Stone Fruit Crops Research Articles

Researches on the reaction of apple varieties to Monilinia fructigena fungus attack

The antagonistic effects of Debaryomyces hansenii KI2a, D. hansenii MI1a and Wickerhamomyces anomalus BS91 were tested against Monilinia fructigena and Monilinia fructicola in in vitro and in vivo trials.All yeast strains demonstrated antifungal activity at different levels depending on species, strain and pathogen. D hansenii KI2a and W. anomalus BS91 showed the highest biocontrol activity in vitro; the production of hydrolytic enzymes, killer toxins and volatile organic compounds (VOCs) were hypothesized as their main mechanisms of action against pathogens. D hansenii KI2a and W. anomalus BS91 significantly reduced brown rot incidence and severity on peach and plum fruits artificially inoculated with M. fructigena and M. fructicola, especially when applied 24 h before pathogen inoculation. On the opposite, D. hansenii MI1a exhibited weak antagonistic activity towards M. fructigena on peach and plum fruits and was ineffective against M. fructicola. The noticeable ability of W. anomalus BS91 to control brown rot could be also correlated with its high capacity to colonize the wound tissue and to increase its population density.Accordingly, the antagonistic strains of D. hansenii and W. anomalus could be proposed as active ingredients for the development of biofungicides against Monilinia species that are responsible for considerable economic losses in stone fruit crops.

Results of breeding of stone fruit crops under conditions of the south of Russia

The results of breeding and cultivar studies of stone fruit crops (sweet cherry, cherry, plum) under conditions of the south of Russia are presented. Characteristics and properties of new-generation cultivars significant for breeding are determined, differing from those of analogues by adaptability to the stresses of the southern region, productivity, and fruit quality. The most promising cultivars of sweet cherry, cherry, and plum bred at the North Caucasus Zonal Research Institute of Horticulture and Viticulture with a set of traits economically valuable and significant for breeding are identified; they make it possible to expand the domestic assortment and create modern fruit orchards of stone fruit crops in the southern regions of the Russian Federation.

Use of Genetic Diversity of the Genus Prunus L. in Selection of Clonal Rootstocks for Stone Fruit Crops and Features of Their Reproduction

Abstract On the basis of diversity of wild types of the genus Prunus L. (P. cerasifera, P. armeniaca, P. persica, P. fruticosa, P. lannesiana, P. maackii, P. tomentosa, P. pumila, and P. incana) in the collection of the Krymsk Experiment Breeding Station, highly adaptive, medium or weak vigour clonal rootstocks for stone fruit crops with good compatibility with grafted cultivars were selected: for plum, apricot and peach - Kuban 86, VVA-1, Evrika 99, Zarevo (Glow), Alab 1, Speaker, Best, VSV-1; and for sweet cherries and sour cherries - L-2, LC-52, VSL-1, VSL-2, and RVL-9. Part of the rootstocks were tested and successfully used in different parts of Russia and some near and far countries. The applied integration of tissue culture in vitro in the selection process at the station considerably promoted the rapid introduction of new rootstocks into world production. Technologies were developed for microclonal reproduction, and green and woody cuttings. The revealed light rooting of woody cuttings of stocks Kuban 86, Evrika 99, Zarevo, Best, VSL-1, RVL-9 (50-80%) allowed to develop technology for growing of young plants on these rootstocks directly in the first field of the nursery.

Impact of Plum pox virus (PPV-D) infection on peach tree growth, productivity and bud cold hardiness

In 2000, the Dideron (D) strain of Plum pox virus (PPV) was detected in commercial peach and nectarine orchards in the Niagara region of Ontario where most of Canada’s stone fruit crops are produced. As part of a disease management research programme, peach (Prunus persica L. Batsch) trees in a commercial orchard at Niagara-on-the-Lake were assayed for PPV annually for 3 years. The orchard consisted of two blocks of the cultivars ‘Allstar’ and ‘Brighton’, of which 4 of 288 and 5 of 252 trees, respectively, were infected with PPV-D. The growth and health of these PPV-infected and non-infected trees were evaluated based on the annual growth rates, vigour (chlorophyll content) and bud winter hardiness. Comparative fruit quantity and quality index values were based on total yield and marketable yield per tree, fruit size and weight, fruit pH, titratable acidity, total soluble solids, flesh firmness, and fruit skin colour. Results from these preliminary studies showed that trees infected with this mild Ontario isolate of PPV produced slightly more fruit of smaller size that ripened earlier than non-infected trees. However, yield efficiencies based on weight of fruit relative to the trunk cross-sectional area did not differ statistically. Screenhouse studies on three graft-inoculated fresh market peach cultivars (‘Babygold’, ‘Catherina’, and ‘Garnet Beauty’) similarly did not demonstrate any differences in growth or fruit production in the second and third year post inoculation, but fruit on infected trees matured somewhat earlier.

