Codling Moth Research Articles

Projecting the Global Potential Distribution of Cydia pomonella (Lepidoptera: Tortricidae) Under Historical and RCP4.5 Climate Scenarios.

The codling moth Cydia pomonella (L.) (Lepidoptera: Tortricidae) is a destructive pest of apple (Malus domestica (Rosales: Rosaceae)), pear (Pyrus spp. (Rosales: Rosaceae)), and other pome tree fruits; outbreaks cause significant ecological and economic losses. In this study, we used CLIMEX model to predict and evaluate the global risk of C. pomonella based on historical climate data (1989–2018) and simulated future climate data (2071–2100) under the RCP4.5 scenarios. Cydia pomonella exhibited a wide distribution under both historical and future climate conditions. Climate change is predicted to expand the northern boundary of the potential distribution from approximately 60°N to 75°N. Temperature was the most dominant factor in climatic suitability for the pest. Combinations of multiple meteorological factors (relative humidity and precipitation) associated with a failure to break diapause in certain regions also affect suitability, particularly in northern South America and central Africa. Irrigation only had a slight impact on species favorability in some areas. The projections established in our study present insight into the global potential suitability of C. pomonella under climate change scenarios by the end of the 21st century. Farmers should be aware of the risk associated with the pest based on the results, which would provide guidance for quarantine agencies and trade negotiators worldwide.

Altered functional properties of the codling moth Orco mutagenized in the intracellular loop-3

Amino acid substitutions within the conserved polypeptide sequence of the insect olfactory receptor co-receptor (Orco) have been demonstrated to influence its pharmacological properties. By sequence analysis and phylogenetic investigation, in the Lepidopteran subgroup Ditrysia we identified a fixed substitution in the intracellular loop-3 (ICL-3) of a conserved histidine to glutamine. By means of HEK293 cells as a heterologous system, we functionally expressed Orco from the Ditrysian model Cydia pomonella (CpomOrco) and compared its functional properties with a site-directed mutagenized version where this ICL-3-glutamine was reverted to histidine (CpomOrcoQ417H). The mutagenized CpomOrcoQ417H displayed decreased responsiveness to VUAA1 and reduced response efficacy to an odorant agonist was observed, when co-transfected with the respective OR subunit. Evidence of reduced responsiveness and sensitivity to ligands for the mutagenized Orco suggest the fixed glutamine substitution to be optimized for functionality of the cation channel within Ditrysia. In addition, contrary to the wild type, the mutagenized CpomOrcoQ417H preserved characteristics of VUAA-binding when physiologic conditions turned to acidic. Taken together, our findings provide further evidence of the importance of ICL-3 in forming basic functional properties of insect Orco- and Orco/OR-channels, and suggest involvement of ICL-3 in the potential functional adaptation of Ditrysian Orcos to acidified extra-/intracellular environment.

Operational Parameters for the Aerial Release of Sterile Codling Moths Using an Uncrewed Aircraft System.

Simple SummaryPest management through the release of sterile codling moths from drones or uncrewed aerial vehicles (UAVs) represents an efficient method for distribution over orchards. In this study, moths released from greater altitudes were more broadly distributed and drifted more in strong winds compared to those released from lower altitudes. Most of the released insects were recaptured in a 50 m wide swath under the release route. Recapture rates from aerially released insects were 40–70% higher compared to those released from the ground. We found that an uncrewed aircraft system (UAS) releasing insects from 35 m above the ground in release routes 50 m apart outperformed standard ground release methods. UASs provide a promising alternative to ground release and conventional aircraft for the release of sterile codling moths.The codling moth is a serious pest of apples in most regions of the world where this fruit is produced. The sterile insect technique is one strategy used to control this pest and is employed as part of an area-wide integrated pest management program for the codling moth in British Columbia, Canada. Modified fixed wing aircraft are the most common method for the release of sterile insects in large area-wide pest management programs. However, aerial release with a full-size aircraft can be prohibitively expensive. We evaluated the use of small, uncrewed aircraft systems (UASs) for the release of sterile codling moths. Sterile codling moths released from greater altitudes were more broadly distributed and drifted more in strong winds, compared to those released from lower altitudes. Most of the released insects were recaptured in a 50 m wide swath under the release route. Recapture rates for aerially released insects were 40–70% higher compared to those released from the ground. UASs provide a promising alternative to ground release and conventional aircraft for the release of sterile codling moths.

