Functional responses of two species of predatory mites (Acari: Phytoseiidae) to eggs and first-instar nymphs of Bactericera Gobica Logniova (Homoptera: Psyllidae).

The goji berry psyllid, Bactericera gobica Logniova (Homoptera: Psyllidae), is one of the most important pests on goji berry plants (Lycium barbarum L.), whose fruits are widely used in traditional Chinese medicine and food. However, chemical control is still the predominant control strategy of this pest. Recently, two species of predatory mites, Neoseiulus setarius Ma, Meng & Fan and Neoseiulus barkeri Hughes were found to be associated with B. gobica in China. To assess their predation potential against B. gobica, the functional responses of these two phytoseiid species feeding on different densities (2, 4, 8, 12, 16, 24 and 32 individuals) of B. gobica eggs and 1st instar nymphs were compared at a temperature of 25ºC ± 1º C. Logistic regression analysis revealed that both predatory mite species exhibited type Holling-II functional responses on eggs and 1st instar nymphs of B. gobica, with the predation number increased for both predators as the density of prey increased. Overall, N. setarius consumed more prey compared to N. barkeri across all levels of prey densities. Meanwhile, the highest attack rate (α = 0.0283), the lowest handling time (Th = 1.1324 h prey- 1), and the highest estimated maximum predation rate (T/Th = 21.19 prey day- 1) were all observed for N. setarius fed with 1st instar nymphs of B. gobica. These findings suggest that it is worthy considering utilizing N. setarius and N. barkeri as candidate biocontrol agents of B. gobica, with N. setarius appearing to be a more effective predator than N. barkeri.

Electrophysiological and behavioral responses of Tamarixia radiata (Hymenoptera: Eulophidae) to volatiles of nymphal Diaphorina citri (Hemiptera: Liviidae).

Huanglongbing (HLB), a devastating citrus disease caused by Candidatus Liberibacter asiaticus, is efficiently vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Tamarixia radiata (Waterston) plays a crucial role as an ectoparasitoid, preying on D. citri nymphs. By collecting and identifying headspace volatiles from fifth instar nymphs of D. citri using a gas chromatograph-mass spectrometer (GC-MS), we obtained a collection of 9 volatile compounds. These compounds were subsequently chosen to investigate the electrophysiological and behavioral responses of female T. radiata. At a concentration of 10 µg/µl, 9 compounds were compared with cis-3-hexen-1-ol (control), resulting in trans-2-nonenal inducing the highest relative electroantennogram (EAG) value, followed by hexanal, heptanal, n-heptadecane, tetradecanal, n-tetradecane, n-pentadecane, 1-tetradecanol, and 1-dodecanol. The top 5 EAG responses of female T. radiata to these compounds were further investigated through EAG dose-response experiments. The results showed positive dose-responses as concentrations increased from 0.01 to 10 µg/µl. In Y-tube olfactometer bioassays, female T. radiata exhibited a preference for specific compounds. They were significantly attracted to tetradecanal at a concentration of 10 µg/µl and trans-2-nonenal at 0.01 µg/µl, while no significant attraction was observed toward hexanal, heptanal, or n-heptadecane. Our report is the first to demonstrate that volatiles produced by D. citri nymphs attract T. radiata, which suggests that this parasitoid may utilize nymph volatiles to locate its host.

Diurnal predators in dim light: the ability of mantids to prey for supper.

Many insects rely heavily on visual cues in foraging and other life activities. Mantids are insect predators that usually ambush prey. The sophisticated visual system of mantids allows them to spot, track, and strike at prey with high accuracy. Mantids are categorized as diurnal animals in most cases, while our field observations suggested that they were active in foraging both day and night. Therefore, we hypothesize that predation in dim light is possible for mantids, while mantids are unable to capture prey in complete darkness. In this study, we experimentally examined whether different light conditions could affect the predation success and efficiency of mantid nymphs and adults, Hierodula chinensis Werner (Mantodea: Mantidae), through behavioral observations. Individual mantids were placed in individual chambers in complete darkness, simulated moonlight (0.1 lux), or simulated dusk (50 lux) conditions and were allowed to forage for prey items for 10 min. Our observations showed no evidence that H. chinensis could capture any prey in complete deprivation of light. The proportion of nymphs with successful predation in simulated moonlight was 50% higher than that in complete darkness and 45.83% lower than that in simulated dusk. The proportion of adults with successful predation in simulated moonlight was 42.11% higher than that in complete darkness and 57.89% lower than that in simulated dusk. Overall, the results provide new insights into the behavioral ecology of diurnal predators at night, with potential association with moonlight, starlight, and light pollution.

