Sucking Insects Research Articles

Symptoms and Prevention Measures of Erysipelas Disease in Pigs

Pig erysipelas is caused by pig erysipelas a kind of acute febrile zoonotic disease, disease quickly, pigs die within 2-4 days, route of infection with endogenous, digestive tract infection, blood sucking insects feeding, skin contact, the disease if not timely control, will threaten the healthy growth of pigs, seriously affect the farmers' actual income. Transmission and spread of erysipelas in pigs. The disease is clinically characterized by high fever and acute death, and is characterized by sow abortion, which can cause infection of pigs and all kinds of animals. After pigs infected with bacteria, various diseases can occur, and then cause pig erysipelas. To the public, the pig industry caused huge economic losses. A comprehensive understanding of erysipelas is important for the prevention and treatment of the disease. The source, route of transmission, prevalence and comprehensive control of the disease are summarized. Pig erysipelas strategy, designed to provide evidence.

Integrated control of white fly (Aleurolobus barodensis) of sugarcane at its grand growth stage: A sustainable approach

White fly and other sucking insect pests are considered the minor pests of sugarcane in Punjab-Pakistan. But in the last few years, the white fly of sugarcane has become a major trouble for the sugarcane growers to handle and for sugar industries to extract proper sugar. A field trial was conducted at the seed farm of Kashmir Sugar Mills (Lat. 30.9370, Long. 72.1105). Treatments were comprised of crysopera eggs cards and insecticide(s). The insecticide(s) was sprayed with tractor mounted Jecto sprayer at the grand growth stage of autumn planted sugarcane (8th-month-old crop). Pre and post-spray population counts of whitefly were recorded. The results were compared with the control with a curved polar bar chart in R using the 'ggplot2' package. It was observed that drenching of chlorantraniloprole @ 250 ml/ha made an excellent control (~88%) and 24.2% over the control treatment. The 2nd most efficient control (86%) (22.7% over control) was recorded in a blend of pyriproxyfen + bifenthrin @ 1250 ml + 1000 ml/ha, respectively than the individual use of said insecticide (61% and 69%, respectively). Very hot and dry weather in the month of May in plains of Punjab Province-Pakistan did not support the Lab. reared crysoperla eggs cards @ 15000/ha in the field. But a large number of natural bio control agents worked well and surpassed some treatments in % mortality of whitefly

Developmental toxicity of a pymetrozine photo-metabolite, 3-pyridinecarboxaldehyde, in zebrafish (Danio rerio) embryos: Abnormal cardiac development and occurrence of heart dysfunction via differential expression of heart formation-related genes

Pymetrozine (PYM) is worldwide used to control sucking insect pests in rice-cultivated fields and it is degraded into various metabolites including 3-pyridinecarboxaldehyde (3-PCA). These two pyridine compounds were used to determine their impacts on aquatic environments, particularly on the aquatic animal model zebrafish (Danio rerio). PYM did not show acute toxicities in terms of lethality, hatching rate, and phenotypic changes in zebrafish embryos in the tested ranges up to a concentration of 20 mg/L. 3-PCA exhibited acute toxicity with LC50 and EC50 values of 10.7 and 2.07 mg/L, respectively. 3-PCA treatment caused phenotypic changes including pericardial edema, yolk sac edema, hyperemia, and curved spine, at a concentration of 10 mg/L after 48 h of exposure. Abnormal cardiac development was observed in 3-PCA-treated zebrafish embryos at a concentration of 5 mg/L with reduced heart function. In a molecular analysis, cacna1c, encoding a voltage-dependent calcium channel, was significantly down-regulated in the 3-PCA-treated embryos, indicating synaptic and behavioral defects. Hyperemia and incomplete intersegmental vessels were observed in 3-PCA-treated embryos. Based on these results, it is necessary to generate scientific information on the acute and chronic toxicity of PYM and its metabolites with regular monitoring of their residues in aquatic environments.

