Pear Psylla Research Articles

Gene expression profiling of Cacopsylla pyricola (Hemiptera: Psyllidae) infected with Ca. Phytoplasma pyri (Acholeplasmatales: Acholeplasmataceae) reveals candidate effectors and mechanisms of infection.

Phytoplasmas can negatively or positively alter vector host fitness. "Candidatus Phytoplasma pyri," is the causal agent of pear decline in commercial pear (Pyrus communis L.; Rosales: Rosaceae) and peach yellow leafroll in peach [Prunus persica (L.); Rosaceae]. This plant pathogen is transmitted by several species of pear psyllids (Cacopsylla spp. Hemiptera: Psyllidae). We sought to explore the relationship between the pear decline phytoplasma and its US vector, Cacopsylla pyricola (Förster), at the molecular genetic level through transcriptomic analysis using RNA-sequencing methodology. We also focused on phytoplasma and insect effectors, which are secreted proteins that can modulate interactions within a pathosystem. In this study, we identified 30 differentially expressed genes, 14 candidate insect effector genes, and 8 Ca. Phytoplasma pyri candidate effectors. Two strains of Ca. Phytoplasma pyri were identified based on immunodominant membrane protein sequence analysis from C. pyricola collected in the Pacific Northwest agricultural region. Here, we present a first genetic look at the pear decline pathosystem and report gene candidates for further exploration of infection mechanisms and potential tools for integrated pest management.

Localization of Genetic Factors that Determine the Economically-Useful Traits of the PEAR (<i>Pyrus</i>) and Methods of Marker-Assisted Selection

DNA markers are an alternative method for accelerated identification of interested genes and loci at the early stages of ontogenesis, and, consequently, DNA markers are able to intensify the breeding process. This article represents overview of research on the localization of economically useful traits in the pear genome and the development and use of marker-assisted selection (MAS) techniques. At the moment, several traits have been localized in the pear genome, i.e.: resistance to scab European (V. pirina Aderh) and Asian (V. nashicola), black spot (Alternaria alternata (Fr.) Keissler), brown spot (Stemphylium vesicarium), fire blight (Erwinia amylovora), pear psylla (Cacopsylla pyri), pear sawfly (Caliroa cerasi), pear blister mite (Eriophyes pyri), self-incompatibility, dwarf trait. Major genes and loci of quantitative traits (QTLs) of fruits characteristics have also been identified, namely: skin color and rustiness of the fruit, size and weight of the fruit, taste, level of ethylene production, harvest time etc. It should be noted that currently Russian research is limited to the validation and use of MAS methods developed abroad. According to the experience of Japanese scientists, the use of MAS for several key traits has made it possible to triple the efficiency of the breeding process. Despite the currently limited list of MBC methods for pears, the high speed of genomic technologies development promises rapid development of new MAS methods in the future. In combination with new breeding technologies (New Breeding Techniques) based on accelerated flowering, the use of MAS for pears is a promising direction of breeding.

Manipulation of juvenile hormone signaling by the fire blight pathogen Erwinia amylovora mediates fecundity enhancement of pear psylla.

In nature, plant pathogens often rely on insect vectors for transmission. Through long-term evolution, plant pathogens and insect vectors have established a mutually beneficial symbiotic relationship. Fire blight, caused by the Gram-negative bacterium Erwinia amylovora (Eam), poses a significant global threat to apple and pear production due to its rapid dissemination among host plants of the Rosaceae family. Despite evidence of E. amylovora transmission by various insects, the association between this pathogen and the pear psylla Cacopsylla chinensis, a common vector insect in pear orchards, remains unclear. Sampling investigations and qRT-PCR results revealed that C. chinensis, from 11 pear orchards severely affected by fire blight disease in Xinjiang of China, harbored varying levels of this pathogen. Eam-positive females exhibited significantly higher fecundity compared to Eam-negative individuals, displaying accelerated ovarian development and a notable increase in egg production. Further RNAi results revealed that juvenile hormone (JH) receptor methoprene-tolerant (CcMet) and a crucial downstream gene Krüppel-homologue 1 (CcKr-h1) mediated the fecundity improvement of C. chinensis induced by Eam. Additionally, miR-2b, which targets CcKr-h1, was identified as being involved in Eam-induced fecundity enhancement in C. chinensis. This study unveils, for the first time, that Eam colonize and amplify the fecundity of C. chinensis females. Host miR-2b targets CcKr-h1 of the JH signaling pathway to regulate the heightened fecundity of C. chinensis induced by Eam. These findings not only broaden our understanding of the interaction between plant pathogens and insect vectors, but also provide novel strategies for managing fire blight and pear psylla. © 2024 Society of Chemical Industry.