Effects of chlorantraniliprole on the development, fecundity and prey consumption of a non-specific predator, Rhynocoris fuscipes (Hemiptera: Reduviidae).

Transplant treatment with chlorantraniliprole (CAP) is a proactive approach to protect transplanted plants from pests during early establishment and has been comprehensively applied in tobacco fields in Guangdong Province, China. However, it is not known whether the high dose of CAP in transplant treatments has lethal or sublethal effects on the generalist predator Rhynocoris fuscipes Fabricius (Hemiptera: Reduviidae). To address this concern, the mortalities of R. fuscipes were assessed when 2nd instar larvae of R. fuscipes were in direct contact with or consuming CAP and when their eggs were exposed to CAP. Furthermore, 2nd instar nymphs R. fuscipes were long-term exposed to CAP until they reached adulthood, and their life table parameters were determined. After exposure to CAP, the activity of detoxification enzymes (P450, CaeE and GST) and the functional respond of R. fuscipes to their preys Agrotis ipsilon larvae were determined. In this study, CAP at all concentrations did not significantly increase the mortality of 2nd instar of R. fuscipes nymphs in comparison with the control. The detoxification enzyme (P450, CarE and GST) activities and the number of A. ipsilon larvae consumed by R. fuscipes in the transplant treatment were not affected by CAP after 3-d or long-term exposure. These results indicated that CAP was harmless to R. fuscipes according to IOBC protocols. However, during the treatment of 2nd instar nymphs with a label rate of 15 g AI/ha and a 5× label rate of 75 g AI/ha, CAP significantly prolonged the pre-adult and pre-oviposition periods, and treated adults had lower oviposition. Attention should be given to the time interval between transplant treatment and the release of this biocontrol agent into the field to minimize the impact of CAP on the predator R. fuscipes.

Risk of migration: not all gregarious locust nymphs reach appropriate refuges.

Sedentary animals choose appropriate refuges against predators, while migratory ones may not necessarily do so. In ectotherms, refuge selection is critical during low temperatures, because they cannot actively evade predators. To understand how migratory ectotherms alter their defensive behaviors depending on refuge quality in cold temperatures, we evaluated migratory gregarious desert locust nymphs (Schistocerca gregaria) in the Sahara Desert, where daily thermal constraints occur. We recorded how roosting plant type (bush/shrub) and its height influenced two alternative defense behaviors (dropping/stationary) during cold mornings, in response to an approaching simulated ground predator. Most locusts in bushes dropped within the bush and hid irrespective of their height, whereas those roosting > 2 m height in shrubs remained stationary. These defenses are effective and match with refuge plant types because dynamic locomotion is not required. When nymphs roosted on shrubs < 1.5-m height, which was an unsafe position, nearly half showed both defensive behaviors, indicating that escaping decisions become ambiguous when the refuges are inappropriate. These results suggest that locusts display flexible defensive behaviors when finding appropriate refuges and selecting refuge before daily thermal limitations occur could be critical for migratory ectotherms, which is a risk associated with migration.

The first record of an established population of Amblyomma maculatum (Acari: Ixodidae) in New Jersey, USA.

Amblyomma maculatum Koch, the Gulf Coast tick, is expanding northward from its original range in the southeastern United States. In 2013, its most northern collection was in Delaware. Amblyomma maculatum has since been found in Connecticut, Illinois, and New York. It is the vector of the human pathogen Rickettsia parkeri, the causative agent of R. parkeri rickettsiosis. We report the first finding of an established population of A. maculatum in Salem County, NJ, with a R. parkeri infection prevalence rate of 23.8%. Our finding of A. maculatum is consistent with other recent findings in the northeastern United States in that specimens were found in open areas devoid of tree canopy. This discovery demonstrates the importance of tick surveillance in order to identify expanding tick populations and the pathogens they may transmit.

