The bacterial endosymbiont Wolbachia has been used to control insect pests owing to its ability to manipulate their life history and suppress infectious diseases. Therefore, knowledge on Wolbachia ...dynamics in natural populations is fundamental. The European cherry fruit fly, Rhagoletis cerasi, is infected with the Wolbachia strain wCer2, mainly present in southern and central European populations, and is currently spreading into wCer2-uninfected populations driven by high unidirectional cytoplasmic incompatibility. Here, we describe the distribution of wCer2 along two transition zones where the infection is spreading into wCer2-uninfected R. cerasi populations. Fine-scale sampling of 19 populations in the Czech Republic showed a smooth decrease of wCer2 frequency from south to north within a distance of less than 20 km. Sampling of 12 Hungarian populations, however, showed a sharp decline of wCer2 infection frequency within a few kilometres. We fitted a standard wave equation to our empirical data and estimated a Wolbachia wave speed of 1.9 km yr−1 in the Czech Republic and 1.0 km yr−1 in Hungary. Considering the univoltine life cycle and limited dispersal ability of R. cerasi, our study highlights a rapid Wolbachia spread in natural host populations.
Insect populations appear with a high spatial, temporal and type-specific diversity in orchards. One of the many monitoring tools for pest management is the manual assessment of sticky traps. ...However, this type of assessment is laborious and time-consuming so that only a few locations can be controlled in an orchard. The aim of this study is to test state-of-the art object detection algorithms from deep learning to automatically detect cherry fruit flies (
Rhagoletis cerasi
), a common insect pest in cherry plantations, within images from yellow sticky traps. An image annotation database was built with images taken from yellow sticky traps with more than 1600 annotated cherry fruit flies. For better handling in the computational algorithms, the images were augmented to smaller ones by the known image preparation methods “flipping” and “cropping” before performing the deep learning. Five deep learning image recognition models were tested including Faster Region-based Convolutional Neural Network (R-CNN) with two different methods of pretraining, Single Shot Detector (SSD), RetinaNet, and You Only Look Once version 5 (YOLOv5). R‑CNN and RetinaNet models outperformed other ones with a detection average precision of 0.9. The results indicate that deep learning can act as an integral component of an automated system for high-throughput assessment of pest insects in orchards. Therefore, this can reduce the time for repetitive and laborious trap assessment but also increase the observed amount of sticky traps
The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is a highly destructive pest of cherries (Prunus spp.) (Rosaceae) in Europe and Asia. In 2016, R. cerasi was detected in ...Ontario, Canada, and in 2017 in New York State, USA, the first records of this pest in North America.The initial detections in Canada caused concern for the major cherry-growing states of Michigan, Washington, Oregon, and California in the United States. Establishment of R. cerasi in the United States could restrict cherry exports to other markets and increase costs needed for fly control, but it is unknown if R. cerasi can establish in U.S. commercial cherry regions. Here, we used the CLIMEX ecological niche model to determine the risk of establishment of R. cerasi in the United States and globally. Within the United States under a no-irrigation scenario, R. cerasi would establish in the East and West Coasts; however, under an irrigation scenario, its distribution would expand to the major cherry-growing regions in the interior of central and eastern Washington and in California. Results also showed that if introduced, R. cerasi would likely establish in eastern China, Japan, the Koreas, Australia, New Zealand, South America, South Africa, Mexico, and Canada. Host plant (Prunus spp. and Lonicera spp. Caprifoliaceae) presence, although not included in models, would affect fly establishment. Our results stress the importance of surveying for R. cerasi to prevent its spread and establishment within the United States and other countries.
The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that undergoes obligatory summer–winter diapause at pupal stage in the soil (2–5 cm) beneath host ...trees. To study the effects of photoperiod and relative humidity on diapause termination and post-winter developmental duration of R. cerasi, pupae collected from Dossenheim (Germany) were exposed to different photoperiod or relative humidity regimes during a chilling period ranging from 2 to 8.5 months. Specifically, pupae were exposed to four photoperiod regimes: (a) light conditions (24L:00D), (b) dark conditions (00L:24D), (c) short photoperiod (08L:16D) and (d) long photoperiod (16L:08D), as well as to three relative humidity regimes: (a) low (40% RH), (b) medium (60% RH) and (c) high (70–80% RH). Data revealed that relative humidity is not a significant predictor of diapause termination, but it affects the post-winter developmental period. Higher relative humidity promotes post-winter pupae development. On the other hand, photoperiod significantly affected both diapause termination and post-winter development of R. cerasi pupae. Light conditions (24L:00D) accelerate adult emergence, particularly for females. Regardless of the photoperiod (24L:00D, 00L:24D, 08L:16D), rates of adult emergence were high (>75%) for chilling intervals longer than 6.5 months. Nonetheless, exposure to a long day photoperiod (16L:08D), during chilling, dramatically reduced the proportion of adult emergence following 6 months exposure to chilling. Our findings broaden the understanding of factors regulating diapause responses in European cherry fruit fly, local adaptation and synchronization of adult emergence with the ripening period of major hosts.