Intraguild Predation or Spatial Separation? The efficacy and Interactions of Two Natural Enemy Species for the Biological Control of Pear Psyllid (Cacopsylla pyri)

AbstractPear psyllid (Cacopsylla pyri) is a persistent pest to the pear industry; with an estimated cost of £5 million per annum in the UK alone. This phloem feeding insect is resistant to a large proportion of approved pesticides, necessitating the use of alternative control strategies. Many pear growers practice integrated pest management (IPM) of pear psyllid, focusing on maximizing natural enemy populations, whilst minimizing the use of agrochemical sprays. The anthocorid Anthocoris nemoralis and the European earwig Forficula auricularia are particularly effective at controlling pear psyllid populations during the summer months. Despite the effectiveness of both natural enemies, there is a lack of understanding on whether both species should be promoted together or separately, due to the risk of intraguild predation (IGP) or interference competition. Furthermore, abiotic factors including temperature may influence both behaviors, altering activity level and niche overlap. Although IGP and interference competition have been documented between multiple species of natural enemies neither have been studied between these two specific predators. Using microcosm experiments, olfactometer assays and survival analyses this study demonstrated whether A. nemoralis and F. auricularia can be used in synchrony to control pear psyllid. Results indicated that IGP is present; F. auricularia will consume A. nemoralis when predators are not spatially separate and in absence of psyllid prey. There was no evidence for interference competition, although both predators consumed more prey at higher temperatures. This confirms that pear growers can encourage both predators for the control of pear psyllid without losing predation efficacy.

Seasonal variation in attraction to plant volatiles by Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae).

Pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), occurs as 2 seasonal morphotypes. Summerforms occur on pear (Pyrus communis L.; Rosales: Rosaceae) where they are a significant pest. The larger and darker winterform morphotype develops in response to shortening daylengths and begins winter in reproductive diapause characterized by the absence of ovarian development. Diapausing winterforms often leave pear to overwinter on coniferous shelter plants and then return to pear in late winter and early spring to begin depositing the eggs that produce the first summerform generation. Cacopsylla pyricola adults are attracted to the color of foliage most of the year, but little is known about the role of plant volatiles in host finding and in seasonal dispersal between host and shelter plants by the psyllid. We used a Y-tube olfactometer and choice assays to investigate the response by C. pyricola adults to volatiles emitted by pear and an evergreen tree (cypress) often used as a shelter plant by wintering C. pyricola. Attraction to pear and cypress volatiles varied by season, tree phenology, and psyllid physiology. Cacopsylla pyricola were attracted to cypress volatiles and preferred to settle on cypress shoots during winter and early spring but then shifted to a marked preference for the pear developmental host in late spring and summer. Female C. pyricola exhibited stronger responses to pear volatiles than did males. Our study is the first to show that plant volatiles have a role in host finding by C. pyricola and provides a foundation for research on chemical ecology and management of C. pyricola.

Natural Enemies of the Pear Psylla, Cacopsylla pyri (Hemiptera: Psyllidae), and the Possibilities for Its Biological Control: A Case Study Review in the Western Balkan Countries

The accessible literature covered in this paper commonly highlights psyllids as a significant group of insects affecting pear trees, posing a continual challenge for commercial orchards. With the development of modern pear cultivation systems, Cacopsylla pyri Linnaeus 1758 (Hemiptera: Psyllidae) has emerged as a major pest in pear orchards across many European countries, including those in the Western Balkans. For years, the agricultural sector has primarily relied on chemical insecticides to control pear psyllas, but these methods often fail to produce satisfactory results. This is largely due to C. pyri’s rapid development of resistance to chemical treatments. Consequently, modern agriculture is increasingly shifting towards biological methods to manage C. pyri, involving the identification and conservation of its natural enemies. Although there is an abundance of research on the natural predators of C. pyri and their biocontrol applications across the globe, the Western Balkan region has conducted relatively few studies on the subject. Globally, various parasitoids, predators, and entomopathogenic fungi are often cited as effective against C. pyri. Specific species registered in the agroecological conditions of the Western Balkans include parasitic wasps such as Trechnites insidiosus Crawford, 1910 (Hymenoptera: Encyrtidae) and Prionomitus mitratus Dalman, 1820 (Hymenoptera: Encyrtidae), as well as the predatory bug Anthocoris nemoralis Fabricius, 1794 (Hemiptera: Anthocoridae). However, most Balkan countries have yet to fully utilise the potential of beneficial entomofauna or develop strategies for their commercial application at a national level. Considering that C. pyri is a major pest in pear cultivation and its natural enemies have not been thoroughly explored in most of the Western Balkans, this paper aims to review the literature data on available natural enemies of pear psyllas and to highlight and promote their undeniable potential in biological control.

