Concurrent cavitary pulmonary tuberculosis and COVID-19 pneumonia with in vitro immune cell anergy.

Tuberculosis (TB) is top infectious disease killer caused by a single organism responsible for 1.5 million deaths in 2018. Both COVID-19 and the pandemic response are risking to affect control measures for TB and continuity of essential services for people affected by this infection in western countries and even more in developing countries. Knowledge about concomitant pulmonary TB and COVID-19 is extremely limited. The double burden of these two diseases can have devastating effects. Here, we describe from both the clinical and the immunological point of view a case of a patient with in vitro immune cell anergy affected by bilateral cavitary pulmonary TB and subsequent COVID-19-associated pneumonia with a worst outcome. COVID-19 can be a precipitating factor in TB respiratory failure and, during ongoing SARS-COV-2 pandemic, clinicians must be aware of this possible co-infection in differential diagnosis of patients with active TB and new or worsening chest imaging.

Image quality and radiation dose reduction in chest CT in pulmonary infection.

PURPOSE: To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan comparing two protocols. MATERIALS AND METHODS: Fifty-nine patients were enrolled. The two CT protocols were applied using Iterative Reconstruction (ASIR™) 40% but different noise indexes, recording dose-length product (DLP) and volume computed tomography dose index (CTDIvol). The subjective IQ was rated based on the distinction of anatomic details using a 4-point Likert scale based on the European Guidelines on Quality Criteria for CT. For each patient, two single CTs, at enrollment (group 1) and at follow-up after lowering the dose (group 2), were evaluated by two radiologists evaluating, for each examination, five different lung regions (central zone-CZ; peripheral zone-PZ; sub-pleural region-SPR; centrilobular region-CLR; and apical zone-AZ). An inter-observer agreement was expressed by weighted Cohen's kappa statistics (k) and intra-individual differences of subjective image analysis through visual grading characteristic (VGC) analysis. RESULTS: An average 50.4% reduction in CTDIvol and 51.5% reduction in DLP delivered were observed using the dose-reduced protocol. An agreement between observers evaluating group 1 CTs was perfect (100%) and moderate to good in group 2 examinations (k-Cohen ranging from 0.56 for PZ and AZ to 0.70 for SPR). In the VGC analysis, image quality ratings were significantly better for group 1 than group 2 scans for all regions (AUCVGC ranging from 0.56 for CZ to 0.62). However, disagreement was limited to a score 4 (excellent)-to-score 3 (good) IQ transition; apart from a single case in PZ, both the observers scored the IQ at follow-up as 2 (sufficient) starting from a score 4 (excellent). CONCLUSION: Dose reduction achieved in the follow-up CT scans, although a lower IQ still allows a good diagnostic confidence.

Patient Access to an Online Portal for Outpatient Radiological Images and Reports: Two Years' Experience.

To assess the incidence of outpatient examinations delivered through a web portal in the Latium Region in 2 years and compare socio-demographic characteristics of these users compared to the total of examinations performed. All radiological exams (including MRI, X-ray and CT) performed from March 2017 to February 2019 were retrospectively analysed. For each exam, anonymized data of users who attended the exam were extracted and their characteristics were compared according to digital access to the reports. Overall, 9068 exams were performed in 6720 patients (55.8% males, median age 58 years, interquartile range (IQR) 46-70) of which 90.2% residents in Rome province, mainly attending a single radiological examination (77.3%). Among all exams, 446 (4.9%) were accessed, of which 190 (4.4%) in the first and 5.4% in the second year (p < 0.041). MRI was the type of exams mostly accessed (175, 7.0%). Being resident in the provinces of the Latium Region other than Rome was associated with a higher access rate (OR = 1.84, p = 0.001). Considering the overall costs sustained to implement a web portal which allows users a personal access to their own reports, if all users would have accessed/downloaded their exams, an overall users' and hospital savings up to €255,808.28 could have been determined. The use of a web portal could represent a consistent economical advantage for the user, the hospital and the environment. Even if increasing over time, the use of web portal is still limited and strategies to increase the use of such systems should be implemented.

