A systematic review of experimental studies on Salmonella persistence in insects

The consumption of insects as food and feed has been recently suggested as a possible alternative to the rising global food need, thus it is crucial to monitor any potential food safety hazards in the insect supply chain. The aims of this systematic review were to collect, select, and evaluate studies investigating the persistence of Salmonella in insects. We searched PUBMED, EMBASE, WEB of Science Core Collection, and Food Science and Technology Abstracts. In total, 36 papers investigating the persistence of Salmonella in insects (both holometabolous and heterometabolous) were included after screening. Regarding complete metamorphosis insects, the longest Salmonella persistence was reported in Phormia regina, in which the pathogen persisted for 29 days at 5 °C. Similarly, Salmonella persisted in the feces of Alphitobius diaperinus for 28 days. The incomplete metamorphosis insect showing the longest Salmonella persistence (>10 months) was Blatella germanica. Periplaneta americana excreted Salmonella via feces for 44 days until all the insects were dead. The retrieved data on the persistence of Salmonella can be useful for further analysis by risk assessors and decision-makers involved in the safety of insect-based food, contributing to defining the sanitary requirements and risk mitigation measures along the supply chain. The review protocol is registered in PROSPERO database (CRD42022329213).

A systematic review and meta-analysis of the sources of Salmonella in poultry production (pre-harvest) and their relative contributions to the microbial risk of poultry meat

Salmonella is a major foodborne pathogen associated with poultry and poultry products and a leading cause for human salmonellosis. Salmonella is known to transmit in poultry flocks both vertically and horizontally. However, there is a lack of knowledge on relative contribution of the factors on Salmonella prevalence in poultry live production system including hatchery, feed, water, environment-interior, and -exterior. Therefore, a systematic review and meta-analysis was conducted to quantify the potential sources of Salmonella during preharvest and their relative contributions to the microbial risk of poultry meat. A total of 16,800 studies identified from Google Scholar and 37 relevant studies were included in the meta-analysis for relative contributions to Salmonella positivity on broilers after applying exclusion criteria. A generalized linear mixed model approach combined with logit transformation was used in the current study to stabilize the variance. The analysis revealed that the hatchery is the most significant contributor of Salmonella with a prevalence of 48.5%. Litter, feces, and poultry house internal environment were the other 3 major contributing factors with a prevalence of 25.4, 16.3, and 7.9%, respectively. Moreover, poultry house external environment (4.7%), feed (4.8%), chicks (4.7%), and drinker water also contributed to the Salmonella positivity. Results from this meta-analysis informed the urgent need for controls in live production to further reduce Salmonella in fresh, processed poultry. The control strategies can include eliminating the sources of Salmonella and incorporating interventions in live production to reduce Salmonella concentrations in broilers.

Chemical Signals Associated With Gender and Sexual Experience Affect Mating and the Attractiveness of the Poultry Pest, Alphitobius diaperinus (Coleoptera: Tenebrionidae)

Alphitobius diaperinus is one of the most significant pests in the poultry industry. Identifying the role of self-produced chemical signals can help control it. Here, we exposed adults to the olfactory signals of other adults of similar and different genders (either males or females) and sexual experiences (i.e., virgin and experienced) to assess their long-range attractiveness and, at short-range, their mating behavior responses (i.e., touching, mounting, and copulation). In olfactometric experiments, our results indicate that adults are attracted to the olfactory signals of other male adults, independently of gender, or sexual condition, indicating the presence of generalized long-range attractive signals, in contrast to female signals, can be both factor-dependent. However, in mating experiments, virgin males developed more robust mating responses (i.e., they mount and copulate longer with females) compared to sexually experienced males, even though they both have similar precopulatory behavioral responses (i.e., time of antennal and leg touching). These results address the importance of short-range chemical signals in eliciting copulation. Furthermore, when virgins of both genders were tested, their mating responses were significantly longer than any other pair combination, indicating that sexual experience also affects mating behavior. Chemical analyses of adult extracts showed that sexual experience, but not gender, is linked to differences in chemical profiles of adults, primarily involved in short-range signaling. These findings provide new insights into the attractiveness and mating responses of A. diaperinus and the role of sexual experience in shaping the behavior and chemical profile of insects that mate multiple times during their lifetime.

