ABSTRACT Cape Saint Paul Wilt Disease (CSPWD), a lethal yellowing‐type disease of coconut associated with ‘ Candidatus Phytoplasma palmicola’ (16SrXXII‐B), continues to threaten coconut production in Ghana. As most phytoplasma putative vectors belong to the suborder Auchenorrhyncha, we conducted field surveys in CSPWD‐devastated, actively diseased and healthy coconut plantations. In total, 13,919 individuals representing five families were collected, with Derbidae being the most abundant. Nested PCR screening of 282 pooled samples (~1900 insects) detected CSPWD (16SrXXII‐B)‐associated phytoplasma in Diostrombus sp. 1, Diostrombus sp. 2 and Patara armata from actively diseased and devastated coconut plantations. Although these taxa also occurred in healthy plantations, they tested negative for the pathogen. While vector competence remains to be verified, these results provide essential baseline data for targeted surveillance and transmission studies aimed at identifying confirmed CSPWD vectors in Ghana.
ABSTRACT Jikradia olitoria Say is a Nearctic leafhopper that was recently reported in several European countries. Given its role as the vector of phytoplasmas associated with Grapevine Yellows diseases (GYD) in its native range, its presence in European vineyard agroecosystems could represent an important phytosanitary risk. In Europe, the quarantine GYD Flavescence dorée (FD) is widespread and causing important economic losses. Its main vector, Scaphoideus titanus Ball, was also introduced from North America. Therefore, investigating the potential role of such new insect species is of crucial importance. In this study, we report the first detailed record of J. olitoria in Switzerland, particularly in the Swiss southern Alps. Systematic monitoring conducted over two consecutive years (i.e., 2023 and 2024) using chromotropic traps in seven sites allowed to confirm its widespread presence in the southern Alps, both inside vineyards as well as in the nearby forest edge compartment. Moreover, a subset of the collected specimens was analysed to test potential infection by phytoplasmas associated with FD. No phytoplasma infections have been detected so far. The surveillance and the early detection of new potential vectors remain, however, crucial to mitigate new potential phytosanitary threats for European viticulture.
ABSTRACT Urbanization is one of the most significant land‐use changes globally, profoundly impacting biodiversity across taxa. Insects, including grasshoppers (Orthoptera), are particularly sensitive to urban pressures, often exhibiting both morphological and behavioural adaptations. While laboratory studies suggest that urban environments favour increased boldness and exploratory behaviour, field‐based evidence remains scarce. In this study, we investigated behavioural differences in the bow‐winged grasshopper, Chorthippus biguttulus , a widespread grasshopper species in Germany, across a gradient of urbanization in and around Münster. Using two behavioural assays, a tonic immobility (hand) test and a tunnel‐based dark‐room escape test, we assessed boldness‐related and exploratory behaviour in 126 individuals from nine grassland sites categorized by low, medium, or high urban land cover. Our results showed that grasshoppers from highly urbanized sites escaped significantly faster from the dark compartment than those from medium or low urbanization levels, indicating increased boldness‐related behaviour. However, urbanization did not significantly affect tonic immobility or exploratory behaviour. Ambient temperature significantly influenced exploratory movement, with individuals moving more quickly at higher temperatures. These findings confirm that urban grasshoppers showed shorter escape latencies, consistent with increased boldness‐related behaviour, under field conditions, likely as an adaptive response to novel and stressful environments. However, the influence of temperature and the lack of changes in exploratory behaviour suggest complex interactions between abiotic and biotic factors. Our study highlights the importance of field‐based behavioural research for understanding insect responses to urbanization and informs future conservation efforts in increasingly urbanized landscapes.