Transcriptome of Cydia pomonella granulovirus in susceptible and type I resistant codling moth larvae.

The baculovirus Cydia pomonella granulovirus (CpGV) is a biocontrol agent used worldwide against the codling moth (CM), Cydia pomonella L., a severe pest in organic and integrated pome fruit production. Its successful application is increasingly challenged by the occurrence of CM populations resistant to commercial CpGV products. Whereas three types (I–III) of CpGV resistance have been identified, type I resistance compromising the efficacy of CpGV-M, the so-called Mexican isolate of CpGV, is assumed to be the most widely distributed resistance type in Central Europe. Despite the wide use of CpGV products as biocontrol agents, little information is available on gene-expression levels in CM larvae. In this study, the in vivo transcriptome of CpGV-M infecting susceptible (CpS) and resistant (CpRR1) CM larvae was analysed at 24, 48, 72, 96 and 120 hours post infection in the midgut and fat body tissue by using a newly developed microarray covering all ORFs of the CpGV genome. According to their transcript abundance, the CpGV genes were grouped into four temporal clusters to which groups of known and unknown function could be assigned. In addition, sets of genes differentially expressed in the midgut and fat body were found in infected susceptible CpS larvae. For the resistant CpRR1 larvae treated with CpGV-M, viral entry in midgut cells could be confirmed from onset but a significantly reduced gene expression, indicating that type I resistance is associated with a block of viral gene transcription and replication.

Top-down and bottom-up regulation of codling moth populations in cider apple orchards

The success of biological control by natural enemies in agricultural crops relies on an understanding of the trophic interactions between natural enemies, pests and host plants. Top-down and bottom-up trophic effects, together with potential landscape and local-scale factors, may regulate pest populations. For two years, we analyzed codling moth populations (Cydia pomonella), their crop damage and their parasitoid communities in 26 low-input cider apple orchards in northern Spain. Codling moth abundance was estimated from overwintering larvae sampled with cardboard traps on trees, parasitism was estimated from parasitoids emerged from lab-reared moth larvae, and pest damage was assessed in apples before ripening. Codling moth abundance differed between orchards across years, and was positively correlated with apple production and the cover of apple plantations in the surrounding landscape. The effects of the apple production on codling moth abundance suggest bottom-up pest regulation. Apple damage in individual orchards reached 71%, but decreased with apple production, indicating codling moth satiation. Seven parasitoid species were recorded on codling moth larvae. Parasitism rate in individual orchards reached 42.5% of codling moth larvae. The number of parasitized larvae per orchard was positively related to parasitoid richness, but also to codling moth abundance, suggesting simultaneous top-down and bottom-up effects between parasitoids and pest. This study highlights the need to tackle the whole parasitoid-pest-plant system in order to better manage codling moth damage in orchards. The conservation of complementary parasitoid species through biodiversity-friendly actions should be combined with the control of apple production at the orchard- and landscape scale.

Spatial distribution of Cydia pomonella (Lepidoptera: Tortricidae) populations and its relation with topographic variables

In this study the spatial distribution of codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) and its relation with topographic variables were investigated. The study was conducted during three growing seasons, 2017–2019. The activity of adult males was monitored using delta-shaped traps baited with sex pheromone. Forty-five traps set at 50–200 m intervals were placed within a 12 ha orchard in 2017, and 30 traps set at 684–7560 m intervals were placed in 30 orchards in 2018 and 2019. The mature larvae were sampled using a 15 cm wide hemp wrapped around 113 tree trunks in three orchards during 2019. Spatial analysis by distance indices (SADIE) was used to determine spatial distribution of adults and larvae. According to the results, adult males of codling moth had significant and stable aggregated distribution during population peaks at local scale, but not at regional scale. Mature larvae populations showed random distribution pattern in the studied orchards. The relation between insect abundance and topographic variables was investigated using spatial regression analysis, and no significant correlation was determined. The findings of this study can be used for spatial forecasting and management of codling moth at local and regional scales.