Efficacy of a Biocidal Paint in Controlling Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) and Improving the Quality of Air and Litter in Poultry Houses

Effective disinfection and disinsection are the keys to successful operation of modern poultry farms and the safety of poultry products. The cleaning and disinfection of poultry houses are important aspects of farm hygiene management. The correct execution of all steps of cleaning, disinfection, and disinsection procedures and the use of appropriate products are crucial for the prevention and control of zoonotic and animal diseases. In this study it was assumed that a water-based slow-release biocidal paint could be useful in controlling insect pests such as Alphitobius diaperinus and reducing microbiological contamination of air and litter in poultry houses and have a beneficial effect on microclimate in poultry houses. Therefore, the locations of A. diaperinus in the poultry houses, the microbiological contamination of air and litter, as well as the microclimatic conditions in the houses and the physicochemical parameters of the litter were evaluated. The results suggest that the tested biocidal paint could be an effective alternative to other insecticides and disinfectants. Additionally, the research is of a practical nature and may be very useful for poultry producers in controlling A. diaperinus populations and maintaining proper hygiene in poultry houses. Further research is needed.

Regional Salmonella Differences in United States Broiler Production from 2016 to 2020 and the Contribution of Multiserovar Populations to Salmonella Surveillance

Poultry remains a considerable source of foodborne salmonellosis despite significant reduction of Salmonella incidence during processing. There are multiple entry points for Salmonella during production that can lead to contamination during slaughter, and it is important to distinguish the serovars present between the different stages to enact appropriate controls. National Salmonella data from the U.S. Department of Agriculture-Food Safety Inspection Service (USDA-FSIS) monitoring of poultry processing was analyzed from 2016 to 2020. The overall Salmonella incidence at processing in broiler carcasses and intact parts (parts) decreased from 9.00 to 6.57% over this period. The incidence in parts was higher (11.15%) than in carcasses (4.78%). Regional differences include higher proportions of serovars Infantis and Typhimurium in the Atlantic and higher proportion of serovar Schwarzengrund in the Southeast. For Georgia, the largest broiler-producing state, USDA-FSIS data were compared to Salmonella monitoring data from breeder flocks over the same period, revealing serovar Kentucky as the major serovar in breeders (67.91%) during production but not at processing, suggesting that it is more effectively removed during antimicrobial interventions. CRISPR-SeroSeq was performed on breeder samples collected between 2020 and 2021 to explain the incongruence between pre- and postharvest and showed that 32% of samples contain multiple serovars, with up to 11 serovars found in a single flock. High-resolution sequencing identifies serovar patterns at the population level and can provide insight to develop targeted controls. The work presented may apply to other food production systems where Salmonella is a concern, since it overcomes limitations associated with conventional culture. IMPORTANCE Salmonella is a leading cause of bacterial foodborne illness in the United States, with poultry as a significant Salmonella reservoir. We show the relative decrease in Salmonella over a 5-year period from 2016 to 2020 in processed chicken parts and highlight regional differences with respect to the prevalence of clinically important Salmonella serovars. Our results show that the discrepancy between Salmonella serovars found in pre- and postharvest poultry during surveillance are due in part by the limited detection depth offered by traditional culture techniques. Despite the reduction of Salmonella at processing, the number of human salmonellosis cases has remained stable, which may be attributed to differences in virulence among serovars and their associated risk. When monitoring for Salmonella, it is imperative to identify all serovars present to appropriately assess public health risk and to implement the most effective Salmonella controls.

Alphitobius diaperinus Panzer (Insecta, Coleoptera) in a single house of a broiler production facility as a potential source of pathogenic bacteria for broilers and humans

Pest infestation in any stage can lead to a quality reduction in the finished products. This study aimed to detect Escherichia coli, Salmonella spp., Campylobacter spp., and Staphylococcus aureus in Alphitobius diaperinus adults, and in samples from broiler swabs, administered water and feed collected in a single house from a broiler production facility in central Italy. Three samplings were carried out, each collecting ninety adult beetles for microbial detection in the external, fecal and internal content; ten cloacal swab samples; and one sample of both administered feed and water. Microbiological cultures and biochemical identification were performed on suspected cultures and confirmed by species-specific PCRs. A. diaperinus was abundantly found near the windows, under the manger and in the corners of the facility. Salmonella enterica serovar Cholerasuis was found at the external surface of the beetles, while Staphylococcus xylosus and E. coli in the fecal content. The latter microrganism together with Staphylococcus lentus, S. xylosus and other staphylococcal species were detected in the internal microbiota. E. coli and Campylobacter spp. were observed in cloacal swabs, and S. xylosus in one feed sample. The study findings support evidence for Salmonella spp. and E. coli, and remark that adherence with sanitation rules and biosecurity procedures are required.

