Blossom Weevil Research Articles

Development of parasite complexes in the ecosystem of the rose garden of the main Botanical Garden of the Russian Academy of Sciences

The article reports on studies (2011-2022) monitoring harmful organisms in the ecosystem of the rose garden of the Main Botanical Garden of the Russian Academy of Sciences. The studies yielded data on the detection of pathogens and pests, as well as the phenotypic manifestation of pathologies and lesions. A total of 21 species of pathogens and 16 species of phytophages were identified. The species composition of harmful organisms in the ecosystem of the rose garden was defined. It is shown that at the initial stage (2011- 2013) of ecosystem establishment, no external signs of viral diseases were observed, and a low level of fungal infections was noted. The development of such harmful pathogens as Peronospora sparsa Jacz., Sphaerotheca pannosa Lev., Phragmidium disciflorum James, and Ph. tuberculatum Mull. was controlled by culling plants of susceptible varieties. The predominant pathogens included Marssonina rosae (Lib.) Died., Phyllosticta rosae Desm., and Septoria rosae Desm., and the susceptibility of specific varieties to these pathogens was established. The populations of pathogens causing spot anthracnose (Sphaceloma rosarum Pass.), ascochyta leaf spot (Ascochyta rosicola Sacc.), and cercospora leaf spot (Cercospora rosicola Pass.) were slightly less common. A wide range of signs of viral infections was identified. Nine viruses belonging to five genera were detected. The frequency of their occurrence was analyzed, and the most common viruses were identified: Prunus necrotic ring spot ilarvirus, Apple mosaic ilarvirus, Tobacco ring spot nepovirus, and Arabis mosaic nepovirus. The species diversity of phytophages was noted: leaf beetles, snout beetles, leafroller moths, sawflies, blossom weevils, earwigs, moths, leafhoppers, aphids, and true bugs. It was found that damage to plants by a range of pests reached only an average level, except for individual varieties (Red Blanket and Prosperity). In general, the phytosanitary assessment of the rose gene pool of the garden according to the phytosanitary monitoring and integrated detection revealed a wide range of parasite complexes: fourteen types of pathogenic complexes, four types of entomological complexes, and five types of entomopathogenic complexes. The tactical and basic directions for control of harmful organisms in the ecosystem of the rose garden are discussed.

Lepidopteran Pests of Apple Trees on the Territory of the City of Vanadzor

Key Words: Lori region, pomaceae, egg, caterpillar, pupa, imago Lepidopteran pests of apple trees in the Lori region have been documented in specialised literature; however, research on these pests in Vanadzor has not been done, despite the fact that many dangerous insects, including lepidoptera, flooded into private gardens in the city of Vanadzor after extensive clearing of orchards nearby. In this area, private farms suffer substantial damage from caterpillars. Additionally, some pests' caterpillars can induce allergic reactions, some of which can be very dangerous, when they come into contact with people's skin, particularly that of youngsters. The investigation of this matter is the focus of this work. As a result of our research, we identified 14 species of leafrollers of apple trees, which belong to the orders Lepidoptera, Coleoptera, Hemiptera and Homoptera. The greatest damage is caused by Apple ermine (Hypomoneuta malinellus Z.), Gypsy (spongy) moth (Lymantria dispar L.), Lackey moth (Malacosoma neustria L.), Brown-tail moth (Euproctis chrysorrhoea L.), Apple blossom weevil (Anthonomus pomorum L.), Tortrix moths especially Rose tortrix moth (Archips rosana L.), and Large fruit-tree tortrix (Archips podana L.). Entomophages have also been obtained, which belong to the families of Braconidae and the Ichneumonidae.

Morphological and olfactory tree traits influence the susceptibility and suitability of the apple species Malus domestica and M. sylvestris to the florivorous weevil Anthonomus pomorum (Coleoptera: Curculionidae).