Central Nervous System involvement in tuberculosis: An MRI study considering differences between patients with and without Human Immunodeficiency Virus 1 infection.

BACKGROUND: Magnetic resonance imaging (MRI) is largely used in the diagnosis of central nervous system involvement of tuberculosis (CNSTB), yet there is no MRI comparison study between HIV+ and HIV- patients with CNSTB. The aim of the present study was to identify MRI differences in CNSTB between HIV+ and HIV- patients and possibly find early characteristics that could raise the suspect of this disease. METHODS: We included all patients admitted in our institution between 2011 and 2018 with confirmed diagnosis of CNSTB, and MRI performed in the first week. Patients with preexisting brain pathology or immunodeficiency not HIV related were excluded. We compared CNSTB MRI features between the two groups. RESULTS: Sixty-nine patients were included (19 HIV+; 50 HIV-). Findings in HIV+ group: 6 lung TB, 5 hydrocephalus, 4 meningeal enhancement, 6 stroke, 2 hemorrhages, and 10 tuberculomas. HIV- group: 22 lung tuberculosis, 15 hydrocephalus, 21 meningeal enhancement, 5 stroke, 4 hemorrhages, 20 tuberculomas. The only statistically significant difference between the two groups was in the stroke occurrence, more frequent in the HIV+ group (P=.028), all involving the basal ganglia. CONCLUSIONS: Stroke involving the basal ganglia best differentiates CNSTB patients who are HIV+ from those HIV-. This finding was not correlated with meningeal enhancement suggesting that small arteries involvement might precede it. Therefore, we think that HIV+ patients with a new onset of stroke should be evaluated for CNSTB. Follow-up MRI should also be planned since meningeal enhancement might appear in later stages of the disease.

Phytotoxic Activity and Structure-Activity Relationships of Radicinin Derivatives against the Invasive Weed Buffelgrass (Cenchrus ciliaris).

Radicinin (1), is a fungal dihydropyranopyran-4,5-dione isolated together with some analogues, namely 3-epi-radicinin, radicinol, 3-epi-radicinol, and cochliotoxin (2-5), from the culture filtrates of the fungus Cochliobolus australiensis, a foliar pathogen of buffelgrass (Cenchrus ciliaris), an invasive weed in North America. Among the different metabolites 1 showed target-specific activity against the host plant and no toxicity on zebrafish embryos, promoting its potential use to develop a natural bioherbicide formulation to manage buffelgrass. These data and the peculiar structural feature of 1 suggested to carry out a structure-activity relationship study, preparing some key hemisynthetic derivatives and to test their phytotoxicity. In particular, p-bromobenzoyl, 5-azidopentanoyl, stearoyl, mesyl and acetyl esters of radicinin were semisynthesized as well as the monoacetyl ester of 3-epi-radicinin, the diacetyl esters of radicinol and its 3 epimer, and two hexa-hydro derivatives of radicinin. The spectroscopic characterization and the activity by leaf puncture bioassay against buffelgrass of all the derivatives is reported. Most of the compounds showed phytotoxicity but none of them had comparable or higher activity than radicinin. Thus, the presence of an α,ß unsaturated carbonyl group at C-4, as well as, the presence of a free secondary hydroxyl group at C-3 and the stereochemistry of the same carbon proved to be the essential feature for activity.

Radicinin, a Fungal Phytotoxin as a Target-Specific Bioherbicide for Invasive Buffelgrass (Cenchrus ciliaris) Control.

The fungal pathogens Cochliobolus australiensis and Pyricularia grisea have recently been isolated from diseased leaves of buffelgrass (Cenchrus ciliaris) in its North American range, and their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides against this invasive weed was investigated. Fourteen secondary metabolites obtained from in vitro cultures of these two pathogens were tested by leaf puncture assay on the host plant at different concentrations. Radicinin and (10S, 11S)-epi-pyriculol proved to be the most promising compounds. Thus, their phytotoxic activity was also evaluated on non-host indigenous plants. Radicinin demonstrated high target-specific toxicity on buffelgrass, low toxicity to native plants, and no teratogenic, sub-lethal, or lethal effects on zebrafish (Brachydanio rerio) embryos. It is now under consideration for the development of a target-specific bioherbicide to be used against buffelgrass in natural systems where synthetic herbicides cause excessive damage to native plants.