Comparison of New Kairomone-Based Lures for Cydia pomonella (Lepidoptera: Tortricidae) in Italy and USA.

Simple SummaryAdult codling moth (Cydia pomonella L.) monitoring with lure-baited traps is a prerequisite to effectively manage this key pest in apple and pear crops without over-spraying insecticides. We evaluated new multi-component lures comprised of blends of sex pheromone and volatile organic compounds (pear ester, dimethyl nonatriene and linalool oxide) loaded into different substrates (septa and PVC lures). Acetic acid in a second membrane lure was used as a co-lure with all blends. Lure comparisons were performed during the period 2019/2020 in Italy and Washington State (USA) in orchards treated with or without sex pheromone dispensers for mating disruption. The highest total moth counts occurred with the sex pheromone/pear ester PVC lure in both countries. The new multi-component PVC lure without sex pheromone captured the greatest number of female moths only in the USA. This geographical disparity may limit the effectiveness of using a ‘female removal’ strategy to manage this pest without insecticides across major production areas.Studies were conducted during the period 2019/2020 to evaluate the effectiveness of four lures for codling moth (Cydia pomonella L.) in pome fruits in Italy and the USA. Multi-component blends of sex pheromone ((E,E)-8,10-dodecadien-1-ol, PH), pear ester ((E,Z)-2,4-ethyl decadienoate, PE), (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and pyranoid linalool oxide (6-ethenyl-2,2,6-trimethyloxan-3-ol, LOX) were loaded in either a halobutyl elastomer septum or a PVC matrix and always used in combination with acetic acid (AA) loaded in a closed membrane co-lure. Total moth capture was significantly greater with the PVC than the septum lure loaded with PH/PE + AA in both countries. Female capture in the USA study was significantly greater for 8 weeks in traps baited with the PE/DMNT/LOX blend + AA co-lure than with other lures and adding PH to this blend in a PVC lure significantly reduced female capture. In contrast, female capture in Italy did not differ among lures and counts were similar in both apple and pear crops treated with or without mating disruption. These results suggest that the effectiveness of ‘female removal’ strategies to manage codling moth may be geographically limited and further comparisons are needed in other production regions and in walnut.

The landscape of lncRNAs in Cydia pomonella provides insights into their signatures and potential roles in transcriptional regulation

BackgroundLong noncoding RNAs (lncRNAs) have emerged as an important class of transcriptional regulators in cellular processes. The past decades have witnessed great progress in lncRNA studies in a variety of organisms. The codling moth (Cydia pomonella L.) is an important invasive insect in China. However, the functional impact of lncRNAs in this insect remains unclear. In this study, an atlas of codling moth lncRNAs was constructed based on publicly available RNA-seq datasets.ResultsIn total, 9875 lncRNA transcripts encoded by 9161 loci were identified in the codling moth. As expected, the lncRNAs exhibited shorter transcript lengths, lower GC contents, and lower expression levels than protein-coding genes (PCGs). Additionally, the lncRNAs were more likely to show tissue-specific expression patterns than PCGs. Interestingly, a substantial fraction of the lncRNAs showed a testis-biased expression pattern. Additionally, conservation analysis indicated that lncRNA sequences were weakly conserved across insect species, though additional lncRNAs with homologous relationships could be identified based on synteny, suggesting that synteny could be a more reliable approach for the cross-species comparison of lncRNAs. Furthermore, the correlation analysis of lncRNAs with neighbouring PCGs indicated a stronger correlation between them, suggesting potential cis-acting roles of these lncRNAs in the regulation of gene expression.ConclusionsTaken together, our work provides a valuable resource for the comparative and functional study of lncRNAs, which will facilitate the understanding of their mechanistic roles in transcriptional regulation.

