Use Of Biological Control Agents Research Articles

Periodic colonization of Trichogramma japonicum for bio-control of yellow stem borer (Scirpophaga incertulas) in summer low-land rice (Oryza sativa)

Yellow stem borer [Scirpophaga incertulas (Walker)], is a major pest of low-land rice (Oryza sativa L.), causing 30–40% yield losses. The use of biological control agents to suppress yellow stem borer (YSB) population and damage across Asia includes inundative releases of the egg parasitoid, Trichogramma japonicum Ashmead. However, information on the time and number of parasitoids’ releases are lacking to control YSB in summer low-land rice. Therefore, an experiment was conducted during summer seasons of 2018 and 2019 at ICAR-National Institute of Biotic Stress Management, Raipur, Chhattisgarh to standardize the time and number of T. japonicum releases for effective biocontrol of YSB. Experiment consisted of 3 different treatment schedules, viz. T1, Four releases of T. japonicum at weekly intervals on the 7th, 14th, 21st, 28th days after planting (DAT); T2, Four releases of T. japonicum at weekly intervals on the 14th, 21st, 28th, 35th DAT; T3, Four releases of T. japonicum at weekly intervals on the 21st, 28th, 35th, 42nd DAT; and T4, Control (no release of wasps). Significant reduction of YSB-induced damage symptoms was observed in the treatment schedule (T2) consisting of four releases of T. japonicum (@50,000 wasps/ha/release) at weekly intervals on the 14th, 21st, 28th, 35th DAT of rice which significantly reduced the dead heart (9.1%, 45.83% reduction over control) and the white ear (1.8%, 47.05% reduction over control), as compared to untreated control plots (T4) (16.8% dead heart, 3.4% white ear) in summer 2018. Similarly, in summer 2019, the reduction in dead heart and white ear by the treatment (T2) was 43.35% and 46.15% over control, respectively. The significant reduction of YSB-induced damages corresponded with the increased grain yield in (T2) from 2018–19 i.e. 12.74–20.18% across the seasons. The results suggest that the (T2) augmentative releases provided ecologically viable bio-control of YSB during the summer seasons in low-land rice.

Biocontrol of common scab in potato cultivation

Biocontrol of common scab in potato cultivation

Insights into the Interaction between the Biocontrol Agent Bacillus amyloliquefaciens QST 713, the Pathogen Monilinia fructicola and Peach Fruit

Brown rot disease caused by Monilinia fructicola is one of the most important peach fruit threats in the world. The use of biological control agents (BCAs), instead of synthetic fungicides, to successfully inhibit postharvest disease development is a challenge in sustainable and efficient crop management. The commercially available BCA Bacillus amyloliquefaciens QST 713 (formerly Bacillus subtilis QST713) is able to inhibit a variety of fungal pathogens and suppress several plant diseases. Our results showed that this BCA inhibited mycelial growth in vitro, and was able to suppress the disease’s severity in peach fruits via delaying and reducing brown rot symptoms. A transcriptomic analysis of fruits during their pre-treatment with this biocontrol agent following M. fructicola challenge revealed a significant upregulation of specific differentially expressed genes (DEGs) at 48 h after inoculation (HAI). These genes are related to the activation of several transcriptional factors, such as members of the WRKY and NAC families, and receptors that are involved in pathogen recognition and signaling transduction (e.g., LRR-RLKs). Furthermore, the inhibition of M. fructicola by this biocontrol agent was confirmed by analyzing the expression profiles of specific fungal genes, which highlighted the direct antimicrobial impact of this bacterial strain against the fungus. Hence, these findings clearly suggest that B. amyloliquefaciens QST 713 is an efficient BCA against brown rot disease, which can directly inhibit M. fructicola and improve peach fruit tolerance.