ABSTRACT Termites are eusocial insects that maintain cohesion and exchange information through frequent physical interactions among nestmates. This social organisation underlies the principle of horizontal insecticide transfer, which is widely exploited as a termite control strategy. However, despite extensive laboratory evidence supporting its effectiveness, the specific behaviours mediating interactions between intoxicated and healthy individuals remain poorly understood. Here, we evaluate how caste‐associated social context shapes behavioural interactions between healthy nestmates and a single imidacloprid‐exposed individual in Nasutitermes corniger (Termitidae: Nasutitermitinae). We compared two biologically relevant social scenarios: worker groups interacting with an exposed worker and mixed worker–soldier groups interacting with an exposed soldier. We quantified alarm‐ and prophylaxis‐related behaviours and subsequently assessed group mortality. Our results show that antennation responses depended on the interaction between insecticide treatment and caste‐associated social context. Vibratory behaviour was more frequent in worker‐only groups, whereas trophallaxis was more frequent in mixed worker–soldier groups, independently of insecticide exposure. Grooming increased independently in mixed groups and following insecticide exposure. Mortality analyses did not provide evidence that the introduction of a single exposed individual consistently altered group‐level mortality risk. Overall, our findings indicate that termite responses to intoxicated nestmates depend on caste‐associated social context, probably reflecting both caste‐specific interaction patterns and the morphological dependence of soldiers on workers.
ABSTRACT The functional response of parasitoids is a key metric for evaluating their effectiveness as biological control agents and has been characterized for numerous host–parasitoid systems under diverse conditions. This study examines how parametric assumptions affect statistical inference in parasitoid functional response analysis, with particular attention to parameter estimation and model selection. Conventional approaches commonly use least squares or maximum likelihood methods based on heuristic distributions, such as the binomial or beta‐binomial distribution. From the perspective of point estimation, least squares can be viewed as equivalent to maximum likelihood under normally distributed errors with constant variance. Using simulations and published datasets, this study shows that arbitrary choices among these methods can lead to different estimates of functional response parameters and different conclusions about whether the response is type II or type III. In addition, a more flexible likelihood‐based approach is developed by characterizing the probability distribution of the data through simulations of the parasitism process. Comparisons with beta‐binomial maximum likelihood show that the simulation‐based model provides a better fit for some datasets, indicating that conventional heuristic distributions may not be flexible enough to describe the variability present in functional response data. The analyses also suggest that some datasets may contain insufficient information to distinguish reliably between competing functional response models, even when conventional model‐selection procedures appear to favour one model. These results show that variability in functional response data should be explicitly considered, because it can strongly influence parameter estimation and model selection.
ABSTRACT As poikilothermic organisms, insects are highly susceptible to climate warming, but most relevant studies have adopted a single‐scale perspective and ignored spatial heterogeneity in pest phenological responses, resulting in insufficient understanding of regional phenological variations. To address this gap, the present work explored the multi‐scale phenological responses of Chilo suppressalis to climate warming at regional and provincial scales. Long‐term phenological datasets of C. suppressalis spanning 1970–2024 and corresponding temperature dates were compiled and matched. Interannual phenological trends of overwintering and subsequent‐generation adults were analysed via linear regression, and the correlations between phenological shifts and temperature variations were assessed using Pearson correlation analyses. Significant increases in annual and seasonal mean temperatures were observed across the five study regions over the 54‐year period, with the most prominent warming detected in Eastern China. Distinct spatial heterogeneity was identified in the phenological responses of C. suppressalis to climate warming, rather than a uniform phenological advance trend. At the regional scale, the first occurrence of overwintering adults advanced in Central China but delayed in Eastern China, while the population peak of subsequent‐generation adults advanced in Southern China but lagged significantly in Eastern China. At the provincial scale, divergent phenological responses were found across provinces, with an advanced population peak in Guangxi and a delayed peak in Zhejiang. Rising spring and annual mean temperatures were confirmed as the key factor driving the phenological advancement of C. suppressalis . This multi‐scale analysis clarifies the spatially heterogeneous phenological responses of C. suppressalis to climate warming, and its findings provide a reliable scientific reference for region‐specific pest monitoring and management in rice agroecosystems under climate change.