The florivorous apple blossom weevil, Anthonomus pomorum (Coleoptera: Curculionidae), is the most economically relevant insect pest of European apple orchards in early spring. Neither efficient monitoring nor ecologically sustainable management of this insect pest has yet been implemented. To identify heritable traits of apple trees that might influence the host selection of A. pomorum, we compared the susceptibility of apple tree species using infestation rates of the domesticated apple, Malus domestica (Rosaceae: Pyreae), and the European crab apple, M. sylvestris. We evaluated the suitability of the two apple species for A. pomorum by quantifying the mass of weevil offspring. Because volatile organic compounds (VOCs) emitted from flower buds of the domesticated apple have previously been suggested to mediate female weevil preference via olfactory cues, we conducted bioassay experiments with blossom buds of both apple species to explore the olfactory preference of adult weevils and, furthermore, identified the headspace VOCs of blossom buds of both apple species through GC-MS analysis. The infestation analysis showed that A. pomorum infested the native European crab apple more prevalently than the domesticated apple, which originated from Central Asia. The European crab apple also appeared to be better suited for weevil larval development than the domesticated apple, as weevils emerging from M. sylvestris had a higher body mass than those emerging from M. domestica. These field observations were supported by olfactory bioassays, which showed that A. pomorum significantly preferred the odor of M. sylvestris buds compared to the odor of M. domestica buds. The analysis of headspace VOCs indicated differences in the blossom bud volatiles separating several M. domestica individuals from M. sylvestris individuals. This knowledge might be employed in further studies to repel A. pomorum from M. domestica blossom buds.

Formation of the yield of oil crops of the Brassicaceae family in the Middle Cis-Urals

The article presents data on the study of the formation of the seed yield of spring oil crops in the conditions of the Middle Cis-Urals. The work is based on the results of a two-factor microfield experiment, where factor A - crops - rape and camelina, factor B - varieties of crops - rape Accord and Podmoskovny, camelina Veles and Yubilyar. The relevance of the study is related to the growing interest in oil crops. The research methodology is generally accepted in agronomy. Camelina was characterized by a faster rate of development, its growing season was 89-109 days, rape - 109-147 days. Morphological and biological features of crops were revealed – a large height of rape plants, their damage by blossom weevil and diamondback moth and the associated lower (50%) survival rate of plants during vegetation; lower seed content (by 44 pcs.) and the formation of smaller seeds (the weight of 1000 seeds was 2.08 g inferior to the same indicator of rape) in camelina. With such a yield structure, camelina had an advantage of 18 g/m2. The crops did not differ in the content of crude protein and fat in the seeds.

Anthonomus rubi on Strawberry Fruit: Its Biology, Ecology, Damage, and Control from an IPM Perspective.

Simple SummaryNew damage on fruit caused by Strawberry Blossom Weevil (SBW) adults has been found in recent years in strawberry fields (soilless system under tunnel) in Trento Province, north-east Italy. According to this new scenario, studies on the biology, ecology, monitoring tools, and potential control methods for SBW were conducted to develop Integrated Pest Management (IPM) strategies. We observed the presence of SBW adults in strawberry fields all year round. In April, the young transplants are promptly visited by SBW adults. The first strawberry severed buds appear immediately after the development of the first flower trusses. Then from May until late October SBW damages the fruit. The mass trapping technique, using the green bucket traps baited with synthetic attractant, showed unsatisfactory results. In contrast, the same attractant combined with yellow or green sticky traps showed good efficacy in capturing adults. The high temperatures provided by the black fabric, the periodic removal of severed buds or adults and the Chlorpyrifos-methyl application constrained pest population build-up effectively. Our observations provide clarification of the new additional feeding habits of SBW and are fundamental in developing IPM strategies.The strawberry blossom weevil (SBW), Anthonomus rubi, is a well-documented pest of strawberry. Recently, in strawberry fields of Trento Province (north-east Italy), new noteworthy damage on fruit linked to SBW adults was observed, combined with a prolonged adult activity until the autumn. In this new scenario, we re-investigated SBW biology, ecology, monitoring tools, and potential control methods to develop Integrated Pest Management (IPM) strategies. Several trials were conducted on strawberry in the laboratory, field and semi-natural habitats. The feeding activity of adult SBW results in small deep holes on berries at different stages, causing yield losses of up to 60%. We observed a prolonged survival of newly emerged adults (>240 days) along with their ability to sever flower buds without laying eggs inside them in the same year (one generation per year). SBW adults were present in the strawberry field year-round, with movement between crop and no crop habitats, underlying a potential role of other host/feeding plants to support its populations. Yellow sticky traps combined with synthetic attractants proved promising for both adult monitoring and mass trapping. Regarding control, adhesive tapes and mass trapping using green bucket pheromone traps gave unsatisfactory results, while the high temperatures provided by the black fabric, the periodic removal of severed buds or adults and Chlorpyrifos-methyl application constrained population build-up. The findings are important for the development of an IPM strategy.

