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1.
J Insect Physiol ; 157: 104684, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39074715

ABSTRACT

Crickets have been extensively studied in recent insect nutritional research, but it remains largely unexplored how they balance the intake of multiple nutrients. Here, we used the nutritional geometry framework to examine the behavioural and physiological regulation of dietary protein and carbohydrate in nymphs of the two-spotted cricket, Gryllus bimaculatus (Orthoptera: Gryllidae). Growth, intake, utilization efficiencies, and body composition were measured from the eighth instar nymphs that received either food pairs or single foods with differing protein and carbohydrate content. When food choices were available, crickets preferentially selected a carbohydrate-biased protein:carbohydrate (P:C) ratio of 1:1.74. During this nutrient selection, carbohydrate intake was more tightly regulated than protein intake. When confined to nutritionally imbalanced foods, crickets adopted a nutrient balancing strategy that maximized the nutrient intake regardless of the nutrient imbalance, reflecting their omnivorous feeding habit. Intake was significantly reduced when crickets were confined to the most carbohydrate-biased food (P:C = 1:5). When nutrients were ingested in excess of the requirements, the post-ingestive utilization efficiencies of these nutrients were down-regulated, thereby buffering the impacts of nutrient imbalances on body nutrient composition. Crickets reared on the most carbohydrate-biased food (P:C = 1:5) suffered delayed development and reduced growth. Our data provide the most accurate description of nutrient regulation in G. bimaculatus and lay the foundation for further nutritional research in this omnivorous insect.


Subject(s)
Gryllidae , Nymph , Animals , Gryllidae/growth & development , Gryllidae/physiology , Nymph/growth & development , Nymph/physiology , Dietary Carbohydrates/metabolism , Animal Nutritional Physiological Phenomena , Dietary Proteins/metabolism , Feeding Behavior , Nutrients/metabolism , Body Composition
2.
J Insect Physiol ; 157: 104681, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39079656

ABSTRACT

Transgenerational phenotypic modification can alter organismal fitness, population demographics, and community interactions. For ectotherms, both dietary composition and temperature have important effects on organismal fitness, but they are rarely investigated together. Mormon crickets Anabrus simplex are capable of diapausing as eggs in the soil for multiple years with duration largely dependent on cumulative heat units or degree days. Because Mormon crickets can be abundant in the landscape in one year and disappear suddenly the next, I asked: does parental nutrition affect the duration of egg diapause? Beginning in the ultimate nymphal instar, Mormon crickets were fed a diet high in protein, one equal in protein to carbohydrate, or a diet high in carbohydrates and the time for eggs to develop after they were laid was measured. If parental nutrition affects temperature-sensitive egg diapause, then that change in sensitivity to temperature might also alter the relationship between embryonic development rate and temperature. I asked: does parental nutrition affect embryonic development rate as a function of temperature? To this end, I manipulated densities of Mormon cricket nymphs and protein-rich prey (grasshoppers) in field cages, collected eggs from the adult Mormon crickets, and measured the optimal temperature, maximum development rate, and thermal breadth for embryonic development of the offspring. I found that Mormon crickets fed a high protein diet laid eggs with shorter diapause. Consistent with this long-term result, those housed with the most grasshoppers to eat laid eggs that had the fastest maximum development rate, whereas those without grasshoppers laid eggs with slower maximum developmental rates but the broadest thermal breadth. Eggs from Mormon crickets housed with intermediate levels of grasshopper densities had a decline in peak development rate with an increase in density. In addition, Mormon crickets housed with more conspecifics laid eggs with faster development rates, whereas thermal breadth and the temperature optima were not affected by cricket density. As predicted, Mormon cricket diets significantly affected egg diapause and development rates. Contrary to expectations based on observed changes in diet preferences during a Mormon cricket outbreak, Mormon crickets fed high protein diets laid eggs with significantly shorter egg diapause and significantly faster egg development rates. Interestingly, doubling of Mormon cricket density caused eggs to develop in nearly half the time. This latter result indicates that Mormon cricket aggregations promote rapid development of progeny. Moreover, the tight, linear structure of migratory bands in which females intermittently stop to lay eggs assures that the progeny hatch and develop in dense cohorts. In this manner, the banding behavior might carry-over into subsequent generations as long as cohorts are dense and protein is available. With band thinning or protein restriction, females spread their bet-hedging and progeny remain longer as eggs in the soil.