ABSTRACT The Tephritidae family, or true fruit flies, comprises approximately 250 species recognized as economically significant due to their capacity to infest commercial fruits. These pests pose serious threats to both food security and trade, and are considered quarantine pests in areas where they are not yet established. In the European Union (EU), regulatory changes in 2021 and 2024 introduced a targeted list of 78 quarantine Tephritidae taxa, requiring precise identification of intercepted larvae during import inspections. To date, traditional morphological identification methods have been facing limitations due to (1) the lack of described larval features for many species and (2) the difficulty of access to specialized equipment, like scanning electron microscopes. To address these limitations, the European Union Reference Laboratory for Insects and Mites (EURL I&M) has developed a simplified morphological identification key for the most frequently intercepted Tephritidae larvae in the EU. To do so, interception data and fruit fly specimens across the EU were collected and analysed. A literature review was performed to allow for comparison between the morphological data obtained in this study and publicly available information. The key is intended to assist National Reference Laboratories (NRLs) and diagnostic laboratories in performing rapid and reliable identifications during import inspections, thus improving phytosanitary decision‐making and regulatory compliance.
Gryllodes sigillatus is an increasingly important species in edible insect production, yet the optimal rearing density for this species under commercial conditions remains poorly defined. This study evaluated the effects of five rearing densities (1.5, 2, 2.5, 3 and 4 mL of newly hatched nymphs, corresponding to approximately 0.144-0.385 crickets/cm2) on survival, adult emergence, mean individual body weight, absolute number of adults and residual nymphs and total biomass per container in a completely randomized design with nine replicates per treatment. At Day 60, rearing density affected all measured variables except total biomass per container. Adult emergence probability declined progressively with increasing density, from 0.422 at 1.5 mL to 0.175 at 4 mL, while mean individual body weight was higher at the two lowest densities compared to all higher treatments. Survival probability was significantly reduced only at the highest density tested (4 mL) relative to 2.5 mL. The absolute number of adults per container was significantly greater at 2.5 mL than at 1.5 and 2 mL, reflecting the compensatory effect of larger initial cohort size. Conversely, the number of residual nymphs increased markedly with density, indicating progressive developmental delay under crowded conditions. Total biomass did not differ across treatments, demonstrating that gains in individual weight at low density were offset by lower absolute survival, rendering total yield effectively density-independent within the range tested. These results reveal that the identity of the optimal rearing density depends on the production objective: within the range tested, 1.5 mL maximises individual quality and developmental completeness, while 2.5 mL maximises absolute adult yield per container, though lower densities than those evaluated here may further improve individual performance.
Soybean (Glycine max (L.) Merr.) is one of the most important crops worldwide, yet its rapid expansion across Brazilian biomes, particularly the Cerrado, raises concerns about pollinator loss and the decline of ecosystem services. Although soybean is mainly self-pollinated, several studies highlight the contribution of wild and managed bees to yield improvement. Understanding how landscape structure and farm management affect bee communities in soybean agroecosystems is therefore essential for sustainable production. This study assessed how the composition of adjacent native vegetation and local management practices influence bee richness, abundance, and community structure in soybean fields with different application frequencies and types of pesticides and fertilizers. Bee samples were collected using pan traps and entomological nets. A total of 599 bee specimens were recorded, with 207 individuals in native vegetation and 392 in soybean fields. Halictidae, especially Dialictus spp., dominated in soybean areas, whereas Ceratina (Crewella) duplocarinata (Apidae) was the most abundant species in native vegetation. Species richness did not differ significantly between habitats, but species composition varied. The sampled native-vegetation assemblage overlapped strongly with, and appeared nested within, the soybean-field assemblage, a pattern that may partly reflect mass-flowering effects and sampling conditions during soybean bloom. Distance from native vegetation negatively affected native bee abundance and richness, while Apis mellifera abundance remained unaffected. Higher fungicide and insecticide use reduced community evenness and showed that species richness and abundance alone may not be good predictors in environments with high disturbance, since a few tolerant species may affect these metrics. These findings suggest that both landscape configuration and management intensity shape bee assemblages in soybean systems. Maintaining nearby native vegetation and reducing reliance on chemical inputs are essential to sustaining diverse bee communities and the pollination services they provide in large-scale soybean production.
