Aseptic Research Articles

Analysis of the Effect of The Error Method Demonstration in The Teaching of Basic Nursing Laboratory Operation

Objective: This paper is mainly to deeply study and systematically explore the practical application of the error- demonstrating method in the teaching of basic nursing laboratory operation and the impact and effect it produces. Methods: 80 cases of nursing interns in our school were randomly selected for analysis and research from January 2023 to December 2023, 40 cases of traditional teaching methods were named as the reference group, and 40 cases of demonstration and error methods were named as the seminar group and in-depth analysis and evaluation of the teaching effect of the two groups after the implementation of different teaching modes were carried out. Results: The seminar group achieved remarkable results in terms of teaching effect, and the performance of the interns in this group was significantly better than that of the reference group in terms of medical key skills such as aseptic operation technique, intravenous infusion operation, intramuscular injection operation, and catheterization operation, P < 0.05, which is of research value. Conclusion: After the nursing interns received the teaching intervention of the demonstration of the error method, their experimental operation performance and hands-on ability were significantly improved, and at the same time effectively stimulated their interest in learning, which is worth using.

Life history and overwintering in multi‐ and univoltine species of family Tephritidae in a subtropical region of northwestern Argentina

AbstractAmong phytophagous insects, life history often evolves as a strategy to cope with seasonality in host plant availability. Whereas specialization often leads to dormancy, aestivation, or longevity, polyphagous species bridge between periods of host availability by exploiting alternative host plants. The aim of the present work was to characterize the life histories of four species of specialist and generalist uni‐ and multivoltine frugivorous fruit flies – Ceratitis capitata Wiedemann, Anastrepha fraterculus Wiedemann, Rhagoletis blanchardi Aczel, and Rhagoletotrypeta pastranai Aczel (all Diptera: Tephritidae) – inhabiting in sympatry in Las Yungas phytogeographical province in Tucumán (northwestern Argentina). For this purpose, infested host plant fruits were sequentially collected during two consecutive years, and flies recovered from these fruits were subjected to demographic experiments to establish longevity and overwintering mechanisms. The results indicated that life cycles were tightly related to host fruit availability, where multivoltine species sequentially exploit different host plants over the year, whereas univoltine species must undergo pupal dormancy to reach the next host fructification period and may extend the duration of dormancy when climatic conditions are acyclic and unpredictable. The present study may broaden knowledge about diapausing Tephritidae in subtropical regions and may contribute to an increased conceptual basis for the improvement of pest control strategies, such as the sterile insect technique (SIT).

The Impact of Climatic Factors on Temporal Mosquito Distribution and Population Dynamics in an Area Targeted for Sterile Insect Technique Pilot Trials.

It is widely accepted that climate affects the mosquito life history traits; however, its precise role in determining mosquito distribution and population dynamics is not fully understood. This study aimed to investigate the influence of various climatic factors on the temporal distribution of Anopheles arabiensis populations in Mamfene, South Africa between 2014 and 2019. Time series analysis, wavelet analysis, cross-correlation analysis, and regression model combined with the autoregressive integrated moving average (ARIMA) model were utilized to assess the relationship between climatic factors and An. arabiensis population density. In total 3826 adult An. arabiensis collected was used for the analysis. ARIMA (0, 1, 2) (0, 0, 1)12 models closely described the trends observed in An. arabiensis population density and distribution. The wavelet coherence and time-lagged correlation analysis showed positive correlations between An. arabiensis population density and temperature (r = 0.537 ), humidity (r = 0.495) and rainfall (r = 0.298) whilst wind showed negative correlations (r = -0.466). The regression model showed that temperature (p = 0.00119), rainfall (p = 0.0436), and humidity (p = 0.0441) as significant predictors for forecasting An. arabiensis abundance. The extended ARIMA model (AIC = 102.08) was a better fit for predicting An. arabiensis abundance compared to the basic model. Anopheles arabiensis still remains the predominant malaria vector in the study area and climate variables were found to have varying effects on the distribution and abundance of An. arabiensis. This necessitates other complementary vector control strategies such as the Sterile Insect Technique (SIT) which involves releasing sterile males into the environment to reduce mosquito populations. This requires timely mosquito and climate information to precisely target releases and enhance the effectiveness of the program, consequently reducing the malaria risk.