Subject(s)
Orthoptera , Animals , Female , Diapause, Insect/physiology , Dietary Proteins , Nymph/growth & development , Nymph/physiology , Orthoptera/growth & development , Orthoptera/physiology , Ovum/physiology , Ovum/growth & development , Temperature
3.
Insect Biochem Mol Biol ; 172: 104154, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38972513

ABSTRACT

Chagas disease affects around 8 million people globally, with Latin America bearing approximately 10,000 deaths each year. Combatting the disease relies heavily on vector control methods, necessitating the identification of new targets. Within insect genomes, genes harboring small open reading frames (smORFs - < 100 amino acids) present numerous potential candidates. In our investigation, we elucidate the pivotal role of the archetypal smORF-containing gene, mille-pattes/polished-rice/tarsalless (mlpt/pri/tal), in the post-embryonic development of the kissing bug Rhodnius prolixus. Injection of double-stranded RNA targeting mlpt (dsmlpt) during nymphal stages yields a spectrum of phenotypes hindering post-embryonic growth. Notably, fourth or fifth stage nymphs subjected to dsmlpt do not undergo molting. These dsmlpt nymphs display heightened mRNA levels of JHAMT-like and EPOX-like, enzymes putatively involved in the juvenile hormone (JH) pathway, alongside increased expression of the transcription factor Kr-h1, indicating changes in the hormonal control. Histological examination reveals structural alterations in the hindgut and external cuticle of dsmlpt nymphs compared to control (dsGFP) counterparts. Furthermore, significant changes in the vector's digestive physiology were observed, with elevated hemozoin and glucose levels in the posterior midgut of dsmlpt nymphs. Importantly, dsmlpt nymphs exhibit impaired metacyclogenesis of Trypanosoma cruzi, the causative agent of Chagas disease, underscoring the crucial role of proper gut organization in parasite differentiation. Thus, our findings constitute the first evidence of a smORF-containing gene's regulatory influence on vector physiology, parasitic cycle, and disease transmission.


Subject(s)
Insect Proteins , Molting , Nymph , Rhodnius , Animals , Rhodnius/genetics , Rhodnius/physiology , Rhodnius/growth & development , Nymph/growth & development , Nymph/genetics , Nymph/physiology , Molting/genetics , Insect Proteins/genetics , Insect Proteins/metabolism , Juvenile Hormones/metabolism , Open Reading Frames , Digestion
4.
Exp Appl Acarol ; 93(2): 409-420, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38869727

ABSTRACT

The aim of this study was to determine the level of infection of Ixodes ricinus ticks with pathogens (Borrelia spp., Rickettsia spp., and Anaplasma spp.) collected from Lacerta agilis and Zootoca vivipara lizards in the urban areas of Wroclaw (SW Poland). The study was carried out in July-August 2020. Lizards were caught by a noose attached to a pole or by bare hands, identified by species, and examined for the presence of ticks. Each lizard was then released at the site of capture. Ticks were removed with tweezers, identified by species using keys, and molecular tests were performed for the presence of pathogens. From 28 lizards (17 specimens of Z. vivipara and 11 specimens of L. agilis) a total of 445 ticks, including 321 larvae and 124 nymphs, identified as I. ricinus were collected. A larger number of ticks were obtained from L. agilis compared to Z. vivipara. Molecular tests for the presence of pathogens were performed on 445 specimens of I. ricinus. The nested PCR method for the fla gene allowed the detection of Borrelia spp. in 9.4% of ticks, and it was higher in ticks from L. agilis (12.0%) than from Z. vivipara (1.0%). The RFLP method showed the presence of three species, including two belonging to the B. burgdorferi s.l. complex (B. lusitaniae and B. afzelii), and B. miyamotoi. The overall level of infection of Rickettsia spp. was 19.3%, including 27.2% in ticks collected from Z. vivipara and 17.0% from L. agilis. Sequencing of randomly selected samples confirmed the presence of R. helvetica. DNA of Anaplasma spp. was detected only in one pool of larvae collected from L. agilis, and sample sequencing confirmed the presence of (A) phagocytophilum. The research results indicate the important role of lizards as hosts of ticks and their role in maintaining pathogens in the environment including urban agglomeration as evidenced by the first recorded presence of (B) miyamotoi and (A) phagocytophilum in I. ricinus ticks collected from L. agilis. However, confirmation of the role of sand lizards in maintaining (B) miyamotoi and A. phagocytophilum requires more studies and sampling of lizard tissue.


