Campylomma Verbasci Research Articles

Pear psylla and natural enemy thresholds for successful integrated pest management in pears.

Pear psylla, Cacopsylla pyricola (Förster), is the most economically challenging pest of commercial pears in Washington and Oregon, the top producers of pears in the United States. The objective of this study was to quantify economic injury levels and thresholds for pear psylla. We used the relationship between pear psylla adult and nymph densities, and fruit downgraded due to psylla honeydew marking to identify injury levels. We calculated economic injury levels using the cost of downgraded fruit and average management costs (spray materials and labor). Using economic injury levels, we determined economic thresholds for pear psylla, which include predicted pest population growth, natural enemy predation, and anticipated delays between when pest populations are measured and when managers apply interventions. Economic thresholds generated by this study were 0.1-0.3 second-generation nymphs per leaf and 0.2-0.8 third-generation nymphs per leaf depending on predicted price and yield for insecticide applications at 1,300 pear psylla degree days in the second generation and 2,600 pear psylla degree days in the third generation. Natural enemy inaction thresholds identified by this study were 6 Deraeocoris brevis or 3 Campylomma verbasci immatures per 30 trays or 2 earwigs per trap for third-generation optional insecticide applications.

Integrated pest management programmes increase natural enemies of pear psylla in Central Washington pear orchards

AbstractNatural enemies are a potentially important component of successful integrated pest management in Pacific Northwest pear orchards. Producers in Washington have dealt with difficult pear psylla, Cacopsylla pyricola (Förster) (Homoptera: Psyllidae), pressure and waning product effectiveness for decades. This study finds that integrated pest management (IPM) programmes can sustain high levels of natural enemies comparable to organic management. True bugs Deraeocoris brevis (Knight) (Hemiptera: Miridae) and Campylomma verbasci (Meyer), lacewings Chrysoperla plorabunda (Fitch) (Neuroptera: Chrysopidae) and Chrysopa nigricornis and the parasitic wasp Trechnites insidiosus (Crawford) (Hymenoptera: Encyrtidae) increased in abundance under IPM management. Biological‐based IPM programmes have the potential to conserve natural enemies providing biological control in late summer when conventional sprays often fail due to pesticide resistance and inability to penetrate dense canopies.

Can Isogroup Selection of Highly Zoophagous Lines of a Zoophytophagous Bug Improve Biocontrol of Spider Mites in Apple Orchards?

Zoophytophagous predators provide benefits in agroecosystems when feeding on pests, but they can also cause crop damage. Optimizing the use of zoophytophagous predators as biocontrol agents would require improving pest control and/or limiting damage. Populations of a zoophytophagous species can be composed of a mix of individuals diverging in their level of diet specialization. Consequently, depending on their level of zoophagy, individuals would vary widely in the benefits and risks they provide to pest management. We tested the hypothesis that manipulating the composition of the population of a zoophytophagous insect, the mullein bug, Campylomma verbasci (Hemiptera: Miridae), towards an increased zoophagy would increase their net benefit in an apple orchard. We compared the inherent benefits and risks of two different isogroup lines of mullein bug that genetically differed in their level of zoophagy. In spring, when damage occurs, both strains infrequently punctured apple fruit, which rarely lead to damage and therefore represented a low risk. During summer, only the highly-zoophagous line impacted the spider mite population, while the lowly-zoophagous line did not differ from the control treatments. We concluded that manipulating the composition of the zoophytophagous predator population provided extra net benefits that improved pest control.

Coexistence of zoophytophagous and phytozoophagous strategies linked to genotypic diet specialization in plant bug.

Zoophytophagous predators can substitute zoophagy for phytophagy to complete their development and reproduction. In such predators, variation in feeding behaviour is observed both across and within populations. This may be caused by genetic variation in diet specialization, some genotypes specializing on plant resources, whereas others rely mostly on prey to meet their energy and nutriment requirements. We tested the hypothesis that genotypes specialize either on prey or plant resources in the zoophytophagous mullein bug Campylomma verbasci. In the laboratory, we reared 11 isogroup lines of the mullein bug and recorded feeding behaviour on two diets. The first diet was composed of two-spotted spider mites and leaves, and in the second we added pollen, a high-quality vegetal resource. Overall differences in zoophagy among isogroup lines remained consistent regardless of the presence or absence of pollen. While some lines were insensitive to changes in trophic resource composition others switched from prey to pollen feeding when the pollen was available, revealing a negative genetic correlation between the probabilities of feeding on both resources. A significant line by diet interaction in the proportion of time spent feeding on prey in presence or absence of pollen indicated a genetic basis for diet preference. In absence of the preferred resource, nymphs act as generalists, but exhibited individual diet specialisation when facing the choice between high-quality animal and vegetal resources. Results suggest that zoophytophagous predators can exhibit genetic variation in diet preference, which can generate important ecological and economic differences in natural or agricultural systems.