Atividade da Metilxantina em pó aplicada na cama de frango sobre adultos de Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae)

Resumo Uma das pragas que mais afetam e comprometem a produção avícola no mundo é o inseto Alphitobius diaperinus, conhecido como cascudinho. Este inseto é vetor de doenças que comprometem não só a produção de frangos como também a saúde humana. Objetivou-se com esse trabalho avaliar a eficácia e determinar a dose adequada de Metilxantina (MTX), inseticida natural extraído da cafeína, para o controle da população adulta de cascudinhos em cama de frango. Foram utilizados 2.500 cascudinhos adultos distribuídos em delineamento inteiramente casualizado, cinco tratamentos, 10 repetições com 50 insetos por repetição. Os tratamentos consistiram de grupo controle e quatro concentrações 14 g/m2, 16 g/m2, 18 g/m2, 20 g/m2 de MTX espalhadas em recipientes plásticos contendo cama de frango reutilizada e ração, alocados em um galpão de frangos de corte a fm de simular a condição de granja. Período experimental foi de 18 dias e realizadas cinco leituras nos dias dois, quatro, seis, 10 e 18. A MTX afetou (P<0,05) a taxa de mortalidade acumulada de cascudinhos, grupos de insetos alojados em caixas tratadas com 16 g/m2 de MTX apresentaram maior mortalidade acumulada (86,6%) ao final do período experimental. Conclui-se que MTX tem ação inseticida sobre adultos de cascudinho, podendo ser utilizada sobre a cama de frango para o controle da população deste inseto em galpões de criação de frangos, a concentração 16 g/MTX/m2 demonstrou maior efetividade.

Activity of powdered methylxanthine applied to poultry litter on adults of Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae)

Abstract One of the pests that most affect and compromise poultry production worldwide is the insect Alphitobius diaperinus, known as the lesser mealworm. This insect is a vector of diseases that compromise not only chicken production but also human health. This study proposes to examine the efficacy and determine the appropriate rate of methylxanthine (MTX), a natural insecticide extracted from cafeine, for the control of an adult population of lesser mealworms in poultry litter. A total of 2,500 adult mealworms were distributed into five treatments in a completely randomized design using 10 replications with 50 insects per replication. The treatments consisted of a control group and four concentrations of MTX (14, 16, 18, and 20 g/m2) spread in plastic boxes containing reused poultry litter and feed, allocated in a broiler shed, to simulate the farm condition. The experimental period was 18 days, and five readings were performed on days 2, 4, 6, 10, and 18. Methylxanthine affected (P<0.05) the mealworms’ cumulative mortality rate, with the groups of insects housed in boxes treated with 16 g /m2 MTX showing the highest cumulative mortality (86.6%) at the end of the experimental period. In conclusion, MTX has insecticidal action on adults of lesser mealworm and can be used on chicken litter to control the population of this insect in poultry sheds. The MTX concentration of 16 g/m2 showed the greatest effectiveness.

Risk factors for Salmonella enterica subsp. enterica persistence in broiler-chicken flocks on Reunion Island

This study was conducted to identify the main risk factors for Salmonella spp. persistence in broiler flocks in Reunion Island. Seventy broiler farms were surveyed from March 2016 to June 2018. Samples of fresh droppings were collected using gauze socks, and a questionnaire was completed with the farmers. Persistence was defined as an infection with the same serovar before and after cleaning and disinfection (C/D) of poultry houses. Salmonella spp. was found to persist on 27% of the farms. Cleaning concrete surrounding areas (OR = 0.23) and disinfecting silos (OR = 0.17) reduced the risk of pathogen persistence. An analysis of infections of pests found in the vicinity of the farms confirmed their role in the persistence of Salmonella spp. Fifteen percent of the pests were infected and the presence of mealworms in poultry litter (OR = 6.69) was found to increase the risk of Salmonella spp. persistence. We conclude that improved cleaning-disinfection, sanitary preventive measures and pest control in the poultry sector are needed to avoid the persistence of Salmonella spp. on broiler farms.