Synthesis and Herbicidal Activity Against Buffelgrass (Cenchrus ciliaris) of (±)-3-deoxyradicinin.

A novel synthetic strategy for obtainment of (±)-3-deoxyradicinin (2) is reported. This synthetic methodology is more efficient than those previously reported in the literature and also shows higher versatility towards the introduction of different side-chains at both C-7 and C-2. The obtained compound (±)-2 shows phytotoxicity against the grass-weed buffelgrass comparable to that of the natural phytotoxin radicinin (1). Therefore, (±)-2 can constitute a more practical synthetic alternative to 1 as bioherbicide for buffelgrass control.

Pulmonary measles disease: old and new imaging tools.

BACKGROUND: Measles virus can cause lower respiratory tract infection, so that chest radiography is necessary to investigate lung involvement in patients with respiratory distress. PURPOSE: To assess measles pneumonia imaging during the measles outbreak occurred in 2016-2017 in Italy. MATERIAL AND METHODS: We retrospectively observed adult patients with a serological diagnosis of measles, who underwent chest-X rays for suspected pneumonia. If a normal radiography resulted, the patient underwent unenhanced CT. A CT post processing software package was used for an additional quantitative lung and airway involvement analysis . RESULTS: Among 290 patients affected by measles, 150 underwent chest-X ray. Traditional imaging allowed the pneumonia diagnosis in 114 patients (76%). The most frequent abnormality at chest X-rays was bronchial wall thickening, observed in 88.5% of the cases; radiological findings are faint in the 25% of the cases (29/114 patients). In nine subjects with a normal chest X-ray, unenhanced CT with a quantitative analysis was performed, and depicted features consistent with constrictive bronchiolitis. CONCLUSION: Measles may produce bronchiolitis and pneumonia. In the cases in which involvement of pulmonary parenchyma is not sufficient to result in radiological abnormalities, CT used with a dedicated postprocessing software package, provides an accurate lungs and airways analysis, also determining the percentage of lung involvement.

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris).

Buffelgrass (Pennisetum ciliare or Cenchrus ciliaris) is a perennial grass that has become highly invasive in the Sonoran Desert of southern Arizona. In the search for novel control strategies against this weed, strains of the foliar fungal pathogen Cochliobolus australiensis from buffelgrass have been screened for their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides in an integrated pest management strategy. A new phytotoxin, named cochliotoxin, was isolated from liquid culture of this fungus together with radicinin, radicinol, and their 3-epimers. Cochliotoxin was characterized, essentially by spectroscopic methods, as 3-hydroxy-2-methyl-7-(3-methyloxiranyl)-2,3-dihydropyrano[4,3-b]pyran-4,5-dione. Its relative stereochemistry was assigned by 1H NMR techniques, while the absolute configuration (2S,3S) was determined applying the advanced Mosher's method by esterification of its hydroxy group at C-3. When bioassayed in a buffelgrass coleoptile elongation test and by leaf puncture bioassay against the host weed and two nontarget grasses, cochliotoxin showed strong phytotoxicity. In the same tests, radicinin and 3-epi-radicinin also showed phytotoxic activity, while radicinol and 3-epi-radicinol were largely inactive. All five compounds were more active in leaf puncture bioassays on buffelgrass than on the nontarget grass tanglehead (Heteropogon contortus), while the nontarget grass Arizona cottontop (Digitaria californica) was more sensitive to radicinin and 3-epi-radicinin. Cochliotoxin at low concentration was significantly more active on buffelgrass than on either native grass, but the difference was small.