Basal tolerance to heat and cold exposure of the spotted wing drosophila, Drosophila suzukii.

The spotted wing Drosophila, Drosophila suzukii, is a new pest in Europe and America which causes severe damages, mostly to stone fruit crops. Temperature and humidity are among the most important abiotic factors governing insect development and fitness. In many situations, temperature can become stressful thus compromising survival. The ability to cope with thermal stress depends on basal level of thermal tolerance. Basic knowledge on temperature-dependent mortality of D. suzukii is essential to facilitate management of this pest. The objective of the present study was to investigate D. suzukii basal cold and heat tolerance. Adults and pupae were subjected to six low temperatures (−5–7.5 °C) and seven high temperatures (30–37 °C) for various durations, and survival-time-temperature relationships were investigated. Data showed that males were globally more cold tolerant than females. At temperature above 5 °C, adult cold mortality became minor even after prolonged exposures (e.g., only 20% mortality after one month at 7.5 °C). Heat tolerance of males was lower than that of females at the highest tested temperatures (34, 35 and 37 °C). Pupae appeared much less cold tolerant than adults at all temperatures (e.g., Lt50 at 5° C: 4–5 d for adults vs. 21 h for pupae). Pupae were more heat tolerant than adults at the most extreme high temperatures (e.g., Lt50 at 37 °C: 30 min for adults vs. 4 h for pupae). The pupal thermal tolerance was further investigated under low vs. high humidity. Low relative humidity did not affect pupal cold survival, but it reduced survival under heat stress. Overall, this study shows that survival of D. suzukii under heat and cold conditions can vary with stress intensity, duration, humidity, sex and stage, and the methodological approach used here, which was based on thermal tolerance landscapes, provides a comprehensive description of D. suzukiithermal tolerance and limits.

Сondition analysis of stone fruit crops during their processing on perforated surface under centrifugal forces

In this article there is analysis of condition of stone fruit crops in fresh during their rotative movement on immobile perforated surface of cylindrical coating under field of centrifugal forces aimed at division onto semi-product (flesh) and waste (stones). Division is being performed via separation of flesh fragments from stones by hole edges. Separation intensiveness (productivity of the process) depends on structural-mechanical properties of fruit fleshes and their rotative speed.On the example of separate fruit it has been experimentally proved that besides rotative movement on inner surface of the coating there is rotative movement of a fruit around its own axle what promotes even separation of flesh. Such a rotation is typical for fruits with maturity stage even throughout the volume, otherwise breach of skin with following flesh separation occurs locally.Experimental researches carried out with apricot fruits and cornel have shown that productivity of the process of fruit separation depends of strength features of tissues and rotative speed of blades. Offered way of processing is carried out in non-stop mode and may be realized for all types of stone fruit crops independently on association between flesh and stone.

Postharvest biocontrol ability of killer yeasts against Monilinia fructigena and Monilinia fructicola on stone fruit

The antagonistic effects of Debaryomyces hansenii KI2a, D. hansenii MI1a and Wickerhamomyces anomalus BS91 were tested against Monilinia fructigena and Monilinia fructicola in in vitro and in vivo trials.All yeast strains demonstrated antifungal activity at different levels depending on species, strain and pathogen. D hansenii KI2a and W. anomalus BS91 showed the highest biocontrol activity in vitro; the production of hydrolytic enzymes, killer toxins and volatile organic compounds (VOCs) were hypothesized as their main mechanisms of action against pathogens. D hansenii KI2a and W. anomalus BS91 significantly reduced brown rot incidence and severity on peach and plum fruits artificially inoculated with M. fructigena and M. fructicola, especially when applied 24 h before pathogen inoculation. On the opposite, D. hansenii MI1a exhibited weak antagonistic activity towards M. fructigena on peach and plum fruits and was ineffective against M. fructicola. The noticeable ability of W. anomalus BS91 to control brown rot could be also correlated with its high capacity to colonize the wound tissue and to increase its population density.Accordingly, the antagonistic strains of D. hansenii and W. anomalus could be proposed as active ingredients for the development of biofungicides against Monilinia species that are responsible for considerable economic losses in stone fruit crops.