Effects of imidacloprid-induced hormesis on the development and reproduction of the rose-grain aphid Metopolophium dirhodum (Hemiptera: Aphididae).

Field populations of insect pests are affected by sub-lethal doses of insecticides, leading to hormesis. Imidacloprid is a neonicotinoid insecticide widely used to control various sucking insect pests, including aphids. In this study, the effects of sub-lethal concentrations of imidacloprid on the life table traits of the rose-grain aphid Metopolophium dirhodum (Walker) were evaluated on parental and first filial generations. The results showed that sub-lethal concentrations of imidacloprid significantly reduced the fecundity, adult longevity, and reproductive period of M. dirhodum in parental generation (F0). However, the imidacloprid-induced hormetic effects on development and reproduction were detected in the F1 generation. These hormetic effects were indicated by significantly higher adult longevity, fecundity, survival rate, intrinsic and finite rates of increase, and net reproductive rate of first filial generation (F1) of M. dirhodum. Our finding indicated that the application of sub-lethal concentrations of imidacloprid inhibited parental generation (F0), but it significantly stimulated the population growth of filial generation (F1) in the M. dirhodum. The results support the inclusion of insecticides in integrated pest management programs for managing wheat aphids.

Special issue: Relationship between insect vectors and plant pathogens

Special issue: Relationship between insect vectors and plant pathogens

Embryonic toxicity of Imidacloprid: Impact on hatchability, survivability, swimming speed and cardiac function of catfish, Clarias gariepinus

Imidacloprid is a systemic insecticide that belongs to the neonicotinoid class of chemicals that act on the central nervous system of insects. Imidacloprid is used to control sucking insects, chewing insects such as termites, soil insects, and fleas on pets, as well as to treat structures, crops, soil, and seeds. As a result of these factors, this pesticide may end up in the aquatic environment via municipal discharges and runoff. Although the presence of imidacloprid in aquatic environments has been underreported as widespread, the toxic effects of this pesticide may have serious implications on aquatic organisms, particularly at environmentally relevant concentrations and demand more attention. Given this knowledge, the goal of this study was to investigate the effects of imidacloprid on Clarias gariepinus embryonic development. Clarias gariepinus embryos (3 h post-fertilization) were exposed to environmentally relevant concentrations of imidacloprid (10, 30, 100, and 500 µg/L) until 48 h post-fertilization using a modified fish embryo acute toxicity test (OECD TG 236). A stereomicroscope was used to assess hatchability, deformity, heart rate, and swimming speed as endpoints. According to our results of the developmental acute toxicity test, imidacloprid significantly reduced the hatching rate and heartbeats of C. gariepinus embryos. It also influenced the swimming kinematics of exposed embryos and caused teratogenic effects such as yolk sac rupture, pericardial oedema, lordosis, an abnormally shaped head, and altered epiboly. Our results allow us to conclude that imidacloprid is a toxic pesticide in the early life stages of C. gariepinus due to its high teratogenic potential.

ДИНАМИКА СОДЕРЖАНИЯ ГИСТАМИНА В КРОВИ ПОСЛЕ ПРИМЕНЕНИЯ КОМБИНИРОВАННОГО ИНСЕКТОАКАРИЦИДНОГО ПРЕПАРАТА

Pyrethroid preparations are used as insecticides and are recommended for the control of ectoparasites in domestic animals, since they are considered relatively non-toxic, or rather less toxic to vertebrates than to insects. The study of the dynamics of histamine content after the use of pyrethroid insecticidal drugs and the study of the features of the allergenic effect of veterinary drugs remains a little-studied area of veterinary clinical pharmacology and toxicology. Insecticidal-acaricidal preparation Creolin-X for external use in the form of a homogeneous oily liquid, transparent in a thin layer, with the smell of coal oil, from dark brown to black-brown. As an active substance it contains: cypermethrin – 2.5%. Creolin-X is a contact drug active against sarcoptoid, ixodic, demodectic mites, lice, fleas, hair eaters, blood–sucking insects and zoophilic flies. Auxiliary substances: carboniferous creolin without phenolic – up to 100%. The purpose of this study is to study the dynamics of histamine content in the blood of calves and to identify the involvement of histamine in the formation of allergic potential after exposure to Creolin-X. Single spraying of calves with Creolin-X in concentrations of 0.2% and 1% did not cause toxic effects in animals. When studying the histamine content in the blood of calves, a significant decrease or increase in 24, 48, 72 and 96 hours after the use of the drug was not established. A single application of Creolin-X to the skin did not affect the duration of histamine shock in guinea pigs. Creolin-X does not have an allergenic effect when applied to the skin.