Chloromonilinic Acids C and D, Phytotoxic Tetrasubstituted 3-Chromanonacrylic Acids Isolated from Cochliobolus australiensis with Potential Herbicidal Activity against Buffelgrass (Cenchrus ciliaris).

The fungal pathogen Cochliobolus australiensis isolated from infected leaves of the invasive weed buffelgrass (Pennisetum ciliare) was grown in vitro to evaluate its ability to produce phytotoxic metabolites that could potentially be used as natural herbicides against this weed. Two new tetrasubstituted 3-chromanonacrylic acids, named chloromonilinic acids C (1) and D (2), were isolated from the liquid cultures of C. australiensis, together with the known chloromonilinic acid B. Chloromonilinic acids C and D were characterized by spectroscopic and chemical methods as (E)-3-chloro-3-[(5-hydroxy-3-(1-hydroxy-2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid and (Z)-3-chloro-3-[(5-hydroxy-3-(2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid, respectively. The stereochemistry of chloromonilinic acids C and D was determined using a combination of spectroscopic and computational methods, including electronic circular dichroism. The fungus produced these compounds in two different liquid media together with cochliotoxin, radicinin, radicinol, and their 3-epimers. The radicinin-related compounds were also produced when the fungus was grown in wheat seed solid culture, but chloromonilinic acids were not found in the solid culture organic extract. All three chloromonilinic acids were toxic to buffelgrass in a seedling elongation bioassay, with significantly delayed germination and dramatically reduced radicle growth, especially at a concentration of 5 × 10-3 M.

Pyriculins A and B, two monosubstituted hex-4-ene-2,3-diols and other phytotoxic metabolites produced by Pyricularia grisea isolated from buffelgrass (Cenchrus ciliaris).

Pyricularia grisea has been identified as a foliar pathogen on buffelgrass (Cenchrus ciliaris) in North America and was studied as a potential source of phytotoxins for buffelgrass control. Two monosubstituted hex-4-ene-2,3-diols, named pyriculins A and B, were isolated from its culture filtrate organic extract together with (10S,11S)-(-)-epipyriculol, trans-3,4-dihydro-3,4,8-trihydroxy-1(2H)-napthalenone, and (4S)-(+)-isosclerone. Pyriculins A and B were characterized by spectroscopic (essentially nuclear magnetic resonance [NMR], High-resolution electrospray ionization mass spectrometry [HRESIMS]) and chemical methods such as (4E)-1-(4-hydroxy-1,3-dihydroisobenzofuran-1-yl)hex-4-ene-2,3-diols. The relative and absolute configuration of these compounds was determined by a combination of spectroscopic (NMR, electronic circular dichroism [ECD]) and computational tools. When bioassayed in a buffelgrass coleoptile and radicle elongation test, (10S,11S)-(-)-epipyriculol proved to be the most toxic compound. Seed germination was much reduced and slowed with respect to the control and radicles failed to elongate. All five compounds delayed germination, but only (10S,11S)-(-)-epipyriculol was able to prevent radicle development of buffelgrass seedlings. It had no effect on coleoptile elongation, while the other four compounds caused significantly increased coleoptile development relative to the control.

Ultrastructure of the Spermiogenesis in Halyomorpha halys (Hemiptera: Pentatomidae): X-Irradiation and New Insights on the Centriolar Region Organization.