Consumption of β-Caryophyllene Increases the Mating Success of Bactrocera zonata Males (Diptera: Tephritidae).

The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), is an economically important polyphagous quarantine pest of horticultural crops endemic to South and Southeast Asia. Methyl eugenol (ME), a naturally occurring phenylpropanoid, is a male attractant used to lure and (when mixed with an insecticide) annihilate the males from the wild population, a method of pest control termed the male annihilation technique (MAT). ME is reported to enhance the mating success of sterile males of Bactrocera spp., which is critical for enhancing the effectiveness of the sterile insect technique (SIT). The suppressed response of ME-treated males to ME-baited traps/devices allows the simultaneous application of the MAT and SIT, increasing the efficiency of area-wide integrated pest management (AW-IPM) programs. However, ME treatment in sterile males in SIT facilities is logistically difficult. β-caryophyllene (BCP) is a widely occurring, safer plant compound and is considered suitable for treating males in SIT facilities. Here, we demonstrate that BCP feeding enhanced B. zonata male mating success to the same extent as ME feeding. Feeding on BCP suppressed the male's subsequent attraction to ME-baited traps, but not to the same degree as feeding on ME. The results are discussed and BCP is suggested as an alternative to ME for the concurrent use of the MAT and SIT.

The Impact of Repeated Steam Sterilization Cycles on the Efficacy of Chairside Adjustment Kits for Polishing Monolithic Multi-Layered Zirconia Dental Restoration Material.

BACKGROUND Before insertion, chairside adjustment kits are heat sterilized for positioning and polishing dental restorations. This study aimed to evaluate the effects of 2 steam sterilization cycles on the efficacy of polishing highly translucent monolithic zirconia (HTMLZ) dental restoration material. MATERIAL AND METHODS 100 HTMLZ disc-shaped specimens were adjusted (grinding, finishing, polishing) with EVE Diacera kit. Two steam sterilization techniques [standard (Gp S), immediate/flash (Gp (F)] of CAK were further subgrouped based on number of sterilization cycles [cycle 1 (control), cycle 5, 10, 15, and 20 (experimental)] (n=10 each). Each subgroup accordingly was evaluated for average surface roughness (Ra) and root mean square roughness (Rq) using a profilometer. Mean and standard deviation of 5 subgroups were statistically analyzed using one-way ANOVA/post hoc Tukey's test. Scanning electron microscopy complemented Ra, Rq measurements. Statistical differences of P≤0.05 were considered significant. RESULTS HTMLZ specimens in both groups showed increased (Ra/Rq) values after repeated sterilization of EVE Diacera kit, with Gp F showing lesser increase than Gp S (20 cycles). Gp F at 10 cycles and Gp S at 15 cycles showed clinically unacceptable roughness threshold (0.25 μm). Differences between subgroups for Ra and Rq values were significant (P≤0.05) with less differences within groups observed in early cycles (1, 10). Results validate the manufacturer's recommendations of using flash sterilization/10 cycles for EVE Diacera kit. CONCLUSIONS Repeated sterilization reduces efficacy of chairside adjustment kit to produce smooth surfaces on HTMLZ. This study recommends flash sterilization to a maximum of 10 times to get the clinically acceptable results of Ra and Rq.