The Eurasian strawberry blossom weevil, Anthonomus rubi (Herbst, 1795), is established in North America

AbstractWe report the strawberry blossom weevil, Anthonomus rubi (Herbst, 1795) (Coleoptera: Curculionidae), a species native to Europe, Asia, and North Africa, as established in British Columbia, Canada. This is the first report of A. rubi in North America. We provide a diagnosis of the species and compare it with other species of the genus Anthonomus Germar in Canada. This species is a pest of plants in Rosaceae Jussieu, including economically important berries such as strawberries (Fragaria Linnaeus) and raspberries (Rubus idaeus Linnaeus), and of native berries of importance to Indigenous peoples in Canada. Female weevils oviposit eggs inside developing flower buds and sever flower stalks, facilitating larval development inside damaged buds and thus reducing fruit yields. Surveys to confirm the presence of A. rubi conducted in 2020 found the weevil to be well established in cultivated and wild hosts throughout the Greater Vancouver area and Fraser Valley, British Columbia. At least one species of parasitoid wasp in the genus Pteromalus Swederus (Hymenoptera: Pteromalidae) has been found in association with A. rubi in the province. Future investigations are required to understand the biology of A. rubi in its new range, assess its impact on berries, and develop management strategies.

Research on the influence of temperature on the strawberry blossom weevil – Anthonomus rubi (Herbst)

Research on the influence of temperature on the strawberry blossom weevil – <i>Anthonomus rubi</i> (Herbst)

Composition of Strawberry Floral Volatiles and their Effects on Behavior of Strawberry Blossom Weevil, Anthonomus rubi

The strawberry blossom weevil (SBW), Anthonomus rubi, is a major pest in strawberry fields throughout Europe. Traps baited with aggregation pheromone are used for pest monitoring. However, a more effective lure is needed. For a number of pests, it has been shown that the attractiveness of a pheromone can be enhanced by host plant volatiles. The goal of this study was to explore floral volatile blends of different strawberry species (Fragaria x ananassa and Fragaria vesca) to identify compounds that might be used to improve the attractiveness of existing lures for SBW. Floral emissions of F. x a. varieties Sonata, Beltran, Korona, and of F. vesca, were collected by both solid-phase microextraction (SPME) and dynamic headspace sampling on Tenax. Analysis by gas chromatography/mass spectrometry showed the floral volatiles of F. x ananassa. and F. vesca were dominated by aromatic compounds and terpenoids, with 4-methoxybenzaldehyde (p-anisaldehyde) and α-muurolene the major compounds produced by the two species, respectively. Multi-dimensional scaling analyses separated the blends of the two species and explained differences between F. vesca genotypes and, to some degree, variation between F. x ananassa varieties In two-choice behavioral tests, SBW preferred odors of flowering strawberry plants to those of non-flowering plants, but weevils did not discriminate between odors from F. x ananassa and F. vesca flowering plants. Adding blends of six synthetic flower volatiles to non-flowering plants of both species increased the preference of SBW for these over the plants alone. When added individually to non-flowering plants, none of the components increased the preference of SBW, indicating a synergistic effect. However, SBW responded to 1,4-dimethoxybenzene, a major component of volatiles from F. viridis, previously found to synergize the attractiveness of the SBW aggregation pheromone in field studies.