Population Dynamics of Sucking Insect Pest and Predator, Chrysoperla carnea in Transgenic Bt Cotton and Non Bt Cotton Varieties

Population Dynamics of Sucking Insect Pest and Predator, Chrysoperla carnea in Transgenic Bt Cotton and Non Bt Cotton Varieties

EFFICACY OF BOTANICAL PLANT EXTRACTS AGAINST LEAF HOPPER (Amrasca spp.) ON OKRA Abelmoschus esculentus CROP

Okra is a vegetable crop belonging to Malvaceae family which is widely cultivated in tropical and subtropical regions around the globe. Many insect pests cause losses in the yield of okra crop, however; the leaf hopper (Amrasca specie) is considered as the most damaging sucking insect pest of okra crop. Jassid can reduce yield up to 50% leading to significant economic losses. A field experiment was conducted at the Faculty of Agricultural Sciences, University of the Punjab Lahore during rabi season 2021-2022. This study was carried to figure out the insecticidal properties of five different plants extracts viz., Botanicals used in the form of extracts, that includes Garlic (Allium sativum L.), Parthenium (Parthenium hysterophorus L.), Turmeric (Curcuma longa L.), Red chilli (capsicum annum L.), and Red chilli + Garlic (capsicum annum + Allium sativum).. The experiment was laid out following RCBD having three replications of each treatment. Each treatment was used at 20% v/v concentration. The data was recorded on the per leaf infestation of jassids after 24, 48, 72, 168, 240 hours of exposure period. Among the trialed botanical extracts, the extracts of Garlic + red chilli extract were found the most effective against leaf hopper while red chilli was found least effective. Among the tested plant products, the extracts of Garlic and Garlic + red chilli extract were found most effective against plant hopper at seven days after treatment and resulted into minimum per leaf population of the tested insect. It is recommended that the extracts of Garlic + red chilli should be used as an effective control measure against the leaf hopper

Different Host Plants Distinctly Influence the Adaptability of Myzus persicae (Hemiptera: Aphididae)

Piercing–sucking insects are prominent phloem-feeding insect pests and understanding their feeding behavior and life characteristics plays a crucial role in studying insect host adaptability. The green peach aphid, Myzus persicae (Hemiptera: Aphididae), is one of the most prominent pests in tobacco-growing areas around the world. This study evaluated the adaptability of M. persicae to five host plants: tobacco, radish, Chinese cabbage, Brassica oleracea, and rape using the electropenetrography, age-stage, two-sex life table and population dynamics. The results demonstrated that the feeding behavior of M. persicae differed significantly according to the target hosts. M. persicae exhibited reduced pathway activities and increased phloem sap ingestion on radish, whereas the opposite was observed on Chinese cabbage. Additionally, the mechanical difficulties of M. persicae mouthparts in the probe pathway phase were significantly lower on tobacco and radish than on other host plants. Life table parameters indicated that for M. persicae reared on radish, preadult duration, longevity, and total preoviposition increased significantly and the fecundity was the highest. Furthermore, the net reproductive rate (R0) increased significantly. The population number of M. persicae on radish after 15 days was significantly higher than that on other hosts, except for tobacco. Although M. persicae can successfully survive on the five plants, our results demonstrated that radish is the optimal host. These results provide significant information for understanding the population dynamics of M. persicae and on different host crops integrated management strategy.