Halyomorpha halys (Heteroptera: Pentatomidae) is an insect pest native to Asia that has spread over the last two decades to most of the North America, parts of South America, Europe and North Africa. Its impact is significant as it can feed on more than 300 host plants, rendering affected fruits and vegetable crops unsellable or of lower quality. Various chemical and biological methods have been used to control this pest, with varying degrees of success. The sterile insect technique (SIT) is a pest control method involving the sterilization of insects via ionizing radiation and their subsequent mass release into the field. In the present contribution, the spermiogenesis of H. halys was studied from an ultrastructural point of view in both irradiated and non-irradiated adult males. In both cases, we observed ultrastructural characteristics typical of hemipteran sperm cells: bridges connecting the mitochondrial derivatives and the axonemal microtubules, the absence of accessory bodies, and the presence of two or three crystalline inclusions within the mitochondrial derivatives, an acrosome composed of tightly packed tubules, and an atypical, plaque-shaped microtubular organizing center (MTOC) in the centriolar region. Moreover, in the same region, we seldom observed the presence of two centrioles in the spermatids, one of which disappeared at a later stage of maturation. This feature is a novelty for insect spermiogenesis. The cysts of irradiated adults were not all uniformly affected by the radiation. However, irradiated cysts sometimes exhibited a general disorganization of sperm arrangement, incomplete divisions of sperm cells resulting in multiple copies of the same organelle within the same cell, failure to reabsorb the cytoplasm, and the lack of axonemes. Finally, rod-shaped viruses or virus-like particles were observed in vasa deferentia independently of irradiation.

Accessing biological control genetic resources: the United States perspective.

The USA has been actively involved in classical biological control projects against invasive insect pests and weeds since 1888. Classical (importation) biological control relies upon natural enemies associated through coevolution with their target species at their geographic origin to also provide long-term, self-sustaining management where the pest/weed has become invasive. Biological control agents are a form of genetic resources and fall under the purview of the 1993 Convention on Biological Diversity (CBD) and its Nagoya Protocol (NP), which entered into force in 2014 to address equitable sharing of benefits arising from utilization of genetic resources. Safe and effective classical biological control agents have historically been shared among countries experiencing problems with invasive species. However, a feature of the Nagoya Protocol is that countries are expected to develop processes governing access to their genetic resources to ensure that the benefits are shared equitably-a concept referred to as "access and benefit sharing" (ABS). Although the USA is not party to the CBD nor the NP, US biological control programs are affected by these international agreements. Surveying, collecting, exporting and importing of natural enemies may be covered by new ABS regulatory processes. Challenges of ABS have arisen as various countries enact new regulations (or not) governing access to genetic resources, and the processes for gaining access and sharing the benefits from these resources have become increasingly complex. In the absence of an overarching national US policy, individual government agencies and institutions follow their own internal procedures. Biological control practitioners in the USA have been encouraged in recent years to observe best practices developed by the biological community for insect and weed biological control.

Applying Satyrization to Insect Pest Control: The Case of the Spotted Wing Drosophila, Drosophila suzukii Matsumura.

Drosophila suzukii represents one of the major agricultural pests worldwide. The identification of safety and long-lasting tools to suppress its populations is therefore crucial to mitigate the environmental and economic damages due to its occurrence. Here, we explore the possibility of using satyrization as a tool to control the abundance of D. suzukii. By using males of D. melanogaster, we realized courtship tests, spermathecae analysis, and multiple-choice experiments to assess the occurrence and extent of pre- and post-zygotic isolation between the two species, as well as the occurrence of fitness costs in D. suzukii females due to satyrization. Our results showed that: (i) D. melanogaster males successfully courted D. suzukii females; (ii) D. melanogaster males significantly affected the total courtship time of D. suzukii males, which reduced from 22.6% to 6.4%; (iii) D. melanogaster males were able to inseminate D. suzukii and reduce their offspring, inducing a high fitness cost. Reproductive interference occurs at different steps between D. melanogaster and D. suzukii, both alone and in combination with other area-wide control approaches.

Paternity Analyses for the Planning of SIT Projects against the Red Palm Weevil.