Life Tables of the Apple Blossom Weevil Populations (Anthonomus pomorum L.) (Coleoptera, Curculionidae) on Apple and Pear Trees in Urbanized Territories of Moscow and Tver Provinces

K-factor life tables and mortality factors of the apple blossom weevil Anthonomus pomorum (L.) (Coleoptera: Curculionidae) populations on apple and pear trees in three urbanized territories in Moscow and Tver provinces for three subsequent years are presented. The larva was the most affected stage. Among the biotic factors, the larvae and pupae were damaged by entomopathogenic microorganisms (presumably bacteria), the parasitoid wasps Pteromalus varians Spinola (= P. grandis Walker) (Pteromalidae), and predators, mainly thrips and sometimes pirate bugs of the genus Anthocoris. In 2016, the strongest effect of the biotic mortality factors on A. pomorum was observed on apple trees in the natural biocenosis of Dubki Park in Moscow, with the total residual mortality ΣK = 0.163; the weakest effect was observed on pear trees in a garden plot of Agronom horticultural partnership in Kimry District of Tver Province (ΣK = 0.079); the total residual mortality of the pest on apple trees in the test plot of the Laboratory of Plant Protection (Russian State Agrarian University – Moscow Timiryazev Agricultural Academy, Moscow) had an intermediate value of ΣK = 0.097. In 2018, the following mortality factors acting on A. pomorum population in Dubki Park were determined: diseases accounted for 2.8% of mortality (k = 0.012); predators, for 1.2% (k = 0.006); parasitoids, for 0.4% (k = 0.002); unknown factors (other than rains), for 18.5% (k = 0.093). In the test plot of the Laboratory of Plant Protection, the weevil mortality from the same factors was 1.35% (k = 0.006), 0.46% (k = 0.002), 0%, and 8.9% (k = 0.041), respectively. In 2017, rains were the dominant mortality factor for the III instar larvae. According to the life tables of A. pomorum on apple and pear trees in Moscow and Tver provinces, the survival of preimaginal stages sheltered inside the flower buds was very high, reaching 64–92%. An attempt was made to estimate the urbanization pressure using two main parameters derived from the life tables: the total population mortality during preimaginal development and mortality from parasitoids. In the growing season with the climatic conditions close to the long-term average, the effect of the urbanization factor on A. pomorum population could be assessed using the first parameter; however, in the season with abnormal weather conditions such assessment was found to be impractical, due to the varying effect of extraordinary precipitation levels on different weevil populations.

Control of Anthonomus spp. weevils in IPM pome fruit orchards

Since the withdrawal of broad spectrum insecticides like carbamates and organophosphates and the restricted use of neonicotinoids, weevils have become an increasing problem in pome fruit in Belgium. In particular, the apple blossom weevil Anthonomus pomorum and the pear bud weevil Anthonomus pyri (syn. A. cinctus or A. piri), that used to be secondary pests, have developed into important pests for many apple and pear growers, respectively. Recently, also the pear blossom weevil Anthonomus spilotus was found to be present in several pear orchards in Belgium, causing considerable damage. Here we present an overview of recent monitoring data, field and laboratory trials, executed in the Belgian fruit growing area near Sint-Truiden. Laboratory trials on A. pyri indicated a high direct contact activity as well as a high indirect residual contact activity of the neonicotinoid insecticides thiacloprid and acetamiprid, while the anthranilic diamide insecticide cyantraniliprole reached only good control activity after exposure of the A. pyri weevils to spray residue on leaves. In a field trial, application of thiacloprid and cyantraliprole targeting the active A. pyri weevils in autumn also resulted in very high control efficacies, leaving opportunities for a successful combination of those insecticides with biological control by the parasitoid Scambus pomorum. This opens perspectives for control strategies in line with sustainable integrated pest management (IPM) principles.