Fighting Sharka in Peach: Current Limitations and Future Perspectives.

Sharka, caused by Plum Pox Virus (PPV), is by far the most important infectious disease of peach [P. persica (L.) Batsch] and other Prunus species. The progressive spread of the virus in many important growing areas throughout Europe poses serious issues to the economic sustainability of stone fruit crops, peach in particular. The adoption of internationally agreed-upon rules for diagnostic tests, strain-specific monitoring schemes and spatial–temporal modeling of virus spread, are all essential for a more effective sharka containment. The EU regulations on nursery activity should be modified based on the zone delimitation of PPV presence, limiting open-field production of propagation materials only to virus-free areas. Increasing the efficiency of preventive measures should be augmented by the short-term development of resistant cultivars. Putative sources of resistance/tolerance have been recently identified in peach germplasm, although the majority of novel resistant sources to PPV-M have been found in almond. However, the complexity of introgression from related-species imposes the search for alternative strategies. The use of genetic engineering, particularly RNA interference (RNAi)-based approaches, appears as one of the most promising perspectives to introduce a durable resistance to PPV in peach germplasm, notwithstanding the well-known difficulties of in vitro plant regeneration in this species. In this regard, rootstock transformation to induce RNAi-mediated systemic resistance would avoid the transformation of numerous commercial cultivars, and may alleviate consumer resistance to the use of GM plants.

МОРОЗОСТОЙКОСТЬ НОВЫХ ФОРМ ПЕРСИКА В КОЛЛЕКЦИИ НИКИТСКОГО БОТАНИЧЕСКОГО САДА

Peach is a stone fruit crop occupying a considerable area of distribution due to its plasticity. Floral buds are especially sensitive to adverse winter and spring conditions. The developed assortment of peach should satisfy climatic conditions of the south of Russia. The analysis of frost resistance of new peach varieties and forms is presented here. Genotypes with the lowest degree of freezing of generative buds have been obtained: Persimira 99-87, Persimira 29586, ‘Sputnik 1’, ‘Snegurochka’, 13-93 and 18-93.

First exploration of parasitoids of Drosophila suzukii in South Korea as potential classical biological agents

The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), a native of East Asia, has widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the recently colonized regions prompted the first foreign exploration for co-evolved parasitoids in South Korea during 2013 and 2014. We collected the larval parasitoids Asobara japonica Belokobylskij, A. leveri (Nixon) and A. brevicauda Guerrieri & van Achterberg (Hym.: Braconidae), Ganaspis brasiliensis (Ihering), Leptopilina japonica japonica Novkovic & Kimura and L. j. formosana Novkovic & Kimura (Hym.: Figitidae); and the pupal parasitoids Pachycrepoideus vindemiae (Rondani) (Hym.: Pteromalidae) and Trichopria drosophilae Perkins (Hym.: Diapriidae). From UC Berkeley quarantine records, percentage parasitism ranged from 0 to 17.1 % and varied by geography, season, and collection methods. Asobara japonica was the most common parasitoid species. Higher numbers of parasitoids were reared from field-picked fruit as opposed to traps baited with uninfested fruit. Quarantine bioassays confirmed that A. japonica, G. brasiliensis, L. j. japonica, P. vindemiae, and T. drosophilae developed from D. suzukii. Female individuals of the endoparasitoid, A. japonica, were larger when reared on the larger D. suzukii larvae compared with those reared on the smaller larvae of D. melanogaster Meigen. Larger parasitoid size was associated with longer developmental time. Several of the South Korean parasitoid species have the potential for use in classical biological control and may contribute to the suppression of D. suzukii in the newly invaded regions.