Subject(s)
Anaplasma , Borrelia , Ixodes , Lizards , Rickettsia , Animals , Female , Male , Anaplasma/isolation & purification , Anaplasma/genetics , Borrelia/isolation & purification , Borrelia/genetics , Cities , Ixodes/microbiology , Ixodes/physiology , Larva/microbiology , Larva/physiology , Lizards/parasitology , Lizards/microbiology , Nymph/microbiology , Nymph/physiology , Poland , Rickettsia/genetics , Rickettsia/isolation & purification
5.
J Econ Entomol ; 117(4): 1336-1346, 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-38870416

ABSTRACT

In recent years, a new phenomenon of early olive drop is causing production losses in olive groves throughout northern Italy. To analyze the possible causes, field and laboratory trials were performed to assess the involvement of fungal pathogens and insect pests in this disease. External and internal symptoms of fungal infections or insect-feeding activities were researched. Fungi present in healthy and dislodged olives were investigated. The relationship between olives that fell and Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) infestation was assessed in a controlled infestation trial, and the effectiveness of an insecticidal strategy in reducing early olive drop was tested in open field conditions. A comparable number of fungi, mostly endophytes, were isolated and identified from both healthy and dislodged olives. The damage observed on dislodged olives was primarily ascribed to pentatomids feeding activity. Six stink bugs species were found in olive canopies, that is, the invasive H. halys, which was by far the most abundant, and Acrosternum heegeri Fieber, Nezara viridula (Linnaeus), Palomena prasina (Linnaeus), Piezodorus lituratus (Fabricious), and Rhaphigaster nebulosa (Poda). Halyomorpha halys caused intense fruit drop in the controlled infestation trial, and its infestation level significantly correlated with the number of olives that fell. Native stink bugs, present in much lower population compared to H. halys, could also partially contribute to early drop of olives. Insect proof net significantly reduced the early olive drop disease, while insecticide applications only partially reduced the stink bugs population density and, proportionally, early olive drop.


Subject(s)
Heteroptera , Olea , Animals , Italy , Insecticides , Insect Control , Nymph/growth & development , Nymph/physiology , Hemiptera
6.
Pest Manag Sci ; 80(9): 4628-4636, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38877352

ABSTRACT

BACKGROUND: Understanding how parasitoids respond to temperature is crucial for improving biological control strategies under the context of global warming. This study examined the suitability of Myzus persicae and its parasitoid Aphidius gifuensis to varying temperature conditions, as well as the stage-specific response of A. gifuensis to high temperatures. RESULTS: High temperatures had a significant impact on the both M. persicae and A. gifuensis. When exposed to 36°C, M. persicae developed more slowly and produced smaller adults compared to control, regardless of the duration of exposure (2, 4 or 6 h); additionally, the survival rate of M. persicae nymphs sharply decreased under these conditions. Exposure to 36°C for 4 h negatively impacted the development of A. gifuensis. Female parasitoids exposed to 32°C developed into smaller adults, whereas males exposed to all three temperature levels were smaller compared to control group. Female parasitoids exposed to high temperatures, regardless of the specific heat level and duration, exhibited reduced longevity and decreased fecundity. None of the parasitoids exposed to 36°C for 6 h daily developed into adults. Heat treated during early developmental stages (2 and 4 days old) had a greater influence on parasitoid development, whereas heat treatment at 4 and 6 days old had a more significant impact on its fecundity. CONCLUSION: High temperatures not only directly affected the performance of A. gifuensis, but also exerted indirect effects by influencing the quality of the host aphids M. persicae. The deleterious effects of high temperature on larvae can persist into the adult stage, affecting the longevity and reproduction of adults. These findings are important for the utilization of A. gifuensis in the control of M. persicae in warming environments. © 2024 Society of Chemical Industry.


Subject(s)
Aphids , Hot Temperature , Nymph , Wasps , Animals , Aphids/parasitology , Aphids/growth & development , Aphids/physiology , Female , Wasps/physiology , Wasps/growth & development , Nymph/growth & development , Nymph/parasitology , Nymph/physiology , Male , Longevity , Host-Parasite Interactions , Pest Control, Biological
7.
Exp Appl Acarol ; 93(1): 197-210, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38869725

ABSTRACT

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.


Subject(s)
Hemiptera , Mites , Nymph , Ovum , Pest Control, Biological , Predatory Behavior , Animals , Mites/physiology , Nymph/growth & development , Nymph/physiology , Ovum/physiology , Ovum/growth & development , Hemiptera/physiology , Female , Population Density
8.
J Med Entomol ; 61(4): 1081-1085, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38712431

ABSTRACT

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.