Don't go chasing waterfalls: the phenology of Amblyomma americanum and increased collection of medically relevant ticks further away from hiking trails in the Piedmont of North Carolina, USA.

Hiking is a popular recreational activity in North Carolina that may expose people to ticks and tick-borne pathogens. However, there is a lack of knowledge on how ticks are distributed on and near trails. Our study tested the hypothesis that ticks are more likely to be encountered when moving further away from trails by measuring differences in relative abundance at various distances. We tested 4 distances (middle of trail, edge of trail, 5 m, 20 m), as well as an on-trail and off-trail grouping. We collected significantly more ticks and ticks were more likely to be collected at our 20 m and 5 m sampling distances rather than directly on or adjacent to trails, and significantly more were collected during off-trail collections than on-trails. When looking only at Amblyomma americanum, post hoc comparisons revealed that significantly more juvenile stages were collected at 5 m and 20 m distances, but not for adults. Our monthly sampling also allowed us to describe the phenology of A. americanum in North Carolina, which is consistent with the phenology of this species in the southeastern United States with adults peaking May-Jun, nymphs Jun-Jul, and larvae in Jul-Aug. These results generally demonstrate the importance of utilizing established trails when hiking to decrease tick-borne disease risk and should be communicated to the public as a recommendation for reducing tick-encounter risk.

Initial study and phylogenetic analysis of hard ticks (Acari: Ixodidae) in Nantong, China along the route of avian migration.

The growing concern about migratory birds potentially spreading ticks due to global warming has become a significant issue. The city of Nantong in this study is situated along the East Asia-Australasian Flyway (EAAF), with numerous wetlands serving as roosting sites for migratory birds. We conducted an investigation of hard ticks and determined the phylogenetic characteristics of tick species in this city. We utilized three different genes for our study: the mitochondrial cytochrome oxidase subunit 1 (COX1) gene, the second internal transcribed spacer (ITS2), and the mitochondrial small subunit rRNA (12 S rRNA) gene. The predominant tick species were Haemaphysalis flava (H. flava) and Haemaphysalis longicornis (H. longicornis). Additionally, specimens of Haemaphysalis campanulata (H. campanulata) and Rhipicephalus sanguineus (R. sanguineus) were collected. The H. flava specimens in this study showed a close genetic relationship with those from inland provinces of China, as well as South Korea and Japan. Furthermore, samples of H. longicornis exhibited a close genetic relationship with those from South Korea, Japan, Australia, and the USA, as well as specific provinces in China. Furthermore, R. sanguineus specimens captured in Nantong showed genetic similarities with specimens from Egypt, Nigeria, and Argentina.

Morphometric study of the legs of the main Chagas vector, Triatoma infestans (Hemiptera: Reduviidae).

In triatomines, vectors of Chagas disease, active dispersal takes place by walking and flying. Flight has received more attention than walking although the last is the dispersal modality used by nymphs due to their lack of wings and also used by adults, which would facilitate the colonization and reinfestation of houses after vector control actions. The present work studied the morphometrical variation of Triatoma infestans legs, the main vector of Chagas disease the Southern Cone of South America. We described morphometric traits and the natural variation of each leg segment. Different linear, size and shape variables of each component of the three right legs of fifth instar nymphs of T. infestans were analyzed using morphometric tools. We analyzed differentiation, variation and correlation for each segment across the fore-, mid and hind legs using different statistical approaches such as general linear model, canonical variates analysis, test of equality of coefficient of variation and partial least square analysis. We also analyzed variation and correlation between segments within each leg with partial least square and morphometric disparity analyses. Our results showed that the segments differed between legs, as general trends, the dimensions (length, width and/or size) were greater in the hind legs, smaller in the forelegs and intermediate in the mid ones. The femur and tibia (length and/or width) showed differences in morphometric variation between legs and the femur and tibia showed the highest levels of correlation between legs. On the other hand, in the fore- and mid legs, the femur (length or width) showed similar variation with tibia and tarsus lengths, but in the hind legs, the femur showed similar variation with all segments and not with the tibia length, and there were strong correlations between linear measurement within each leg. Our results suggest that the femur and tibia could play a determining role in the coordination between the legs that determines the walking pattern. Considering that these segments would also be linked to the specific function that each leg has, this study suggests a preponderant role of the femur and tibia in the walking locomotion of T. infestans.

