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Historically, the neogregarine Apicystis bombi was isolated almost exclusively from bumble bees ( Bombus spp.) where it disrupts adipose tissue, increasing hosts' mortality rates. Records in solitary bees are scarce worldwide. To check for its presence in carpenter bees (genus Xylocopa ), campaigns were performed in Argentina capturing 154 individuals of five species ( X. augusti , X. splendidula , X. atamisquensis , X. frontalis , X. nigrocincta ). The presence of A. bombi was detected by molecular means in X. augusti , X. atamisquensis, and X. nigrocincta in four of the nine provinces screened. The pathogenesis and eventual impact that A. bombi may cause in individuals or populations of Xylocopa species remain unknown. The presence of A. bombi in northern Argentina would be contradictory to the hypothesis that its occurrence is the exclusive result of its introduction to South America through invasive, infected exotic bumble bees., Competing Interests: None., (© 2023 The Authors.)

Background: Dengue is the world's most prevalent mosquito-borne viral disease. It is endemic in many tropical and subtropical countries and represents a significant global health burden. The first reports of dengue virus (DENV) circulation in the South West Indian Ocean (SWIO) islands date back to the early 1940s; however, an increase in DENV circulation has been reported in the SWIO in recent years. The aim of this review is to trace the history of DENV in the SWIO islands using available records from the Comoros, Madagascar, Mauritius, Mayotte, Seychelles, and Reunion. We focus in particular on the most extensive data from Reunion Island, highlighting factors that may explain the observed increasing incidence, and the potential shift from one-off outbreaks to endemic dengue transmission., Methods: Following the PRISMA guidelines, the literature review focused queried different databases using the keywords "dengue" or "Aedes albopictus" combined with each of the following SWIO islands the Comoros, Madagascar, Mauritius, Mayotte, Seychelles, and Reunion. We also compiled case report data for dengue in Mayotte and Reunion in collaboration with the regional public health agencies in these French territories. References and data were discarded when original sources were not identified. We examined reports of climatic, anthropogenic, and mosquito-related factors that may influence the maintenance of dengue transmission independently of case importation linked to travel., Findings and Conclusions: The first report of dengue circulation in the SWIO was documented in 1943 in the Comoros. Then not until an outbreak in 1976 to 1977 that affected approximately 80% of the population of the Seychelles. DENV was also reported in 1977 to 1978 in Reunion with an estimate of nearly 30% of the population infected. In the following 40-year period, DENV circulation was qualified as interepidemic with sporadic cases. However, in recent years, the region has experienced uninterrupted DENV transmission at elevated incidence. Since 2017, Reunion witnessed the cocirculation of 3 serotypes (DENV-1, DENV-2 and DENV-3) and an increased number of cases with severe forms and deaths. Reinforced molecular and serological identification of DENV serotypes and genotypes circulating in the SWIO as well as vector control strategies is necessary to protect exposed human populations and limit the spread of dengue., Competing Interests: The authors have declared that no competing interests exist.

The expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.

Mosquitoes are responsible for the transmission of major pathogens worldwide. Modelling their population dynamics and mapping their distribution can contribute effectively to disease surveillance and control systems. Two main approaches are classically used to understand and predict mosquito abundance in space and time, namely empirical (or statistical) and process-based models. In this work, we used both approaches to model the population dynamics in Reunion Island of the 'Tiger mosquito', Aedes albopictus, a vector of dengue and chikungunya viruses, using rainfall and temperature data. We aimed to i) evaluate and compare the two types of models, and ii) develop an operational tool that could be used by public health authorities and vector control services. Our results showed that Ae. albopictus dynamics in Reunion Island are driven by both rainfall and temperature with a non-linear relationship. The predictions of the two approaches were consistent with the observed abundances of Ae. albopictus aquatic stages. An operational tool with a user-friendly interface was developed, allowing the creation of maps of Ae. albopictus densities over the whole territory using meteorological data collected from a network of weather stations. It is now routinely used by the services in charge of vector control in Reunion Island., Competing Interests: The authors have declared that no competing interests exist.

An initial survey in 2009 carried out at a site in northwestern Patagonia region, Argentina, revealed for the first time in South America the presence of the flagellate Crithidia bombi and the neogregarine Apicystis bombi, two pathogens associated with the Palaearctic invasive bumble bee Bombus terrestris. In order to determine the long-term persistence and dynamics of this microparasite complex, four additional collections at the same site (San Carlos de Bariloche) were conducted along the following seven years. Both protists were detected in all collections: prevalence was 2%-21.6% for C. bombi and 1.2%-14% for A. bombi. In addition, the microsporidium Nosema bombi was recorded for the first time in the country in the last two collections, at prevalences of 12.4% and 2.4% and unusually high infection intensities (Average = 6.56 × 10 7 spores per individual). Due to the exceptional dispersal ability of the exotic B. terrestris, these three multihost pathogens should be considered as potential threats to South American native bumble bees., (© 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.)