Influence of extraguild prey and intraguild predators on the phytophagy of the zoophytophagous bug Campylomma verbasci

The mullein bug, Campylomma verbasci (Meyer-Dur) (Hemiptera: Miridae), a palearctic zoophytophagous insect or plant-feeding predator, is common in apple orchards of North America. The aim of this study was to evaluate the influence of the biotic environment (extraguild prey and intraguild predators) on the phytophagy of this zoophytophagous bug. We hypothesized that (1) the presence of extraguild prey should reduce the intensity of phytophagy by the mullein bug and that (2) the presence of intraguild predators should reduce the intensity of phytophagy by the mullein bug as an intraguild prey. Phytophagy was evaluated by observing (1) mullein bug feeding punctures in the laboratory and (2) apple fruit damage by mullein bug in the field. Two extraguild prey types were tested: Aphis pomi De Geer (Hemiptera: Aphididae) and Panonychus ulmi (Koch) (Acari: Tetranychidae), at four densities each (zero, four, eight, and 16). Seven combinations of insects were tested using one mullein bug nymph with or without an intraguild predator (coccinellid). Our results confirm the first hypothesis, but only partially confirm the second. The number of feeding punctures only decreased in the presence of some intraguild predators.

Evidence of genetic basis of zoophagy and nymphal developmental time in isogroup lines of the zoophytophagous mullein bug, Campylomma verbasci

In zoophytophagous predators genetically determined efficiency to exploit either animal or plant resources could lead to diet specialization, and a trade-off between fitness performances on animal and plant diet. Such a trade-off would have important consequences on the efficiency of zoophytophagous species as biocontrol agents. We estimated the genetic basis for zoophagy and nymphal development length and the genetic correlation between these two traits, in the mullein bug, Campylomma verbasci (Meyer) (Hemiptera: Miridae). In the laboratory, we counted the number of spider mites and aphids killed in 24 h by C. verbasci from 12 isogroup lines, and the nymphal development length under a plant and a mixed diet. Among-line variance in the level of zoophagy on both prey was significant and positively correlated. Diet had no significant effect on the mean nymphal development length, but lines differed in nymphal development regardless of the diet. Our results reveal genetic differences in foraging efficiency on prey, which suggest that some genotypes in population of the zoophytophagous mullein bug could provide more benefits in apple orchards.

Influence of plant, animal and mixed resources on development of the zoophytophagous plant bug Campylomma verbasci (Hemiptera: Miridae)

The mullein bug, Campylomma verbasci (Meyer-Dür) (Hemiptera: Miridae), exploits both plant and animal resources. The aim of this study was (1) to evaluate the quality of different plant, animal and mixed diets (i.e. plant material or prey from the overwintering host, the summer host or the laboratory rearing) for the development and survival of mullein bug, and (2) to evaluate if the suitability of the resource changes according to the nymphal instar of C. verbasci. Mullein bug nymphs were reared individually in Petri dishes containing different diets and observed daily until reaching adulthood or dying. The rearing diet (living potato aphids + potato leaf + Ephestia eggs + apple pollen) was a high-quality diet. The medium-quality diets were apple fruit + apple pollen, Ephestia eggs and Sitotroga eggs. The low-quality diets included mullein leaf, frozen aphids, living aphids + potato leaf and apple fruit + living aphids + potato leaf. Finally, the inappropriate diets (when no nymphs reached adulthood) were agar gel, apple fruit, apple pollen, apple leaf, potato leaf, frozen spider mites and frozen conspecifics. When comparing the value of the diets for different instars, living aphids + potato leaf was a high-quality diet for third instar. Apple pollen and frozen conspecifics were low-quality diets for third instar. ‘Red Delicious’ fruit was a high-quality diet for fifth instar and low-quality for third instar. ‘Honeycrisp’ fruit constituted an inappropriate diet whatever the instar. Thus, a whole mixed diet maximises development and survival of C. verbasci nymphs.

