Citrus Flower Moth Research Articles

The first appearance of the citrus flower moth (Prays citri(Millière, 1873)) (Lepidoptera: Praydidae) in Lithuania

The first appearance of the citrus flower moth (Prays citri(Millière, 1873)) (Lepidoptera: Praydidae) in Lithuania

Ecological and Biological Studies on the Citrus Flower Moth Prays citri (Millière) (Lepidoptera: Hyponomeutidae) in Qalyubia Governorate, Egypt

The investigation was carried out during two years in citrus orchards in Qalyubia Governorate 2015 – 2016, to study ecological and biological aspects of the Citrus Flower Moth Prays citri (Milliere) (Lepidoptera: Hyponomeutidae). Data illustrated from ecological and biological points of view. Ranjpure lime (Citrus auranifolia) was the most preferred variety (highly susceptible) of infested by P. citri. While lemon (Citrus limon) which is considered as “moderately susceptible” exhibit less preferable to P. citri, but not seen any infested flowers in navel orange (Citrus sinensis) was the lowest preferred variety, throughout the investigation 2015 – 2016. One peak of infestation of P. citri in spring under weather conditions of Qalyubia Governorate. Predatory potential of Chrysoperla carnea (Steph) larvae on citrus flower moth P. citri larvae, under laboratory conditions was highly significant in mean consumption rate of 2nd and 3rd instars The total consumption by the third instar of C. carnea was significantly than the second instar . Biological results indicated that Female laid eggs both individually 54.6 eggs in average per female, Incubation period lasted 1.07 days, hatchability was 67.7 % in average, Larval and pupal stage period was 6.37 and 5.33 days respectively, female and male longevity lasted 4.3 and 3.6 days respectively. Life cycle 12.77 days while Generation lasted 13.79 days under 29.4°C and 62.7 % RH.

Ecological and Biological Studies on the Citrus Flower Moth, Prays citri (Millière) (Lepidoptera: Hyponomeutidae).

The present investigation indicated that the citrus flower moth, Prays citri (Milliere) showed that differences in their response to host plant species. However, P. citri population greatly preferred lime over navel orange and mandarin. Lime flowers received the highest numbers of P. citri throughout the whole period of investigation, while no infestation occurred on mandarin. Navel orange flowers were of intermediate rank for P. citri population. The obtained results illustrated that both larval and pupal populations exhibited one peak of seasonal abundance during 2015 and 2016 seasons. Distribution of P. citri population within host plants, based on the analysis of variance, was affected by directions. However, P. citri population was significantly higher at the south direction than the other cardinal directions (north, west and east) and center of the canopies. The present study showed that P. citri population exhibited positive response to the increase of mean temperature, while, it showed negative response to both relative humidity and wind speed. No significant differences were observed between the duration periods of all developmental stages which reared on different host (lime, navel orange and mandarin) flowers. Analysis of life table of P. citri population indicated that mortality of larval stage is the Key-stage mortality, which can induce population changes comparing to other specific stage mortalities.

INTEGRATED PEST AND DISEASE MANAGEMENT IN NEW ZEALAND: PROGRESS, CHANGES AND CHALLENGES SINCE 2004

A three-year integrated pest and disease management research programme financed by the New Zealand government and citrus growers ended in 2005. We give an overview of the key results and the changes and challenges since then. The Australian citrus whitefly Orchamoplatus citri (Hemiptera: Aleyrodidae) was first detected in New Zealand in 2000 and spread to all growing areas by 2006. It has resulted in significant orchard management changes, including additional insecticide sprays. Its phenology, economic importance and chemical control strategies are outlined. The prospect for biological control using imported parasitoids identified from field surveys in Australia is described. In lemons, the focus has been on the citrus flower moth Prays nephelomima (Lepidoptera: Yponomeutidae), which causes rind spotting and yield reduction, mainly on ‘Yen Ben’ lemon. The pest's phenology, susceptibility to insecticides, and the response to mating disruption trials using 500 to 1000 dispensers per hectare containing the female sex pheromone, are described. Further work is planned using lure-and-kill techniques. Citrus disease research has focused on understanding the disease cycle and control of anthracnose (Colletotrichum gloeosporioides), a pre-harvest disease of Satsuma mandarins.