Effectiveness of Biocidal Paint Containing Permethrin, Ultramarine and Violet 23 Against Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) in Laboratories and Poultry Houses

Reducing Alphitobius diaperinus in poultry production is a difficult task. However, attempts should be made to control the insect pest, as it poses a serious threat to the life and health of the chickens, as well as the workers on a farm. Our research was conducted in two stages to assess the effectiveness of the biocidal paint against A. diaperinus, containing active substances such as permethrin and a mixture of ultramarine and violet 23. In the first stage, under laboratory conditions, after 22 days, 100% mortality of A. diaperinus larvae and adults was achieved. This allowed us to assume that the biocidal paint may also be effective in poultry houses. In the poultry house where biocidal paint was applied, the number of insects decreased continuously alongside the sampling dates. In both research stages, the biocidal paint proved more effective against A. diaperinus than traditional limewash, and also the time to effective interaction of the paint was noted. Additionally, it was observed that the larvae were more susceptible to the active substances than adults. The research was practical, however, further analyses are necessary to fully control A. diaperinus, especially in poultry houses.

Salmonella Typhimurium Level in Mealworms (Tenebrio molitor) After Exposure to Contaminated Substrate

Findings of viable Salmonella spp., which are important foodborne pathogens, are seemingly not reported in mealworms (Tenebrio molitor) for feed and food. Still, the bacterial load of mealworms is naturally high and includes members of the Enterobacteriaceae family to which Salmonella belong. This indicates that Salmonella may be able to thrive in mealworms if introduced into the production. Therefore, this study aimed to assess the quantitative level of Salmonella enterica serovar Typhimurium (ST) in mealworms over a 14-day course after exposure to substrate contaminated with ST levels from 1.7 to 7.4 log CFU/g at start (i.e., day 0). The level of ST found in larvae was below the quantitative detection level (1 or 2 log CFU/g) on day 1 in larvae exposed to contamination levels of 1.7, 3.4, and 3.6 log CFU/g opposed to contamination levels of 5.4, 5.6, and 7.4 log CFU/g, respectively. The maximum level of ST detected in individual 1-g larvae samples was 5.8 log CFU/g, but the level varied among the triplicate samples from each sampling, and the highest average value was 5.3 ± 0.3. Beyond day 7, only larvae exposed to the contamination level of 7.4 log CFU/g were >1.0 log CFU/g in the triplicate samples. However, qualitative testing (10 g) showed the presence of ST in larvae until the end of the experiment on day 14 except for the lowest contamination level of 1.7 log CFU/g. Parallel testing of surface disinfected larvae indicated that some larvae may be ST-positive due to Salmonella residing on the surface only. Still, any detection of Salmonella is of concern from a food safety perspective. In substrate with contamination levels below 3.6 log CFU/g, the level of ST was below the quantitative detection limit within a few days. Still, ST was detected until the end of experiment on day 14 except for the lowest contamination level of 1.7 log CFU/g. This study indicates the importance of avoiding introduction of Salmonella into the production, e.g., via contaminated substrate in order to avoid Salmonella-positive larvae as they remained positive for at least 14 days (except at the lowest contamination level).

Use of Starch Granules Enriched with Carvacrol for the Lesser Mealworm, Alphitobius diaperinus Control in Chicken House: Effects on Insects and Poultry

The aim of this study was to investigate the effect of starch granules enriched with carvacrol and mixed with straw pellets (as poultry litter) on the mortality of larvae and adults of the lesser mealworm, Alphitobius diaperinus Panzer, a cosmopolitan pest inhabiting chicken houses in vast numbers worldwide. Additionally, the effect of starch granules on the growth parameters and survival of broiler chickens exposed to treated litter was examined. In this study, granules containing 3, 5, and 10% carvacrol was used. In a simulated chicken house bioassay, this material was mixed with pellets in three different proportions: 30/70%, 40/60%, and 50/50% (granules/pellets, respectively). On this medium, young larvae (approximately 10 days old), older larvae (last stage before pupa), and unsexed 7–10 days old adults of the lesser mealworm, with access to food, were colonized. Experiments were performed at 29°C in the dark. The study shows that poultry litter with the addition of starch granules enriched with 10% of carvacrol in the proportion of 40:60% (granules:pellets) appears to be the optimal medium applicable to broiler houses for A. diaperinus control. In this environment, all larvae and adults died within 3–4 days and the overall development of the experimental chickens was similar to that of the control. However, the feed conversion rate was slightly higher in the treated group (1.72) than in the control group (1.56). The average final body weight in the treated group was 100 g lower than that in the control group (the differences were not statistically significant).