Disentangling Shifts in the Soil Microbiome of Potatoes Infected with Rhizoctonia solani Anastomosis Group 3-PT in Search of Potential Biocontrol Agents

Rhizoctonia solani anastomosis group (AG) 3-PT is a devastating pathogenic fungus that causes several diseases in potatoes both in South Africa and globally. The removal of various fungicides from the market and strict regulations on the use of synthetic chemicals make disease management difficult. Therefore, alternative, environmentally safe control measures are being considered, such as the use of biological control agents (BCAs). BCAs are an attractive alternative for improving plant and soil health of economically important crops. To identify key microbial indicators of disease suppression against R. solani AG 3-PT, a greenhouse pot trial experiment was conducted using soil from a potato-growing region in KwaZulu-Natal, South Africa. High-throughput sequencing of fungal internal transcribed spacer and bacterial 16S ribosomal RNA was used to characterize the respective fungal and bacterial community composition in the soil with and without artificial inoculation with R. solani AG 3-PT. Results indicated that the pathogen caused dysbiosis in the potato soil microbiome, leading to a shift in fungal and bacterial community composition. Differentially abundant microbial taxa in R. solani AG 3-PT inoculated soils suggest a promising potential for disease-suppressive activity. Network analysis also confirmed the presence of key taxa involved in the microbial community shifts, which could support their role in the suppression of R. solani AG 3-PT. The identification of key microbial indicators against Rhizoctonia diseases can contribute to the development of environmentally sustainable potato production systems, which are particularly important considering the implementation of the European Green Deal.

Farmers’ Knowledge, Perceptions, and Management Practices of False Codling Moth (Thaumatotibia leucotreta) in Smallholder Capsicum sp. Cropping Systems in Kenya

False codling moth (FCM) Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae) is currently the main pest of phytosanitary concern in international trade, causing rejection and decline of horticultural produce from Kenya exported to the European Union (EU). Overreliance on synthetic insecticides to control this pest is ineffective and unsustainable in the long run, whereas continuous use of pesticides results in high levels of residues in the produce. To gather farmers’ knowledge, attitudes, and practices used by smallholder farmers to manage this pest, a field survey was carried out in 10 Capsicum sp. (Solanales: Solanaceae)-producing counties in Kenya. Data were collected using semi-structured questionnaires administered through face-to-face interviews and focus group discussions involving 108 individual farmers, 20 key informants, and 10 focus group discussions. The majority of the respondents (83.33%) were aware of the FCM infesting Capsicum sp. About three quarters of the farmers (76.85%) reported yield losses and unmarketable quality of FCM-infested Capsicum sp. Most farmers interviewed (99.07%) used insecticides as a management tool. In contrast, only 39.81% of the farmers applied integrated pest management strategies including use of biological control agents and intercropping with repellent plants to control this pest. The results show that FCM is perceived as a significant threat to the horticultural industry of Kenya. Training needs for smallholder farmers and key informants to avoid overreliance on synthetic chemical pesticides and to maintain export goals to the EU where identified.

Genus:Platycleis Fieber, 1853 Determination of Harm Forms in Grain Fields of Some Species Güroymak, Bitlis, Türkiye

In this study, species belonging to the genus: Platycleis which have shown large population increases in agricultural lands and especially in cereal products in recent years, have been identified and species identifications have been made. Species identified are Platycleis affinis, Fieber, 1853, Platycleis intermedia Serville, 1838 and, Platycleis escalerai escalerai Bolivar, 1899. These species reach a density of 30-50 per m2 in the lands where they are found, and it has been determined that they damage plant products. Although the numbers reached by the species could not reach a herd-like reproduction, it was determined that they caused damage after a certain density. However, it has been observed that they cause economic loss in products. It has been determined that these species increase the damage size by intensifying in certain periods on the crops they damage, wild wheat, wheat, barley, and corn plants. In-plant protection against these pests, preventive measures within the framework of integrated pest management principles, cultural control practices, and the use of biological control agents at the focal point show significant results that appears to have been taken.