ABSTRACT Globally, citrus production areas are threatened by greening diseases, also known as Huánglóngbíng (HLB), associated with phloem‐limited gram‐negative species of the genus Candidatus Liberibacter. Those pathogens are transmitted by either the Asian citrus psyllid, Diaphorina citri Kuwayama 1908 (Hemiptera: Psyllidae), or the African citrus triozid, Trioza erytreae (Del Guercio, 1918) (Hemiptera: Triozidae). Asian citrus greening associated with ‘ Candidatus Liberibacter asiaticus’ (HLB‐CLas) is the most severe form of the disease and is primarily transmitted by D. citri , although T. erytreae can also acquire and transmit the pathogen. African citrus greening associated with ‘ Candidatus Liberibacter africanus’ (HLB‐CLaf), vectored by T. erytreae , caused major yield losses in South Africa during the 1970s. Diaphorina citri was detected in East Africa in 2015, while T. erytreae was reported in Southern Europe around the same time. Currently, the most effective way to limit citrus tree infection by HLB is to manage its vectors, which requires that their biology be understood. While there is extensive literature on D. citri , we show that T. erytreae is currently understudied. Using a systematic map approach, we reviewed the literature for T. erytreae and identified knowledge gaps for this species. Among the 86 articles identified, most were on distribution and monitoring (31.03%) and control methods (17.24%). Topics such as thermal biology, chemical ecology or host plants represent the largest knowledge gap, with each category representing < 7% of the research literature.
Asian citrus psyllid, Diaphorina citri, was first detected in Cyprus in 2023. This finding initiated an eradication campaign and a classical biological control program based on the introduced ectoparasitoid Tamarixia radiata. Recent integrative taxonomic work revealed the presence of a second primary parasitoid species, Tamarixia citricola, associated with D. citri nymphs in Cypriot citrus orchards. Here, we provide a post-release monitoring update on this biological control program based on field surveys conducted in late October 2025 at citrus sites selected because of previous records of D. citri or recent reports of psyllid activity from the Cypriot Plant Health Services. Overall, adult D. citri abundance was very low; adults were absent from nearly all orchards and were detected at clearly higher levels in only one site, where 60% of tap-sampled flush shoots were positive for adult presence. Nymphs showed a similar pattern, with only sparse, low-density colonies detected across the surveyed orchards. Importantly, the site with the highest D. citri density also showed the highest nymph parasitism (96.2%), consistent with strong parasitoid-associated suppression. Of the primary parasitoids that emerged, 96.9% were T. radiata, whereas 3.1% were T. citricola. For the first time in Cyprus, we also recorded the hyperparasitoid Marietta leopardina, which reached 26.7% hyperparasitism and showed a marked association with primary parasitoids developing in third-instar nymphs. These results support the important role of T. radiata in the current classical biological control program in Cyprus and underscore the need for continued monitoring to understand better emerging trophic interactions that may influence long-term outcomes.
ABSTRACT Fall armyworm ( Spodoptera frugiperda J.E. Smith) (FAW) is a major pest in maize farming. In 2017, the FAW infestation rate in maize fields was reported to be 100% in Kenya, 93%–100% in Tanzania, and 33%–100% in Ethiopia. Management of this pest is challenging due to its wide range of host plants, rapid reproduction, and fast migration. No single approach has been successfully used to control the FAW. Therefore, an integrated pest management (IPM) strategy is key to FAW control. This involves using biological, cultural, chemical, and host plant resistance (HPR) methods. Host plant resistance is an integral component of IPM and is the most effective, safe, and reliable method of controlling pests. In addition, HPR is heritable and can be enhanced using plant breeding strategies. Host plant resistance improvement through conventional plant breeding requires the identification of sources of resistant genes, crosses, backcrossing, evaluation, and selection of progenies. Developing hybrid maize through conventional plant breeding takes up to 10 years. However, the application of modern plant breeding technologies, such as genome‐wide association studies (GWAS), genomic selection, transcriptomics, proteomics, genome editing, enviromics, and phenomics, may reduce the time required to develop FAW‐resistant maize varieties. This review provides information on the status of the use of modern plant breeding technologies for the management of FAW in maize in Eastern Africa. In addition, recommendations and future prospects for the use of these technologies to enhance genetic improvement of FAW resistance in maize are documented.