MODELING AND ANALYSIS OF OPTIMAL IMPLEMENTATION OF STERILE INSECT TECHNIQUE TO SUPPRESS MOSQUITO POPULATION

Sterile Insect Technique (SIT) is a biological insect (or pest) control tool aiming to reduce or eliminate wild insect (or pest) populations by releasing sterile insects (or pests). In this paper, we propose and study a stage- and sex-structured entomological model describing the dynamics of wild-type mosquito population and observed that the extinction equilibrium of the model is globally asymptotically stable when the basic offspring number is less than unity. However, when the basic offspring number is greater than unity, the extinction equilibrium becomes unstable, followed by the emergence of the stable interior equilibrium. We extend the model by introducing sterile male mosquitoes as a biological control agent against wild-type mosquito species. We have considered the Allee effect in the fertile female mosquito population due to the presence of non-egg-laying females in the mosquito population. While the wild mosquito-free equilibrium of the SIT model is always locally asymptotically stable, there exists either no interior equilibrium or a pair of interior equilibria, among which one is always unstable, and the other is always locally asymptotically stable. We observed that the wild mosquito population of the SIT system goes to extinction, followed by a saddle-node bifurcation when the supply rate of sterile males increases through some critical threshold value. As an alternative to the eradication policy, we formulated an optimal control problem to suppress the wild mosquito population, which suggests increasing the investment in awareness campaigns to suppress the mosquito population.

Verification of AKT and CDK5 Gene and RNA Interference Combined with Irradiation to Mediate Fertility Changes in Plutella xylostella (Linnaeus).

Plutella xylostella (Linnaeus) mainly damages cruciferous crops and causes huge economic losses. Presently, chemical pesticides dominate its control, but prolonged use has led to the development of high resistance. In contrast, the sterile insect technique provides a preventive and control method to avoid the development of resistance. We discovered two genes related to the reproduction of Plutella xylostella and investigated the efficacy of combining irradiation with RNA interference for pest management. The results demonstrate that after injecting PxAKT and PxCDK5, there was a significant decrease of 28.06% and 25.64% in egg production, and a decrease of 19.09% and 15.35% in the hatching rate compared to the control. The ratio of eupyrene sperm bundles to apyrene sperm bundles also decreased. PxAKT and PxCDK5 were identified as pivotal genes influencing male reproductive processes. We established a dose-response relationship for irradiation (0-200 Gy and 200-400 Gy) and derived the irradiation dose equivalent to RNA interference targeting PxAKT and PxCDK5. Combining RNA interference with low-dose irradiation achieved a sub-sterile effect on Plutella xylostella, surpassing either irradiation or RNA interference alone. This study enhances our understanding of the genes associated with the reproduction of Plutella xylostella and proposes a novel approach for pest management by combining irradiation and RNA interference.

Emergency Physician Performed Ultrasound-Guided Abdominal Paracentesis: A Retrospective Analysis.

Emergency physicians commonly perform ultrasound-assisted abdominal paracentesis, using point of care ultrasound (POCUS) to identify ascites and select a site for needle insertion. However, ultrasound-guided paracentesis has the benefit of real-time needle visualization during the entire procedure. Our objective was to characterize the performance of emergency physician-performed ultrasound-guided paracentesis using POCUS, their ability to achieve good in-plane needle visualization, and factors associated with procedural success. A POCUS database was retrospectively reviewed for examinations where abdominal paracentesis was performed by an emergency physician at two academic urban emergency departments over a six-year period. Medical records were reviewed for demographics, presenting history, complications, and hospital course. Descriptive statistics were used to summarize the data. 131 patients were included in the final analysis. The success rate for ultrasound-guided paracentesis was 97.7% (84/86 [95% CI: 92-100%]) compared to 95.6% (43/45 [95% CI: 85-99%]) for ultrasound-assisted paracentesis (p=0.503). 58% (50/86) demonstrated good in-plane needle visualization; 17% (15/86) had partial or out-of-plane visualization; and 24% (21/86) did not demonstrate needle visibility on their saved POCUS images. All four procedural failures were performed by first- or second-year residents using a curvilinear transducer, while all procedures using a linear transducer were successful. The most common complications were ascites leak, infection at the site, and minor bleeding. Emergency physicians with training in real-time needle guidance with ultrasound were able to use POCUS to perform ultrasound-guided paracentesis in the emergency department with a high success rate and no fatal complications. Based on our experience, we recommend performing ultrasound-guided paracentesis using a linear transducer, with attention to identifying vessels near the procedure site and maintaining sterile technique.