Biological control of weeds in Aotearoa / New Zealand: History, science and achievements to date

Aotearoa / New Zealand is the leading country globally in the use of biological control agents to combat introduced pest weed species. Here we review the history of biological control in Aotearoa / New Zealand, compile a list of current, self-introduced and accidentally introduced biocontrol agents, and list the agents currently under consideration for introduction to Aotearoa / New Zealand (accurate to 2021). We discuss the science and procedures in place for the safe introduction of a new biocontrol agent and discuss the public’s perception of biological control within Aotearoa / New Zealand. Since the 1920s there have been 79 control agents released; 68 of those species were deliberate introductions, eight self-introductions and three accidental introductions. Additionally, there have been eight reported occurrences of non-target-species attack by biological control agents in Aotearoa / New Zealand, all of which cause minor damage to their unintended hosts. Prior to their introduction to Aotearoa / New Zealand, potential biological control agents are required to undergo rigorous research and host-specificity testing to ensure that the agent does not pose a risk to indigenous taxa through non-target attack. This research is essential, as it ensures a precautionary approach is taken prior to introductions, which, in turn, provides the wider public with confidence in the validity of biocontrol agents as a means to manage weed species in Aotearoa / New Zealand.

The hymenopterous parasitoids of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), on cruciferous vegetables in Delhi, India

BackgroundThe diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a serious and economically important pest of crucifers in Delhi, India. Larvae and pupae of the pest were collected from the cabbage, cauliflower and broccoli crops grown in vegetable fields at the farm of ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi-110012, from December 2021 to June 2022. The larvae and pupae of the pest were transferred to the laboratory and reared for emergence of parasitoids’ adults at 25 ± 0.5 °C and RH 70 ± 5%.ResultsFour parasitoid species were emerged, viz. Apanteles mohandasi Sumodan & Narendran 1990, Cotesia vestalis (Haliday, 1834), Diadegma insulare (Cresson, 1865) and Diadromus collaris (Gravenhorst, 1829). Among them, A. mohandasi, C. vestalis and D. collaris were reported for the first time in Delhi, whereas D. insulare (Hymenoptera: Ichneumonidae) is recorded here for the first time in India. Additionally, the first record of parasitism by A. mohandasi on P. xylostella from Delhi was established. The highest parasitism percentage was that of C. vestalis and D. collaris. Moreover, higher parasitism rate was recorded during May 2022 in organically cultivated fields. The parasitism percentage by A. mohandasi, C. vestalis, D. insulare and D. collaris was 7.5, 22.5, 12.5 and 15%, respectively. Conversely, in conventionally farmed fields, the parasitism rates were 3.57, 16.67, 10 and 13.33%, respectively.ConclusionThe use of biological control agents particularly the parasitoids in the IPM program of P. xylostella should be considered, thereby reducing reliance on insecticides and increasing the efficacy of hymenopteran parasitoids.

Biocontrol potential of inflorescence rot of date palm caused by <i>Mauginiella scaettae</i> in the Biskra region (Algeria)

Date palm inflorescence rot (known as Khamedj disease) caused by Mauginiella scaettae is a serious problem in most date palm-growing areas of the world, and it causes considerable yield loss. The extensive use of fungicides has resulted in the emergence of fungicide-resistant pathogens, and concerns have been raised over the residual effects on the environment and human health. In this regard, biocontrol agents have been proposed as an alternative to standard fungicides. The aim of our study was to evaluate the biocontrol agent Aspergillus niger against the pathogen M. scaettae. In vitro confrontation tests between M. scaettae and A. niger showed that, after 10 days of incubation, the Petri dish was almost completely covered by the antagonist A. niger, while the pathogen M. scaettae occupied only 0.61±0.015 cm of diameter, which corresponds to a considerable inhibition of the mycelial growth (85.33%). Microscopic observations showed an abundant sporulation of A. niger around the colony of M. scaettae and marked a very important mycoparasitic power. In conclusion, the use of biological control agents is cost-effective, easy to use, and environmentally friendly for the control of Khamedj disease.