True bugs (Hemiptera, Heteroptera) as psyllid predators (Hemiptera, Psylloidea)

Data on natural enemies of psyllids are rare and can usually be found in papers about economically significant species. During an investigation of psyllid fauna in Serbia, natural enemies were investigated, too. True bugs were the most numerous among them. From 28 psyllid species, 21 species of true bugs from families Anthocoridae and Miridae were reared. Seven species of Anthocoridae were identified: Anthocoris amplicollis (Horváth, 1839), Anthocoris confusus Reuter, 1884, Anthocoris nemoralis (Fabricius, 1794), Anthocoris nemorum (Linnaeus, 1761), Orius majusculus Reuter, 1884, Orius minutus (Linnaeus, 1758) and Orius niger Wolff, 1811. The following 14 species of Miridae were identified: Atractotomus mali Meyer-Dür, 1843, Campylomma verbasci (Meyer-Dür, 1843), Deraeocoris flavilinea (A. Costa, 1862), Deraeocoris ruber (Linnaeus, 1758), Deraeocoris lutescens (Schilling, 1836), Heterocordylus genistae (Scopoli, 1763), Hypseloecus visci (Puton, 1888), Malacocoris chlorizans Panzer, 1794, Miris striatus (Linnaeus, 1758), Orthotylus marginalis Reuter, 1884, Psallus assimilis Stichel, 1956, Psallus quercus Kirschbaum, 1856, Psallus flavellus Stichel, 1933 and Pseudoloxops coccinea (Meyer-Dür, 1843). The aim of the research was to provide list of true bugs recorded as predators of psyllids in order to preserve their diversity and significance, especially on cultivated plants.

Biology of rosy apple aphid, Dysaphis plantaginea Passerini (Homoptera: Aphididae), on its summer hosts in eastern Washington

In surveys of apple-production areas east of the Cascade Mountains of Washington, broadleaf plantain, Plantago major Linnaeus (Plantaginaceae) was common throughout while narrowleaf plantain, P. lanceolata Linnaeus, was most common south of Orondo, Douglas County (47.7° latitude). Rosy apple aphid was the most common aphid on these two herbaceous plants; however, colonies were scarce, on only 19% of broadleaf and 11% of narrowleaf plantain samples. Colonies were also generally small, fewer than 25 individuals. Adult rosy apple aphid was collected on plantain from late May through October. Adults reached their highest levels in July before declining in August. Colonies increased again in September and October. Relatively few predators (mainly syrphids) and parasitoids (two species of Aphidius) were found on plantain. On apple, the most common predators were the mirid Campylomma verbasci (Meyer-Dür), earwigs, coccinellids, cecidomyiids and syrphids; the most common primary parasitoid was Lysiphlebus testaceipes (Cresson). Secondary or hyperparasitoids consistently outnumbered the primary parasitoids. Plantains growing outside of orchards but within 1 km of apple trees had the highest incidence of RAA infestation. The potential for management of RAA on its summer hosts is discussed.

MORPHOLOGICAL STUDY ON CAMPYLOMMA VERBASCI MEYER-DURE (HEMIPTERA: MIRIDAE) AND INSURANCE IT'S CLASSIFICATION AS GENERA AND SPECIES

A new specious Campylomma verbasci was recorded in Syria that causes damage to apple fruits. A newly hatched nymph of C. verbasci collected from infested apple orchards has been reared on Turtica which placed on apple leaf under laboratory conditions during the year 2008 to study of it's morphology. Results showed that its development passes in five nymphal instars to reach adult stage, and we can distinguish between nymphal instsrs by wings pads which appeared in rd nymphal instal- and covered a certain abdomen segment in the next nymphal instars, results showed also there was a significant differences pa0.05 in the following characters body's length, abdomen's width, antenna's length, rostrum's length for nymphal and adult stages

Predators and parasitoids of Cacopsylla pyri (L.) (Hemiptera: Psyllidae) in Serbia