Population dynamics and biorational management of sucking insect vectors on chili (Capsicum annuum L.) in Bangladesh.

To evaluate population fluctuations in relation to weather parameters and biorational management of sucking insect vectors in chili (Capsicum annuum L.), we conducted a study at the experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, in 2020 and 2021. It has been shown in this study that sucking insects (aphids, jassids, whiteflies, and thrips) were active throughout the study period. The highest count of sucking insect vectors (24.67 aphids, 13.72 whitefly, and 56.56 thrips) in Marchand (14.83 jassid) in April was recorded at average temperatures of 34-36°C and 31°C, respectively. There was a positive correlation between pest abundance and temperature, relative humidity, and rainfall for all insects, with the exception of a negative correlation between whiteflies and temperature and rainfall. The results of linear regression models showed that abiotic factors contribute to pest abundance levels, with 100R2 values of 14.9 (thrips), 46.3 (jassids), 7.1 (whiteflies), and 0.67 (aphids); the results were statistically significant for all models in the case of thrips, jassids, and whiteflies, but not significant in the case of aphids. The most effective treatment was spinosad 45SC, a bacterium-derived pesticide recommended for the control of sucking insect vector complexes in chili. The results from the spinosad-treated plot, in terms of insect counts and corresponding mortality rates, were as follows: aphids (3.68), 68.89%; jassids (3.52), 72.01%; whiteflies (3.00), 66.69%; and thrips (3.40), 69.20%. The results of this study will aid in developing predictive models of different control agents against sucking insect vectors in vegetable crops.

Seasonal Incidence of Major Insect Pests of Mungbean

A field experiment conducted during the kharif 2018 evaluated the seasonal incidence of insect pests of mungbean. The results revealed occurrence of major sucking insect pests viz., whitefly Bemisia tabaci (Genn.), leafhopper Empoasca kerri Pruthi, aphid Aphis craccivora Koch from vegetative stage to maturity stage. The lepidopterans viz., tobacco caterpillar Spodoptera litura (F.) and blue butterfly Lampides boeticus L., were observed from reproductive to maturity stage. Maximum incidence of B. tabaci was -at 9.70 nymphs and adults/ cage, E. kerri at 4.97 nymphs and adults/ plant, A. craccivora at 2.17 nymphs and adults/ plant, S. litura at 0.33 larvae/ plant and L. boeticus at 0.37 larvae/ plant and during the 39<sup>th</sup> standard week. Incidence of B. tabaci, A. craccivora, S. litura and L. boeticus showed significant positive correlation with maximum temperature, (r=0.79, 0.76, 0.82 and 0.85, respectively; B. tabaci with rainfall and S. litura with evening relative humidity showed a significant negative correlation (r=-0.76, -0.81, respectively).

Knockdown of TRPV gene Nanchung decreases resistance to the novel pyropene insecticide, afidopyropen, in Bemisia tabaci

Insect TRPV is one subfamily of transient receptor potential (TRP) channels, and it is composed of Inactive (Iav) and Nanchung (Nan), the molecular targets of afidopyropen in several sucking insect pests. In this study, we performed successive selection and synergism tests based on previous work. The resistant afidopyropen strain HD-Afi of Bemisia tabaci reached about 86-fold resistance to afidopyropen, and only part of the resistance resulted from detoxification of cytochrome P450 monooxygenases. Then, we cloned and characterized Nan and Iav from B. tabaci (BtNan and BtIav), and found that they were expressed in all stages of development and tissues of adult, and the expression level of BtNan in strains of HD-S and HD-Afi were significantly increased after afidopyropen treatment. Further, expression of BtNan was downregulated after gene silencing, and it resulted in significantly decreased afidopyropen resistance in the strain of HD-Afi. Our data revealed the first evidence that overexpression of the TRPV Nan gene is responsible for causing afidopyropen resistance in B. tabaci, and our results could provide new visions on the function of TRPVs in the development of resistance to pesticide and supply evidence for developing novel strategies of pest management.