In recent years, chlorantraniliprole has been one of the most used active ingredients for the control of lepidopteran pests, including the corn earworm, Helicoverpa zea (Boddie), on row crops in the southern US Chlorantraniliprole is in the diamide class of insecticides. It possesses high efficacy and long residual activity for the control of susceptible caterpillar species. These desirable properties have led to an increase in its usage since its introduction in the US Several studies have examined the susceptibilities of H. zea to chlorantraniliprole. These studies generally test neonate or third-instar caterpillars using insecticide-diet-incorporated bioassays and present lethal concentration (e.g., LC50) values based on survival at a particular time point. These assays provide partial information of the survival of H. zea for only a fragmented part of their development. We examined the ultimate survival of the F-1 generation of an H. zea colony originally collected from crimson clover (Trifolium incarnatum L., Fabaceae). Neonate larvae were placed on an artificial diet incorporating six different concentrations (0-16 ng/mL) of chlorantraniliprole and allowed to grow inside cups filled with the treated diet. Surviving male and female moths were paired within each treatment concentration, and the number of eggs laid per female was recorded. Survival to the pupal stage ranged from similar to 12% to 85%, while survival from pupae to moths ranged from 60% to 90%. As insecticide concentration increased, days to reach the pupal stage increased, and pupal weight decreased. Once moths reached the pupal stage, days to emergence were similar for all concentrations. The number of eggs laid per adult female were not significantly related to the insecticide and averaged 45-120 eggs. These data present the fate of H. zea larvae that develop on chlorantraniliprole for their entire larval development and may be used to supplement traditional insecticide bioassays.
ABSTRACT The pest status of pea aphid ( Acyrthosiphum pisum H.) in faba bean ( Vicia faba L.) cultivation has gained importance because it transmits Pea necrotic yellow dwarf virus (PNYDV), a novel nanovirus in Europe. This study evaluated two faba bean varieties, ‘Fuego’ and ‘GL Sunrise’, grown under sole crop (SC) and intercrop (IC) conditions with oat ( Avena sativa L.) to assess their response to biotic stress by vector infestation and PNYDV infection. In a 2‐year field experiment (2021–2022), an additive, alternate row design with infector rows in each plot receiving regular releases of viruliferous A. pisum was used. ‘GL Sunrise’ consistently had lower aphid infestations than ‘Fuego’ in both cropping systems. Furthermore, intercropping with oat reduced vector movement due to the row barrier effect. In 2021, PNYDV was absent, so aphid pressure mainly resulted in nutrient depletion, with minor effects on nitrogen fixation and yield. Land equivalent ratios (LER) were slightly below 1.0. In 2022, PNYDV infection compounded by heat and drought led to a significant reduction in symbiotic N‐fixation and yield of V. faba in SC systems. In IC systems, the oat component benefited from the reduced competitiveness of both stressed V. faba varieties, and this additional oat yield resulted in LER values above 1.0. The IC system thus ensured a lower spread of aphids and PNYDV and greater yield stability. Due to the only moderate agronomic performance of GL Sunrise under Central German growing conditions, a further screening for stress‐tolerant faba bean genotypes is recommended.