The presence of C. pyri and its natural enemies was studied in both treated and untreated pear orchards in Serbia from 2005 to 2009. Five parasitoid and 21 predator species were identified as present on a considerable number of sites. The following parasitoid species were found: Prionomitus mitratus (Dalman), Psyllaephagus procerus Marcet, Syrphophagus ariantes (Walker), Syrphophagus taeniatus (F?rster) and Tamarixia sp. In the study, the species Psyllaephagus procerus, Syrphophagus ariantes and Tamarixia sp. were for the first time identified as parasitoids of C. pyri and as new species in the Serbian fauna. Among the parasitoids determined, Prionomitus mitratus predominated. Of the predators, the following species in four orders were registered: Dermaptera [Forficula auricularia Linnaeus (Forficulidae)], Heteroptera [Anthocoris nemoralis (Fabricius), Anthocoris nemorum (Linnaeus), Orius (Heterorius) minutus (Linnaeus), Orius (Heterorius) niger Wolff (Anthocoridae), Campylomma verbasci (Mayer-D?r), Deraeocoris (Deraeocoris) ruber (Linnaeus) and Deraeocoris (Knightocarsus) lutescens (Schilling) (Miridae)], Neuroptera [Chrysopa pallens Rambur, Chrysoperla carnea (Stephens), Chrysopa sp. (Chrysopidae)], and Coleoptera [Coccinella septempunctata Linnaeus, Adalia bipunctata Linnaeus, Adalia decempunctata (Linnaeus), Hippodamia tredecimpunctata (Linnaeus), Hippodamia variegata (Goeze), Propylea quatuordecimpunctata (Linnaeus), Calvia (Anisocalvia) quatuordecimguttata (Linnaeus) (Coccinellidae), Cantharis rustica Fall?n, Rhagonycha fulva (Scopoli) and Rh. testacea (Linnaeus) (Cantharidae)]. Of the predators determined, 12 species were registered for the first time as predators of C. pyri in Serbia, while C. rustica, Rhagonycha fulva and Rh. testacea have so far been known neither in Serbia nor in the world as predators of pear suckers.

Reproductive biology of two species of Canavalia DC. (Fabaceae)—A non-conventional wild legume

The reproductive biology of two important species of Canavalia, i.e. Canavalia gladiata and Canavalia virosa, was investigated in detail by studying floral phenology, floral biology including fruit and seed set, breeding system and pollinator's activity. Both the species flower and set their seed primarily from August to December. The study of pollen–-pistil interaction indicated the existence of morphological protandry in both species, and pollen germination occurred only after rupture of the stigmatic surface. This suggests that some form of self-incompatibility operates in these species. Ants were the common vectors tripping the stigma and transporting some foreign pollen. Campylomma verbasci (large black ants) were only seen on the flowers of C. virosa, while Monomorium minimum (small black ants) were restricted to the flowers of C. gladiata. Inadequacy of reliable pollinators and high rate of bud/flower drop may be the main factors for low fruit and seed set in both the species.

Horticultural mineral oil applications for apple powdery mildew and codling moth, Cydia pomonella (L.)

Horticultural mineral oil (Orchex 796) was tested in two treatment regimes, either a three-spray early season program targeting apple powdery mildew, Podosphaera leucotricha (All. & Evherh.) Salm. (Oil/Disease treatment) or a six-spray program targeting both generations of codling moth, Cydia pomonella (L.) (Oil/CM treatment), on apple, Malus domestica Borkhausen. These treatments were compared with a check, which received no post-bloom applications of oil. Apple powdery mildew shoot infestation was suppressed only in 1 year of the study (1999) by the Oil/Disease treatment, but no differences in fruit damage were found. The six-spray program of horticultural mineral oil produced the highest percentage of clean fruit, and the lowest level of codling moth-damaged fruit, but only one out of the 3 years of the study. Even in the best treatment in this year, codling moth damage was unacceptably high. Campylomma verbasci (Meyer-Dür) fruit damage was reduced by the oil sprays timed for mildew, probably because of the petal fall spray included in this treatment. Rosy apple aphid, Dysaphis plantaginea (Passerini), densities were suppressed (1 year only) by both oil treatments, while apple aphid, Aphis pomi De Geer, populations were not influenced by oil treatments at any time during the study. White apple leafhopper nymphs, Typhlocyba pomaria McAtee, and tetranychid mite populations were consistently suppressed by both oil treatment regimes, with generally higher levels of suppression occurring with the higher number of applications, despite the lack of specific timing. The same was true of apple rust mite, Aculus schlechtendali (Nalepa), and the western predatory mite, Galandromus occidentalis (Nesbitt).