Biological effectiveness of insecticides in pear psylla control

Biological effectiveness of insecticides in pear psylla control

ОЦЕНКА ЭФФЕКТИВНОСТИ ИНСЕКТИЦИДОВ ШИРОКОГО СПЕКТРА ДЕЙСТВИЯ В КОНТРОЛЕ ГРУШЕВОЙ МЕДЯНИЦЫ

Pear psylla Psylla pyri L. it is one of the main pests of pears worldwide. Decisions on the timing of preventive treatments and the choice of plant protection products used are made on the basis of regular monitoring of the stages of phytophagan development and taking into account the specifics of the action of insecticides on a particular stage of pest development. The article analyzes the range of insecticides allowed on pear against pear psylla, which is represented by preparations from 8 chemical classes. To reduce the resistance of pear psylla to the used pesticides, it is necessary to expand the range of broad-spectrum insecticides against this phytophagan. In this study, insecticides with larvicidal action, such as Voliam Flexi, SC, Lirum, SC, Lufox, EC, were tested in laboratory conditions. The characteristics of the used pesticides are given and the mechanisms of their action are described.Samples of annual pear growth were selected in the Prikuban zone of the Zakuban horticulture subzone of the Krasnodar region, Ust-Labinsk district. As a result of the study, it was found that the following pesticides have the best biological efficacy against nymphs (first-third age) of pear psylla: Voliam Flexi, SC with a consumption rate of 0.5 l/ha and Lirum, SC 1.5 l/ha. On the seventh day, they showed a maximum biological efficacy of 100 %, which was at the level of the standard preparation Movento Energy, SC. In this experiment, Lufox, SC had low efficacy, due to the fact that the drug has a longer mechanism of action, it takes 10-12 days for a good effect. We recommend using the data obtained in the case of registration of tested preparations for the control of pear psylla.

Wing buzzing as a mechanism for generating vibrational signals in psyllids (Hemiptera: Psylloidea).

Psyllids, or jumping plant lice (Hemiptera: Sternorrhyncha: Psylloidea), are a group of small phytophagous insects that include some important pests of crops worldwide. Sexual communication of psyllids occurs via vibrations transmitted through host plants, which play an important role in mate recognition and localization. The signals are species-specific and can be used to aid in psyllid taxonomy and pest control. Several hypotheses have been proposed for the mechanism that generates these vibrations, of which stridulation, that is, friction between parts of the forewing and thorax, has received the most attention. We have investigated vibrational communication in the European pear psyllid species Cacopsylla pyrisuga (Foerster, 1848) using laser vibrometry and high-speed video recording, to directly observe the movements associated with signal production. We describe for the first time the basic characteristics of the signals and signal emission of this species. Based on observations and analysis of the video recordings using a point-tracking algorithm, and their comparison with laser vibrometer recordings, we argue that males of C. pyrisuga produce the vibrations primarily by wing buzzing, that is, tremulation that does not involve friction between the wings and thorax. Comparing observed signal properties with previously published data, we predict that wing buzzing is the main mechanism of signal production in all vibrating psyllids.

Psyllids in Natural Habitats as Alternative Resources for Key Natural Enemies of the Pear Psyllids (Hemiptera: Psylloidea).