The "tomato moth," Tuto absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a neotropical oligophagous insect considered a key pest of tomato crops. It was detected in Europe seven years ago and quickly spread to several regions of Asia and North Africa. In Argentina, its control is done by chemical pesticides mainly. The indiscriminate use of chemical broad spectrum pesticides have caused several problems in the control of this pest due to resistance mechanism involved to several insecticides including pyrethroids, organophosphates and biopesticides. In this context, the searching and evaluation of new compounds- compatible with integrated pest management programs- has become relevant. Within the phenylpropanoids, alkyl cinnamates, whether natural or synthetic, have been reported with biological activity: repellence, antifeedant and insecticide. Therefore, the cinnamates could be a valuable alternative to replace the conventional insecticides. The aim of this work was to study the antifeedant effect of three alkyl cinnamates (methyl, ethyl and propyl cinnamate) on the consumption rate patterns of second instar larvae of T. absoluta. A series of concentrations of each compound (100, 250 and 500 micrograms/milliliter) were prepared using acetone (analytical grade) - distilled water as solvent and a surfactant (Tween 80) was added to each solution to improve the wet of leaves. Tomato leaf disks of 2 cm diameter were treated by immersion in each solution during 15 seconds. Afterward, the treated discs were dried under fume hood and each disk was placed in a plastic capsule. A larva with 6-8 hours of starvation was added to each experimental unit. Each treatment was replicated between 24-30 times. The area consumed by each larva was measured after 24, 48 and 72 hours post-treatment. We also evaluated development time, weight of the pupa, adult emergence, fecundity and fertility as sublethal effects. The results were analyzed using ANOVA test. None of the compounds tested at the aforementioned concentrations exhibited insecticidal effect. However, ethyl cinnamate showed a strong antifeedant effect. The results observed on the leaf consumption and other sublethal effects assessed will be discussed. According to these preliminary results, further studies are needed to complete its toxicological profile by other exposure methods.

The generalist predator Chrysoperla externa (Neuroptera: Chrysopidae) is distributed in the Neotropical Region and presents a strong potential as a biological control agent due to its easily rearing, high voracity and tolerance to several pesticides. This species feeds on relevant pests such as aphids, whiteflies, trips and various lepidopterans. In Argentina, an indiscriminate chemical control with broad spectrum pesticides is still the first option for controlling pests causing resistance problems and reduction of beneficial organisms. Therefore, it would be desirable that predators or parasitoids develop tolerance or resistance as phytophagous pests for their maintenance in the agricultural ecosystems. The objective of this work was to evaluate the tolerance of C. externo to the pyrethroid cypermethrin by topical exposure in laboratory conditions. The symptoms evaluated were tremors, movement, knockdown, inability to walk due to being glued. Recovery from poisoning symptoms was also evaluated. Six different concentrations of the pesticide, including the full field one, were tested. The exposure method was by topical applications on third larval instar. A low toxicity on larvae at 24 h post-treatment was observed, even at the highest concentration evaluated. Most of treated individuals looked normal at 24 h post-treatment; those who were knocked down showed a complete recovery between 48 and 72 h post-treatment. C externa demonstrated a high tolerance to pyrethroids. This could be due to the activity involved in pyrethroids biotransformation (for example, esterases and mixed-function oxidases), or to a low sensitivity of the molecular target. Future studies should be addressed at biochemical and molecular levels to complete our knowledge about insecticide effects on this predator.

The Bemisia tabaci Gennadius (Homoptera:Aleyrodidae) biotype complex is a key pest of several worldwide crops. The management and control of this pest has become difficult mainly due to its high reproductive rate and capacity to develop resistance to broad spectrum insecticides. In Argentina B. tabaci whitefly, causes economic losses in most areas of agricultural production. Eretmocerus mundus Mercet (Hymenoptera:Aphelinidae) is the most important parasitoid of B. tabaci and is commercialized as a biocontrol agent, mainly in Europe. Conservation of this biological control agent in Argentinean orchards requires the adoption of sustainable pest management practices due the negative impact of traditional pesticides on non-target organisms. Spirotetramat (Movento) belongs to a new class of pesticides that acts as a lipid biosynthesis inhibitor and claims to be selective towards natural enemies. The objectives of this work were 1) to evaluate the effectiveness of spirotetramat on eggs and nymphs of B. tabaci and 2) to determine the selectivity of spirotetramat towards E. mundus. Whitefly's eggs and nymphs (first nymphal settled instar) were exposed to the insecticide by foliar immersion whereas parasitoid adults (6 days old) were exposed to the insecticide by residual method for one hour, to simulate exposure of the parasitoid to the insecticide in the field. Lethal and sublethal effects of the insecticide were recorded daily. These preliminary studies have shown a high effectiveness of spirotetramat on the first nymphal instar of B. tabaci as well as a high selectivity for the pest in comparison to the parasitoid adults showing a low acute toxicity to them. These results suggest Movento could be included in Integrated Pest Management programs although more studies are required to complete its ecotoxicological profile.