ABSTRACT Liquid‐sprayable cellulose hydromulches (HM) are alternatives to plastic polyethylene (PE) mulches for weed suppression in organic agriculture. However, their impact on arthropod pests and natural enemies remains unexplored. Various HMs made of shredded newsprint, water and guar gum were compared against white‐on‐black PE mulch, paper sheet mulch, a weedy check and a weed‐free control. Four HM treatments combining application rates (low: 5800 or high: 8700 kg dry weight ha −1 ) and colour intensity (dark or light) were tested in raised‐bed, drip‐irrigated organic strawberry crops at two sites: Absaraka and Fargo, ND. Densities of insect pests and natural enemies were measured via pitfall traps and pest‐specific sampling methods. Mulch treatments affected Lygus and Nysius bugs densities (Hemiptera: Miridae, Lygaeidae) via indirect positive effects of weed density. There were no effects of mulch on densities of spotted‐wing drosophila [ Drosophila suzukii Matsumura (Diptera: Drosophilidae)] or fruit infestation. Activity‐density of harvestmen, spiders, and large carabid beetles was similar among mulch treatments, likely reflecting high mobility across uneven surfaces. Activity‐density of medium‐ and small‐sized carabid beetles was typically highest in weed‐free or weedy plots. HMs appeared to have disrupted the movement of medium‐ and small‐sized carabid beetles at one location, although impacts on other arthropods appeared to be minimal or related to weed density. HMs are a promising weed management tool in organic strawberry systems, but our findings reveal complex relationships between mulch physical properties, weed communities, and arthropods that need to be considered.
Rice planthoppers, including Nilaparvata lugens (Stål), Laodelphax striatellus (Fallén), and Sogatella furcifera (Horváth), pose substantial threats to global rice production through direct feeding damage and transmission of viral diseases. Although chemical control remains the primary management approach, insecticide concentrations below lethal levels (also referred to as ‘sublethal doses’) produce significant biological effects that extend well beyond immediate mortality. This review synthesises current knowledge on how sublethal insecticide exposure fundamentally alters rice planthopper biology through multiple pathways, including nerve system disruption, hormonal imbalance, cellular stress, and heritable genetic changes. Sublethal exposure modifies rice planthopper behaviour by disrupting feeding activity and movement coordination, while simultaneously activating detoxification enzyme systems (cytochrome P450s, glutathione‐ S ‐transferases, and carboxylesterases) that promote insecticide resistance. Reproductive impacts are substantial, with egg production commonly reduced by more than 60%, alongside delayed egg‐laying and damaged ovarian tissues. Interestingly, low doses occasionally stimulate increased reproduction, causing temporary population increases. Developmental effects include prolonged immature stages, enhanced production of winged forms capable of long‐distance migration, and impacts that persist across multiple generations through epigenetic mechanisms. The ecological consequences including pest resurgence, secondary pest outbreak, and impact on non‐target organisms are equally important. Insecticides affect natural enemies (predators and parasitoids) more severely than pests and as a result, surviving rice planthopper populations can rebound rapidly when predation pressure decreases. Broad‐spectrum insecticide applications also enable formerly minor pests to become major problems. Furthermore, beneficial organisms such as pollinators, parasitic wasps, and aquatic predators suffer collateral damage, compromising essential ecosystem functions and creating feedback loops that progressively reduce pesticide effectiveness. Following this review, sustainable rice planthopper management requires integrated strategies combining resistant rice varieties, biological control organisms, precision application technologies, and innovative approaches such as RNA interference‐based biopesticides. Future research should prioritise quantifying impacts on beneficial insects, understanding molecular mechanisms of transgenerational effects, and developing practical decision‐support tools for farmers.