Subject(s)
Amblyomma , Rickettsia , Animals , Amblyomma/physiology , Amblyomma/growth & development , Amblyomma/microbiology , New Jersey/epidemiology , Rickettsia/isolation & purification , Female , Male , Animal Distribution , Nymph/growth & development , Nymph/physiology , Nymph/microbiology
9.
J Med Entomol ; 61(4): 911-918, 2024 07 12.
Article in English | MEDLINE | ID: mdl-38742817

ABSTRACT

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.


Subject(s)
Amblyomma , Animals , North Carolina , Amblyomma/growth & development , Amblyomma/physiology , Nymph/growth & development , Nymph/physiology , Animal Distribution , Female , Larva/growth & development , Larva/physiology , Walking
10.
J Econ Entomol ; 117(4): 1616-1622, 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-38757660

ABSTRACT

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is challenging to control using chemical pesticides owing to its resistance to many insecticides. Thus, there has been an increasing demand for alternative control measures. Thus, this study evaluated the efficacy of a newly designed pest suction machine to manage whiteflies on tomato plants (Solanum lycopersicum L.) (Solanales: Solanaceae) in greenhouses over 2 seasons. The suction machine comprised a battery-powered cart with a mounted suction unit, an ultrasonic device, and green lights. Ultrasonic irradiation provided non-contact vibration, facilitating the movement of adult whiteflies away from the plants, and green lights attracted them to the suction device. This combination effectively captured whitefly adults, even with a weak suction force, saving electricity consumption. The efficacy of suction machine was further evaluated by measuring the number of whitefly adults caught by the machine and the number of adults and nymphs remaining on the tomato leaves. The whitefly population was considerably lower in the treated blocks than in the non-treated blocks in the autumn trial. The machine reduced the density of whitefly adults without using chemical pesticides. Although a lot of optimizations would be required, suction control is an additional and alternative strategy that may be incorporated in the integrated pest management of whiteflies on greenhouse tomato plants.


Subject(s)
Hemiptera , Insect Control , Solanum lycopersicum , Animals , Insect Control/methods , Insect Control/instrumentation , Nymph/growth & development , Nymph/physiology
11.
J Econ Entomol ; 117(4): 1367-1376, 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-38780155

ABSTRACT

Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae) and Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) have been detrimental to cowpea production in many countries. Laboratory experiments were conducted to determine the prey stage preference and functional response of 2 predatory mites species, Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae), and Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), towards 2 thrips species (TS), M. usitatus, and F. intonsa, at varying densities and life stages on cowpea. Results shown that Neoseiulus species had a preference for different life stages of prey. Neoseiulus barkeri consumed more M. usitatus nymphs, while N. californicus consumed more F. intonsa (second-instar nymphs). The functional response of the 2 Neoseiulus spp. to nymphs of 2 TS was Type II on cowpea. The higher attack rate coefficient (a') and shorter handling time (Th) values were found on N. barkeri against M. usitatus, and a similar trend was found for those in N. californicus against F. intonsa. Field-caged trials were conducted to evaluate the effectiveness of Neoseiulus spp. in controlling 2 TS. The results have shown that Neoseiulus spp. was effective in controlling the 2 TS, with varying control efficacies at high or low release rates. The study provided valuable information on using Neoseiulus spp. as biological control agents against M. usitatus and F. intonsa in cowpea crops.


Subject(s)
Mites , Nymph , Pest Control, Biological , Thysanoptera , Vigna , Animals , Mites/physiology , Thysanoptera/physiology , Nymph/growth & development , Nymph/physiology , Predatory Behavior , Larva/growth & development , Larva/physiology
12.
Naturwissenschaften ; 111(3): 28, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695961

ABSTRACT

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.


Subject(s)
Animal Migration , Grasshoppers , Nymph , Animals , Nymph/physiology , Nymph/growth & development , Grasshoppers/physiology , Grasshoppers/growth & development , Animal Migration/physiology , Cold Temperature , Desert Climate
13.
J Insect Sci ; 24(3)2024 May 01.
Article in English | MEDLINE | ID: mdl-38809687

ABSTRACT

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.


Subject(s)
Hemiptera , Nymph , Volatile Organic Compounds , Animals , Nymph/growth & development , Nymph/physiology , Hemiptera/physiology , Female , Wasps/physiology , Electrophysiological Phenomena , Behavior, Animal/drug effects , Arthropod Antennae/physiology , Arthropod Antennae/drug effects
14.
Environ Entomol ; 53(3): 347-353, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38691060

ABSTRACT

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.