Monitoring the form of resistance of populations of schools of culture and culture to the insecticide

Goal. To study the toxicity of the modern variety of insecticides from different classes of chemical substances at the level of the mean concentration (СК50, %) of the active substance for the common cereal aphids, cabbage flea, rape blossom weevil, common spider mite. Based on these data to determine the rate of resistance of natural populations of these species of phytophagous arthropods to insecticides.&#x0D; Methodology. The sensitivity of phytophagous arthropods was studied on natural populations collected on crops of winter wheat, canola, soybeans in the Kiev region in 2015—2018. For the poisoning of cereal aphids and mites using the method of immersion of the populated lists wheat and soybeans, and flea beetles and pollen beetle — dip them in a gauze bag for 3 seconds in the appropriate solution of insecticides. Were taken 24 hours after poisoning. Toxicological parameters were calculated by using Proban.&#x0D; Results. Identifies the different sensitivity of the natural arthropod populations to current insecticides. In terms of the mean concentration (СК50, %) of the active substance rapeseed pollen beetle were most sensitive to Configure, while the rest of the drugs is almost the same. Over the years research is more resistant to Decis Profi turned ordinary spider mites. This pest was a higher resistance.&#x0D; Conclusions. The sensitivity of arthropods to insecticides of different chemical classes depends on the characteristics of the pest and the properties of the drug. Indicators of resistance are determined by the biology of the phytophage and terms of use of insecticide. The highest PR was observed for polyvoltine species (aphids, mites). Low levels of resistance to phytophagous pyrethroid insecticides can be explained by two factors: a smaller volume of use or reversion (return of chuvstvitelnosti to the initial level).

Unravelling pest infestation and biological control in low-input orchards: the case of apple blossom weevil

Low-input farming is an alternative production system that provides a great opportunity to disentangle the natural mechanisms regulating crop pests, since neither pests nor their natural enemies are disrupted by pesticides. Here, we use a key apple pest in Europe, the apple blossom weevil (Anthonomus pomorum), as a model case to unravel the factors driving pest infestation and its biological control in a low-input context, namely the cider apple orchards of NW Spain. We applied a holistic approach based on the complete life cycle of the pest and combined large-scale observation (23 orchards) with small-scale experimental assessment. Weevil attack (0.4–37.4% of flowers) increased with the proportion on apple trees in the immediate orchard neighbourhood and with semi-natural woody habitat in the surrounding landscape and decreased with tree distance to orchard edge and apple bloom level. Thus, the prevalence of the pest depended on the availability of the various resources required for foraging, egg-lying and overwintering. Three types of natural enemies supplied complementary pest control by preying on weevils at different stages in their life cycle: seven parasitoid species attacked immature weevils (6.4–81.5%), while the additive effects of birds and crawling arthropods were evident in terms of the removal of adult weevils (31–44%). We conclude that the effective biological control of A. pomorum can be achieved in low-input systems to maintain the pest at non-harmful levels, through combined management of the pest, its habitat and its natural enemies.

Combining plant volatiles and pheromones to catch two insect pests in the same trap: Examples from two berry crops