Network Modeling for Post-Entry Management of Invasive Pest Species in the Philippines: The Case of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say, 1824) (Coleoptera: Chrysomelidae).

Crop shifting is considered as an important strategy to secure future food supply in the face of climate change. However, use of this adaptation strategy needs to consider the risk posed by changes in the geographic range of pests that feed on selected crops. Failure to account for this threat can lead to disastrous results. Models can be used to give insights on how best to manage these risks. In this paper, the socioecological process graph technique is used to develop a network model of interactions among crops, invasive pests, and biological control agents. The model is applied to a prospective analysis of the potential entry of the Colorado potato beetle into the Philippines just as efforts are being made to scale up potato cultivation as a food security measure. The modeling scenarios indicate the existence of alternative viable pest control strategies based on the use of biological control agents. Insights drawn from the model can be used as the basis to ecologically engineer agricultural systems that are resistant to pests.

Biological Control Mechanisms of Bacillus cabrialesii subsp. tritici TSO2T against Fusarium languescens, the Causal Agent of Wilt in Jalapeño Peppers

Jalapeño peppers (Capsicum annuum var. Jalapeño) represent one of the most important crops in Mexico. However, many plant diseases, such as wilt caused by strains of the genus Fusarium, reduce its yield. A sustainable alternative to control diseases is the use of biological control agents (BCAs), for example, beneficial microorganisms such as strains of the genus Bacillus. This study aims to analyze the potential use of B. cabrialesii subsp. tritici TSO2T as a BCA and elucidate its potential modes of action against Fusarium strains causing wilt in Jalapeño peppers. For this, symptomatic samples were collected in a commercial field in the Yaqui Valley, Mexico. Six Fusarium isolates were morphologically and molecularly characterized. After pathogenicity tests, F. languescens CE2 was found to be pathogenic. In screening assays for biocontrol bacteria, strain TSO2T, which was isolated from soil in a wheat commercial field under an organic production system and preserved in the Culture Collection of Native Soil and Endophytic Microorganisms (COLMENA), had the best biocontrol effect against CE2, and its cell-free filtrate reduced mycelial growth by 30.95%. Genome mining (antiSMASH) of strain TSO2T allows us to identify gene clusters associated with biocontrol, such as fengycin, surfactin, bacillibactin, bacilysin, bacillaene, subtilosin A, and sporulation killing factor, which codify to antimicrobial metabolites and are associated with swarming motility of the studied beneficial strain. These results demonstrate the effectiveness of B. cabrialesii subsp. tritici TSO2T as a potential BCA for the control of Fusarium wilt, through competition and a complex of antifungal metabolites, which still need to be validated through metabolomic analysis. This study highlights the importance of the use of integrative genomic and bioactivity-guided methodologies in understanding biocontrol pathosystems.

Transcriptome analysis of lemon leaves (Citrus limon) infected by Plenodomus tracheiphilus reveals the effectiveness of Pseudomonas mediterranea in priming the plant response to mal secco disease

ABSTRACT The use of biological control agents (BCAs) to cope with diseases has received considerable attention owing to its high efficiency and environmental safety. The aim of our study was to investigate the potential role of Pseudomonas mediterranea pretreatment in the response of lemon [Citrus limon (L.) Burm. f.] against mal secco, which is a devastating citrus disease caused by the fungus Plenodomus tracheiphilus. RNAseq analysis revealed that the fungus induced marked reprogramming of the transcriptome, but P. mediterranea pretreatment strongly reduced lemon leaf transcriptome modifications and limited the amount of fungal DNA inside the plant tissue. Furthermore, P. mediterranea prevented the downregulation of the genes involved in effector-triggered immunity (ETI) and the deregulation of genes involved in the biosynthesis and perception of the main phytohormones. To the best of our knowledge, this work represents the first report on the analysis of the P. tracheiphilus-lemon plant-BCA interaction at the molecular level.