Study of the Species Composition of Harmful Organisms in Akunk Educational Research Farm

The article considers the species composition of pests studied in the apple and pear orchards of Akunk Organic Agricultural Experimental Farm in 2020-2021. Twenty four species of harmful organisms have been identified, 17 of which are pests, 1 is a tick and 6 are diseases. Among the harmful organisms the Hoplocampa testudinea and Cydia pomonella were identified on the apple trees, and Fire blight was found on the pear trees.

Assessment of the influence of a biorational insecticide of the juvenoid class on the state of fruit cenoses

The dominant pests in the apple and plum cenoses are representatives of the tortrix family (Tortricidae) on the apple - the codling moth (Cydia pomonella L.), on the plum - the plum moth (Grapholitha funebrana Mats.), which develop in the region of southern Russia in three full generations. The loss of yield from the vital activity of these phytophages can reach 60-80%. It has been established that the inclusion of a 2-fold application of the insecticide Insegar, WDG in the apple and plum protection system allows preserving 98.9% of apple fruits and 94.6-99.2% of plum fruits. The stimulating effect of the use of insecticides of the juvenile group on the agrobiological indicators of the apple-tree variety Golden Reinders and the plum Kabardinskaya early was revealed, namely, the increase in the length of the one-year growth. It has been proven that the double application of Insegar, WDG in apple and plum plantations does not lead to violation of hygienic standards for the content of fenoxycarb in soil and fruits.

Biorational method for controlling the abundance of Cydia pomonella L. in apple agrocenoses of the Krasnodar region

In the region of Krasnodar Territory, Cydia pomonella L. belongs to the dominant pests of the apple tree, against which 8-10 treatments with insecticides are carried out during the growing season. In world practice, pheromones Shin-Etsu® MD CTT, D and BRIZ® are used in apple agrocenoses for the control of C. pomonella. abstention or reduction of insecticidal treatments leads to a decrease in the pesticide load on the agrocenosis of the garden by a factor of two or more. The objective of our research was to determine the biological pheromones effectiveness in controlling C. pomonella quantity. The test was carried out in two horticultural zones of the Krasnodar Territory, in areas with different numbers of phytophage. The experiment as a result, it was found that in the experimental plots the percentage of damaged fruits in the drop was 1.3-1.5%. Fruit damage wasn’t observed in a removable crop, which corresponds to the results of the standard version, with the use of insecticidal treatments. It was found that the pheromones usage in the Black Sea horticultural zone of the Krasnodar Territory is economically feasible. Сost reduction for the purchase of insecticides amounted to 9089.2 rub/ha, a decrease in pesticide load by 70%.

EFFICACY OF DIFFERENT INSECTICIDES AGAINST CYDIA POMONELLA INFESTATION FROM APPLE ORCHARDS IN GILGIT-BALTISTAN, PAKISTAN

Codling moth (Cydia pomonella Linn.) is a serious pest of apple and other stone fruits and causes serious economic damage. Present study was conducted to evaluate the efficacy of different insecticides against C. pomonella infestation in Gilgit-Baltistan. In case of cypermethrin, maximum infestation (7.3, 6.3 and 6) was recorded after ten days of first, second and third spray. After this, infestation started decreasing to reach to the minimum (2.3, 1.6 and 1.3) after 30 days of first, second and third spray. Lambda showed the minimum infestation (3.3, 2.6 and 1.6) after 30 days of first, second and third spray. In case of neem seed oil, maximum infestation (8.0, 7.0 and 6.3) was estimated after 10 days of first, second and third spray. Minimum infestation (3.0, 2.6 and 2.3) was recorded after 30 days of first, second and third spray. Before spray, maximum fruit infestation rate was observed and it started decreasing after first spray and minimum infestation was recorded after the third spray and same trend was seen in case of days. This trend was observed with all insecticides i.e. cypermethrin, lambda and neem seed oil. Infestation was recorded as decreasing with the passage of time and maximum was after ten days while minimum was recorded after 30 days with all treatments. There was significant difference of fruit infestation among the first, second and third spray and among the results after 10, 20 and 30 days of sprays. Present results showed that before spray all fields had maximum fruit infestation caused by codling moth and infestation rate decreased after the treatments. It is concluded that cypermthrin is the most favorable insecticides for local apple former of this region to control codling moth infestation.