The fall armyworm (Spodoptera frugiperda) poses a significant threat to maize production across sub-Saharan Africa (SSA), necessitating sustainable and effective integrated pest management (IPM) strategies. Among the existing IPM technologies, biological control and diversified cropping systems, particularly the use of Cotesia icipe (a larval endoparasitoid) and the push-pull cropping system, are among the most widely promoted approaches in SSA. However, their integration into large-scale, practical pest management programmes remains underexplored and is still at a subsistence level. This calls for a fundamental change in these practices, with a specific focus on suitable areas and their widespread adoption across several maize-growing regions in SSA. Additionally, there is a need for large-scale, integrated IPM packages to ensure long-term FAW management. This study employed ecological niche modelling and the Jaccard similarity index to identify regions across SSA where the suitability of C. icipe and push-pull companion plants overlap, thus providing a spatially informed framework for IPM implementation. Across Africa, the model proposes a pathway for identifying the locations that are ecologically suitable for FAW IPM interventions based on the use of C. icipe and push-pull cropping system. The results highlight key co-suitable regions across several maize-growing agroecological zones, including West Africa's coastal areas, large portions of Central Africa and significant areas in East Africa, particularly around Ethiopia and Kenya. Large suitable areas were also identified in Southern Africa, particularly in regions conducive to intensive agricultural practices. These findings provide a scalable decision-support tool for targeting IPM interventions in zones with the highest ecological potential for success. By prioritizing interventions in these identified suitable areas, policymakers, stakeholders, researchers and extension services can improve the effectiveness of FAW management, enhance food security, crop protection and promote climate-resilient agricultural development across vulnerable farming regions in SSA.
The litchi stink bug, Tessaratoma papillosa, is a major pest threatening lychee production across Asia. In Guangdong Province, China, its feeding habits cause significant losses in fruit yield and quality. Despite a long history of biological control efforts using parasitoids against this pest, the parasitoid community associated with its eggs remains poorly characterised. This study assesses the parasitoid community associated with T. papillosa eggs across 13 lychee orchards in 2024 and 2025, focusing on their diversity, composition, distribution and parasitism rates. A total of 403 egg masses were collected and reared in the laboratory, resulting in the identification of six parasitoid species: Anastatus dexingensis, Anastatus fulloi, Anastatus shichengensis, Ooencyrtus phongi, Ooencyrtus utetheisae and a Baryscapus sp. Notably, O. phongi was the most widely distributed species, while A. fulloi was prevalent in fewer locations. Parasitism rates varied significantly across locations and were influenced by orchard management, surrounding habitat and orchard size. Specifically, higher parasitism was observed in orchards under no control management and those adjacent to nature reserves, whereas orchard size showed a weak but significant negative correlation with parasitism. These findings provide a critical baseline for understanding parasitoid community composition and highlight the importance of parasitoid diversity and ecological interactions for improving biological control strategies against T. papillosa in lychee orchards.
Fig (Ficus carica L.) production is increasingly constrained by the black fig fly, Silba adipata McAlpine (Diptera: Lonchaeidae), an invasive frugivorous pest that causes premature fruit abscission and significant economic losses. Amongst the poorly studied control strategies, toxic bait formulations represent a promising alternative within integrated pest management (IPM) programmes, particularly given the documented requirement for protein feeding by adult females. This study provides the first evaluation of the oral toxicity of three biorational insecticides, spinosad, abamectin and emamectin benzoate, against adult S. adipata. Median lethal concentrations (LC 50) and median lethal times were estimated under laboratory conditions. Spinosad and emamectin benzoate exhibited high oral toxicity, with LC 50 values ranging from 3.9 to 5.0 mg L-1, and were significantly more toxic than abamectin (LC 50 = 33 mg L-1). Sex-specific differences in susceptibility were observed, although these differences could not be fully explained by body weight. When sex differences were not considered, mean lethal times were similar amongst insecticides, ranging from 4 to 8 h. A significantly higher proportion of adults consumed the sugar-abamectin bait compared with the other insecticides in one experiment but not in the other. Considering both toxicity and speed of kill, spinosad and emamectin benzoate appear to be the most suitable candidates for toxic bait development against S. adipata, although the partial attraction of S. adipata adults to abamectin-based baits warrants further investigation. This study establishes baseline toxicological information for this species and provides a scientific foundation for the development of sustainable attract-and-kill strategies targeting this poorly studied invasive pest. Future studies should focus on improving bait formulations to enhance attraction and toxic persistence under field conditions.