Millennial Farmer Strategies in Horticultural Entrepreneurship

Indonesia has abundant agricultural resources and great potential in agricultural development. The existence of these agricultural resources has not been matched by the low regeneration of millennial farmers. The Ministry of Agriculture of the Republic of Indonesia through the Agriculture and Food Security Service of Gunungkidul Regency projects a Horticulture Village program to be implemented in Karangrejek Village, Kapanewon Wonosari. This program encourages millennial farmers who have their own innovations and strategies in agricultural development, especially in running farming in the horticulture sector. This paper aims to find out the strategies and innovations carried out by millennial farmers in running farming in the horticulture sector. The millennial farmer strategy is carried out when cultivating and marketing horticultural products, especially shallots and chilies. The strategies carried out in the cultivation aspect are: planting with the intercropping method, off season farming, selection of superior seeds, use of biological control agents, and use of high beds. On the marketing aspect of the results: digital media marketing, post-harvest packaging. The characteristics of millennial farmers in dealing with entrepreneurial problems are: never give up, keep trying, innovate and stay afloat in horticultural farming.

Evaluation of Bacillus subtilis Czk1 Metabolites by LC–MS/MS and Their Antifungal Potential against Pyrrhoderma noxium Causing Brow Rot Disease

Brown rot disease caused by Pyrrhoderma noxium is a widespread disease that severely affects the roots of rubber trees (Hevea brasiliensis Muell. Arg.). The economic losses, along with environmental and health problems arising from the use of disease control chemicals, have raised the interest of scholars to explore the use of biological control agents for the effective control of fungal pathogen P. noxium. Here, the inhibition effect of the culture filtrate of B. subtilis Czk1 on P. noxium was demonstrated. The findings indicate that the antifungal activity of this strain is mediated wholly or partly by compounds produced in the culture filtrate. The combined use of liquid chromatography–tandem mass spectrometry and antifungal activity assays rapidly identified compounds produced by B. subtilis Czk1. Metabolic profiles were assessed and used to identify major metabolites based on the scores of variable importance in the projection and the plot scores of principal component analysis. A total of 296 differential metabolites were screened, including 208 in positive ion mode and 88 in negative ion mode. Two key metabolites, diacetyl and trans-2-octenoic acid, were screened from 29 metabolites by antifungal activity assays. The median effective concentration (EC50) of trans-2-octenoic acid and diacetyl were 0.9075 mg/mL and 4.8213 mg/mL, respectively. The antifungal metabolites can disrupt the internal structure of the pathogenic fungal mycelium, thereby impeding its growth. This study is expected to contribute to the existing knowledge of Czk1-produced metabolites and their future antifungal applications. This study is also expected to provide a new biopreservative perspective on unexplored antifungal metabolites produced by Czk1 as a biocontrol agent.

Field evaluation of biological wound treatments for the management of almond, cherry, and grapevine fungal canker diseases

The ascomycete fungi that cause wood canker diseases in perennial, horticultural crops are often generalist pathogens able to infect multiple host plants. These pathogens frequently infect pruning wounds, and the protection of such wounds with chemicals or biological control agents (BCAs) is an essential component of disease management. This study aimed at assessing four commercial BCAs for their ability to prevent almond, cherry, and grapevine pruning wound infections by three canker pathogens under field conditions for two growing seasons: Calosphaeria pulchella in cherry, Neofusicoccum parvum in almond and grapevine, and Eutypa lata in all three hosts. The two bacterial BCAs tested, Bacillus amyloliquefasciens MBI 600 and Streptomyces lydicus WYEC 108, performed poorly overall as infection rates in treated wounds were not significantly different than in the water-treated wounds for most pathogens in all crops. Trichoderma atroviride SC1 provided the best protection against E. lata and N. parvum in grapevine, achieving superior or equivalent protection than the standard conventional chemical thiophanate-methyl. Field trials also demonstrated that Clonostachys rosea J1446 provided satisfactory protection of pruning wounds against E. lata and C. pulchella in cherry and against E. lata and N. parvum in almond trees. The identification of effective BCAs for use in multiple crops and against multiple pathogens is a great step towards a sustainable management of fungal canker diseases by mitigating the negative impacts of chemical fungicides.

