Extrafloral nectar in an apple ecosystem to enhance biological control

A common goal of conservation biological control is to enhance biodiversity and increase abundance and effectiveness of predators and parasitoids. Although many studies report an increase in abundance of natural enemies, it has been difficult to document increases in rates of biological control. To enhance parasitism of the tufted apple bud moth, Platynota idaeusalis (Walker) (Lepidoptera: Tortricidae), alternate food was provided by interplanting peaches bearing extrafloral nectaries into apple (Malus spp.) orchards. Laboratory studies showed that the presence of nectar increased longevity and parasitism rates by Goniozus floridanus (Bethylidae), the dominant parasitoid of tufted apple bud moth in West Virginia. In orchard studies, we found the total number of hymenopteran parasitoids was higher on peach (Prunus spp.) trees than on adjacent apple trees. Abundance of parasitic Hymenoptera also was significantly higher on the side of traps facing away from rather than toward peach trees, indicating attraction to peach trees. However, total parasitism rates of tufted apple bud moth were not affected by the presence of peach extrafloral nectar in any field studies. Insect injury to fruit at harvest showed that fruit from orchards with interplanted peach trees had less injury from San Jose scale, Quadraspidiotus perniciosus (Comstock) and stink bugs (Pentatomidae) than fruit from an apple monoculture. Although interplanting with peach trees did not produce the hypothesized result of increased biological control, the experiment did have beneficial results for pest management. These results demonstrate the importance of collecting data on variables beyond the targeted species when evaluating habitat manipulation experiments to fully assess the impact on the ecosystem.     

Releases of Trichogramma platneri (Hymenoptera: Trichogrammatidae) in Apple Orchards under a Sterile Codling Moth Release Program

Based on the premise that augmented host numbers may help multiply and support parasitoid populations, the egg parasitoid Trichogramma platneri Nargarkatti was released in apple orchards which were participating in a sterile codling moth, Cydia pomonella (L.), release program. Nonviable eggs resulting from matings involving at least one sterile codling moth partner can be successfully parasitized by T. platneri. Grain moth-reared, as well as codling moth-reared, T. platneri were released either in the spring or in the spring and summer oviposition period(s) of wild codling moth. Sentinel codling moth eggs were hung weekly, for 3-day periods, from May until September to determine fluctuations in T. platneri populations both during and between releases. Low numbers of wild or nonviable codling moth eggs or other susceptible host eggs resulted in sufficient eggs to maintain low spring- or summer-introduced T. platneri populations. T. platneri reduced codling moth damage in trees in which the Trichogramma were released.     

Parasitism and predation as agents of mortality of winter moth populations in neglected apple orchards in Nova Scotia

Abstract.

• 1 This study compared the roles of pupal mortality and parasitism in winter moth (Operophtera brumata) population dynamics in Nova Scotian apple orchards and assessed the importance of beetles as pupal predators.
• 2 The component of pupal mortality termed predation accounted for greater stage-specific mortality of winter moth than parasitism by Cyzenis albicans in four neglected orchards.
• 3 Parasitism by Cyzenis albicans was not spatially density-dependent in any orchard, whereas the predation component of pupal mortality was spatially density-dependent in the two orchards most densely populated by winter moth.
• 4 Field experiments indicated that over 60% of pupal predation may be attributed to beetles, and that about 46% of pupal predation occurred within 4 weeks after pupal drop.
• 5 Mortality of introduced populations of winter moth in Nova Scotia resembles that of native populations in England where density-dependent predation regulates the winter moth population and reduces the parasitoid population to minimal levels. The situation in Nova Scotia appears to have changed appreciably since the establishment of parasitoids into the system in the 1950s.

     

Delayed density-dependent parasitism of eggs and pupae as a contributor to the cyclic population dynamics of the autumnal moth