Coccinellid predation efficiency on Aphis gossypii (Hemiptera: Aphididae) under laboratory conditions.

In this study, we investigated the biological aspects and predation efficiency of 3 aphidophagous ladybird beetles, Coccinella novemnotata, Hippodamia variegata, and Coccinella septempunctata, on the cotton aphid, Aphis gossypii, reared on cucumber plants (Cucumis sativus L. cultivar barracuda) under laboratory conditions. The developmental periods of C. novemnotata, H. variegata, and C. septempunctata were observed to be 16.00 ±â€…0.25, 16.00 ±â€…0.25, and 20.58 ±â€…0.40 days, respectively. The larvae of these ladybird beetles consumed an average of 218.93 ±â€…8.86, 254.77 ±â€…8.86, and 537.36 ±â€…10.49 aphids, respectively. Fourth-instar larvae were particularly efficient, consuming 53.68%, 52.68%, and 52.64% of total aphids for C. novemnotata, H. variegata, and C. septempunctata, respectively. Adult emergence rates were promising, with 91.67%, 100.00%, and 92.86%, accompanied by sex ratios of 63.64%, 53.84%, and 61.54%, respectively. Notably, a single female of C. novemnotata, H. variegata, and C. septempunctata consumed an average of 2,215.30, 2,232.00, and 3,364.50 aphids, respectively, over its lifespan. Coccinella septempunctata demonstrated the highest predation efficiency among the 3 species, suggesting its potential for biological control of A. gossypii in both open fields and greenhouses, promoting sustainable agricultural practices.

Effects of host plants on spotted lanternfly (Hemiptera: Fulgoridae) nymphal survival and development.

Spotted lanternfly, Lycorma delicatula (White), is an invasive planthopper from China, which was first detected in Berks County, PA, in 2014 and has since spread to adjacent states including New Jersey in 2018. Lycorma delicatula is a polyphagous species that gregariously feeds on over 172 known hosts. We investigated development on key host plants Ailanthus altissima (Miller) (Sapindales: Simaroubaceae), Juglans nigra (L.) (Fagales: Juglandaceae), Acer rubrum (L.) (Sapindales: Sapindaceae), and Vitis vinifera (L.) (Vitales: Vitaceae) for each instar to elucidate potential host use throughout the season and target monitoring efforts. Our study indicated significant differences in survivorship and time spent in each nymphal life stage between host plants. We applied a host suitability index as a function of survivorship and development for each host plant and instar, which indicated A. altissima and J. nigra as suitable hosts for all 4 nymphal instars. Vitis vinifera was highly suitable for first and second instars but had low indices for the third and fourth instars, although suitability of V. vinifera may have varied based on variety and age of the vine. Lycorma delicatula nymphs had the lowest survivorship and longest development time on A. rubrum across all 4 life stages, despite this being a preferred oviposition host. Host had a significant effect on the morphometrics we measured within the first and second instars.

Phenology and sampling crawlers of rhodesgrass mealybug (Hemiptera: Pseudococcidae) in Georgia golf course putting greens.