The red palm weevil Rhynchophorus ferrugineus is an invasive pest from southeastern Asia and Melanesia that has spread widely across the Middle East and the Mediterranean Basin over the last 30 years. Its endophagous larvae cause huge amounts of damage to several palm tree species from the Arecaceae family. Many of these palms are economically important for agricultural and ornamental purposes. Therefore, a lot of attention has recently been focused on studying this species with the aim of identifying sustainable and effective eradication strategies. Sterile insect techniques are biological control strategies that are currently being investigated for their potential to eradicate this pest in selected invasion areas. Mating system features (e.g., polyandry and related features) can affect the success and suitability of these approaches. The main goal of this research was to assess the performance of a previously developed microsatellite panel in terms of the paternity assignment of progeny from laboratory mating experiments. Using a simulation approach, we evaluated the reliability of the microsatellite markers in the paternity tests both in complex laboratory experiment scenarios and on the progeny of wild-caught gravid females to help future studies on the RPW mating system. As a case study of the simulation results, we performed two double-mating experiments, genotyped the progeny and estimated the P2 values to compare to the expected progeny genotypes according to the crossing scheme of each experiment. The results of our simulations on laboratory experiments showed that it was possible to carry out paternity assignments for all progeny with reliable statistical confidence using our 13 microsatellites set. On the contrary the low genetic variability measured in red palm weevil populations in invaded areas made the resolution power of our loci too low to carry out paternity analyses on natural populations. Results of laboratory crossing were completely congruent with the expectations from the Mendelian laws.

Using Gamma Irradiation to Predict Sperm Competition Mechanism in Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae): Insights for a Future Management Strategy.

The stink bug, Bagrada hilaris, is a pest of mainly Brassicaceae crops. It is native to Africa and Asia and was recently reported as invasive in the southwestern part of the USA and in South America. There are no mitigation programs in place that do not involve pesticides. Therefore, much attention has recently been paid to the study of this species in order to identify sustainable and effective control strategies, such as the Sterile Insect Technique (SIT). In order to evaluate the suitability of the SIT on this pest, the mechanism of post-copulatory sperm competition was investigated. This is a polyandrous species, and it is thus important to understand whether irradiated males are able to compete with wild, e.g., non-irradiated, males for sperm competition after matings. Sperm competition was studied by sequentially mating a healthy virgin female first with a non-irradiated male, and then with a γ-irradiated (Co-60) one, and again in the opposite order. Males were irradiated at three different doses: 60, 80, and 100 Gy. The fecundity and fertility of the females, in the two orders of mating, were scored in order to perform an initial assessment of the success of sperm competition with a P2 index. Sperm from the non-irradiated male were utilized at the lowest irradiation doses (60 and 80 Gy), whereas the irradiated sperm were preferentially utilized at the highest dose (100 Gy). Bagrada hilaris exhibited high variability in P2 indexes, indicating a sperm-mixing mechanism.

Combining Irradiation and Biological Control against Brown Marmorated Stink Bug: Are Sterile Eggs a Suitable Substrate for the Egg Parasitoid Trissolcus japonicus?

The brown marmorated stink bug (BMSB), Halyomorpha halys, is a phytophagous invasive pest native to south-eastern Asia, and it is now distributed worldwide. This species is considered to be one of the most damaging insect pests in North America and in Europe. In agriculture, the predominant approach to managing BMSB is based on the use of insecticides, specifically pyrethroids and neonicotinoids. Unfortunately, the biology of the species and its facility to develop mechanisms of resistance to available pesticides has induced farmers and scientists to develop different, least-toxic, and more effective strategies of control. In a territorial area-wide approach, the use of a classical biological control program in combination with other least-toxic strategies has been given prominent consideration. Following exploratory surveys in the native range, attention has focused on Trissolcus japonicus, a small scelionid egg parasitoid wasp that is able to oviposit and complete its larval development in a single egg of H. halys. A common method for detecting egg parasitoids in the native range involves the placement of so-called 'sentinel' egg masses of the pest in the environment for a short period, which are then returned to the laboratory to determine if any of them are parasitized. Outside of the area of origin, the use of fertile sentinel eggs of the alien species may lead to the further release of the pest species; an alternative is to use sterile sentinel eggs to record the presence of new indigenous egg parasitoids or to detect the dispersal of alien species (in this case, T. japonicus) released in a new environment to control the target insect pest species. This study evaluated the performance of three types of sterile sentinel eggs as a suitable substrate for the oviposition and larval development of the egg parasitoid T. japonicus in a context of combining classical biological control with a Sterile Insect Technique (SIT) approach.