The use of yellow mealworm (T. molitor) as alternative source of protein in poultry diets: a review

Protein sources are known to be the second largest component in the poultry sector. Traditionally, fish and soya-bean meals are known to supply very good protein; however, these are restricted in supply and more expensive than energy sources. The prices of soya-bean meal are currently high and tend to fluctuate with changes in climatic conditions and social situations in the countries where it is produced. Developing countries like South Africa have made enormous investments in soya-bean production, despite that the country still imports considerable volumes of this crop and is not self-sufficient. This then means that there is an urgent need to seek for alternative and cost-effective protein sources that can provide the same nutrients as soya-bean and fish meal for poultry production. Tenebrio molitor L. which is commonly known as yellow mealworm has a huge potential to substitute commonly used protein sources in poultry diets. Mealworms are easy to breed and do not require large area for production. Moreover, they have high nutritional value comparable to that of soya-bean and fishmeal. However, the only limiting nutrient for mealworms is calcium which can be easily supplemented in the diets. Therefore, this review sets out to explore the importance of replacing soya bean with mealworms in poultry diets. Furthermore, the life cycle of meal worms will also be discussed.

Biochemical Properties of α-Amylase from Midgut of Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) Larvae

The lesser mealworm, Alphitobius diaperinus (Panzer), is the main insect pest in the poultry industry, thus causing serious damage to production. In this work, the properties of midgut α-amylase from larvae of A. diaperinus were characterized, and its in vitro activity to proteinaceous preparations from different cultivars of common bean (Phaseolus vulgaris) was determined, as well as the amylolitic activity of insects reared on different types of poultry diet. In order to establish some assay conditions, time course and enzyme concentration upon the reaction rate were determined. Product proceeded linearly with time, and the activity was directly proportional to the enzyme concentration. Banding patterns in mildly denaturing electrophoresis showed a single band with apparent molecular weight of 42 kDa. α-Amylase reached optimal temperature at 45°C and pH 5.0 as the optimal one. It maintained 34.6% of the activity after being kept at 60°C for 5 min, and 23%, after 60 min. However, at 80°C, only 14 and 6% remained after 5 and 60 min, respectively. The presence of Ca²⁺ and Na⁺ ions decreased the enzyme activity at concentrations higher than 2 and 100 mM, respectively. The activity was significantly inhibited by some proteinaceous extracts from common bean cultivars, and it declined with increasing proteinaceous concentration. No significant difference was observed when the amylolytic activity was determined in A. diaperinus reared on different poultry diets, offered to broilers in the starter, grower, finisher, and layer phases.

Impact of Skip-a-Day and Every-Day Feeding Programs for Broiler Breeder Pullets on the Recovery of Salmonella and Campylobacter following challenge

The impact of restrictive feeding programs on Salmonella and Campylobacter colonization and persistence after challenge was investigated for broiler breeder pullets housed in an experimental rearing facility. Pullet-chicks were placed on litter in 3 feeding program rooms and each room contained 2 replicate pens. The feeding programs were: (1) Skip-a-day in trough feeders (SAD); (2) Every-day in trough feeders (EDT); (3) Every-day on the pen litter (EDL). On d 1, an additional group of hatchmate chicks were housed in a separate room and gavaged with Salmonella Typhimurium, to later serve as seeder chicks. After seeders were confirmed Salmonella-positive at wk 4, at wk 5 seeders were placed into each feeding program pen to commingle with 135 penmates. At 7, 9, 11, 17, 18, and 20 wk the litter surface in each pen was sampled using intermittently stepped-on drag-swabs. At 8, 12, 16, and 20 wk of age the ceca were sampled from 10 penmates/pen and 2 pooled spleen samples/pen were collected. SAD litter remained Salmonella-positive through 20 wk of age while EDL and EDT pens had no detectible litter Salmonella recovery by 18 and 20 wk. EDL fed pens had no direct (<102 cfu/mL) litter Salmonella recovery during the entirety of the experiment. Salmonella prevalence for ceca from SAD pullets was significantly (P < 0.05) higher at 8 wk (70%) compared to EDT (40%) and EDL (30%). At wk 12, SAD pullets for both on and off-feed sampling days had significantly higher Salmonella recovery (40%), compared to EDT and EDL (both at 5% recovery). By 16 and 20 wk, only the SAD pullets on the on-feed day (48 h without feed) had recovery of Salmonella at 20%. Salmonella recovery in pooled spleen samples did not appear associated with feeding treatments (22% positive). The remaining pullets challenged with Campylobacter at 21 wk produced similar trends as was seen for Salmonella. SAD program pullets had significantly higher Campylobacter from ceca (80 to 100%) compared to pullets on EDL (30 to 60%) or EDT (40 to 95%). These results suggest that using a Skip-a-Day feeding program for broiler breeder pullets contributes to persistently higher Salmonella and Campylobacter ceca colonization and litter prevalence.