Impacts of seasonal kaolin particle films on apple pest management

AbstractThe impact of multiple applications of the kaolin-based particle film M96-018 on the population density of selected pests of apple, Malus domestica (Borkh) (Rosaceae), and their natural enemy populations were measured in several Washington State orchards from 1997 to 1999. Densities of western tentiform leafminer, Phyllonorycter elmaella (Doganlar and Mutuura) (Lepidoptera: Gracillariidae), were significantly higher and percent parasitism was generally lower in treated plots than in untreated plots. The effect of M96-018 on green aphids (Aphis spp.) (Hemiptera: Aphididae) was variable between orchards; however, populations of rosy apple aphid, Dysaphis plantaginea Passerini (Hemiptera: Aphididae), were higher in treated plots than in untreated plots. M96-018 reduced the mean density of the white apple leafhopper, Typhlocyba pomaria (McAtee) (Hemiptera: Cicadellidae), and the density of spiders (Araneae) compared with untreated plots. Fruit injury by codling moth, Cydia pomonella (L.), and fruittree leafroller, Archips argyrospilus (Walker) (Lepidoptera: Tortricidae), was significantly reduced in the treated plots compared with the untreated plots. The effect of M96-018 on the mullein bug, Campylomma verbasci (Meyer) (Hemiptera: Miridae), was variable between orchards and years. Stink bug (Hemiptera: Pentatomidae) density and related fruit injury were unaffected by M96-018. Fruit infestation by San Jose scale, Quadraspidiotus perniciosus (Comstock) (Hemiptera: Diaspididae), was significantly higher in treated plots than in untreated plots. Discontinuing applications of M96-018 at mid-season reduced the number of aphid-infested leaves and increased fruit injury by leafroller compared with a full-season program. No differences in pest densities occurred in plots treated for one versus two consecutive years; however, the density of phytophagous mites (Acari: Tetranychidae) was significantly higher the subsequent year after plots were treated with M96-018. Further studies are needed to elucidate how these disruptive impacts of particle films can be minimized.

Influence of timing and prey availability on fruit damage to apple by Campylomma verbasci (Hemiptera: Miridae).

Campylomma verbasci Meyer is a zoophytophagous mirid that feeds on small arthropods as well as apple (Malus domestica Borkhausen) fruits, causing economic damage to some cultivars. The influence of timing and prey availability on the amount of fruit damage was studied to determine whether either factor could be used to refine a management program. C. verbasci nymphs were caged on branches of fruiting 'Golden Delicious' apple trees during the period from bloom through early fruit set. The greatest amount of fruit damage occurred during the bloom period; little or no damage occurred after fruit reached approximately equals 13 mm in diameter. The availability of prey did not reduce the incidence of fruit damage by C. verbasci, nor did it influence the survival of nymphs. Nymphal survival was higher, however, in cages where a blossom or fruitlet was present versus a vegetative spur. These data support the hypothesis that post petal fall insecticide applications (those made after the fruit is greater than approximately equals 10-13 mm in diameter) are not useful in preventing economic levels of fruit damage in Washington State, and that petal fall applications would only prevent a fraction of the total amount of damage by this pest. The data from this study do not support the hypothesis that manipulating arthropod prey species of C. verbasci will prevent fruit damage. There was evidence to support the hypothesis that nymphs can survive a relatively short period (7 d) without arthropod prey.

EFFECT OF EARLY SEASON ACTARA APPLICATIONS ON WHITE APPLE LEAFHOPPER, CAMPYLOMMA VERBASCI, AND WESTERN FLOWER THRIPS, 2000

EFFECT OF EARLY SEASON ACTARA APPLICATIONS ON WHITE APPLE LEAFHOPPER, CAMPYLOMMA VERBASCI, AND WESTERN FLOWER THRIPS, 2000

On-line Thermal Desorption–Gas Chromatography of Intact Insects for Pheromone Analysis

By using a thermodesorption system (TDS) together with a programmable temperature vaporizer (PTV) injector, we confirmed the composition of the sex pheromone of Adoxophyes orana (Lepidoptera: Tortricidae) and Campylomma verbasci (Heteroptera: Miridae) from a single insect per analysis. Intact females and males or pheromone glands were placed in the oven part of the TDS, which was subsequently heated. The compounds released were transferred to the PTV, which was cooled to −150°C. Injection was on a dual-column GC by heating the PTV rapidly to 250°C. The major sex pheromone compounds of A. orana were found only in the pheromone gland of females. Male and female C. verbasci showed fingerprint-identical chromatograms, except for the two sex pheromone compounds, which were present only in females. No distinct differences were found in compounds released from female and male Lygocoris pabulinus (Heteroptera: Miridae). The advantages of this rapid method are the high sensitivity and the low degree of degradation and contamination. This technique was effective in analyzing small insects by gas chromatography–mass spectrometry (GC-MS) without prior manipulation, such as solvent extraction or distillation.