Effects of Irradiation on Biology and Mating Behaviour of Wild Males of Brown Marmorated Stink Bug Using a 6 MV Medical Linear Accelerator.

The brown marmorated stink bug, Halyomorpha halys, is a pentatomid bug of Eastern Asian origin that became an economically relevant pest in the Eurasian and American continents. Management of this species is limited to use of chemical insecticides: an inefficient method due to the strong adaptability of the target pest. The sterile insect technique (SIT) is potentially a valid tactic in the search for nontoxic alternatives. In this work, we investigated the suitability of mass-trapped overwintering males, collected during the aggregation phase before the winter diapause, for their release as competitive sterile males in an SIT programme. Differently from previous studies, irradiation was applied with a linear accelerator device that produced high-energy photons. Following a similar scientific protocol with newly emerged irradiated males, the effects of X-ray irradiation on physiological parameters (longevity, fecundity and fertility) were assessed. In addition, behavioural bioassays were carried out in no-choice conditions to evaluate if irradiation interferes with mating processes. The results are very encouraging; the effects of the irradiation at 32 Gy did not differ from the controls in the longevity or fecundity of the exposed overwintering adults. The hatching rate of the eggs laid by the fertile females that had mated with the irradiated males was less than 5%. The results of behavioural bioassays showed that the irradiation did not cause a significant impact on the quality of the sterile males. More research is warranted to evaluate the mating competitiveness of sterile males in semi-field and field conditions.

The Effect of the Sterile Insect Technique on Vibrational Communication: The Case of Bagrada hilaris (Hemiptera: Pentatomidae).

The painted bug, Bagrada hilaris, is an agricultural pest in its original areas (Africa, South Asia, and the Middle East), and it has recently been recorded as an invasive species in southwestern part of the US, Chile, Mexico, and two islands in the Mediterranean basin. Its polyphagous diet causes severe damage to economically important crops. The control of this pest is primarily achieved by means of synthetic pesticides, which are often expensive, ineffective, and harmful to the ecosystem. Recent physiological bioassays to assess its potential control through the sterile insect technique demonstrated that mating between untreated females and males irradiated at doses of 64 and 100 Gy, respectively, resulted in 90% and 100% sterility of the eggs produced by the females. In this study, the mating abilities of virgin males irradiated at 60 and 100 Gy with virgin females were measured through a study of short-range courtship mediated by vibrational communication. The results indicate that males irradiated at 100 Gy emit signals with lower peak frequencies, mate significantly less than unirradiated males do, and do not surpass the early stages of courtship. Conversely, males irradiated at 60 Gy present vibrational signal frequencies that are comparable to those of the control and successfully mated males. Our findings suggest that B. hilaris individuals irradiated at 60 Gy are good candidates for the control of this species, given that they retain sexual competitiveness regardless of their sterility, through an area-wide program that incorporates the sterile insect technique.

Effects of γ-Irradiation on Mating Behavior of Red Palm Weevil, Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera: Dryophthoridae).

Red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier 1790) is a highly invasive species originating from Southeast Asia and Melanesia. Over the past 30 years, this alien pest has spread extensively in the Middle East and the Mediterranean basin. Its endophagous larvae feed on various palm species, causing significant damage that leads to the death of palm trees. Controlling RPW infestations is challenging due to their gregarious nature and the lack of detectable early symptoms. Systemic insecticides are effective means of control, but their use in urban areas is prohibited and resistance can develop. Considering alternative options with minimal environmental impact, the Sterile Insect Technique (SIT) has been explored. Previous research has shown that male RPWs irradiated at 80 Gy or higher achieve full sterility. This study aimed to investigate in laboratory conditions whether RPW sterile males (irradiated at 60 and 80 Gy) could compete sexually with non-irradiate males. Laboratory bio-assays under both no-choice and choice conditions assessed sexual performance in terms of number of matings, mating duration and time elapsed until the first mating. The results confirmed that irradiation does not negatively affect the mating performance of sterile males, demonstrating their ability to compete successfully with non-irradiated males in both experimental setups.