Subject(s)
Light , Mantodea , Nymph , Predatory Behavior , Animals , Mantodea/physiology , Nymph/physiology , Nymph/growth & development , Darkness , Circadian Rhythm
15.
Ecotoxicol Environ Saf ; 279: 116491, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38805832

ABSTRACT

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.


Subject(s)
Fertility , Insecticides , Larva , Nymph , Predatory Behavior , ortho-Aminobenzoates , Animals , ortho-Aminobenzoates/toxicity , Larva/drug effects , Insecticides/toxicity , Nymph/drug effects , Nymph/growth & development , Nymph/physiology , Fertility/drug effects , Predatory Behavior/drug effects , Hemiptera/drug effects , Hemiptera/physiology , China , Female , Heteroptera/drug effects , Heteroptera/physiology , Food Chain
16.
J Econ Entomol ; 117(3): 809-816, 2024 06 10.
Article in English | MEDLINE | ID: mdl-38568949

ABSTRACT

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.


Subject(s)
Aphids , Coleoptera , Larva , Pest Control, Biological , Predatory Behavior , Animals , Aphids/physiology , Coleoptera/physiology , Larva/growth & development , Larva/physiology , Cucumis sativus , Female , Male , Food Chain , Nymph/growth & development , Nymph/physiology
17.
Med Vet Entomol ; 38(3): 314-324, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38567802

ABSTRACT

Geographically expanding and invading ticks are a global concern. The Asian longhorned tick (ALT, Haemaphysalis longicornis) was introduced to the mid-Atlantic US between 2010 and 2017 and recently invaded Ohio, an inland state. To date, ALTs in the US have been associated with livestock exsanguination and transmission of the agent of bovine theileriosis. To inform management, studies describing tick ecology and epidemiology of associated disease agents are critical. In this study, we described phenology, habitat and host associations, and tested for agents of medical and veterinary concern at the site of the first known established ALT population in Ohio, where pesticide treatment was applied in early fall 2021. In spring-fall 2022, we sampled wildlife (small mammals) and collected ticks from forest, edge, and grassland habitats. We also opportunistically sampled harvested white-tailed deer at nearby processing stations and fresh wildlife carcasses found near roads. Field-collected ALTs were tested for five agents using real-time PCR. We found that ALT nymphs emerged in June, followed by adults, and concluded with larvae in the fall. ALTs were detected in all habitats but not in wildlife. We also found a 4.88% (2/41) prevalence of Anaplasma phagocytophilum across ALT adults and nymphs. Host and habitat associations were similar to other studies in the eastern United States, but two potential differences in phenology were identified. Whether ALTs will acquire more endemic disease agents requires further investigations. Our findings provide the first evidence regarding ALT life history from the Midwest region of the United States and can inform exposure risk and guide integrated management.


Subject(s)
Deer , Ecosystem , Introduced Species , Ixodidae , Nymph , Animals , Ohio , Ixodidae/physiology , Nymph/growth & development , Nymph/physiology , Tick Infestations/veterinary , Tick Infestations/epidemiology , Tick Infestations/parasitology , Female , Male , Seasons , Larva/growth & development , Larva/physiology
18.
Exp Appl Acarol ; 92(4): 871-883, 2024 May.
Article in English | MEDLINE | ID: mdl-38656472

ABSTRACT

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.


Subject(s)
Animal Migration , Birds , Electron Transport Complex IV , Ixodidae , Phylogeny , Animals , China , Ixodidae/genetics , Ixodidae/classification , Ixodidae/physiology , Electron Transport Complex IV/genetics , Electron Transport Complex IV/analysis , RNA, Ribosomal/genetics , RNA, Ribosomal/analysis , Nymph/growth & development , Nymph/classification , Nymph/genetics , Nymph/physiology , Arthropod Proteins/genetics , Arthropod Proteins/analysis , DNA, Ribosomal Spacer/analysis
19.
Acta Trop ; 255: 107219, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38649106

ABSTRACT

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.


Subject(s)
Insect Vectors , Nymph , Triatoma , Animals , Triatoma/anatomy & histology , Triatoma/growth & development , Triatoma/physiology , Insect Vectors/anatomy & histology , Insect Vectors/physiology , Nymph/anatomy & histology , Nymph/physiology , Nymph/growth & development , Chagas Disease/transmission , Extremities/anatomy & histology
20.
Environ Entomol ; 53(3): 480-486, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38564408

ABSTRACT

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.


Subject(s)
Hemiptera , Nymph , Animals , Hemiptera/growth & development , Hemiptera/physiology , Nymph/growth & development , Nymph/physiology , Herbivory , Longevity , Food Chain , Ailanthus/growth & development
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