Clinical and microbiological profiling of infections in open tibia fractures at Muhimbili Orthopaedic Institute

Background: Fracture-Related Infection (FRI) is a challenging complication after surgical fracture treatment. Consequences include reoperations, increased medical costs, loss of function and even amputation. Objectives: This study aimed to analyze the rate, predictors of infection, clinical-radiological presentation and microbial profiles of open tibia FRI. Methods: Between January 2022 and June 2022, a descriptive cross-sectional observational study was conducted at Muhimbili Orthopaedic Institute (MOI) involving patients aged 18 years and above with surgically managed open tibial shaft fractures in the preceding 12 months. Microbiological culture of three intraoperative tissue and bone specimens were taken by sterile techniques using separate and sterile instruments. Results: There were 190 patients between 18-72 years with a mean age of 35.6 ±10 years. After surgical debridement, all 190 (100%) were managed with either an external fixator or an intramedullary nail. It was found, 49 (25.8%) patients had FRI. A smoking history was identified as a predictor of infection (AOR= 2.21 95% CI 0.84-5.59, P value 0.108). Delayed union was a complication found in 70.3% of patients with infection attending 12th week follow-up and beyond. Almost all (96.5%) intraoperative tissue samples were culture positive, yielding most isolates as polymicrobial (57.9%) and the predominant pathogen identified being Gram-negative bacteria in delayed and late infections. Conclusion: About one-quarter of open tibial shaft fractures are at risk of FRI. The risk is higher among smokers. Intraoperative tissue sampling provides significant cultural yield with predominant gramnegative infection in delayed and late presentation.

Knowledge and Practices of Nurses Regarding Aseptic Techniques for Infection Prevention in Operating Room at Tertiary Care Hospital

Background: Surgical site infections (SSIs) remain a significant concern in operating rooms, largely influenced by the adherence to aseptic techniques by healthcare professionals. Despite the critical role of operating room nurses in preventing these infections, gaps in knowledge and practice persist, affecting the overall quality of patient care in tertiary healthcare settings. Objective: This study aimed to assess the knowledge and practices of operating room nurses regarding aseptic techniques for infection prevention in tertiary care hospitals. Methods: A descriptive cross-sectional study was conducted at a tertiary care hospital in Lahore, involving 130 operating room nurses with over a year of service. The study employed purposive sampling to administer a validated questionnaire assessing demographic data, knowledge, and practices related to aseptic techniques. Data were collected from January to March 2023 and analyzed using SPSS version 25, employing descriptive and inferential statistics to explore the relationship between demographic factors and knowledge/practices of aseptic techniques. Results: The study found that 60% of nurses were aware that a gown is considered sterile in specified areas, and 54.6% understood the contamination risks of dropped sterile packages. Approximately 62.3% recognized the importance of maintaining a safe distance during procedures. Despite these knowledge indicators, 94% of nurses routinely practiced sterile techniques, and 91% adhered to proper handwashing protocols. However, the overall level of knowledge concerning aseptic techniques was low, with significant gaps that could potentially impact patient safety. Conclusion: The study highlights a discrepancy between the knowledge and practices of operating room nurses regarding aseptic techniques, indicating a critical need for enhanced training and continuous education to bridge these gaps and improve infection control measures in surgical settings.

Generalized linear models applied to the analysis of the effectiveness of the Sterile Insect Technique

Aedes aegypti mosquito, popularly known as the dengue mosquito, represents a serious public health problem, because it is the vector responsible for several serious diseases such as Chikungunya fever, Zika virus and Dengue, the latter of which has a higher incidence in the Brazilian population. That mosquito has a high capacity for adaptation in the most diverse types of environments, mainly in places with high population density and lack of basic sanitation, factors that favor its proliferation. The control methods used by the epidemiological surveillance agencies are divided into three modalities: mechanical control, chemical control and biological control. Among the biological control methods, the Sterile Insect Technique (SIT) technique stands out, which consists of introducing sterile males into the mosquito population. This article presents reproduction analyzes of a population of natural mosquitoes compared to a population of mosquitoes with the insertion of males sterilized by ionizing radiation, seeking to observe the impact caused by this control method. The statistical analyzes showed the Negative Binomial regression model presented a better fit to the daily egg count data, when this model was compared to the Poisson model. In addition, the introduction of irradiated males decreases the average oviposition rate by approximately 30%.