Combined Effects of Mating Disruption, Insecticides, and the Sterile Insect Technique on Cydia pomonella in New Zealand.

Simple SummaryCodling moth is a major pest of apples, and was accidentally introduced into New Zealand over 150 years ago. Many countries that New Zealand exports apples to do not have codling moth present and they want to keep it out. Therefore, apple growers must heavily control codling moth populations on their orchards. Currently, the main control tactics are insecticide applications and mating disruption, which uses the moth’s own sex pheromone to make the males unable to find females to mate. We aimed to supplement these tactics with the sterile insect technique (SIT) to further suppress the codling moth on orchards. SIT involves mass rearing and sterilizing codling moth and then releasing them onto orchards where they mate with wild insects resulting in no offspring. We released sterile insects onto seven orchards using unmanned aerial vehicles and ground releases. Six years of the program saw significant drops (90–99%) in wild moth populations. The SIT is an excellent tactic for reducing moth populations in export apple orchards.Codling moth was introduced into New Zealand, and remains a critical pest for the apple industry. Apples exported to some markets require strict phytosanitary measures to eliminate the risk of larval infestation. Mating disruption and insecticide applications are the principal means of suppression in New Zealand. We tested the potential for the sterile insect technique (SIT) to supplement these measures to achieve local eradication or suppression of this pest. SIT was trialed in an isolated group of six integrated fruit production (IFP) orchards and one organic orchard (total 391 ha), using sterilized insects imported from Canada, with release by unmanned aerial vehicle and from the ground. Eradication was not achieved across the region, but a very high level of codling moth suppression was achieved at individual orchards after the introduction of sterile moths in combination with mating disruption and larvicides. After six years of releases, catches of wild codling moths at three IFP orchards (224 ha) were 90–99% lower than in 2013–2014, the year before releases began. Catches at three other IFP orchards (129 ha) decreased by 67–97% from the year before releases began (2015–2016), from lower initial levels. At a certified organic orchard with a higher initial population under only organic larvicides and mating disruption, by 2019–2020, there was an 81% reduction in wild moths capture from 2016–2017, the year before releases began.

Occurrence of granulovirus infecting Cydia pomonella in high altitude cold arid region of India.

Codling moth (Cydia pomonella, Lepidoptera: Tortricidae) is a quarantine pest of apple in Ladakh, India. We report Cydia pomonella granulovirus from infected larvae of codling moth for the first time in India. The two CpGV isolates were identified as (CpGV SKUAST-1 and CpGV SKUAST-2) and published in Genbank under accession number, MK801791 and MK801792, respectively. The mortality of CpGV was evaluated against 3rd instar larvae of codling moth at various concentrations viz., 102, 104, 106, 108, 1010, 1012 and 1014 OBS/ml. The median lethal concentrations (LC50 and LC90) were observed at 7.08 and 28.56 OBS/ml, respectively. In field, the infection rate by CpGV was 5.95 to 15.65%. Based on typical infection symptoms on the larvae, morphological features under the microscope and sequence results of the amplified product confirmed the first occurrence of CpGV from India. Thus, CpGV will form an important non-chemical strategy for managing this pest.

A novel Bacillus thuringiensis Cry9Ea-like protein with high insecticidal activity towards Cydia pomonella larvae.