In Argentina, transgenic soybean crop (Roundup Ready, RR) has undergone a major expansion over the last 15 years, with the consequent increase of glyphosate applications, a broad-spectrum and post emergence herbicide. Soybean crops are inhabited by several arthropods. Eriopis connexa Germar (Coleoptera: Coccinelidae) is a predator associated to soybean soft-bodies pest and have a Neotropical distribution. Nowadays, it is being considered a potentially biological control agent in South America. The objectives of this work were to evaluate the side-effects of glyphosate on larvae (third instar) and adults of this predator. Commercial compound and the maximum registered concentrations for field use were employed: GlifoGlex 48 (48% glyphosate, 192 mg a.i./litre, Gleba Argentina S.A.). The exposure was by ingestion through the treated prey (Rophalosiphum padi) or by drinking treated water during 48 h for treatment of the adult. The herbicide solutions were prepared using distilled water as solvent. The bioassays were carried out in the laboratory under controlled conditions: 23 +/- 0.5 degrees C, 75 +/- 5% RH and 16:8 (L:D) of photoperiod. Development time, weight of pupae, adult emergence, pre-oviposition period, fecundity and fertility were evaluated as endpoints. Larvae from glyphosate treatment molted earlier than controls. In addition, the weight of pupae, longevity, fecundity and fertility were drastically reduced in treated organisms. The reductions were more drastic when the treatments were performed at the third larval stage than as adult. The reproduction capacity of the predator was the most affected parameter and could be related to a hormonal disruption by glyphosate in the treated organisms. This work can confirm the deleterious effects of this herbicide on beneficial organisms. Also, it agrees with prior studies carried out on other predators associated to soybean pest, such as Chrysoperla externa (Neuroptera: Chrysopidae) and Alpaida veniliae (Araneae: Araneidae).

The integrated pest management (IPM) premises claim for a joint use of beneficial organisms (parasitoids and predators) and selective pesticides. Botanical pesticides are being considered as selective pesticides. During the last 20 years of the 20th century, the plant family Meliaceae was identified as a promising source of compounds with insect-control properties. The Chinaberry tree, Melia azedarach L., is a deciduous tree native to Persia, India, and China, but has been cultivated in many countries including Africa, Australia, and the Americas. It is a source of tetranortriterpenoid compounds called meliatoxins, which have similar structures and insecticidal activities compared to azadirachtin. Eriopis connexa Germar (Coleoptera: Coccinelidae) is a native predator from the Neotropical Region. It is a beneficial organism associated to several agro-ecosystems, feeding on soft-bodies pest such as aphids, whiteflies and thrips. In horticultural crops, it has been observed to feed on worldwide important pest such as Bemisia tabaci Gennadius (Heteroptera: Aleyrodeidae) and Myzus persicae L. (Heteroptera: Aphididae), both of them considered as virus vectors. The objectives of this work were to evaluate the side-effects of M. azaderach (Meliaceas) extract on eggs, larvae and adults of Eriopis connexa. Extracts from unripe fruits (1%, w/w, obtained by the CEPROCOR, Cordoba-Argentina) were employed for ecotoxicological bioassays. The exposure method was by immersion for eggs and by ingestion of drinking water for adults. The botanical extract solutions were prepared using distilled water as solvent and a tensioactive (Tween 20) for topical application. The bioassays were carried out in the laboratory under controlled conditions: 23 +/- 0.5 degrees C temperature, 75 +/- 5% RH and 16:8 (L:D) photoperiod. Hatching, development time, adult emergence, pre-oviposition period, fecundity and fertility were evaluated as endpoints. No detrimental effects were observed in treated organisms irrespective of the exposure way and development stage. According to these preliminary results, M. azaderach fruit extracts can be compatible with E. connexa for pest control. However, future studies should be addressed to conclude about its toxicity on beneficial organisms.