PARTIAL MASTECTOMY IN A DAIRY BEETAL GOAT AFFECTED WITH A MAMMARY TUMOR – A CASE REPORT

Mammary tumors are relatively common in dairy goats, negatively impacting production and farmers' economies. Irreversible loss of respective udder reduces milk yield or culling of the animals. In a current case report, A Beetal goat was presented at the UVAS surgery clinic with a udder tumor. After confirmation, a partial mastectomy was performed under general anesthesia and aseptic surgery. The neoplastic growth was resected, and surgery was completed. The overall health status of the animals was improved with an increase in milk yield during post-operative care and a follow-up period of 30 days. The surgical removal of udder tumor could be useful in small ruminants to restore udder health and milk production.

Development and characterization of microsatellite markers for population genetics of the cocoa pod borer Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae).

The cocoa pod borer (CPB) Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae) is one of the major constraints for cocoa production in South East Asia. In addition to cultural and chemical control methods, autocidal control tactics such as the Sterile Insect Technique (SIT) could be an efficient addition to the currently control strategy, however SIT implementation will depend on the population genetics of the targeted pest. The aim of the present work was to search for suitable microsatellite loci in the genome of CPB that is partially sequenced. Twelve microsatellites were initially selected and used to analyze moths collected from Indonesia, Malaysia, and the Philippines. A quality control verification process was carried out and seven microsatellites found to be suitable and efficient to distinguish differences between CPB populations from different locations. The selected microsatellites were also tested against a closely related species, i.e. the lychee fruit borer Conopomorpha sinensis (LFB) from Vietnam and eight loci were found to be suitable. The availability of these novel microsatellite loci will provide useful tools for the analysis of the population genetics and gene flow of these pests, to select suitable CPB strains to implement the SIT.

Impact of different sterilisation techniques on sorption and NER formation of test chemicals in soil

Standard OECD tests are used to generate data on biodegradation (OECD 307) and sorption (OECD 106) of test chemicals in soil. In such tests, data on abiotic degradation using sterile samples are utilised to investigate any losses due to abiotic processes. The data from sterile samples are also used to interpret results and findings of non-sterile samples, especially in the context of sorption and non-extractable residue (NER) formation. However, to ensure the comparability of the data obtained from sterile and non-sterile experiments, effects of sterilisation on the soil matrix should be minimal. The objective of this study was to investigate the efficiencies of different sterilisation techniques and the impact of the sterilisation on sorption and NER formation in soil. In this study, experiments in accordance with OECD 307 and OECD 106 guidelines were performed with two soils covering wide range of soil characteristics and treated with the three sterilisation techniques autoclaving, gamma(γ)-radiation and adding 1% (w/w) sodium azide. As a test item, 14C-labelled phenanthrene and bromoxynil was used for OECD 307 test, whereas non-labelled phenanthrene and atrazine was used for OECD 106. The sterilisation efficiencies were investigated using traditional viable plate count and molecular approaches (RNA extraction method). The results suggest that none of the tested techniques resulted in completely sterilised soil with autoclaving being the most efficient technique. Adding sodium azide led to most inefficient sterilisation and a significant increase (0.56 units) in soil pH. OECD 307 results showed differences in NER formation of the test chemicals, especially for soil poisoning and γ-radiation, which could be due to inefficient sterilisation and/or change in soil physico-chemical properties. OECD 106 results suggest that none of the sterilisation techniques considerably affected sorption behaviour of the test chemicals. Based on our results, we recommend autoclaving as most suitable sterilisation technique.

Unexpected positive culture (UPC) in adults revision spine surgery: a systematic review and meta-analysis of incidence, risk factors, and management.