The pear psyllids (Cacopsylla spp.; Psylloidea) comprise ~24 species of sap-feeding insects distributed in Europe, temperate Asia, and (as introductions) in the Americas. These pear-specialized insects are among the most damaging and difficult to control pests in orchards. Biological control increasingly is being used to replace or partially replace insecticidal management of pear psyllids. Many key natural enemies of pear psyllids regularly occur in non-orchard habitats on native plants. The presence of beneficial species both in orchard and non-orchard habitats (here referred to as "spillover") has prompted suggestions that native plants and their associated psyllids should be conserved as alternative resources for natural enemies of pear psyllids. The expectation is that the natural enemies will move from those habitats into psyllid-infested orchards. This review shows that psyllids in native habitats are important resources for several key predators and parasitoids of pear psyllids. These resources are critical enough that some beneficials exhibit an almost nomadic existence as they move between plant species, tracking the seasonal appearance and disappearance of psyllid species. In contrast, other natural enemies show minimal or no spillover between orchard and non-orchard habitats, which likely is evidence that they exhibit limited movement at best between orchard and non-orchard habitats. To show conclusively that spillover also indicates that a beneficial species disperses between native habitats and orchards requires difficult research on insect movement. This review concludes with a brief discussion of these difficulties and possible solutions.

Evaluation of a push-and-pull strategy using volatiles of host and non-host plants for the management of pear psyllids in organic farming.

Pear decline (PD) is one of the most devastating diseases of Pyrus communis in Europe and North America. It is caused by the pathogen 'Candidatus Phytoplasma pyri' and transmitted by pear psyllids (Cacopsylla pyri, C. pyricola, and C. pyrisuga). Identifying attractant and repellent volatile organic compounds (VOCs) could improve the development of alternative plant protection measurements like push-pull or attract-and-kill strategies against pear psyllids. Our objective was to investigate which chemical cues of the host plant could influence the host-seeking behavior of pear psyllids, and if cedarwood (CWO) and cinnamon bark (CBO) essential oils could serve as repellents. Based on the literature, the five most abundant VOCs from pear plants elicited EAG responses in both C. pyri and C. pyrisuga psyllid species. In Y-olfactometer trials, single compounds were not attractive to C. pyri. However, the main compound mixture was attractive to C. pyri and C. pyrisuga females. CWO and CBO were repellent against C. pyri, and when formulated into nanofibers (NF), both were repellent in olfactometer trials. However, CBO nanoformulation was ineffective in masking the odors of pear plants. In a field trial, attractive, repellent CWO and blank formulated NF were inserted in attractive green sticky traps. C. pyri captures in traps with CWO NF were statistically lower than in traps with the attractive mixture. Nevertheless, no statistical differences in the numbers of caught specimens were observed between CWO NF and those captured in green traps baited with blank NF. Transparent traps captured fewer psyllids than green ones. In a second field study with a completed different design (push-and-count design), dispensers filled with CBO were distributed within the plantation, and attractive green sticky traps were placed around the plantation. The numbers of trapped pear psyllids increased significantly in the border of the treated plantation, showing that psyllids were repelled by the EOs in the plantation. Although further field evaluation is needed to assess and improve their effectiveness, our results show that these aromatic compounds, repellent or attractive both in nanoformulations and marking pen dispensers, offer great potential as an environmentally sustainable alternative to currently applied methods for managing pear decline vectors.

Effects of Cinnerate, Ultor, and Bexar against pear psylla, 2019

Effects of Cinnerate, Ultor, and Bexar against pear psylla, 2019

Control of pear psylla in pear, 2023

Control of pear psylla in pear, 2023

Turning a Pest into a Natural Enemy: Removing Earwigs from Stone Fruit and Releasing Them in Pome Fruit Enhances Pest Control.

The European earwig Forficula auricularia (L.) (Dermaptera: Forficulidae) is an omnivorous insect that is considered a minor pest of stone fruit and a key predator of pests in pome fruit orchards. In many pome fruit orchards, earwigs are absent or in low abundance due to broad-spectrum spray programs and the slow recolonization rate of earwigs. Orchards in transition to organic or "selective" conventional programs often struggle to achieve effective levels of biological control, and thus, may benefit from inoculating earwigs to expedite their re-establishment. In a two-year study, we evaluated the potential for mass trapping earwigs from stone fruit using rolled cardboard traps to reduce fruit damage and provide earwigs for augmentation in pome fruit. We also tested whether a single mass release or five releases (on alternating weeks) of the same total number of earwigs in apples and pears reduced pests relative to plots where no releases occurred. Mass trapping did not decrease earwig abundance or substantially reduce fruit damage in stone fruit orchards. However, trapping was an efficient method for providing earwigs for augmentation. Earwig abundances were only increased in orchards where earwigs were previously low or absent; however, multiple orchards with varying prior levels of earwigs exhibited reductions in key pests (woolly apple aphid and pear psylla). For some other pests evaluated, plots with mass releases of earwigs had a slight trend in overall lower pest density when compared with control plots. A strategy for moving earwigs out of stone fruit orchards and into pome fruit orchards could be an effective method for augmenting orchard predator populations.