Rhodesgrass mealybug, Antonina graminis Maskell (Hemiptera: Pseudococcidae), is an emerging pest of turfgrass in Georgia golf course putting greens. Because the feeding damage of A. graminis severely affects the aesthetics of the putting surface, it is necessary to understand the phenology of A. graminis on putting greens. To develop management strategies, the temporal emergence of crawlers is determined; however, a sampling tool for A. graminis crawlers on putting greens has not been developed. Thus, the objectives were to determine (i) the phenology of A. graminis and turfgrass quality and (ii) the best trap types for sampling crawlers on the putting greens in Georgia. From 2019 to 2022, 10-20 turfgrass plugs were sampled from the putting greens at biweekly intervals from the spring to fall. The numbers of crawlers, sessile nymphs, and adults of A. graminis were quantified from these plug samples. To determine the best trap types for sampling crawlers, 6 trap types were evaluated on the putting greens in 2021 and 2022. In the spring, the A. graminis densities remained low until June or July, then all stages of A. graminis increased. In the late fall and winter, A. graminis densities declined and remained low. The turfgrass quality improved temporally from April to June but progressively declined from the mid-to-late summer to fall. Significantly greater numbers of crawlers were sampled in the paper-folded sticky card method than in the turfgrass plug method. Thus, sticky traps could be used to sample crawlers for pest management decision.

First use of unmanned aerial vehicles to monitor Halyomorpha halys and recognize it using artificial intelligence.

BACKGROUND: Halyomorpha halys is one of the most damaging invasive agricultural pests in North America and southern Europe. It is commonly monitored using pheromone traps, which are not very effective because few bugs are caught and some escape and/or remain outside the trap on surrounding plants where they feed, increasing the damage. Other monitoring techniques are based on visual sampling, sweep-netting and tree-beating. However, all these methods require several hours of human labor and are difficult to apply to large areas. The aim of this work is to develop an automated monitoring system that integrates image acquisition through the use of drones with H. halys detection through the use of artificial intelligence (AI). RESULTS: The study results allowed the development of an automated flight protocol using a mobile app to capture high-resolution images. The drone caused only low levels of disturbance in both adult and intermediate instars, inducing freezing behavior in adults. Each of the AI models used achieved very good performance, with a detection accuracy of up to 97% and recall of up to 87% for the X-TL model. CONCLUSION: The first application of this novel monitoring system demonstrated the potential of drones and AI to detect and quantify the presence of H. halys. The ability to capture high-altitude, high-resolution images makes this method potentially suitable for use with a range of crops and pests. © 2024 Society of Chemical Industry.

Biological and physiological effects in Bemisia tabaci feeding on tomatoes endophytically colonized by Beauveria bassiana.

BACKGROUND: Entomopathogenic fungi (EPF) treatment of plants may affect the survival and feeding preferences of herbivorous pests. However, comprehensive studies on the fitness across their entire life cycle, feeding behavior, and physiological changes in herbivores consuming EPF-treated plants within the tripartite interactions of EPF, plants, and pests are still limited. In this study, we utilized life tables, electrical penetration graph (EPG), and metabolomics to uncover the biological and physiological characteristics of Bemisia tabaci on tomato plants inoculated with Beauveria bassiana through root irrigation. RESULTS: Our study indicated that Beauveria bassiana Bb252 can penetrate the entire tissue from the point of inoculation, primarily colonizing the intercellular spaces and vascular tissue. However, this colonization is temporary, lasting no more than 35 days. Moreover, the population fitness and feeding behavior of Bemisia tabaci on tomato plants treated with Beauveria bassiana via root irrigation were significantly affected, showing a substantial 41.4% decrease in net reproductive rate (R0), a notable reduction in watery salivation, and shortened phloem ingestion. Lastly, we observed a significant decrease in hormones and amino acids of whiteflies that fed on Beauveria bassiana-treated tomato plants by root irrigation. CONCLUSIONS: Our results indicated that the endophyte, Beauveria bassiana Bb252, reduced demographic fitness of Bemisia tabaci by altering its hormones and amino acids levels. These findings enhance our understanding of multitrophic interactions in integrated pest management. © 2024 Society of Chemical Industry.

Parasitism on domestic cats by Amblyomma auricularium and serological evidence of exposure to Rickettsia amblyommatis.