Many populations of forest Lepidoptera exhibit 10-year cycles in densities, with impressive outbreaks across large regions. Delayed density-dependent interactions with natural enemies are recognized as key factors driving these cyclic population dynamics, but emphasis has typically been on the larval stages. Eggs, pupae and adults also suffer mortality from predators, parasitoids and pathogens, but little is known about possible density relationships between mortality factors and these non-feeding life stages. In a long-term field study, we experimentally deployed autumnal moth (Epirrita autumnata) eggs and pupae to their natural enemies yearly throughout the 10-year population cycle in northern Norway. The abundance of another geometrid, the winter moth (Operophtera brumata), increased in the study area, permitting comparisons between the two moth species in predation and parasitism. Survival of autumnal moth eggs and pupae was related to the moth abundance in an inverse and delayed manner. Egg and pupal parasitoids dominated as density-dependent mortality factors and predicted the subsequent growth rate of the host population size. In contrast, effects of egg and pupal predators were weakly density dependent, and generally predation remained low. Parasitism rates did not differ between the autumnal and winter moth pupae, whereas predators preferred winter moth pupae over those of the autumnal moth. We conclude that parasitism of the autumnal moth by egg and pupal parasitoids can be related to the changes of the moth density in a delayed density-dependent manner. Furthermore, egg and pupal parasitoids cannot be overlooked as causal factors for the population cycles of forest Lepidoptera in general.     

Predation of codling moth Cydia pomonella L. by the Silvereye Zosterops lateralis (Latham)

Predation of cocooned larvae of codling moth Cydia pomonella by silvereyes Zosterops lateralis was studied in an apple orchard in Nelson, New Zealand. Apple logs with known larval densities were made available to the birds for known periods of time, either in cages or exposed in the apple orchard. The numbers of silvereyes and the natural predation of codling moth were recorded in the same orchard. Predation was density dependent. On caged logs with an initial high density of 32 larvae, 1.1 larvae were consumed per bird‐hour; in contrast, one larva was consumed per 34.5 bird‐hours at three larvae per log. A curvilinear relationship was demonstrated between larval density and the bird‐hours required for predation; this relationship was consistent with the known density dependence of silvereye predation of codling moth. A regression of the total annual winter bird predation of larvae in the orchard on bird numbers was significant. However, the density dependence of predation resulted in declining rates of predation over the winter as larval density declined; the first birds to arrive in the orchard benefitted from particularly high predation rates. As a consequence, fluctuations in bird numbers during the winter had only a secondary influence on predation rates. The numbers of silvereyes in the orchard showed no relationship to the density of the codling moth population present. This study confirmed the importance of silvereyes in the predation of codling moth and a functional, not numerical, rseponse of these birds to codling moth density.     

Pheromone pre-exposure and mating modulate codling moth (Lepidoptera: Tortricidae) response to host plant volatiles

Abstract 1 Two codling moth Cydia pomonella kairomonal attractants, ethyl (E,Z)‐2,4‐decadienoate (pear ester) and (E)‐β‐farnesene, were tested in an insecticide‐sprayed apple orchard and an orchard treated for mating disruption with synthetic pheromone (E,E)‐8,10‐dodecadienol (codlemone). Male captures with pear ester were higher in the pheromone‐treated than in the insecticide‐treated orchard, whereas captures with (E)‐β‐farnesene were not different. Subsequent wind tunnel experiments confirmed that pre‐exposure to sex pheromone codlemone increased the behavioural response of codling moth males to pear ester. This supports the idea that male attraction to the plant volatile pear ester and sex pheromone codlemone is mediated through the same sensory channels. 2 Pear ester is a bisexual codling moth attractant and even captures of female moths were significantly increased in the pheromone‐treated orchard. In the laboratory wind tunnel, pheromone pre‐exposure had no effect on female response to pear ester, but significantly more mated than unmated codling moth females flew upwind towards a pear ester source. Differences in mating status in insecticide‐treated vs. pheromone‐treated orchards may thus account for the differences in female trap captures with pear ester. 3 These findings are important with respect to monitoring of codling moth with pear ester in mating disruption orchards. They also emphasize the importance of host plant volatiles in pheromone‐mediated mating disruption, which has been neglected to date.     

Particle films for suppression of the codling moth (Lepidoptera: Tortricidae) in apple and pear orchards

Studies were conducted in 1997 and 1998 to evaluate the effects of three particle film formulations consisting of kaolin and adjuvants on neonate larvae, ovipositing adult females, and eggs of the codling moth, Cydia pomonella (L.). Neonate larval walking speed, fruit discovery rate, and fruit penetration rate on apple host plants coated with particle films were significantly lower than on host plants without particle films in laboratory assays. Females oviposited less on host plants covered with a particle film residue than on untreated plants in laboratory choice and no-choice tests. Hatch rate of codling moth neonate larvae was unaffected by particle films sprayed on host plants either before or after oviposition. Fruit infestation rates were significantly reduced on particle film-treated trees compared with untreated trees for both first- and second-generation codling moth in field trials in both apple and pear orchards. Particle films appear to be a promising supplemental control approach for codling moth in orchards where moth density is high, and may represent a stand-alone method where moth densities are lower.     