Most horticultural crops are attacked by more than one insect pest. As broad-spectrum chemical control options are becoming increasingly restricted, there is a need to develop novel control methods. Semiochemical attractants are available for three important horticultural pests, strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), European tarnished plant bug, Lygus rugulipennis Poppius (Hemiptera: Miridae) and raspberry beetle, Byturus tomentosus deGeer (Coleoptera: Byturidae). Traps targeting more than one pest species would be more practical and economical for both monitoring and mass trapping than traps for single-species. In this study we aimed to (1) improve the effectiveness of existing traps for insect pests in strawberry and raspberry crops by increasing catches of each species, and (2) test if attractants for two unrelated pest species could be combined to capture both in the same trap without decreasing the total catches. Field tests were carried out in four European countries and different combinations of semiochemicals were compared. A volatile from strawberry flowers, 1,4 dimethoxybenzene (DMB), increased the attractiveness of the aggregation pheromone to both sexes of A. rubi. The host-plant volatile, phenylacetaldehyde (PAA), increased the attraction of female L. rugulipennis to the sex pheromone, and, in strawberry, there was some evidence that adding DMB increased catches further. Traps baited with the aggregation pheromone of A. rubi, DMB, the sex pheromone of L. rugulipennis and PAA attracted both target species to the same trap with no significant difference in catches compared to those single-species traps. In raspberry, catches in traps baited with a combination of A. rubi aggregation pheromone, DMB and the commercially available lure for B. tomentosus, based on raspberry flower volatiles, were similar to those in single-species traps. In both crops the efficiency of the traps still needs improvement, but the multi-species traps are adequate for monitoring and should not lead to confusion for the user as the target species are easy to distinguish from each other.

Pest categorisation of Anthonomus bisignifer.

The Panel on Plant Health performed a pest categorisation of the strawberry blossom weevil, Anthonomus bisignifer Schenkling, (Coleoptera: Curculionidae), for the EU. Anthonomus bisignifer is a well‐defined and distinguishable species, recognised as an occasional pest of strawberry (Fragaria) fruit production in Japan where it is also feeds on Rubus and Rosa spp. Adults clip developing buds, preventing fruit development and reducing yield. Losses are variable and are likely to depend on the cultivars attacked. Severe damage to Fragaria spp. has been reported but is rare. Flowers of ornamental garden Rosa spp. are more commonly damaged. Anthonomus bisignifer is not known to occur in the EU. A. bisignifer is listed in Annex IIAI of Council Directive 2000/29/EC. Host plants for planting could provide a pathway although only a few non‐EU countries can export Fragaria plants for planting to the EU and A. bisignifer is not known to occur in any of them. However, Rubus and Rosa plants for planting could provide a potential pathway to introduce A. bisignifer. Considering climatic similarities of the region where A. bisignifer occurs and where hosts occur in the EU, A. bisignifer has the potential to establish within the EU. There would be one generation per year, as in Japan. Impacts could be expected on field grown and protected Fragaria, field grown Rubus and garden Rosa spp. There is uncertainty regarding which other hosts exist within Rosaceae, hence impacts could potentially be seen on other species too. Phytosanitary measures are available to reduce the likelihood of introduction of A. bisignifer. All criteria assessed by EFSA for consideration as a potential Union quarantine pest are met. As A. bisignifer is not known to occur in the EU, this criterion assessed by EFSA to consider it as a Union regulated non‐quarantine pest is not met.

Newly introduced strawberry genotypes for Nordic Baltic conditions

Eight recently introduced strawberry genotypes ‘Chambly’, ‘Clery’, ‘Darselect’, ‘Delia’, ‘Harmonie’, ‘Matis’, ‘Sallybright’, ‘Salsa’ and ‘Senga Sengana’ (standard cultivar) were evaluated at the Polli Horticultural Research Centre of the Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences. Phenology, winter hardiness, strawberry blossom weevil (Anthonomus rubi) injury, yield, fruit weight, soluble solids, sugar, acid and ascorbic acid content of the fruit were determined. Genotypes more suited to the Estonian climate conditions are the winter hardy, late-yielding cultivars ‘Salsa’ and ‘Harmonie’. ‘Salsa’ has a good, high quality yield with large attractive fruit. The fruit of ‘Harmonie’ contains much ascorbic acid, but the sugar-acid ratio is less balanced. Early genotypes ‘Chambly’, ‘Clery’, ‘Darselect’, ‘Delia’, ‘Sallybright’ and the late genotype ’Matis’ have a lower yield than the standard cultivar ‘Senga Sengana’.