The apple maggot fly, Rhagoletis pomonella Walsh (Diptera: Tephritidae), is a serious quarantine pest in the apple-growing regions of central Washington and Oregon. The fly is believed to have been ...introduced into the Pacific Northwest via the transport of larval-infested apples near Portland, Oregon, within the last 40 yr. However, R. pomonella also attacks native black hawthorn, Crataegus douglasii Lindley (Rosales: Rosaceae), and introduced ornamental hawthorn, Crataegus monogyna Jacquin, in the region. It is, therefore, possible that R. pomonella was not introduced but has always been present on black hawthorn. If true, then the fly may have independently shifted from hawthorn onto apple in the Pacific Northwest within the last 40 yr after apples were introduced. Here, we test the introduction hypothesis through a microsatellite genetic survey of 10 R. pomonella sites in Washington and 5 in the eastern United States, as well as a comparison to patterns of genetic variation between populations of Rhagoletis cingulata Loew and Rhagoletis indifferens Curran, two sister species of cherry-infesting flies known to be native to the eastern and western United States, respectively. We report results based on genetic distance networks, patterns of allelic variation, and estimated times of population divergence that are consistent with the introduction hypothesis for R. pomonella. The results have important implications for R. pomonella management, suggesting that black hawthorn-infesting flies near commercial apple-growing regions of central Washington may harbor sufficient variation to utilize apple as an alternate host, urging careful monitoring, and possible removal of hawthorn trees near orchards.
The paper reports application of a Markov-like stochastic process agent-based model and a "virtual farm" concept for enhancement of site-specific Integrated Pest Management. Conceptually, the model ...represents a "bottom-up ethological" approach and emulates behavior of the "primary IPM actors"-large cohorts of individual insects-within seasonally changing mosaics of spatiotemporally complex faming landscape, under the challenge of the local IPM actions. Algorithms of the proprietary PESTonFARM model were adjusted to reflect behavior and ecology of R. cerasi. Model parametrization was based on compiled published information about R. cerasi and the results of auxiliary on-farm experiments. The experiments were conducted on sweet cherry farms located in Austria, Germany, and Belgium. For each farm, a customized model-module was prepared, reflecting its spatiotemporal features. Historical data about pest monitoring, IPM treatments and fruit infestation were used to specify the model assumptions and calibrate it further. Finally, for each of the farms, virtual IPM experiments were simulated and the model-generated results were compared with the results of the real experiments conducted on the same farms. Implications of the findings for broader applicability of the model and the "virtual farm" approach-were discussed.
This study was carried out to determine the preference of tree direction and orchard direction of the Cherry fruit fly,
Rhagoletis cerasi
L. (Diptera: Tephritidae), which harmed growing cherry in ...Erzincan province, Turkey, in 2017–2018. The studies were carried out in 10 orchards, including five orchards in Erzincan Central district and five orchards in Üzümlü district. Samplings were carried out according to Lazarov and Grigorovʼs (1961) method in randomly selected orchards during May through July. A total of 400 fruits were randomly collected and examined from the orchards where the study was carried out, 100 of them from all directions. As a result of the study, it was determined that
R. cerasi
was mostly harmful in the southern direction of the cherry trees and in the northwest direction of the orchards. In addition, it was found that Cherry fruit fly damage was higher south × northwest and east × northwest in tree direction × orchard direction interactions.