Egg mortality in the cedar processionary moth,Thaumetopoea bonjeani (Lepidoptera: Notodontidae), in an outbreak area of Algeria

The cedar processionary moth, Thaumetopoea bonjeani (Lepidoptera: Notodontidae), is one of the most serious pests of Cedrus atlantica in north-western Africa (Algeria and Morocco). We report on T. bonjeani egg mortality and the diversity and abundance of parasitoids associated with its eggs in the area of Djurdjura Mountain (Tala-Guilef, Algeria). For this goal, 223 egg batches were collected from C. atlantica over two cohorts (2012 and 2013). The average number of eggs per egg batch increased from 143 in 2012 to 171 in 2013, while the egg mortality decreased from 47.4% and 23.9%, respectively, possibly because of a dilution effect. The most important factors of egg mortality were parasitoids and predators, with hymenopteran egg parasitoids killing from 12.1% to 34.9%, and predators from 5.2% to 7.4% of the eggs. The pattern of egg parasitism was driven largely by Ooencyrtus pityocampae, accounting for about 94% of the total parasitoids, followed by Baryscapus servadeii and Trichogramma embryophagum. An hyperparasitoid Chartocerus sp. was collected for the first time from eggs of Thaumetopoea species. As the two major egg parasitoids are shared with the pine processionary moth Thaumetopoea pityocampa in the same area, it is likely that parasitoid abundance may depend on the occurrence of both hosts.     

Adjusting the phenology model of codling moth (lepidoptera: tortricidae) in Washington State apple orchards

Studies were conducted with codling moth, Cydia pomonella L., to fit cumulative curves for the occurrence of injured fruits and male moth catches in sex pheromone-baited traps as a function of accumulated degree-days after the start of moth flight. Twelve data sets were collected from seven apple, Malus domestica Bordhausen, orchards in Washington State from 2003 to 2006. Cumulative data were grouped across years for orchards either treated with sex pheromone dispensers or untreated and fit to logistic equations for both the first and second generation. No significant differences were found for the cumulative curves of moth flight or egg hatch between pheromone-treated and untreated orchards; thus, these data were combined. These new logistic models for moth flight and egg hatch were compared with a widely used distributed-delay model originally developed in Michigan. The cumulative flight curves for the logistic and distributed-delay models were statistically different (slopes) for the first but not the second generation. Cumulative egg hatch in the logistic model was significantly different from the distributed-delay model (intercepts and slopes) for both generations. Most strikingly, the timing of 50% egg hatch during the first generation was delayed 100 DD in the logistic model. The potential impact of this change in the characterization of codling moth's phenology on the effectiveness of insecticide programs targeting eggs and newly eclosed larvae was examined. Possible explanations for this significant difference between the models are discussed.     

Seasonal and cultivar-associated variation in oviposition preference of Oriental fruit moth (Lepidoptera: Tortricidae) adults and feeding behavior of neonate larvae in apples

The Oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) has become a pest of tree fruits since its introduction to the United States in the early twentieth century. Oriental fruit moth has historically been a major pest problem in peach production, and outbreaks in commercial apple (Malus spp.) orchards in the eastern United States were rare until the late 1990s. Recent outbreaks in Mid-Atlantic apple orchards have lead researchers to investigate host-associated effects on oriental fruit moth biology, behavior, and population dynamics. Studies were designed to assess cultivar level effects in apples on oviposition and larval feeding behavior of oriental fruit moth. In a mixed cultivar apple orchard, total oriental fruit moth oviposition and oviposition site preferences varied between cultivars. These preferences also varied over time, when sampling was repeated at various times of the growing season. Although most adult female oriental fruit moth preferentially oviposited in the calyx and stem areas of apple fruit, noticeable numbers of eggs also were laid on the sides of fruit, contradicting some previous reports. Oriental fruit moth females exhibited a strong ovipositional preference for fruit that were previously damaged by oriental fruit moth or codling moth, Cydia ponmonella (L.). The majority of newly hatched oriental fruit moth larvae were observed to spend <24 h on the surface of apple fruit before entry, and this behavior was observed on several apple cultivars. Neonate larvae exhibited a preference for entering fruit at either the stem or calyx ends, regardless of their initial site of placement. Our findings underscore the importance of adequate spray coverage and accurate timing of insecticide applications targeting oriental fruit moth.     