Chemical composition, antimicromicrobial activity and insecticidal activity against the lesser mealworm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) of Origanum vulgare L. ssp. hirtum (Link) and Artemisia dracunculus L. essential oils

BACKGROUND

Essential oils (EOs) from Artemisia dracunculus L. and Origanum vulgare L. ssp. hirtum were obtained and the qualitative and quantitative chemical composition of the extracts was investigated. The insecticidal activity of EOs against the larval stages of Alphitobius diaperinus (Panzer) was studied. Moreover, the antimicrobial activity of these oils against pathogens transmitted by this pest was also investigated.

RESULTS

The obtained results indicate the possibility of using Greek oregano EO with a high content of carvacrol as a feed additive in poultry nutrition. The use of the Greek oregano oil at 1% (w/w) dose showed stronger reduction of body weight gain of stage IV larvae. Their body mass was only 10.92% of the control. Moreover, EOs from O. vulgare strongly inhibited the growth of tested bacterial strains as well as Candida albicans.

CONCLUSION

Greek oregano EO may be a good alternative to antibiotic growth promoters and coccidiostats whose use in feeding farm animals has been prohibited since January 2006 under European Union directives. The introduction of O. vulgare L. ssp. hirtum EO into the premises of farm and poultry houses may help to improve sanitary conditions and control of the lesser mealworm inhabiting these buildings. © 2017 Society of Chemical Industry.

The horizontal transfer of Salmonella between the lesser mealworm (Alphitobius diaperinus) and poultry manure

There is need to determine the nature of enduring reservoirs of Salmonella contributing to perpetual contamination within poultry flocks. The dispersal of Salmonella between birds, litter and the lesser mealworm has been established, but the extent that these act as critical components in the epidemiology of Salmonella infection during broiler grow-out and flock rotation has not been delineated; in particular, the level of participation by the lesser mealworm beetles (LMB) as agents of retention and dispersal. This study defines this route of transmission and provides empirical data on bacterial loads that facilitate Salmonella transfer. Results showed differential Salmonella transfer dependent on bacterial concentration. At 10³  cfu/ml, only a small, but not significant, amount of Salmonella was transferred, from the LMB to the manure and back to uninfected LMB; while from 10⁵ to 10⁷  cfu/ml, a significant acquisition and transfer occurred both internally and externally to the LMB over 4 and 24 hr exposures. These data will be used in correlation with facility management practices to develop intervention strategies to mitigate the establishment and spreading of reservoir Salmonella populations contributing to pre-harvest contamination of poultry flocks.

Susceptibility of Alphitobius diaperinus in Texas to permethrin- and β-cyfluthrin-treated surfaces

BACKGROUND

Effective control of the lesser mealworm beetle, Alphitobius diaperinus, relies heavily on insecticides. The susceptibility level of beetles to these insecticides can be dependent on active ingredient, population treated, formulation, surface treated and timing of observation. The susceptibility of adult beetles from six populations to β-cyfluthrin was determined up to 48 h after exposure. The susceptibility of adult beetles to the label rate of β-cyfluthrin and permethrin formulations on concrete, wood-chip-type particle board and pressure-treated wood was determined up to 48 h post-exposure.

RESULTS

Variation in LC₅₀ values at 2 and 24 h was found within and between beetle populations from two regions of Texas. The permethrin formulation had lower mean mortality than the β-cyfluthrin formulation on all surfaces tested. The permethrin formulation had high levels of recovery on all surfaces tested after 2 h. Surface affected the efficacy of the insecticides tested on killing adult beetles.