Without clear signs of infection, spinal implant failure is attributed to mechanical overloads and aseptic loosening. However, how low-grade infections contribute to seemingly aseptic implant failure is unclear. The systematic review examined unexpected positive cultures (UPCs) in revision spine surgery regarding prevalence, isolated pathogens, risk factors, and strategies to reduce infection among asymptomatic patients undergoing revision spine surgery. We followed the PRISMA guidelines and searched four main databases (PubMed, EMBASE, SCOPUS, Web of Science) comprehensively until January 2023 for articles reporting UPC after presumed aseptic adult revision spine surgery. The UPC rates were pooled, and risk factors were compared with the culture-negative control group and represented as odds ratio (OR) or mean difference (MD). Fifteen studies of 1057 individuals were included in two groups: culture-positive or UPCs (n = 317) and culture-negative or control (n = 740). The overall UPC prevalence was 33.2% (317/1057, range: 0 to 53%, 95% CI = 30.2%-36.4%), and Cutibacterium acnes (43.0%, 95% CI = 37.4%-48.8%), Coagulase-negative Staphylococci (CoNS), (39.5%, 95% CI = 33.2%-46.2%), and Staphylococcus species in general (49.5%, 95%CI = 43.7%-55.4%) were reported the most common isolated microbes. 16.1% of the UPCs were polymicrobial. Risk factors associated with UPC rates were female sex (OR = 2.62, 95%CI = 1.76-3.90, P < 0.001), screw loosening (OR = 4.43, 95%CI = 1.31-15.02, P = 0.02), number of operated levels (MD = 0.77, 95%CI = 0.33-1.22, P = 0.0007), and shorter time since index surgery (MD = - 8.57 months, 95%CI = - 14.76, -2.39, P = 0.02). One-third of patients undergoing spine revision surgery revealed UPC in this study. Each UPC pathogen interpretation and antibiotic use decision should be interpreted case by case. IV.

Antimicrobial resistance in surgical infections: experience from open tibia fracture-related infection intraoperative tissue specimens

Background Antimicrobial resistance in surgical infections is known to have significant morbidity and mortality in extreme cases on top of increased costs in medical expenditure. This study aimed to analyze antimicrobial resistance patterns of microbes in open tibia fracture-related infection (FRI) using intraoperative tissue samples. Methods Between January and June 2022, a descriptive cross-sectional observational study was conducted involving patients aged 18 and above with open tibial shaft fractures. Microbiological culture and sensitivity of three intraoperative deep tissue and bone samples taken by sterile techniques using separate instruments in patients with infection. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method along with biomechanical tests for microbial identification. Results Fifty-seven deep tissue samples were taken from 19 patients with FRI who underwent surgery during the study period were analyzed. Almost all (96.5%) intraoperative tissue samples were culture-positive identifying 73 bacterial isolates out of which 57.9% were polymicrobial. The most frequent isolated bacteria were Gram-negative bacteria 56 (76.7%) with a predominance of Proteus spp 13 (17.8%). Methicilin Resistance Staphyaureus comprised 12 (16.4%) of the isolates whereas Inducible Clindamycin resistance was identified in 8 (57.1%) of Staphyloccus aureus isolates. More than half of the isolates 30 (53.6%) comprised of Extended Spectrum Beta Lactamase producing bacteria. There was high resistance to Cephalosporins and Amoxyclavulanic acid as the efficacy was low ranging from 28.2, 27.8, and 30.0% for cefotaxime, ceftazidime and amoxicillin/clavulanic acid, respectively. Almost all Gram-negative bacteria 47 (83.9%) had multidrug resistance pattern except for Pseudomonas aureginosa that had 77.8 to 88.9% susceptibility to all tested antibiotics. Conclusion High resistance to cephalosporins in patients with delayed or late infection in open tibia FRI is alarming and further studies to establish causes are indicated.

Sexual selection in Thaumatotibia leucotreta (Meyrick) is shaped by contrasting geographic adaptations, but does it matter for area‐wide sex pheromone control tools?

AbstractThaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a quarantine pest for certain export markets due to its phytosanitary status in affected crops in sub‐Saharan Africa, including citrus. Consequently, there is a zero‐tolerance policy for T. leucotreta in export markets. In South Africa, an integrated pest management strategy, incorporating a systems approach is used to achieve complete control of T. leucotreta. Preharvest management is multi‐faceted, including reliance on sex pheromone tools such as monitoring, attract‐and‐kill, mating disruptions, and sterile insect technique (SIT). Geographically isolated populations of T. leucotreta occur in South Africa, and there is speculation concerning the possible loss of sexual communication between these isolated populations, thereby compromising the efficiency of sex pheromone tools. To investigate this possibility, we collected samples from five geographically isolated populations of T. leucotreta and a population used for SIT in South Africa. These were subjected to sexual attraction trials under choice and no‐choice scenarios in a semi‐natural environment. Results of the choice tests revealed that males of each population preferred their corresponding population females, except irradiated males. However, when we deprived males of their preferred females, these preferences dissipated, and they were equally attracted to females from all populations. These results indicate that local adaptation and other selection forces in contrasting environments are important in sexual communication and selection in T. leucotreta but do not necessarily prevent recognition of sexual signals and attraction between geographically isolated populations. These findings are crucial for area‐wide IPM and precision control of T. leucotreta.

Volatiles of essential oils and yeast derivatives influence mating behaviour of Anastrepha fraterculus males under field cage conditions

AbstractThe sterile insect technique (SIT) is used for the management of tephritid fruit fly pests. The South American fruit fly, Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), is one potential pest to be targeted by means of SIT. The success of SIT depends, to a large extent, on the sexual performance of sterile males. Various approaches have been evaluated with the aim of improving their sexual performance. These include the exposure to plant‐derived compounds and/or the provision of protein sources in the adults' diet capable of stimulating male mating success. The present study aimed to determine whether exposure to volatiles of Citrus limon (L.) Burm. F. (Rutaceae) essential oil and limonene confers a mating advantage to A. fraterculus laboratory males fed two distinct dietary regimes when competing with wild males for wild females under field cage conditions. Dietary regimes were, one, with non‐hydrolysed brewer's yeast and sugar (1:3 ratio), and the other with brewer's yeast hydrolysate enzymatic and sugar (1:12 ratio). The effect was evaluated in four variables associated with mating success: number of copulas obtained, latency to mate, copula duration, and copula location. Exposure to volatiles did not affect the number of matings achieved, irrespective of the diet given to the males. When laboratory males were fed with brewer's yeast hydrolysate, the effect of volatile exposure was shown in latency to mate, copula duration, and copula location. When the laboratory males were fed with non‐hydrolysed brewer's yeast, the effect of volatile exposure was shown only in copula duration. Laboratory males fed brewer's yeast hydrolysate achieved the same number of matings as wild males, whereas laboratory males fed non‐hydrolysed brewer's yeast had lower performance.

Season-long comparison of trap lures for integrated management of the navel orangeworm (Lepidoptera: Pyralidae) in almond and pistachio

Monitoring navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae) using pheromone lures is now complicated by the use of mating disruption. Two commercially available lures that are minimally affected by mating disruption use either natural ovipositional substrates (Bait lures) or a combination of phenyl propionate (PPO), a volatile chemical that attracts both sexes and pheromone lures (Combo lures). We compared the season-long trap capture for these two lures in a sterile insect technique (SIT) demonstration project in Fresno County, California, 2020–2023. A total of 194,233 males (96.52%) were caught using Combo lures and 7006 (3.48%) caught using Bait lures, while 95,947 females (48.83%) were caught using Combo lures and 100,532 (51.17%) caught using Bait lures. Capture of A. transitella was 2.3-fold higher in pistachio (278,492) than in almond (119, 316), and within a commodity, there was a moderate correlation in female capture between the two lures; correlation was stronger during the period leading up to July 21 (Julian date 202). For Bait lures, 48.7% of the trap catch in almond occurred by July 21 and 87.1% of the trap catch occurred in pistachio by July 21. For Combo lures, 38.9% of the trap catch in almond occurred by July 21 while 54.6% of the catch occurred in pistachio. Bait lures became less effective after July 21, likely due to diminished attractiveness as new crop nuts split in August through October. Our data indicate that Combo lures are preferable when the goal is consistent season-long capture of A. transitella in almond and pistachio.

Do sterile males and females synergistically suppress pests targeted by the sterile insect technique?

Do sterile males and females synergistically suppress pests targeted by the sterile insect technique?