Rootstock breeding in Prunus species: Ongoing efforts and new challenges

The current global agricultural challenges imply the need to generate new technologies and farming systems. In this context, rootstocks are an essential component in modern agriculture. Most currently used are those clonally propagated and there are several ongoing efforts to develop this type of plant material. Despite this tendency, lesser number of rootstock breeding programs exists in comparison to the large number of breeding programs for scion cultivars. In the case of rootstocks, traits evaluated in new selection lines are quite different: From the agronomic standpoint vigor is a key issue in order to establish high-density orchards. Other important agronomic traits include compatibility with a wide spectrum of cultivars from different species, good tolerance to root hypoxia, water use efficiency, aptitude to extract or exclude certain soil nutrients, and tolerance to soil or water salinity. Biotic stresses are also important: Resistance/tolerance to pests and diseases, such as nematodes, soil-borne fungi, crown gall, bacterial canker, and several virus, viroids, and phytoplasms. In this sense, the creation of new rootstocks at Centro de Estudios Avanzados en Fruticultura (CEAF) offers an alternative to stone fruit crop, particularly in Chile, where just a few alternatives are commercially available, and there are site-specific problems. The implementation of molecular markers in order to give support to the phenotypic evaluation of plant breeding has great potential assisting the selection of new genotypes of rootstocks. Marker-Assisted Selection (MAS) can shorten the time required to obtain new cultivars and can make the process more cost-effective than selection based exclusively on phenotype, but more basic research is needed to well understood the molecular and physiological mechanisms behind the studied trait.

Genetic relationships and diversity of common apricot (Prunus armeniaca L.) based on simple sequence repeat (SSR) markers

Apricot (Prunus armeniaca L.) is considered as an important species of the stone-fruit crops, and grown in temperate zones. In the current study, the genetic diversity of 37 apricot genotypes was investigated using 13 simple sequence repeat (SSR) markers. Totally, 60 alleles were identified with an average of 4.62 alleles per locus, implying that the studied apricot germplasm presented a high level of genetic diversity. A significant ratio of transferability was measured, and we deduced that the tested markers derived from peach and almond have enough potential to detect polymorphism and differentiation in apricot. The UPGMA and Bayesian clustering analyses outlined the genetic relationships of apricot genotypes tested from different geographical distributions and separated the genotypes into four main clusters. This study will facilitate the understanding of the conservation strategies of the genetic diversity in apricot in Iran.

FIRST RESULTS OF THE EVALUATION OF SIX PRUNUS INTERSPECIFIC ROOTSTOCK SELECTIONS IN COMPARATIVE TRIALS SET UP IN TWO DIFFERENT ENVIRONMENTS

Peach culture is increasingly extended to areas which often do not offer soil conditions truly suited to this crop. Replanting, limestone chlorosis, soilborne pests and pathogens are among the most common problems in many Mediterranean basin countries. In a collaborative project supported by EU (1999-2003), interspecific crosses among different Prunus species originated several hybrid progenies, from which potential new rootstocks for the main stone fruit crops were selected for their resistance to biotic and/or abiotic stresses. Six of these were agronomically evaluated in two rootstock comparative trials set up in two important peach-growing areas located in the North (Romagna, Southern Po Valley) and South of Italy (Metaponto, Basilicata). In both trials, the rootstock selections P.2175 A— P. davidiana-1, P.2175 A— Garnem-3, P2175 A— P. davidiana-4, P2175 A— Garnem-16, P2980 A— Felinem-23 and P2980 A— Garnem-9 were compared with the peach A— almond hybrid GF677, susceptible to root-rot disease and by far the widest spread rootstock in Italy. The trial in Romagna was set up on a replanting soil infected by A. mellea, which had caused the explanting of the previous peach orchard; in addition to GF677, this trial included also GF43 (P. domestica) and Adesoto 101 (P. insititia) as control rootstocks, known as being endowed with some tolerance to this fungal disease. Although evaluation is still in progress, preliminary results showed variability for graft compatibility and induced vigour depending on the rootstock and on the scion cultivar. Total yield/tree was generally higher onto GF667, but some of the hybrid rootstock selections positively affected fruit size and sugar content, yield efficiency and/or significantly anticipated harvest time.

First Report of the Presence of Plum pox virus Rec Strain in France.