The host specificity of known Bacillus thuringiensis Cry and Vip pesticidal proteins still needs extensive investigation and the proteins currently used in crop protection are not effective against many pest species. Cydia pomonella (L.) is a widespread and economically important pest of apples, very difficult to control, since the larvae spend most of their life inside a fruit. Currently, large amounts of broad-spectrum, detrimental synthetic agents are used to combat this herbivore and therefore biopesticides with high activity against C. pomonella are very much needed. The toxicity of B. thuringiensis Cry9Ea along with five distinct pesticidal proteins (Cry1Aa, Cry1Ca, Cry1Ia, Cry2Ab and Vip3Aa) has been determined towards the first-instar larvae of C. pomonella. Cry9Ea has much higher activity than the remaining tested proteins (30-1200-fold lower LC50 ) and possibly is the most potent B. thuringiensis pesticidal protein bioassayed against C. pomonella so far. In contrast, Cry9Ea is not toxic towards Spodoptera exigua (Hübn.), indicating a potentially narrow spectrum of activity. Both insect species show high variability in susceptibility to the remaining Cry/Vip proteins. The obtained results extend the existing knowledge regarding B. thuringiensis pesticidal protein host range and indicate Cry9Ea as a promising candidate for successful biological control of C. pomonella. © 2020 Society of Chemical Industry.

Assessment of Insecticidal Activity of Benzylisoquinoline Alkaloids from Chilean Rhamnaceae Plants against Fruit-Fly Drosophila melanogaster and the Lepidopteran Crop Pest Cydia pomonella.

The Chilean plants Discaria chacaye, Talguenea quinquenervia (Rhamnaceae), Peumus boldus (Monimiaceae), and Cryptocarya alba (Lauraceae) were evaluated against Codling moth: Cydia pomonella L. (Lepidoptera: Tortricidae) and fruit fly Drosophila melanogaster (Diptera: Drosophilidae), which is one of the most widespread and destructive primary pests of Prunus (plums, cherries, peaches, nectarines, apricots, almonds), pear, walnuts, and chestnuts, among other. Four benzylisoquinoline alkaloids (coclaurine, laurolitsine, boldine, and pukateine) were isolated from the above mentioned plant species and evaluated regarding their insecticidal activity against the codling moth and fruit fly. The results showed that these alkaloids possess acute and chronic insecticidal effects. The most relevant effect was observed at 10 µg/mL against D. melanogaster and at 50 µg/mL against C. pomonella, being the alteration of the feeding, deformations, failure in the displacement of the larvae in the feeding medium of D. melanogaster, and mortality visible effects. In addition, the docking results show that these type of alkaloids present a good interaction with octopamine and ecdysone receptor showing a possible action mechanism.

Identification and Functional Characterization of a Sigma Glutathione S-Transferase CpGSTs2 Involved in λ-Cyhalothrin Resistance in the Codling Moth Cydia pomonella.

The codling moth, Cydia pomonella (L.), is a quarantine pest of global significance impacting pome fruits and walnuts. It has evolved resistance to many commonly used insecticides including λ-cyhalothrin. Glutathione S-transferases (GSTs) are multifunctional enzymes playing a crucial role in the detoxification of insecticides in insects. However, the role of specific GST gene in λ-cyhalothrin resistance in C. pomonella is unclear. In this study, we identified three sigma-class genes (CpGSTs1, CpGSTs2, and CpGSTs3). These genes were ubiquitously expressed at all developmental stages, and of these, the expression level of CpGSTs2 in the larval stage was significantly higher than in the egg, pupal, and adult stages. Moreover, CpGSTs2 was predominantly expressed in the fat body while lower levels in the cuticle. In addition to exposure of larvae to LD10 of λ-cyhalothrin elevating the expression level of CpGSTs2, mRNA levels of CpGSTs2 in a field population (ZW_R) from northeast China, which has developed moderate level resistance to λ-cyhalothrin, was significantly higher than that of susceptible strains. In vitro inhibition assays demonstrated that λ-cyhalothrin inhibited the conjugating activities of recombinant CpGSTs2, and metabolic assays indicated that λ-cyhalothrin could be depleted by recombinant CpGSTs2. These results bring evidence for the involvement of CpGSTs2 in C. pomonella in resistance to λ-cyhalothrin.