Crop cultivar affects performance of herbivore enemies and may trigger enhanced pest control by coaction of different parasitoid species

Abstract Pest control by naturally occurring predators and parasitoids is an ecosystem service that may benefit from greater diversity of the pest’s natural enemies. Co-occurrence of different enemy species, which act as service providers, can increase or stabilize pest control. Simultaneous cultivar diversity in varietal mixtures might foster such service providers, and the diverse cultivars might finally profit from occurrence of different natural enemies. Here, we tested how the ecosystem service pest control may be influenced by different crop cultivars and by the action of different parasitoid species. We investigated naturally occurring control of an apple pest, the apple blossom weevil Anthonomus pomorum (Curculionidae), by the parasitoid wasp species Scambus pomorum (Ichneumonidae) and Bracon variator (Braconidae) on five different cultivars (genotypes) of domestic apple Malus domestica in an organic orchard ecosystem. We quantified parasitism of the apple blossom weevil on the apple cultivars at three different times during the pest’s development period. We evaluated whether apple cultivar and pest developmental status lead to comparable or to divergent parasitism patterns by different wasp species. We further assessed size and sex ratio of the wasps to estimate their performance and biocontrol potential on different cultivars. We found that pest parasitism was increased and homogenized across cultivars by coaction of the two wasp species, which belong to the same guild and contributed differently to parasitism – (i) with progressing time and (ii) on the different cultivars. Furthermore, female size differed significantly between cultivars for both wasp species, and it followed the preference-performance hypothesis for S. pomorum, where it was positively related to parasitism. Repeated sampling revealed that only the last sampling (shortly before adult weevil emergence) provides a complete estimate of effective parasitism by both wasp species. In conclusion, intraspecific variation among crop cultivars can result in divergent performance of parasitoids, and it may trigger enhanced pest control through different parasitoid species. The coaction of different species may thus contribute to maximization and stabilization of pest control in heterogeneous cropping systems.

Design and deployment of semiochemical traps for capturing Anthonomus rubi Herbst (Coleoptera: Curculionidae) and Lygus rugulipennis Poppius (Hetereoptera: Miridae) in soft fruit crops

Strawberry blossom weevil (SBW), Anthonomus rubi Herbst (Coleoptera: Curculionidae) and European tarnished plant bug (ETB), Lygus rugulipennis Poppius (Hetereoptera: Miridae), cause significant damage to strawberry and raspberry crops. Using the SBW aggregation pheromone and ETB sex pheromone we optimized and tested a single trap for both species. A series of field experiments in crops and semi-natural habitats in five European countries tested capture of the target pests and the ability to avoid captures of beneficial arthropods. A Unitrap containing a trapping agent of water and detergent and with a cross vane was more efficient at capturing both species compared to traps which incorporated glue as a trapping agent. Adding a green cross vane deterred attraction of non-pest species such as bees, but did not compromise catches of the target pests. The trap caught higher numbers of ETB and SBW if deployed at ground level and although a cross vane was not important for catches of ETB it was needed for significant captures of SBW. The potential for mass trapping SBW and ETB simultaneously in soft fruit crops is discussed including potential improvements to make this more effective and economic to deploy.