Plum pox virus (PPV) is the most detrimental virus in stone fruit crops (Prunus sp.). At least nine monophyletic PPV strains are recognized, three of which, PPV-D, PPV-M, and PPV-Rec, have broad distributions (2). PPV-Rec is characterized by a unique founding recombination event and has been reported mostly from Central and South-Central Europe (2). It is generally considered poorly adapted to peach, and the weak and transient symptoms it causes in the GF305 peach seedling indicator may complicate its biological detection (2). During surveys in the Alsace region of France in spring 2013, a plum orchard with trees (Prunus domestica cv. Quetsche d'Alsace 3066) showing dubious leaf symptoms possibly reminiscent of PPV infection was identified. Testing of material from this plant by ELISA (Bioreba AG, Switzerland) gave clear positive reactions, putting the overall infection rate of the orchard at 6.25%, while a second nearby orchard was found infected at a rate of 0.8%. The presence of PPV was confirmed by polymerase chain reaction (PCR) amplification using either the P1-P2 polyvalent primer pair or the P3M-P4b primer pair, which allows the specific amplification of isolates of the Rec and M strains (1). Sequencing of the 467-nt-long P3M-P4b PCR product (Genbank Accession No. KM035763), which spans the end of the NIb gene and the N-terminal hypervariable end of the coat protein gene, provided clear identification of the PPV isolate as belonging to the Rec strain, since it contained all the PPV-Rec specific mutations in the amplified region and showed 98.7 to 97.7% identity with a range of PPV Rec isolates mostly originating from the Balkans. Identification as a PPV-Rec isolate was also confirmed using a strain-specific reverse-transcription-PCR assay (3). This is, to our knowledge, the first report of the presence of PPV-Rec in France. This finding is worrisome given that PPV-Rec is considered well adapted to plum (2), the most important Prunus crop in Alsace. Further surveillance in Alsace during 2014 failed to provide evidence for the presence of PPV-Rec in other areas of the region away from the initial infection focus, which is currently undergoing eradication efforts.

Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

The European earwig Forficula auricularia L. (Dermaptera: Forficulidae) has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate.

The sexually dimorphic behaviour of adult Drosophila suzukii: elevated female locomotor activity and loss of siesta is a post-mating response.

The polyphagous Drosophila suzukii is a highly invasive species that causes extensive damage to a wide range of berry and stone fruit crops. A better understanding of its biology and especially its behaviour will aid the development of new control strategies. We investigated the locomotor behaviour of D. suzukii in a semi-natural environment resembling a typical summer in northern England and show that adult female D. suzukii are at least 4-fold more active during daylight hours than adult males. This result was reproduced in several laboratory environments and was shown to be a robust feature of mated, but not virgin, female flies. Both males and virgin females kept on a 12 h light:12 h dark (12LD) cycle and constant temperature displayed night-time inactivity (sleep) followed by weak activity in the morning, an afternoon period of quiescence (siesta) and then a prominent evening peak of activity. Both the siesta and the sharp evening peak at lights off were severely reduced in females after mating. Flies of either sex entrained in 12LD displayed a circadian pattern of activity in constant darkness confirming the importance of an endogenous clock in regulating adult activity. This response of females to mating is similar to that elicited in female Drosophila melanogaster by the male sex peptide (SP). We used mass spectrometry to identify a molecular ion (m/z, 5145) corresponding to the poly-hydroxylated SP of D. suzukii and to show that this molecule is transferred to the female reproductive tract during copulation. We propose that the siesta experienced by male and virgin female D. suzukii is an adaptation to avoid unnecessary exposure to the afternoon sun, but that mated females faced with the challenge of obtaining resources for egg production and finding oviposition sites take greater risks, and we suggest that the change in female behaviour is induced by the male SP.

DNA variation and polymorphism in Tunisian plum species (Prunus spp): contribution of flow cytometry and molecular markers.