Population Genetic Characterization of the Pear Pest, Cacopsylla jukyungi (Kwon, 1983) (Hemiptera: Psyllidae), Using Novel Microsatellite Markers

The pear pest, Cacopsylla jukyungi (Hemiptera: Psyllidae), is the most damaging insect to commercial pears in South Korea. An assessment of the population genetic characteristics of the species will raise the potential of effective control. In the present study, we developed eight microsatellite markers specific to C. jukyungi and genotyped 132 individuals collected from 11 localities throughout South Korea. Populations showed lower observed heterozygosity than expected heterozygosity and slightly or highly positive values of inbreeding coefficients, suggesting that C. jukyungi is subjected to inbreeding. A strong dependence on commercial pear trees throughout the whole life cycle, even during overwintering, and a nationwide targeting of the overwintered adults are likely contributors to such heterozygosity deficiency. On the other hand, population analyses consistently indicated strong gene flow among populations, implying the presence of persistent factors that have facilitated this process. The nationwide expansion of pear orchards and the replacement with a popular new cultivar during the last 50 years, which may have accompanied the spread of C. jukyungi-bearing pear grafts and scions, are likely causes of such facilitated dispersal. Thus, a management strategy against unintended anthropogenic dispersal of the pear psyllid will be required for better control of C. jukyungi.

Preference of pear psyllid (Cacopsylla pyri) for specific colour inspires new application in plant protection

AbstractUnderstanding the cues used by insects to select their hosts is essential for developing sustainable control strategies, particularly for plant disease vectors. Pear psyllids (Cacopsylla pyri) are vectors of the bacterial disease pear decline caused by ‘Candidatus Phytoplasma pyri’. Yellow sticky traps are typically used to monitor pest insects, but they are non‐specific and capture many beneficial insects, too. Against the background of improving visual traps, this research aimed to investigate the colour choice behaviour of C. pyri. Our first approach was to screen insect colour preferences by performing choice assays with different LED colour wavelengths in a small‐scale choice arena under controlled conditions. Over six LEDs tested, there was a strong significant preference of C. pyri for green 1 (532 nm) followed by green 2 (549 nm). Yellow (576 nm), orange (593 nm), red 1 (619 nm) and red 2 (633 nm) were less attractive than green. Subsequently, the trapping of pear psyllids was tested in the field using newly developed traps covered with transparent‐coloured PVC sheets with a similar wavelength of the preferred LEDs. Red and completely transparent traps have been used as control and combined in randomized blocks in a pear orchard. Field trials revealed that green traps ranging from 525 to 537 nm attracted significantly more pear psyllids than longer wavelength green (543 nm), red and transparent ones. The construction of specific green‐coloured sticky traps seems promising for improving psyllid trapping, especially during an early infestation at low population densities. Thus, these visual traps should be considered in future and integrated into psyllid monitoring as part of integrated pest management.

Characterizing Substrate-Borne Vibrational Mating Signals Produced by Pear Psylla, Cacopsylla pyricola (Hemiptera: Psyllidae)

AbstractTactics that manipulate insect behavior are a component of many pest management strategies. Pheromone-based mating disruption is one such tactic widely used in agricultural systems, but few studies have assessed disrupting other mate communication mechanisms, such as acoustic signals. The most destructive pear pest in the Pacific Northwest USA, pear psylla (Cacopsylla pyricola) is believed to use acoustic signals to find mates, making it a candidate for this type of disruption. This species has two adult morphs, overwintering adults (winterforms) that emerge in the spring and subsequent generations (summerforms). Our study characterized the mating signals for both sexes and morphs of pear psylla, and assessed whether temperature and previous exposure to adult conspecifics altered signals and likelihood of signaling. While there are descriptions for acoustic signals of other psyllid species, this study provides the first evidence that C. pyricola communicates acoustically. The two sexes communicate via duetting; males signal to attract a female and the female signals back if she is receptive for mating. We showed that both morphotypes’ male signals contain a group of chirps followed by a trill, while females respond with chirps. Male signal trills differed significantly in frequency (Hz) between winterform and summerform psylla. The signal frequency among morphs also had a positive linear relationship with temperature, suggesting that dissimilarity in signals among morphs had some relationship to temperature. Males were more likely to signal when they had previous exposure to females compared to males without exposure to females. Our results provide new information on how pear psylla communicate acoustically for mating, advancing the potential to develop mating disruption strategies for integrated pest management (IPM).