Mass Trapping of <I>Prays nephelomima</I> (Lepidoptera: Yponomeutidae) in Citrus Orchards: Optimizing Trap Design and Density

The moth Prays nephelomima (Meirick) (Lepidoptera: Yponomeutidae) is a significant pest of citrus (Citrus spp.), and the recent identification of the female sex pheromone has enabled new direct control tactics to be considered. Six trap designs were compared for suitability in mass trapping, and Pherocon III delta traps were chosen to further evaluate mass trapping. A mass trapping field trial was carried out at five lemon, Citrus limon L., orchards to determine the effect of trap density on catch and rind spot damage on fruit. One plot (0.33-1.0 ha) of each of the five trap density treatments (3, 10, 30, 100, and 300 traps/ha) were operated at each orchard over 12 wk. Catch per trap was reduced as trap density increased and a mean of 12,000 and 16,000 males per ha were killed at the trap densities of 100 and 300 traps per ha, respectively. Increased trap density reduced the percentage of flowers infested with P. nephelomima larvae and reduced the number of moths emerging from flowers. The incidence of rindspot damage on fruit decreased from 45 to 16% as the density of traps increased from 3 to 100 traps per ha. Incidence (percentage of fruit with rindspot) and severity (number of rindspots per fruit) was similar at 100 and 300 traps per ha, indicating that the optimal trap density for reducing rindspot damage is likely to be between 30 and 100 traps per ha. Prospects for converting mass trapping to a lure and kill system are discussed.

Sex Pheromone of the Citrus Flower Moth Prays nephelomima: Pheromone Identification, Field Trapping Trials, and Phenology

Analysis of sex pheromone gland extract of the citrus flower moth, Prays nephelomima (Lepidoptera: Yponomeutidae) by coupled gas chromatography-electroantennogram detection, revealed one electrophysiologically active compound. Structural analysis using gas chromatography, gas chromatography-mass spectrometry, and dimethyldisulfide derivatization identified this as the monounsaturated aldehyde (Z)-7-tetradecenal. Field trials in commercial citrus orchards on the North Island of New Zealand showed that (Z)-7-tetradecenal was highly attractive to male P. nephelomima. Phenology data, collected over 19 months in three commercial orchards, from traps baited with the sex pheromone at a lure loading of 300 microg on a red rubber septum, indicated that male moths may be present throughout the year, with numbers peaking in late summer and autumn.

The attractiveness of the pheromone (z)7tetradecenal to citrus flower moth (<i>Prays nephelomima</i>)

The attractiveness of the pheromone (z)7tetradecenal to citrus flower moth (<i>Prays nephelomima</i>)

Rearing of Prays citri on callus derived from lemon stigma and style culture

A new method for rearing the citrus flower moth (Prays citri Mill.) (Lepidoptera, Yponomeutidae) on lemon [Citrus limon (L.) Burm.] callus is reported. In the present research callus (an undifferentiated mass of plant cells that can be grown under sterile conditions on an artificial medium in vitro) was induced from lemon stigma and style explants cultured on Murashige and Skoog (MS) medium supplemented with 500 mg l -1 malt extract, 13.3 μM 6-benzylaminopurine, and 146 mM sucrose. Also somatic embryogenesis and plant regeneration were obtained from the cultures of styles and stigmas of lemon. Adults were obtained from larvae on infested flowers collected in the field. Different oviposition substrates were used: white oval pearls (WOP), black oval pearls (BOP), rooted shoots (RS) of lemon obtained in vitro, and artificial flowers containing lemon callus (AF). Larvae were reared on lemon callus. Adults oviposited on RS, on WOP, and on AF. BOP were rejected as oviposition substrates. The flower moth reared on callus oviposited fertile eggs. In our tests P. citri completed three generations on callus or on callus plus shoots. In the latter case the larvae preferred callus and fed on shoots only after callus was completely eaten. The life cycle on callus at 23 ± 1 °C lasted about 21 days. There were significant differences between oviposition substrates for what concerns the number of eggs laid. It was observed that females generally preferred WOP (about 25 eggs/female) to AF (about 20 eggs/female) or RS (about 12 eggs/female) as oviposition substrate. Nevertheless the percentage of eggs that developed into adults was higher when AF sealed with stretched Paratilm were used (about 70% of eggs developed into adults). The method of rearing P. citri with AF was labour-saving and the feeding substrate (callus) had less tendency to become mouldy or decompose than when WOP and RS were used. Since such a diet is available for the insect all year round and callus can be produced in unlimited quantity, it could be possible to obtain a mass production of this moth.

Laboratory evaluation and field application of bacterial and fungal insecticides on the Citrus Flower Moth …

Laboratory evaluation and field application of bacterial and fungal insecticides on the Citrus Flower Moth …

Laboratory evaluation and field application of bacterial and fungal insecticides on the citrus flower moth,Prays citri miller (Lep., hyponomeutidae) in lime orchards in Egypt