Intercropping impact on population of cotton sucking insect pests

The cotton intercropping experiment was conducted for the management of sucking pests, viz. leafhopper, Amrasca biguttula biguttula Ishida (Hemiptera: Cicadellidae); whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and thrips, Thrips tabaci Linderman (Thysanoptera: Thripidae) in desi cotton, Gossypium arborium. The results of the study revealed that less mean population of leafhopper nymphs, whitefly and thrips adults was recorded from the treatments T7 (2.47, 2.61 and 2.10/leaf, respectively) and T8 (2.49, 2.52 and 2.25/leaf, respectively) where pearl millet (Pennisetum glaucum L.) and sorghum (Sorghum bicolor L.) crops grown as border crops around cotton, respectively. Cotton as sole crop (T9) recorded the highest mean population of leafhopper nymphs, whitefly and thrips adults i.e. 3.54, 3.97, 3.59/leaf, respectively. However, the maximum net returns was recorded in cotton intercropped with sesame 1:1 (T1: 104140 `/ha) whereas minimum net returns was recorded in sole cotton (T9: 80021 `/ha).

Selecting non-linear mixed effect model for growth and development of pecan nut

Pecan is the only commercial tree nut native to the United States. The optimal times for orchard irrigation, pesticide sprays, and harvest are difficult to identify. Growth and development of the nut as a function of heat unit accumulation is a potential tool predicting different nut growth stages. Growth models utilizing heat unit accumulation are useful decision making tools for growers to fine tune inputs. The objective of this research was to compare different non-linear growth models and determine which best fits the growth and development of the pecan nut components i.e., embryo, shell, and shuck. The sampled nuts were collected in two different years (2019 and 2020). In 2019, three varieties of nuts were sampled from five different locations. In 2020, samples of two varieties were collected from one location. Separate models were fitted for (1) the 2019 data to capture the variation among different locations and varieties and (2) the 2019 and 2020 data within one location that also considered the random effect between years for the two cultivars. A comparison of the coefficient of determination (R2) and Akaike information criteria (AIC) among the fitted models, demonstrated the Gompertz model best fit the embryo development for both datasets. It also best described the shuck growth in the 2019 data. The Logistic model performed slightly better than Gompertz for modeling shell growth for both datasets and the shuck for the two-year data. In both years, slow initial growth of fruit was observed until the beginning of the water stage, followed by an increase in size until the gel stage through nut filling in the dough stage. Our findings suggest that irrigation is more crucial during the water stage of pecan, whereas thinning should be done at the late water stage prior to the nut filling stage. Similarly, pesticide use can be minimized by determining when the pecan shell lignifies and is not susceptible to piercing sucking insect mouthparts. These results can guide pecan growers in fine tuning irrigation, thinning, and pest management based on an integrated growth model of the three phenotypic traits, shuck, shell, and embryo, as a function of accumulated heat units.

Systemic whitefly-induced metabolic responses in newly developed distal leaves of husk tomato plants (Physalis philadelphica) impairs whiteflies development.

Metabolic reconfiguration in plants is a hallmark response to insect herbivory that occurs in the attack site and systemically in undamaged tissues. Metabolomic systemic responses can occur rapidly while the herbivore is still present and may persist in newly developed tissue to counterattack future herbivore attacks. This study analyzed the metabolic profile of local and newly developed distal (systemic) leaves of husk tomato (Physalis philadelphica) plants after whitefly Trialeurodes vaporariorum infestation. In addition, the effect of these metabolomic adjustments on whitefly oviposition and development was evaluated. Our results indicate that T.vaporariorum infestation induced significant changes in husk tomato metabolic profiles, not only locally in infested leaves, but also systemically in distal leaves that developed after infestation. The distinctive metabolic profile produced in newly developed leaves affected whitefly nymphal development but did not affect female oviposition, suggesting that changes driven by whitefly herbivory persist in the young leaves that developed after the infestation event to avoid future herbivore attacks. This report contributes to further understanding the plant responses to sucking insects by describing the metabolic reconfiguration in newly developed, undamaged systemic leaf tissues of husk tomato plants after whitefly infestation. © 2022 Society of Chemical Industry.