CONCLUSION

Permethrin-based insecticide had lower knockdown and persistence on various surfaces over time than β-cyfluthrin-based insecticide. Beetle recovery in less susceptible populations may necessitate longer observation periods for efficacy evaluations. Our study also shows that surfaces chosen can affect the efficacy of the compound on killing adult beetles. © 2016 Society of Chemical Industry.

Revisiting the Male-Produced Aggregation Pheromone of the Lesser Mealworm, Alphitobius diaperinus (Coleoptera, Tenebrionidae): Identification of a Six-Component Pheromone from a Brazilian Population

The lesser mealworm, Alphitobius diaperinus Panzer 1797 (Coleoptera: Tenebrionidae), is a cosmopolitan insect pest affecting poultry production. Due to its cryptic behavior, insecticide control is usually not efficient. Thus, sustainable and effective methods would have an enormous and positive impact in poultry production. The aim of this study was to confirm the identity of the male-produced aggregation pheromone for a Brazilian population of A. diaperinus and to evaluate its biological activity in behavioral assays. Six male-specific compounds were identified: (R)-limonene (1), (E)-ocimene (2), 2-nonanone (3), (S)-linalool (4), (R)-daucene (5), all described before in an American population, and a sixth component, (E,E)-α-farnesene (6), which is apparently exclusive to a Brazilian population. Y-Tube bioassays confirmed the presence of a male-produced aggregation pheromone and showed that all components need to be present in a similar ratio and concentration as emitted by male A. diaperinus to produce a positive chemotactic response.

Preharvest Food Safety in Broiler Chicken Production

Preharvest food safety in broiler production is a systematic approach to control the introduction, propagation, and dissemination of Salmonella and Campylobacter from breeder flocks to the end of their progeny (broilers) life cycle. New and revised more stringent performance standards for these pathogens at the processing plant level require continuous evaluation of the preharvest management practices and intervention strategies used by the poultry industry. The implementation of stricter biosecurity plans, vaccination of breeder flocks for Salmonella , and usage of feed that is free of animal by-products are some of the measures recommended to control the pathogens. Interventions shown to be effective in experimental settings need to be assessed for their cost-effectiveness and efficiency when applied at the farm level.

Effects of Miscanthus × giganteus and Wheat Straw on Behavior, Survival, and Growth of Alphitobius diaperinus (Coleoptera: Tenebrionidae)

The lesser mealworm, Alphitobius diaperinus (Panzer), damages poultry barns, vectors poultry diseases, inhibits poultry weight gain, and consumes poultry feed. Management of the pest is a challenge because of its resistance to several insecticides, difficulty in treating infestations that can be concealed in locations within barns, and the high populations that occur around spilled poultry feed. However, few A. diaperinus were observed in Miscanthus  ×  giganteus straw in a case where it was used as an alternative bedding material in open-floor poultry production in Ontario. To investigate this, we tested the effects of Miscanthus  ×  giganteus and wheat straw on A. diaperinus behavior, survival, and growth in laboratory experiments. In these experiments, adult beetles preferred to inhabit wheat straw, whereas late-instar larvae preferred Miscanthus  ×  giganteus . As a result, more adult beetles emerged from pupae in Miscanthus  ×  giganteus than in wheat, but there was no difference in emerged beetle weight. Early-instar larvae survived and increased in weight at similar rates in both straw types. Thus, while adult A. diaperinus strongly preferred wheat straw given a choice, late-instar preference and pupae emergence suggest that Miscanthus  ×  giganteus may not be useful for suppressing A. diaperinus populations.

Chemical Composition of Alphitobius diaperinus (Coleoptera: Tenebrionidae) Abdominal Glands and the Influence of 1,4-benzoquinones on its Behavior

This study aimed to identify and quantify the compounds present in the abdominal glands of Alphitobius diaperinus Panzer, 1797 (Coleoptera: Tenebrionidae) and to evaluate the influence of these compounds on its behavior. The extraction of volatiles present in the abdominal glands was made by dissection (10 individuals per sex) and by air entrainment (200 insects per sex), and they were analyzed by gas chromatography-flame ionization detector, gas chromatograph-mass spectrometer, and gas chromatograph-electroantennography detector (GC-EAD). The influence of these volatiles on the behavior of conspecifics was evaluated in a four-arm olfactometer. Twenty-three compounds were identified from male and female abdominal gland extracts, of which six were quinones: the 2-methyl-1,4-benzoquinone and the 2-ethyl-1,4-benzoquinone were the major components, and 1,4 benzoquinone and three hydroquinones were registered for the first time for this species. The GC-EAD analysis using the crude extracts from abdominal glands showed that male and female antennae responded to the three major benzoquinones. For the olfactometer bioassays, both genders were repelled either by the abdominal gland extracts or by synthetic solutions containing the three benzoquinones. The results suggest that the 1,4-benzoquinones play a role as a repellent to A. diaperinus.