This study was carried out to determine the distribution, population development, infestation and damage rate of the Cherry fruit fly,
Rhagoletis cerasi
L. (Diptera: Tephritidae), which harmed the ...growing of cherries and sour cherries in Erzincan province, Turkey, in 2016–2018. The main materials of this study were the adult and preadult periods of
R. cerasi
. Attractive Rebell traps with ammonia salt, insect aspirator, culture cages, etc., were also used. The investigations had four steps: determination of the distribution, population development, flight period, and infestation and damage rate of the cherry fruit fly. Sampling was carried out according to the Lazarov and Grigorov (1961) method in randomly selected orchards. According to the results of the study, it was determined that the pest distributed in the cherry and sour cherry trees in all locations where the study was carried out in the Central and Üzümlü districts of Erzincan. The population development of the Cherry fruit fly was found to be highest in the orchards in the Üzümlü district with coordinates 39.715490° 39.704287° (164 adults) and 39.713162° 39.679763° (158 adults) in 2016, coordinates 39.715490° 39.704287° (24 adults) and 39.713162° 39.679763° (48 adults) in 2017, and coordinates 39.715490° 39.704287° (309 adults) and 39.711130° 39.688508° (376 adults) in 2018; among the orchards in the Central district, population development was highest in Ekmekli (39.750837° 39.354710° 438 adults) and Bahçeliköy (39.751601° 39.361090° 1404 adults) in 2016, Elmaköy (39.790915° 39.357436° 107 adults) and Bahçeliköy (39.751601° 39.361090° 169.5 adults) in 2017, and Elmaköy (39.790915° 39.357436° 1815.5 adults) and Bahçeliköy (39.751601° 39.361090° 918.5 adults) in 2018. The adult flight period was found to be 55–78 days, and the infestation rate of the pest was found to be 83.33% in Erzincan province. In addition, it was determined that the damage rate of the pest was between 52.6% and 54.6% in the Central district of Erzincan and between 26.2% and 31.2% in the Üzümlü district.
Western cherry fruit fly,
Rhagoletis indifferens
Curran (Diptera: Tephritidae), is a pest of cherries (
Prunus
spp.) in western North America that potentially could be managed using the fungus
...Beauveria bassiana
(Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae). Here, the product CX-10282 containing 11.3%
B. bassiana s
train GHA was evaluated as a potential control agent for adult
R. indifferens
by determining whether it can cause 100% fly mortality in the laboratory. Low or high label rates of 5.4 × 10
7
or 1.7 × 10
8
conidia/ml in five different modes of application and application volumes were tested. When one 1-μl drop of CX-10282 containing 1.6 × 10
5
conidia was applied onto a single female fly, 100% mortality was reached by 4 or 7 d. When CX-10282 was sprayed into a container with flies to produce 2.2 × 10
5
to 6.9 × 10
5
conidia/cm
2
and flies left in containers, 76.2–99.5% mortality was reached by 15–21 d. When sprayed flies were moved into clean containers, 74.8% mortality was reached by 25 d. When a 9-cm diam filter paper with 2.8 × 10
7
conidia/cm
2
was exposed to flies inside a container, 100% mortality was reached by 9 d. When flies were exposed to CX-10282 mixed with or without sucrose on filter paper, mortality was 98.2 or 99.7% by 20 d. Dead treatment flies had mycoses rates of 68.8–93.0%. Findings suggest that field studies to evaluate CX-10282 as an organic control product for adult
R. indifferens
are worth pursuing.
Western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), is a major quarantine pest of cherries (Prunus spp.) in western North America that is often managed using the organic ...insecticide spinosad, but there is a question of whether its semisynthetic relative spinetoram is more toxic and better to use for controlling the fly. Here, spinosad and spinetoram effects on R. indifferens kill and oviposition were determined by exposing 3-4, 7-10, or 14-18 d old flies to dry spinosad and spinetoram (0.21 or 0.33 mg active ingredient a.i. per dish) and untreated cherries or to insecticide-treated cherries at 15.6, 22.5, and 29.4°C. Kill was not affected by fly age. Spinetoram killed more female flies by day 1 than spinosad at all temperatures. In both treatments, kill was lower at 15.6°C than 22.5 and 29.4°C, although a difference between 22.5 and 29.4°C was detected more often in spinosad treatments. Both insecticides killed 3-4 d old flies quickly enough to prevent oviposition, but neither prevented oviposition by 7-10 and 14-18 d old flies. Significantly, oviposition by flies exposed to spinosad and spinetoram did not differ at any temperature. Results indicate spinetoram is more toxic to R. indifferens than spinosad. However, this higher toxicity is not needed to prevent oviposition by younger flies. Furthermore, spinetoram residues are not sufficiently toxic to kill older flies quickly enough to reduce oviposition more than spinosad. Taken together, these conclusions imply that spinosad and spinetoram are equal for controlling R. indifferens infestations.
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