Integrated Potential of Microbial, Botanical, and Chemical Pesticides for the Control of Viral Disease Vector Whiteflies (Hemiptera: Aleyrodidae) on Tomato under Greenhouse and Field Perspectives

Whiteflies are one of the most devastating horticultural pests attacking tomatoes. Although there are several control methods for the control of whitefly pests, the integrated application of entomopathogenic fungi (IPM) with chemical and botanical insecticides has proven more effective than individual control agents. This study was carried out to evaluate individual and combined treatments of entomopathogens B. bassiana, M. anisopliae, B. thuringiensis, Hunter 40 EC, and neem oil for the control of whitefly species on tomato (Solanum lycopersicum) under greenhouse and field condition. The greenhouse study showed that the different treatments resulted in a 58.48 to 100% reduction of nymphs and a 52.06 to 100% reduction of adults on both Galilea and Melkashola tomato varieties under greenhouse conditions. The combined treatments of AAUMB-29 + Neem oil displayed a higher yield (423.3 g fruits/plant) on the Gelilea tomato variety, and AAUDM-43 + Hunter 40 EC displayed a yield of (376.66 g/plant) on the Melkashola tomato variety. Under field conditions, the application of AAUMB-29 + Hunter 40 EC + Neem oil significantly decreased the whitefly population by 91.93% (P<0.001) after 10 days of the fourth spray. The result of fruit yield of tomato was significantly higher in all treatments (31.17 t to 70.42 t·ha−1) compared to untreated control (25.83 t·ha−1). Among the treatments, AAUMB-29 + Hunter 40 EC + Neem oil gave the highest fruit yield of 70.42 t·ha−1 followed by AAUMB-29 + Hunter 40 EC (64.50 t·ha−1) on the Galilea tomato variety under field conditions. The combined treatment of AAUMB-29 + Hunter 40 EC + Neem oil was the most effective with lower whitefly infestation, higher marketable yields, and less percentage of yield losses. Further investigations are required to determine the optimization and practicability of this integrated application of treatments for the control of both sucking and chewing insect pests under field conditions.

Heterologous expression of cry1Ia12 insecticidal gene in cotton encodes resistance against pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae); an alternate insecticidal gene for insect pest management.

Cotton is continuously exposed to sucking and chewing insect pest pressure since emergence to harvesting. Pink bollworm (Pectinophora gossypiella) has become major chewing insect pest to reduce the cotton yield and results in bad lint quality even in transgenic crops. The efficiency of insecticidal genes has been compromised due to extensive utilization of transgenic crops. The present study was conducted to evaluate the efficacy of an alternate cry1Ia12 insecticidal gene against pink bollworm (PBW) in cotton. Agrobacterium tumefaciens strain LBA4404 harboring pCAMBIA2300 expression vector containing cry1Ia12 gene under the control of 35S CaMV was used to transform a local cotton cultivar GS-01. The various molecular analyses revealed the transgene integration and expression in primary transformants. Among five selected transgenic plants, tcL-08 showed maximum (16.06-fold) mRNA expression of cry1Ia12 gene whereas tcL-03 showed minimum (2.33-fold) expression. Feeding bioassays of 2nd and 3rd instar pink bollworm (PBW) larvae on immature cotton bolls, flowers and cotton squares revealed up to 33.33% mortality on tcL-08 while lowest mortality (13.33%) was observed in tcL-03 and tcL-15. Furthermore, the average weight and size of survived larvae fed on transgenic plants was significantly lesser than the average weight of larvae survived on non-transgenic plants. The present study suggests the cry1Ia12 gene as an alternate insecticidal gene for the resistance management of cotton bollworms, especially PBW.