Synthesis and Antifeedant Activity of Racemic and Optically Active Hydroxy Lactones with the p-Menthane System

Two racemic and two enantiomeric pairs of new δ-hydroxy-γ-lactones based on the p-menthane system were prepared from racemic and optically active cis- and trans-piperitols. The Johnson-Claisen rearrangement of the piperitols, epoxidation of the γδ-unsaturated esters, and acidic lactonization of the epoxy esters were described. The structures of the compounds were confirmed spectroscopically. The antifeedant activities of the hydroxy lactones and racemic piperitone were evaluated against three insect pests: lesser mealworm, Alphitobius diaperinus (Panzer); Colorado potato beetle, Leptinotarsa decemlineata (Say); and peach-potato aphid, Myzus persicae (Sulz.). The chemical transformation of piperitone by the introduction of a lactone moiety and a hydroxy group changed its antifeedant properties. Behavioral bioassays showed that the feeding deterrent activity depended on the insect species and the structure of the compounds. All hydroxy lactones deterred the settling of M. persicae. Among chewing insects, the highest sensitivity showed A. diaperinus adults.

Fontes de infecção e perfil de suscetibilidade aos antimicrobianos de Salmonella sp. isoladas no fluxo de produção de frangos de corte

Este trabalho foi desenvolvido com objetivo de pesquisar Salmonella em amostras de fígado, coração, saco da gema e mecônio de pintos de corte de um dia; inglúvios e cecos obtidos em abatedouros e em suabes de arrasto; larvas ou adultos de Alphitobius diaperinus. Complementarmente, determinou-se o perfil de suscetibilidade aos antimicrobianos: amoxicilina (10 mcg), ampicilina (10 mcg), ciprofloxacina (5 mcg), enrofloxacina (5 mcg), florfenicol (30 mcg), neomicina (30 mcg), sulfonamida (300 mcg), tetraciclina (30 mcg) e trimetoprim-sulfametoxazol (25 mcg) dos serovares tipificados isolados. As amostras foram submetidas às análises microbiológicas pelos métodos bacteriológicos convencionais. Salmonella sp. foi isolada em 6,2% (4/64) do fígado, 4,7% (3/64) do coração, 3,1% (2/64) dos sacos da gema e 4,7% (3/64) do mecônio, num total de 4,7% (12/256) (pinto de um dia); em 10,2% (13/128) das amostras ambientais, sendo 9,4% (9/96) de suabes de arrasto 12,5%, (4/32) de larvas e adultos Alphitobius diaperinus e em 4,4% (28/640) das amostras em abatedouros, sendo 6,5% (21/320) dos inglúvios e 2,2% (7/320) dos conteúdos cecais de abatedouro. Salmonella enterica ser. Enteritidis foi identificada em suabes de arrasto e em amostras de Alphitobius diaperinus, enquanto Salmonella enterica ser. Typhimurium foi encontrada nos inglúvios e cecos. Salmonella enterica ser. Enteritidis apresentaram 75% (6/8) de resistência às sulfonamidas e Salmonella enterica ser. Typhimurium 100% (3/3). A amoxicilina foi outro antimicrobiano com elevada frequência de resistência. Adicionalmente, 20,7% (11/53) dos serovares apresentaram resistência simultânea a pelo menos dois princípios ativos. Conclui-se que Salmonella encontra-se amplamente distribuída no fluxo de produção de frangos de corte, e a via vertical continua sendo uma fonte de introdução de Salmonella sp. à cadeia de produção; cama e insetos podem perpetuar e veicular Salmonella de interesse zoonótico no ambiente avícola; a existência de cepas resistentes aos antimicrobianos, bem como a resistência múltipla, constituem ameaça à saúde pública.