POTENTIAL FOR PHEROMONE-BASED MATING DISRUPTION OF THE MULLEIN BUG, CAMPYLOMMA VERBASCI (MEYER) (HETEROPTERA: MIRIDAE)

AbstractAtmospheric permeation of apple orchards with 16:1 butyl butyrate (BB): 2(E)-crotyl butyrate (CB), the sex pheromone of the mullein bug, Campylomma verbasci (Meyer) (Heteroptera: Miridae), demonstrated potential for pheromone-based mating disruption; atmospheric permeation with single components did not. In traps baited with 16:1 BB:CB, catches of male C. verbasci were 3, 64, and 105% of catches in nontreated controls for disruption treatments of 16:1 BB:CB, CB alone, and BB alone, respectively. With the two-component pheromone as a disruptant, catches of male C. verbasci were significantly reduced relative to controls at dispenser densities of 250, 500, and 1000 per hectare; catches were lowest at 1000 dispensers per hectare. For monitoring of operational trials, pheromone-baited open wing traps hung 1.5 m above ground were judged to be more practical than open wing traps hung 2.5 m above ground, or closed wing traps or white sticky cards at either height. Atmospheric permeation with pheromone did not affect numbers of males and females captured on nonbaited white sticky cards, and trap height did not affect catches of females. However, in pheromone-treated plots, significantly more males were captured on 2.5-m-high nonbaited cards than on 1.5-m-high cards, probably representing incidental catches of males following false trails to pheromone dispensers hung in the upper canopy. This study is the first reported example of pheromone-based disruption of orientation behavior in the Heteroptera.

Modification of responses byCampylomma verbasci (Heteroptera: Miridae) to pheromone blends in atmospheres permeated with synthetic sex pheromone or individual components

Trapping experiments were conducted in orchards to test the hypothesis that exposure of the mullein bug,Campylomma verbasci (Meyer), to atmospheres permeated with its synthetic sex pheromone, a 94:6 blend of butyl butyrate (BB) and (E)-crotyl butyrate (CB), or BB or CB alone, would alter the pheromone responses of males toward off-ratio blends. Exposure to the natural 94:6 blend shifted the response preference away from the natural ratio to blends enriched in BB, including a 99:1 blend, which is normally significantly less attractive than the natural ratio. In an atmosphere permeated with CB, male mullein bugs were as responsive to blends containing 20, 33, and 43% CB, up to seven times the natural percentage, as they were to the 94:6 blend. In an atmosphere permeated with BB, responses to five blends ranging from 94:6 to 99:1 BB:CB were not significantly different, whereas in an untreated atmosphere blends of 98:2 and 99:1 were significantly less attractive than the 94:6 blend. Individual components appeared to disrupt pheromone communication primarily through the creation of a sensory imbalance and modified interpretation of pheromone blend ratios, whereas disruption by the complete pheromone blend apparently involves several mechanisms, including false-trail following and camouflage. Disruption of pheromone communication was most effective with the natural 94:6 sex pheromone blend.

Campylomma verbasci (Heteroptera: Miridae): Pheromone-Based Seasonal Flight Patterns and Prediction of Nymphal Densities in Apple Orchards

Weekly catches of adult male Campylomma verbasci (Meyer) in sex pheromone-baited wing traps provided a seasonal record of Right activity during 1991 in apple orchards and patches of mullein in the interior of British Columbia. The first of two periods of flight activity reflected migration from apple to mullein, and the second probably represented two generations on mullein followed by migration back to apple. Monitoring of adult male C. verbasci using sex pheromone-baited traps in fall of 1990 and 1991 followed by limb-tap samples for first-generation nymphs the following years showed a significant positive relationship between fall catches and density of nymphs in conventional apple orchards. This result suggests that a pheromone-based monitoring system during fall could be developed to predict the density of nymphs the following spring. There was no such relationship in organic orchards, where adult populations in the fall were similar to those in conventional orchards, but mean counts of nymphs in the spring were 20 times lower. Two probable hypotheses could account for this disparity. Either female C. verbasci lay fewer overwintering eggs in organic orchards or mortality is higher, possibly resulting from biological-control agents acting in some organic orchards.