Field and Cage Studies Show No Effects of Exposure to Flonicamid on Honey Bees at Field-Relevant Concentrations.

Simple SummaryThe effects of pesticides on honey bees are of great concern to beekeepers and the general public. In particular, a class of pesticides called neonicotinoids has been found in some studies to affect bee learning and colony function. A pesticide classified as a neonicotinoid, flonicamid, has been detected in the residue analyses of honey and pollen samples for a published study, and that compound was tested at three concentrations (0, 50, and 250 parts per billion (ppb)) in sugar syrup in a field study with bee colonies and in two cage studies. Colony population levels, hive weight changes, thermoregulation, and CO2 concentrations were measured in the field study, and syrup consumption, thermoregulation, and survivorship by worker bees were measured in the cage studies. No significant treatment effects of the pesticide exposure were observed in either the field or the cage studies. These results support the idea that flonicamid is safe for honey bees at these concentrations. Publishing such results when they occur is important, so people use safe pesticides when they need them.The extent to which insecticides harm non-target beneficial insects is controversial. The effects of long-term exposure on honey bees to sublethal concentrations of flonicamid, a pyridinecarboxamide compound used as a systemic insecticide against sucking insects, were examined in a field study and two cage studies. The field study involved the continuous weight, temperature, and CO2 monitoring of 18 honey bee colonies, 6 of which were exposed over six weeks to 50 ppb flonicamid in sugar syrup, 6 exposed to 250 ppb flonicamid in syrup, and 6 exposed to unadulterated syrup (control). Treatments were derived from concentrations observed in honey samples in a published study. No effects were observed on foraging activity, hive weight gain, thermoregulation, or average CO2 concentrations. However, Varroa mite infestations may have also contributed to experimental variability. The two cage studies, in which cages (200 newly-emerged bees in each) were exposed to the same flonicamid concentrations as the field study and kept in a variable-temperature incubator, likewise did not show any experiment-wide effects on survivorship, thermoregulation, or syrup consumption. These results suggest that field applications of flonicamid that result in concentrations as high as 250 ppb in honey may be largely safe for honey bees.

Insect‐plant‐fungus interactions in mycorrhizal associations, with a focus on spittlebugs and ectomycorrhizal host plants

Abstract Mycorrhizal plants mediate interactions between their root‐associated fungal symbionts and insect herbivores. Arbuscular mycorrhizal (AM) associations tend to boost phloem sap sucking insects and host specialist chewing insects but depress host generalist chewing insects. In turn, insect herbivores have only small negative effects on the abundance of AM fungi. Ectomycorrhizal (EM) associations, less studied, have no consistent effect on phloem sap‐sucking or chewing insects, but their insect herbivores have strong negative effects on EM fungal abundance. Spittlebugs (Hemiptera: Cercopoidea) feed on xylem sap and are disproportionately associated with EM plants, probably because many EM fungi are especially well equipped to access nitrogen (N) from complex soil organic matter. Assimilated N is transported in host plant xylem sap as amino acids, the primary food source for xylem‐feeding insects. Although EM plants account for only 2% of all vascular plants, about 19% of spittlebugs have EM primary hosts. This compares to 9% of hosts that are rhizobial or actinorhizal N‐fixing plants, alternative modes of root‐associated N acquisition that also attract spittlebugs. Notable spittlebug EM host plants include Pinus and Abies (Pinaceae), Quercus, Alnus and Betula (Fagales), Salix (Salicaceae), Eucalyptus (Myrtaceae) and the gymnosperm Gnetum (Gnetales). Some EM plants, including several Pinus species, host spittlebug pests and some play an important role in the ecology of spittlebug vectors of the bacterial plant pathogen Xylella fastidiosa. The fossil record and dated molecular phylogenies suggest that spittlebugs initially evolved in parallel with EM Pinaceae.