The efficacy of two commercial products of Bactospeine and Bio-fly onPrays citri of lime trees was studied under laboratory and field conditions throughout the two seasons of 1996 and 1997. Laboratory results indicated that the pathogenic effect of Bactospeine,Bacillus thuringiensis (Berliner) was higher than that of Bio-fly,Beauveria bassiana in spite of the latter was applied with higher doses. Bactospeine at the rate (2 cc/1 l.w.) effected on the larvae more than on the adults, that treatment reduced no. of eggs/female by 81.70% and decreased the larval infestation by 90.08%. Bio-fly at the highest concentration (4 cc/1 l.w.) reduced the infestation with the eggs, the larvae and the pupae by 65.83%, 68.45% and 72.55%, respectively. Advanced effects of bacterial and fungal treatments on the final reduction rates ofP. citri infestation were recorded. Field applications revealed that two sprays with Bactospeine or Bio-fly gave good control ofP. citri more than one spray. Bactospeine at the rate (2 cc/1 l.w.) and Biofly at the rate (4 cc/1 l.w.) reduced the infestation by (89.82–93.43%) and (76.32–78.83%), respectively. In all cases, higher doses of bioinsecticides produced potentiation effects of infestation reduction. It is recommended that two sprays of Bactospeine at a rate (2cc/1 l.w.) are adequate effective to reduce the population of P. citri in lime orchards during the main flowering period of trees without need of chemical insecticides.

Prays citri . [Distribution map

Abstract A new distribution map is provided for Prays citri (Mill.) (Lepid., Yponomeutidae) (Citrus Flower Moth). Host Plant: Citrus . Information is given on the geographical distribution in EUROPE, Corsica, Dodecanese Islands, France, Greece, Italy, Malta, Portugal, Sardinia, Sicily, Spain, ASIA, Cyprus, Israel, Lebanon, Turkey, AFRICA, Algeria, Canary Islands, Egypt, Libya, Madeira, Mauritius, Morocco, Seychelles, South Africa, Tunisia, Zimbabwe.

Field evaluation of the synthetic female sex pheromone of the citrus flower moth,Prays Citri (mill.) (Lepidoptera: Yponomeutidae), and related compounds

The synthetic female sex pheromone ofPrays citri, (Z)-7-tetradecenal, proved to be highly attractive to male moths in the field when released from a variety of dispensers in five different designs of sticky trap. When the pheromone was released from impregnated polyethylene vials, a wide range of initial loadings from 10 μg to 20 mg was attractive, and loadings of 40 μg and above were more attractive than a virgin female moth. Initial loadings of 0.5 mg and 1.0 mg remained attractive for at least five months in the field. Release rates of pheromone from the polyethylene vials under constant laboratory conditions were measured for two different initial loadings. Other isomers of the pheromone and a pheromone ‘mimic’, (Z)-5-dodecenyl formate, were unattractive to male moths and did not affect the attractiveness of the synthetic pheromone or of a virgin female moth.

Identification and synthesis of the female sex pheromone of the citrus flower moth, Prays citri

The female sex pheromone of the citrus flower moth, Prays citri, has been identified as (Z)-7- tetradecenal . The unusually small amounts of pheromone which could be extracted from the female moth precluded identification by classical methods. Instead, the basic structure of the pheromone was deduced from its gas chromatographic (GC) behaviour using a male moth prepared for electroantennographic (EAG) recording as detector; double bond position and geometry were determined by high resolution GC of the natural pheromone and a range of tetradecenal isomers, and by recording male moth EAG responses to these isomers. Synthetic (Z)-7- tetradecenal was shown to be highly attractive to male Prays citri when tested in citrus groves in Israel. This is the first reported identification of the female sex pheromone of a member of the Yponomeutidae.

The citrus blossom midge,Contarinia Citri Barnes (Diptera: Cecidomyiidae), in Israel

The citrus blossom midge,Contarinia citri Barnes, was sampled in two lemon groves. Infestation lasted from December through April. Midge-infested blossoms were seldom concomitantly attacked by the citrus flower moth,Prays citri Mill. Some midge larvae completed their development in the laboratory, their numbers declining and the period required for pupation becoming shorter toward the end of the season. Very few parasitoids were obtained. It is suggested thatC. citri andP. citri may be partially mutually-exclusive in lemon flowers, that the number of annual midge generations depends on the availability of blossoms, and that the midge may undergo a prolonged diapause in the soil.

New records of plant pests in New Zealand

Abstract Three insect pests (Coccus elongatus (Signoret), Aleyrodes proletella (L.) and Prays nephelomima Meyr.) and two mites, (Tarsonemus waitei Banks and Phyllocoptruta oleivora (Ashmead)) are recorded from New Zealand for the first time. In addition pests are recorded from 12 new host plants. A mealworm (Alphitobius diaperinus (Panz.)) is recorded as attacking polystyrene insulation, and the range of known occurrence of Australian Soldierfly (Inopus rubriceps (Macq.)) is extended northward to Kaikohe.

Prove di Lotta Contro ilPrays citri Mill. a mezzo diBacillus thuringiensis

For the first time the Authors have proved in the laboratory and in the fieldB. thuringiensis against the citrus-flower moth (Prays citriMill.) successfully.