers (83%), had waxy bloom (39.64%) and produced prop roots (87%). Loose and semi-loose erect panicles dominated (69%) while 83% of the accessions had slightly exerted peduncles. The two Eigen values in PCA explained 67% of the total variance. Phenotypic cluster analysis gave two major groups subdivided into four sub clusters.

Genetic and cytological analyses of the male sterility mutation induced in a sorghum tissue culture with streptomycin

Treatment of sorghum callus cultures with 500-1000 mg/l streptomycin led to a high regeneration frequency of plants with complete or partial male sterility (MS), up to 100% of all green regenerants. The induced MS mutation (ms-str) was preserved in the F1 and BC1 progenies and was genetically unstable: many families produced semisterile and fertile revertants, whose progenies again contained semisterile and sterile mutants. The ms-str mutation was maintained through eight generations via selection and self-pollination of semisterile plants. The mutation was inherited as a recessive nuclear mutation in tester crosses of sterile plants segregated in the progenies of fertile and semisterile revertants and was expressed only in single cases in a test cross for ms-str transfer through pollen of hybrids with restored male fertility. Recessive nuclear mutations determining a low plant height (dwarfness) and the lack of waxy bloom on the stem and leaves (bloomless) were found in male-sterile plants with the ms-str mutation. Cytological analysis of sterile plants reveal multiple alterations of various pollen development stages and tapetal cells: cytomyxis, defects of chromosome conjugation, distorted cytokinesis in meiotic division II, a lack of tetrad separation, a defective formation of the microspore coat, generation of microspores with two to four nuclei, and the formation of micronuclei and large vacuoles in tapetal cells. A possible transfer of the induced cytoplasmic MS mutation into the nuclear genome and the causes of the high genetic instability are discussed.

Mechanisms of resistance to shoot fly, Atherigona soccata in sorghum

Sorghum shoot fly, Atherigona soccata (Rondani) is an important pest of sorghum in Asia, Africa, and Mediterranean Europe, and host plant resistance is an important component for the management of this pest. The levels of resistance in the cultivated germplasm are low to moderate, and therefore, it is important to identify genotypes with different mechanisms of resistance to pyramid the resistance genes. We studied the antixenosis for oviposition, antibiosis, and tolerance components of resistance in a diverse array of shoot fly-resistant and -susceptible genotypes. The main plants and tillers of SFCR 151, ICSV 705, SFCR 125, and, IS 18551 experienced lower shoot fly deadhearts at 28 days after seedling emergence, produced more number of productive tillers. The insects fed on these genotypes also exhibited longer larval period (10.1–11.0 days compared to 9.3 days on Swarna), lower larval survival and adult emergence (54.7–67.8 and 46.7–52.2% compared to 73.3 and 60.6% on Swarna, respectively), and lower growth and adult emergence indices as compared to the susceptible check, Swarna. Physico-chemical traits such as leaf glossiness, trichome density, and plumule and leaf sheath pigmentation were found to be associated with resistance, and chlorophyll content, leaf surface wetness, seedling vigor, and waxy bloom with susceptibility to shoot fly and explained 88.5% of the total variation in deadhearts. Step-wise regression indicated that 90.4% of the total variation in deadhearts was due to leaf glossiness and trichome density. The direct and indirect effects, correlation coefficients, multiple and step-wise regression analysis suggested that deadhearts, plants with eggs, leaf glossiness, trichomes on the abaxial surface of the leaf, and leaf sheath pigmentation can be used as marker traits to select for resistance to shoot fly, A. soccata in sorghum.

Arthropod diversity in peas with normal or reduced waxy bloom

Crop traits can alter economically important interactions between plants, pests, and biological control agents. For example, a reduced waxy bloom on the surface of pea plants alters interactions between pea aphids and their natural enemies. In this study, we assess whether the effect of wax reduction extends beyond the 2 or 3 arthropod species closely associated with the plants and into the structure of the broader arthropod community of over 200 taxa at our site. We sampled arthropods on lines of peas with normal and reduced wax in Latah Co., Idaho using pitfall traps within randomly assigned pairs of 5 × 5 meter plots. During the 1998 and 1999 growing seasons, we collected 12,113 individual arthropods from 221 unambiguously identified morphospecies. The number of individuals collected from each morphospecies responded idiosyncratically to the reduced wax peas. To test whether arthropod community structure differed between the collections from plots having peas with normal or reduced wax, we performed a randomization test. The collection from peas with reduced wax had higher species evenness and thus higher community diversity despite having lower species richness. Our results demonstrate the potential of a single plant trait, epicuticular wax, to affect a community of arthropods. Two pests of peas had opposite responses to peas with reduced wax. The number of pea aphids collected was greater from peas with normal wax peas than those with reduced wax. In contrast, the number of pea leaf weevils collected was greater from peas with reduced wax.

Waxy bloom in peas influences the performance and behavior ofAphidius ervi, a parasitoid of the pea aphid

AbstractLeaf surface waxy bloom can influence the predator–prey interactions that take place on peas. We tested whether the interaction between the pea aphidAcyrthosiphon pisumHarris (Homoptera: Aphidae) and a parasitoid,Aphidius erviHaliday (Hymenoptera: Aphidiidae), is affected by reduced wax. We performed greenhouse experiments comparing aphid parasitism by individualA. ervion two varieties of reduced wax peas to two normal wax sister varieties. We also observed the behavior of individualA. erviin the greenhouse and measured field parasitism in small plots of reduced wax and normal wax peas. In the greenhouse, individualA. erviparasitized more aphids on the reduced wax varieties than on their normal wax counterparts. Wasps spent more time actively foraging on reduced wax pea plants, which may contribute to the higher parasitism observed on those varieties. The greenhouse results suggested that the improved performance of individualA. ervion reduced wax peas might contribute to a higher parasitism on reduced wax peas in the field. Field parasitism was significantly higher in reduced wax pea plots during 2000. Overall parasitism was higher in 2000 than in 2001 and 2002. In the latter years, parasitism was higher on reduced wax plants, but not significantly different from normal wax plants. Improved foraging by individualA. erviresembles improved foraging by other carnivorous insects on reduced wax peas. The advantages of reduced wax for biological control of the pea aphid may hold when any of several different natural enemies is abundant.