Effects of Irradiation on Codling Moth (Lepidoptera: Tortricidae) First through Third Instars in Sweet Cherries1

Abstract Codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is a serious pest of apple (Malus domestica [Borkh.]), pear (Pyrus communis [L.]), and occasionally, stone fruit (Prunus persica [L.]). Its presence in sweet cherries is rare and presumed to occur in areas where high populations in pome fruits occur near sweet cherries, Prunus avium (L.). Nevertheless, the potential of codling moth residing in a sweet cherry destined for an export market, especially to Asian Pacific countries, has led to the continued use of methyl bromide, an ozone-depleting fumigant, to prevent the accidental spread of this pest. Over the past 20 yr, internationally accepted alternative phytosanitary treatments using ionizing radiation have been developed. This is the first report of an irradiation dose response of codling moth in sweet cherries. We treated the first three instars of codling moth in export-quality sweet cherries and found that the third instar was the most radio-resistant, requiring a dose of approximately 250 Gy to prevent adult emergence. This dose is higher than those reported for fifth-instar codling moth in apples and artificial diet but should not delay any efforts in using this highly effective treatment to meet quarantine restrictions against this pest.

Using phenology models to estimate insecticide effects on population dynamics: examples from codling moth and obliquebanded leafroller.

Phenology models based on degree-days were modified to estimate the effects of insecticide applications on the codling moth, Cydia pomonella (L.), and the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). Because the models inherently track stage structure of the population over the course of the season, stage specific mortality can be applied for various durations and intensities allowing the user to simulate different types of pesticides (ovicides, larvicides, organic or conventional materials). The models presented incorporate reproduction, effects of an application on subsequent generations, and the effects of each insecticide by itself as well as the combination of all the treatments. By comparing the treated populations to an untreated control, an estimate of how much the population size is reduced by different treatment programs over the entire season provides a clear assessment of the effectiveness of the treatment program. Simulations for codling moth also allow the insecticide effects to be simulated in conjunction with mating disruption (or not) and simulations for obliquebanded leafroller include the effect of insecticides on both instars 1-3 and 4-6. The simulations show there are distinct windows of opportunity for management programs, with rather large windows where an insecticide application has only a minor effect on population growth and also shows that intergenerational effects greatly affect optimal timings in subsequent generations. The models are especially useful in assessing current management strategies, testing potential improvements in timings, and evaluating cost savings and reducing non-target effects.

Compatibility and efficacy of Metarhizium anisopliae and sex pheromone for controlling Thaumatotibia leucotreta

A sound IPM management for false codling moth (FCM), Thaumatotibia leucotreta, a devastating pest threatening horticultural production in Africa, is urgently needed. The compatibility of the dry conidia of virulent fungal isolate, Metarhizium anisopliae ICIPE 69 with FCM sex pheromone (Crytrack®) in the autoinoculation was assessed. The effect of the pheromone on the conidial germination was monitored for 4 weeks under field conditions. The multilocation trial was implemented in Machakos and Makueni counties in Kenya to test the efficacy of M. anisopliae ICIPE 69 and Last Call FCM® for T. leucotreta control in orange orchards. The treatments evaluated were (1) M. anisopliae ICIPE 69 (Campaign® and dry conidia); (2) Last Call FCM®; (3) M. anisopliae ICIPE 69 (Campaign® and dry conidia) and Last Call FCM®; and (4) Untreated control orchards. Results show that the conidial viability is not affected by the pheromone. For the multilocation FCM control trial, all treated orchards recorded a significant reduction in the FCM population and consequently fruit infestation, relative to the control (no intervention). FCM infested fruits were 18, 27, 5, and 49% in the treatments 1, 2, 3, and 4, respectively, in Machakos, and 24, 31, 7, and 54% for treatments 1, 2, 3 and 4 in Makueni. The highest marketable yield was recorded in orchards that received treatment 3 for both counties. The yield was 10,880.68 and 11,192.26 kg orange fruit/ha for Machakos and Makueni, respectively. The implication for the management of FCM is discussed in light of the findings of this study.