The domestic cat is not considered a primary host for any specific tick species; however, it can be affected by some Ixodidae species, such as Rhipicephalus sanguineus sensu lato and Amblyomma spp. The study reports parasitism by Amblyomma auricularium and the detection of anti-Rickettsia spp. antibodies in domestic cats from a rural property in the Afrânio municipality, Pernambuco, Brazil. Amblyomma auricularium (24 nymphs, six females, and four males) and Amblyomma sp. (42 larvae) parasitized three cats, and 73 free-living ticks were captured in armadillo burrows: A. auricularium (36 nymphs, six females, five males) and Amblyomma sp. (26 larvae). Blood samples from cats were collected and the obtained plasma were subjected to indirect immunofluorescence assay (IFA) to detect antibodies against Rickettsia antigens. Thus, anti-Rickettsia spp. antibodies were determined (titers ranging from 128 to 512) and showed a predominant antibody response to Rickettsia amblyommatis or a very closely related genotype. This study reports the first infestation of nymphs and adults of A. auricularium on cats in a new area of occurrence in the semi-arid region of Northeastern Brazil and reports for the first time the presence of anti-Ricketsia antibodies in cats in the region, with R. amblyommatis as the probable infectious agent.

Vitellogenin and its upstream gene TOR play essential roles in the reproduction of Dermanyssus gallinae.

In Dermanyssus gallinae, a hematophagous mite, the initiation of vitellogenesis induced by blood feeding is essential for its reproduction. However, the precise gene structures and physiological functions of Vg in D. gallinae and its upstream gene, Target of Rapamycin (TOR), have not been fully understood. This study revealed the presence of four homologous genes within D. gallinae, named Dg-Vg1, Dg-Vg1-like, Dg-Vg2, and Dg-Vg2-like, especially, Dg-Vg2-like was firstly identified in the mites. The expression levels of all these Vg genes were significantly higher in adult females than other stages. Following blood feeding, the expression levels of these genes increased significantly, followed by a subsequent decrease, aligning with egg production. Silencing Dg-Vgs by RNA interference (RNAi) led to decreased fecundity and egg hatching rates, as well as abnormal embryonic development, suggesting a vital role for Dg-Vgs in both egg formation and embryonic development. Furthermore, the knockdown of Dg-TOR significantly reduced the expression of Dg-Vgs and negatively impacted the reproductive capabilities of PRMs, indicating that TOR influences PRM reproduction by regulating the expression of Dg-Vgs. In summary, these findings demonstrated the crucial roles of Dg-Vgs and Dg-TOR in PRM reproduction, highlighting their potential as targets for pest control.

Cascading impacts of overstory structure in managed forests on understory structure, microclimate conditions, and Ixodes scapularis (Acari: Ixodidae) densities.

Forest management practices designed to meet varied landowner objectives affect wildlife habitat and may interrupt the life-cycle stages of disease vectors, including the black-legged tick, Ixodes scapularis Say (Acari: Ixodidae). Ixodes scapularis transmits multiple pathogens including Borrelia burgdorferi, the causative agent of Lyme disease, which is the most common tick-borne disease in the United States. There is evidence that a range of active forest management practices (e.g., invasive plant removal, prescribed burning) can alter tick densities and pathogen transmission. However, few studies have investigated relationships between forest stand structural variables commonly manipulated by timber harvesting and tick ecology. Foresters may harvest timber to create certain forest structural conditions like the mean number of trees, or basal area, per hectare. This study used a spatially replicated experiment in a blocked design to compare forest stands with a range of overstory structures and document variations in the midstory, understory, and forest floor, as well as microclimate conditions within tick off-host habitat. Greater numbers of trees or basal area per hectare correlated with greater canopy closure but less understory cover, stabilized microclimate temperature, higher microclimate humidity, and greater I. scapularis nymph densities. A random forest model identified understory forest structure as the strongest predictor of nymph densities. There was no relationship between the number of trees or basal area per hectare and daily deer (Odocoileus virginianus Zimmermann) activity or nymphal infection prevalence. These findings provide a deeper understanding of tick-habitat associations within a forest stand and have the potential to inform forest management decisions.

Additive intercropping system or acaricides: which one is more efficient to prevent population buildup of two-spotted spider mite?