Plums (Prunus spp) are among the most important stone fruit crops in the world. European (Prunus domestica) and Japanese (Prunus salicina) plums are characterized by different levels of ploidy. Because genetic variability is the prerequisite for any plant-breeding program, we aimed to establish the taxonomic status of Tunisian plums and study their genetic variability. The nuclear DNA content of 45 wild and cultivated Tunisian plums was determined by flow cytometry. Two arbitrary primers (AD10, AD17) were used to elaborate SCAR markers useful to identify plum species. Three wild trees, Zenou 1, Zenou 6, and Zenou 3, which had 2C nuclear DNA contents of 1.99, 2.05, and 2.13 pg, were shown to be hexaploid (2n = 6x = 48), whereas the others were diploid (2n = 2x = 16). These results suggest that the three hexaploid wild plums belong to Prunus insititia, and the others belong to Prunus salicina. No SCAR markers were revealed using the AD10 and AD17 RAPD primers in relation to the ploidy of plums. We note also that AD17 primer appears to be the most informative concerning the genetic diversity. Morphological and pomological traits revealed similarity between introduced and Tunisian plum cultivars. Despite the significant morphological differences found, all the cultivars studied belong to P. salicina. The information obtained in this analysis provided on local plum genetic resources will be helpful to establish a core collection, to evaluate genetic diversity, and to initiate an improvement and selection program.

Xanthomonas arboricola Diseases of Stone Fruit, Almond, and Walnut Trees: Progress Toward Understanding and Management.

Stone fruit (Prunus spp.: apricot, cherry, peach, nectarine, plum, and sloe), almond (Prunus spp.), and walnut (Juglans spp.) crops are among the most economically important tree crops worldwide and are cultivated to a different extent on all continents. The number of countries growing these crops has increased in the last decade with a subsequent increase in acreage globally. Throughout the range of cultivation, Prunus spp. and Juglans spp. are often subjected to pathogen attack. Among them, Xanthomonas arboricola has become markedly important over the last decade. The putative pathovars of X. arboricola, pv. pruni and pv. juglandis, cause bacterial canker and spot and bacterial blight on stone fruits and almond, and on walnut, respectively. In recent years, disease outbreaks caused by X. arboricola on Prunus and on Juglans have increased, as has international concern. The rate at which these outbreaks are occurring suggests the possibility of future epidemics. To address the consequences of such disease emergences, it is important to understand the epidemiology of these diseases, about which little is known to date. The objectives of this review are to provide an overview of X. arboricola diseases of stone fruit, almond, and walnut trees, and to discuss current and future management strategies.

Phototaxis of Grapholitha molesta (Lepidoptera: Olethreutidae) to Different Light Sources.

The Oriental Fruit Moth Grapholita molesta (Busck) causes substantial damage to stone and pome fruit crops worldwide. Light-based traps offer a potential means for pest monitoring and management. In this study, we tested the preference of G. molesta for the following light sources: monochromatic light produced from light-emitting diodes (LEDs) (red, orange, yellow, green, blue, violet, and white), specific wavelengths of light produced from filters (405, 450, 480, 512, 540, 576, and 610 nm), and polychromatic light produced by different numbers (0, 12, 24, and 36) of green, blue, and violet LEDs. The arrangement of polychromatic lights was based on an orthogonal design matrix of L16 (4(3)). Based on the results of former studies, we further determined the optimal number of green and violet LEDs. The results showed that: 1) G. molesta strongly preferred the green, violet, and blue LEDs; 2) G. molesta significantly preferred light at 405 nm, followed by 540 nm, and showed no phototaxis to 480 nm; 3) for the polychromatic light configuration, violet and green were the factors that determined the preference of G. molesta, and the lamp with 12 violet LEDs captured the most moths; and 4) for the lamps with different light intensities, 36 violet LEDs or 12 green LEDs attracted the most moths, with the former performing better.

Aggregation behavior in the European earwig: Response to impregnated shelters

The European earwig Forficula auricularia Linnaeus (Dermaptera: Forficulidae) is a key predator of pests in pip fruit orchards; however, this insect can also cause economic damage in stone fruit crops. Pheromone-impregnated shelters may be useful to promote earwigs in orchards devoted to pip fruit and also to capture them in those used for stone fruit production. By using corrugated cardboard traps in four orchards during two years, we observed the aggregation behavior of European earwig in canopies. Under laboratory conditions, corrugated cardboard shelters impregnated by 0.2 individuals/cm2 over one week attracted earwigs for 5 weeks within a range of 50 cm. Future field work should examine the potential of impregnated shelters to promote earwigs in pip fruit orchards and to remove them from stone fruit ones.