Seasonal wild dance of dual endosymbionts in the pear psyllid Cacopsylla pyricola (Hemiptera: Psylloidea)

Most sap-feeding insects maintain obligate relationships with endosymbiotic bacteria that provide their hosts with essential nutrients. However, knowledge about the dynamics of endosymbiont titers across seasons in natural host populations is scarce. Here, we used quantitative PCR to investigate the seasonal dynamics of the dual endosymbionts “Candidatus Carsonella ruddii” and “Ca. Psyllophila symbiotica” in a natural population of the pear psyllid Cacopsylla pyricola (Hemiptera: Psylloidea: Psyllidae). Psyllid individuals were collected across an entire year, covering both summer and overwintering generations. Immatures harboured the highest titers of both endosymbionts, while the lowest endosymbiont density was observed in males. The density of Carsonella remained high and relatively stable across the vegetative period of the pear trees, but significantly dropped during the non-vegetative period, overlapping with C. pyricola’s reproductive diapause. In contrast, the titer of Psyllophila was consistently higher than Carsonella’s and exhibited fluctuations throughout the sampling year, which might be related to host age. Despite a tightly integrated metabolic complementarity between Carsonella and Psyllophila, our findings highlight differences in their density dynamics throughout the year, that might be linked to their metabolic roles at different life stages of the host.

Diversity, biology, and management of the pear psyllids: a global look

AbstractThe pear psyllids (Cacopsylla Ossiannilsson; Hemiptera: Psylloidea: Psyllidae) are a taxonomically difficult group of at least 24 species native to the Palaearctic region. One or more species occur in most pear-growing regions, in some cases as invasive introductions. Existing reviews of this group are primarily of taxonomic focus with limited overviews of biology. The earliest biological studies of the pear psyllids centered on a core group of a few western European species. In part, this focus arose because diversity of the pear psyllids was poorly understood. As taxonomic understanding has advanced over the last 3 decades, research has expanded taxonomically. Increasing difficulties in controlling the pear psyllids additionally has contributed to growth in research. Here, we review a now-extensive literature on diversity, biology, and management of the pear psyllids. Three broad observations emerged from this synthesis. First, large gaps in biological understanding of the pear psyllids persist for several geographic faunas, most notably for psyllids of the Eastern Palaearctic region. Second, taxonomic diversity is accompanied by biological diversity. Despite the commonality in host use among the pear psyllids, with each species being limited to development on Pyrus, striking differences exist among species in life cycles, wintering, and other biological traits. Third, many of the tools being used to manage pear psyllids today are in existence because of the long history of basic research which has targeted these pests. These tools include new insecticides of higher selectivity, various cultural and horticultural tactics, and practices that conserve natural enemies in orchards.

Pre-bloom control of pear psylla (Cacopsylla pyricola) using chemical compounds in combination with yellow sticky traps

Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae) is an important pest of pear in Iran. This study was carried out to evaluate the combination of using chemical compounds with yellow sticky traps for control of the pest at pre-bloom stage of pear trees. The experiments were performed using three treatments (2% oil and sticky traps, 1% oil plus Pyriproxyfen and sticky traps, and 1% oil plus fenoxycarb-lufenuron and sticky traps) along with the untreated control in a randomized complete block design. Treatment spraying was performed at bud swelling stage of pear trees, and then four yellow sticky traps were placed on tree branches in all treatments but the control. All the treatments were replicated three times. The mortality data were subjected to one-way ANOVA. The results showed combination of the tested compounds and yellow sticky traps could reduce the pest population up to 99.8%. The findings indicated that 2% oil in combination with sticky traps is very effective in controlling psylla.