Habitat manipulation such as intercropping can be used as a simple and common cultural practice in pest management. This method is based on the principle of reducing pest populations by increasing the diversity of an ecosystem. This study has been carried out to evaluate the influence of additive series intercropping common bean with some aromatic plants (AP), and 2 acaricides on the different life stages (egg, immature mobile stages, and adult) of Tetranychus urticae Koch (Trombidiformes: Tetranychidae), over 2 yr of experimentation (2020 and 2021). This experiment was conducted following a randomized complete block design with 7 treatments including common bean monoculture, common bean sprayed by spiromesifen or Dayabon, and common bean + companion plants (coriander, ajwain, basil, or dill). Each treatment was replicated 3 replicates. The lowest and highest number of eggs, immature mobile stages, and adults were observed in common bean + spiromesifen and the common bean monoculture, respectively. Additionally, the common bean + Dayabon supported significantly different T. urticae life stage densities compared to common bean monoculture. Also, among intercropped treatments, common bean + basil showed the lowest number of T. urticae (eggs, immature mobile stages, and adults). The highest yield and land equivalent ratio were recorded in common bean + basil and common bean + spiromesifen, respectively. Finally, it can be concluded that additive intercropping with these AP can effectively decrease the T. urticae population density, which is useful for the safe production of common bean.

Seasonal population fluctuation and life history in different temperatures of Myzus cerasi (Hemiptera: Aphididae) on cherry trees: a field and laboratory study.

This study determined the seasonal population fluctuation of Myzus cerasi (Fabricius) (Hemiptera: Aphididae) in cherry orchards and the effect of different temperatures on the life-history parameters of these aphids under laboratory conditions. Our field results showed that the population fluctuations and densities of M. cerasi on cherry trees were positively affected by the temperature increase between seasons. Also, our laboratory results showed that M. cerasi survived and reproduced at all temperatures tested under laboratory conditions. Female longevity was observed as 19.00 ±â€…2.38, 18.72 ±â€…0.49, and 12.59 ±â€…0.74 days, and fecundity was 10.14 ±â€…2.26, 9.36 ±â€…0.59, and 7.27 ±â€…0.84 offspring/female at 20, 25, and 30 °C, respectively. Although the highest net reproductive rate (R0) was observed numerically at 25 °C (7.80 offspring/female), there was no significant difference compared to 20 °C (7.10 offspring/female). The highest intrinsic rate of increase (r) and the highest finite rate of increase (λ) were calculated at 30 °C (0.15 ±â€…0.01 and 1.16 ±â€…0.01 day-1, respectively), and there was no significant difference compared to 25 °C. The mean generation time (T) of M. cerasi showed a significant difference at all temperatures tested and decreased from 22.59 ±â€…0.33 days at 20 °C to 12.78 ±â€…0.37 days at 30 °C. Consequently, our results revealed that the seasonal population fluctuation and the life history of M. cerasi in the field and laboratory conditions were affected significantly by different temperatures. Our data obtained in the field and the laboratory will contribute to the understanding of M. cerasi biology and to the management of the pest.

Observation of key phenological stages of hemlock woolly adelgid (Hemiptera: Adelgidae): using citizen science as a tool to inform research and management.

Increasing efficiency of data gathering at the landscape scale on the growing number of pests and pathogens threatening forests worldwide has potential to improve management outcomes. Citizen science is expanding, with growing support and utility in environmental and conservation fields. We present a case study showing how citizen science observations can be used to inform research and management of a devastating forest pest. Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), was introduced to eastern North America, leading to decline and mortality of eastern [Tsuga canadensis (L.) Carrière] (Pinales: Pinaceae) and Carolina hemlock (Tsuga caroliniana Engelmann) trees. Management activities, most notably biological control, rely on observations of A. tsugae phenology to inform the timing of releases and monitoring surveys of their highly synchronized specialist predators. In this article, we outline a citizen science program and report phenological observations on A. tsugae. Additionally, we report data comparing A. tsugae estivation break in Virginia (VA) and New York (NY) State, revealing that estivation break is synchronized between NY and VA. This observation is supported by 6 years of citizen scientist observations, showing similar patterns throughout NY, with egg laying shown to be much more variable than estivation break.