Parasitoid complex of the bird cherry ermine moth Yponomeuta evonymellus in Korea

The parasitoid complex of Yponomeuta evonymellus L. (Lepidoptera: Yponomeutidae), the bird cherry ermine moth (BCEM), was sought in South Korea with the goal of identifying its potential biological controls. Thirteen primary and two secondary parasitoids were found. Diadegma armillatum (Grav.), Herpestomus brunnicornis Grav. (Icheumonidae), and Zenillia dolosa (Meigen) (Tachinidae) were the most important parasitoids causing 3.5%, 7.1%, and 7.7% of the combined parasitism of the host larvae and pupae, respectively. The composition of parasitoid species was more diverse in larvae than in pupae; 10 species were reared from larvae, compared to six from pupae. The parasitoid complex contributed to the relatively low mortality levels of Yponomeuta evonymellus with the combined total rate of parasitism of 29.6% for the host larvae and pupae. This level is below that found in some European populations (50%) and is not greater than the larval rate of parasitism (31%) found in the congeneric apple ermine moth in Korea. This low rate of parasitism is partly attributed to the parasitism by Ageniaspis fuscicollis (1%) detected in Yponomeuta evonymellus, which is similar to that detected in Yponomeuta evonymellus in European reports. This is the first report of the parasitoid complex attacking the BCEM in Korea.     

Characterisation of Cydia pomonella granulovirus from codling moths in a laboratory colony and in orchards of British Columbia*

Sequence analyses indicate that a granulovirus isolated from a laboratory colony of codling moth in British Columbia, Canada is identical or very similar to the Mexican isolate of Cydia pomonella granulovirus (CpGV-M). In addition to codling moth, the vims was found to cause mortality of secondary leafroller pests of North American orchards, including the fruit tree leafroller and the obliquebanded leafroller. A survey in apple growing regions of British Columbia indicates that 23% of the wild population of codling moth larvae carry CpGV.     

The response of Hyssopus pallidus to hosts previously parasitised by Ascogaster quadridentata: heterospecific discrimination and host quality

1. Two basic tenets of competition among parasitoids, that taxonomically distinct parasitoids are unable to discriminate against hosts that have previously been attacked by a competitor and that previous parasitism reduces the quality of a host, were tested by monitoring the oviposition response of Hyssopus pallidus, a gregarious ectoparasitoid, to healthy codling moth larvae and codling moth larvae that had previously been parasitised by a solitary endoparasitoid, Ascogaster quadridentata. 2. Hyssopus pallidus accepted both categories of host larva for oviposition when its competitor was constrained as a first‐instar larva by the diapause development of its host, but discriminated against previously parasitised host larvae when its competitor was present as a larger larva in a non‐diapausing host. 3. Hyssopus pallidus distinguished between the two categories of host larva by allocating twice as many eggs to host larvae previously parasitised by A. quadridentata, a response that was not influenced by previous oviposition experience. 4. The larger clutch sizes allocated to previously parasitised host larvae produced twice as many female progeny, each of a typical size, such that the total biomass was twice that produced from the smaller clutches laid on healthy host larvae. Possible confounding influences of host age and diapause are discounted. 5. These results demonstrate that interspecific discrimination does occur in H. pallidus and that host quality can be improved through previous parasitism by an endoparasitoid. Although interspecific discrimination appears rare among insect parasitoids, it may have been overlooked among ectoparasitoids and requires examination of the fitness consequences of interspecific interactions to clarify its adaptive significance.     

Insecticidal resistance and cross-resistance in populations of Cydia pomonella (Lepidoptera: Tortricidae) in central Europe

Insecticide bioassays were used to investigate resistance of Cydia pomonella (L.) (Lepidoptera: Tortricidae) to insecticides with various types of active ingredients. The efficacy baselines of selected insect growth regulators (fenoxycarb), insect growth inhibitors (diflubenzuron and teflubenzuron), organophoshorous insecticides (phosalone), and neonicotinoids (thiacloprid) against the eggs and first and fifth instars of sensitive laboratory strains of codling moth were determined. According to concentration-mortality baseline, 50% lethality concentration values and 90% lethality concentration values were determined for all the tested insecticides. The lethal concentration ratio quantified the relation between the efficacy of selected insecticides against fifth instars found by topical application and against first instars found by diet-treated bioassay. No difference was detected when the efficacy of technical grade diflubenzuron diluted in tetrahydrofuran and diflubenzuron in the formulated product Dimilin 48 SC diluted in water was compared. However, just before the application of insecticide, the integument of larvae must be treated with acetone. Two bioassays were used to monitor the resistance of codling moths collected in 2003-2005 in two apple (Malus spp.) orchards with different intensities of chemical control. Resistance ratios (RRs) to the tested insecticides were determined for both field populations of codling moth. For the population of codling moth from a commercial apple orchard in Velké Bílovice, cross-resistance to fenoxycarb, teflubenzuron, and phosalone was detected after the topical application of insecticides to fifth instars. The population of codling moth from Prague-Ruzyne was slightly resistant to phosalone and teflubenzuron. No resistance to diflubenzuron was detected in either tested population.     