Low-drift nozzles vs. standard nozzles for pesticide application in the biological efficacy trials of pesticides in apple pest and disease control

The coarse spray air-induction nozzles have documented pesticide drift reducing potential and hence pose lower risk of environmental pollution than the standard fine spray hollow cone nozzles. However, it is questioned that use of the low-drift nozzles might not provide as effective crop protection as the standard nozzles. The objective of work was to assess the pest and disease control efficacy as affected by spray volume rate and nozzle type. The experiment was carried out in apple orchard, cv Jonagold/M26. The evaluated treatments were combinations of three spray volume rates: 250, 500 and 750lha−1, and two types of nozzles: hollow cone nozzles generating very fine spray, and flat fan air induction nozzles producing coarse droplets. The biological performance of treatments was determined based on severity of diseases: apple scab (Venturia inaequalis), powdery mildew (Podosphaera leucotricha) and bull's eye rot (Pezicula spp.), as well as population or damage caused by pests: green apple aphid (Aphis pomi), rosy apple aphid (Dysaphis plantaginea Pass.), woolly apple aphid (Eriosoma lanigerum), apple rust mite (Aculus schlechtendali) and apple blossom weevil (Anthonomus pomorum L.). In general apple scab was equally controlled by all treatments. Only in the years of high infection pressure efficacy of powdery mildew control was better for fine spray nozzles and high volume rates. Green and rosy apple aphids were better controlled with higher volume rates, though significance of the advantage over the lower rates was occasional. No effect of spray quality on efficacy of aphid and mite control was found for any spray volume rate. Better control of apple blossom weevil and woolly apple aphid was achieved with the high spray volume rate providing heavy coverage to the point of run-off. The air induction nozzles having drift reducing potential are biologically efficacious alternative to conventional hollow cone nozzles.

Differential susceptibility and suitability of domestic and wild apple species for a florivorous weevil and its parasitoids

AbstractCrop plant domestication can change plant resistance to herbivores leading to differences in pest pressure experienced by crop plants and their wild relatives. To compare resistance to herbivores between domesticated and wild fruit trees, we quantified direct resistance and indirect resistance to a pest insect, the florivorous apple blossom weevil Anthonomus pomorum (Coleoptera: Curculionidae), for the cultivated apple Malus domestica and two wild apple species, the European crab apple M. sylvestris and the exotic M. kirghisorum. We measured weevil infestation and performance (weight, sex ratio), and weevil parasitism by parasitoid wasps for different cultivars of M. domestica and for the two wild apple species. To explain weevil and parasitoid responses to different apple species, we quantified tree characteristics including nitrogen content, size of flower buds, bark roughness, tree size, tree phenology and tree position. We found significant differences in susceptibility to weevil infestation between apple species, with lowest infestation (highest apple resistance) in M. domestica and highest infestation in M. kirghisorum. The suitability of apple species also varied significantly: weevils emerging from M. sylvestris were significantly lighter than those from M. kirghisorum. Parasitism of A. pomorum by different parasitoid species was significantly higher in M. sylvestris than in M. domestica. Infestation, weevil weight and parasitism were positively related to tree characteristics: infestation to bud nitrogen content and bark roughness, weevil size to nitrogen content and bud size, and parasitism to tree height and bud density. Our study revealed marked differences between apple species in susceptibility and suitability for the pest herbivore, but also for antagonistic parasitoids. Whereas direct resistance appeared to be higher in cultivated apple, indirect resistance via parasitoids was apparently higher in wild apple trees. Our findings suggest that wild and cultivated apple trees possess different resistance traits that may be combined to optimize resistance in commercial apple cultivars.

Management of insect pests using semiochemical traps

In the absence of effective control measures, the strawberry blossom weevil (Anthonomus rubi) (SBW) and the raspberry beetle (Byturus tomentosus) (RB) cause large (10 - >80%) losses in yield and quality in organically grown raspberry. Attractive lures for both pests were combined into a single multitrap for the economical management of both of these pests at the same time. This is one of the first approaches to pest management of non-lepidopteran insect pests of horticultural crops using semiochemicals in the EU, and probably the first to target multiple species from different insect orders. The aim is to develop optimized lures and cost-effective trap designs for mass trapping and to determine the optimum density and spatial and temporal patterns of deployment of the traps for controlling these pests by mass trapping. The combination between an aggregation pheromone that attracts Anthonomus rubi and a raspberry flower volatile that attracts Byturus tomentosus seems to be the best combination.