Cuticular hydrocarbon profiles of codling moth larvae,Cydia pomonella (Lepidoptera: Tortricidae), reflect those of their host plant species

The cuticular hydrocarbons (CHCs) of codling moth larvae collected in the field from their host plant species, apple and walnut, were analyzed and compared with the CHCs of fruits from these two phylogenetically distant hosts. The CHC profiles of the larvae consisted solely of n‐alkanes (C₂₃–C₃₁) and differed quantitatively between host populations. Amounts of the CHCs from the walnut‐collected larvae were shifted towards longer‐chain alkanes compared to those from apple‐collected larvae. A similar shift was observed for the CHC profiles of walnut and apple fruits. Analysis of the CHCs of larvae reared on artificial diet, in comparison with hydrocarbons from the diet, confirmed that larval CHCs scarcely reflect hydrocarbons from the food source. This finding indicates that the larval hydrocarbons must be biosynthesized to a large degree by the insect, rather than being gained directly from its diet. Hence, codling moth populations from apple and walnut each synthesize their own CHC profiles, which largely resemble those of their respective host plant, yielding a potential tool of chemical camouflage from certain natural antagonists of the larvae. The findings of the present study, together with recent molecular population analyses, provides evidence for a process that might ultimately lead to sympatric speciation of this herbivore species. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 376–384.     

Parasitism of obliquebanded leafroller (Lepidoptera: Tortricidae) in commercially managed Michigan apple orchards

The obliquebanded leafroller, Choristoneura rosaceana (Harris), is one of the major arthropod pests of apple in the United States. In 1999 and 2000, a survey of the obliquebanded leafroller parasitoid complex in commercially managed apple orchards in Michigan's two largest fruit production regions was conducted to determine the species present and their importance to obliquebanded leafroller population management. In total, 8,961 obliquebanded leafroller larvae were collected of which 2,174 were parasitized. Parasitism increased from the overwintering generation to the summer generation for both regions and both years. In 1999, 11% of the 1,126 overwintering obliquebanded leafrollers collected were parasitized, whereas 28% of the 3,669 summer generation were parasitized. In 2000, 8% of the 489 overwintering obliquebanded leafrollers collected were parasitized, whereas 26% of the 3,677 summer generation obliquebanded leafrollers collected were parasitized. In total, 20 species of hymenopteran and dipteran parasitoids from seven families were recovered from obliquebanded leafroller larvae over the course of the study. The most abundant hymenopteran parasitoids were Bassus dimidiator Nees (Braconidae) comprising 48% of the total parasitoids, followed by Colpoclypeus florus (Walker) (Eulophidae) (8% of the total) and Macrocentrus linearis (Nees) (Braconidae) (2% of the total). Dipteran parasitoids (Tachinidae) accounted for 36% of the parasitism and were largely comprised of Nilea erecta (Coquillett) (5%) and Actia interrupta Curran (13%). These collections represent new host records for B. dimidiator, Bassus annulipes (Cresson) Hyphantrophaga blanda (Osten Sacken), and Compsilura concinnata (Meigen). The parasitoid C. florus is also reported from Michigan for the first time.     

Resistance of Spanish codling moth (Cydia pomonella) populations to insecticides and activity of detoxifying enzymatic systems

Resistance of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), to insecticides has become a major problem in many apple and pear production areas. Our aim was to determine the level of insecticide resistance in Spanish field populations. Seven field populations collected from apple, Malus domestica Borkhausen (Rosaceae), orchards, and three laboratory susceptible strains of codling moth were studied. Damage at harvest in all the conventional orchards from which codling moth populations were collected was higher than the economic threshold. The efficacy of eight insecticides, with five modes of action, was evaluated by topical application of the diagnostic concentrations on post‐diapausing larvae. The enzymatic activity of mixed‐function oxidases (MFOs), glutathione transferases (GSTs), and esterases (ESTs) was evaluated for each population. The susceptibility to insecticides and the biochemical activity of the three laboratory strains and one organic orchard population were not significantly different. Field populations were less susceptible to the tested insecticides than the susceptible strains, especially for azinphos‐methyl, diflubenzuron, fenoxycarb, and phosalone. The efficacy of all insecticides was significantly dependent on the activity of MFOs. Only the toxicity of the three insecticides most used in Spain when the populations were collected (azinphos‐methyl, fenoxycarb, and phosalone) was also dependent on the activity of ESTs and GSTs activity. We conclude that the control failures were because of the existence of populations resistant to the main insecticides used.     

Studies of transovum and transstadial transmission of a granulosis virus of the codling moth

Capsules of a granulosis virus of the codling moth were never found in codling moth eggs, although they were observed in the larval, pupal, and adult stages. However, eggs obtained from a British Columbia codling moth colony were found to have virus on the egg surface.Transstadial transmission of the virus from the larval to the pupal stage occasionally occurred after intact capsules had been inoculated per os into the larva. The virus was also occasionally transmitted from the pupal to the adult stage, but only after virions had been injected into the hemocoel of the pupa.Fertile eggs obtained from virus-injected insects were not shown to contain active virus. Eggs were tested by maceration in antiserum, by the fluorescent-antibody technique, and by bioassay of their contents.Only one larva of the F₁ and F₂ generations obtained from virus-injected insects succumbed to granulosis even when the larvae were exposed to various types of stressors.Circumstantial evidence supports the hypothesis of transovum transmission, but such transmission cannot be attributed to injections of virus into larvae and pupae in this study.     

Seasonal phenology and stage-specific parasitism of the apple ermine moth, Yponomeuta malinellus Zeller, in Korea

The apple ermine moth, Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae), is a tent caterpillar that feeds on Malus spp. in Korea. Populations of the moth in native areas appeared to be regulated by the assemblage of parasitoids. Phenological associations between host stages and parasitoids, susceptible stage(s) of the host for each parasitoid, and stage‐specific parasitism were studied. The egg larval parasitoid Ageniaspis fuscicollis (Dalman) had highest parasitism of first instar larvae (24%), with 14% parasitism of other larval stages. Dolichogenidea delecta (Haliday) was recovered from all larval instars with the highest parasitism rate of second instar larvae (20.1%), followed by 19.9% parasitism of mid‐larval hosts. Herpestomus brunicornis Gravenhorst was reared from second instar larvae through to pupal collection, and had the highest parasitism rate (29.9%) at the pupal stage. The larval pupal parasitoid Zenillia dolosa (Meigen) was recovered from mid‐larval to pupal stages with the highest parasitism rate (5.5%) occurring in third to fourth instar larvae. The host stages for developing A. fuscicollis completely overlap with those of D. delecta, and with those of H. brunicornis to some degree. A statistically significant negative correlation exists between A. fuscicollis and these dominant parasitoids, indicating competitive interaction within the host.     

Overwintering of codling moth (Lepidoptera: Tortricidae) larvae in apple harvest bins and subsequent moth emergence.

Codling moths, Cydia pomonella (L.), have long been suspected of emerging from stacks of harvest bins in the spring and causing damage to nearby apple and pear orchards. With increased use of mating disruption for codling moth control, outside sources of infestation have become more of a concern for growers using pheromone based mating disruption systems. Studies were designed to provide information on bins as a source of codling moth and the pattern of codling moth emergence from stacks of bins. In these studies, codling moth larvae colonized wood harvest bins at a much higher frequency than harvest bins made of injection molded plastic (189 moths emerged from wood compared with five from plastic). There was no statistical difference in the number of moths infesting bins that had been filled with infested fruit compared with bins left empty at harvest. This suggests that codling moth enter the bins during the time that the bins are in the orchard before harvest. Emergence of laboratory reared adult codling moth from wood bins placed in stacks was found to be prolonged compared with field populations. Temperature differences within the bin stacks accounted for this attenuated emergence pattern. Covering bin stacks with clear plastic accelerated codling moth development in the upper levels of the stack. Codling moth emergence patterns from plastic-covered stacks more closely coincided with male flight in field populations. This information could be important in developing a technique for neutralizing codling moth-infested bins, and in understanding how infested bins may influence pest management in fruit orchards that are located near bin piles. Implications for control of codling moth in conventional orchards and in those using mating disruption as the principal component of an integrated pest management system include increased numbers of treatments directed at areas affected by infested bins.