Synergism of a mixed diet of Myzus persicae and egg of Ephestia kuehniella on fitness of the predator Nabis stenoferus

Nabis stenoferus is a zoophytophagous predator that lives in grasslands around agricultural fields. It is a candidate biological control agent for use via augmentation or conservation. To find a suitable food source for mass-rearing and to better understand this predator’s biology, we compared the life history characteristics of N. stenoferus under the three different diets: aphids only (Myzus persicae), moth eggs only (Ephestia kuehniella), or a mixed diet of aphids and moth eggs. Interestingly, when only aphids were supplied, N. stenoferus developed to the adult stage but lacked normal levels of fecundity. There was a significant synergism of the mixed diet on N. stenoferus fitness in both the immature and adult stages, i.e., a 13% reduction in the nymphal developmental period and an 87.3-fold increase in fecundity, compared to aphid-only diet. Furthermore, the intrinsic rate of increase was significantly higher for the mixed diet (0.139) than either aphids only (0.022) or moth eggs only (0.097). These results show that M. persicae alone is not a complete diet for the mass-rearing of N. stenoferus, whereas this aphid can be a supplementary food when combined with E. kuehniella eggs. Implications and applications of these findings for biological control are discussed.

Evaluation of a guardian plant system to suppress Frankliniella occidentalis (Thysanoptera: Thripidae) in greenhouse ornamentals.

Western flower thrips (WFT), Franklinella occidentalis (Pergande), is an economically damaging pest of greenhouse ornamentals. A 'guardian plant system' (GPS) that targeted WFT was evaluated under controlled and commercial greenhouse conditions. This system used mycotized millet grains with the entomopathogenic fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin applied to soil of potted marigolds, Tagetes patula (L.), combined with the foliar-dwelling predatory mite Neoseiulus (=Amblyseius) cucumeris (Oudemans) in slow-release sachets under controlled greenhouse conditions, and with the addition of a pheromone lure under commercial settings. Significantly fewer WFT and less foliar damage on GPS was observed over the 10 and 12 weeks experimental periods compared to the untreated controls. Predatory mites were maintained up to 10 weeks with one release under controlled greenhouse conditions and 12 weeks with two releases in commercial greenhouses. In commercial greenhouses, greater numbers of WFT were found on marigolds than on crop plants within 1 m of the system. Fungal granules persisted for 12 weeks up to 2.5 × 105 CFU g-1 in the GPS soil. The use of biological control agents to suppress WFT within a GPS could be a useful IPM strategy for greenhouse production. The marigold GPS attracted WFT which were suppressed primarily through predation by foliar-dwelling predatory mites and to a lesser extent, infection from conidia produced by the granular fungal formulation in the soil. Further investigations into system deployment and fungal granular application rates and new fungal formulations are suggested to improve system efficacy. © 2023 Society of Chemical Industry.

Health of shallot bulbs planted with mycorrhizal applications and several types of mulch in moler disease conducive land

Moler is one of the important diseases of shallots caused by Fusarium oxysporum f.sp. cepae. Recently, it is very detrimental to one of the shallot production centers in Indonesia, namely Brebes, Central Java. The intensity and yield loss of this pathogen attack can exceed 60% and 50% respectively. Efforts to develop sustainable control are urgently carried out, such as the use of biological control agents and environmental management by using mulch. This paper reports on the health of shallot bulbs grown with the application of mycorrhiza and mulch. This research was conducted on shallot land conducive to moler disease, in Sidamulya, Wanasari District, Brebes Regency, Central Java with alluvial soil type. The results showed that the health Index of bulbs in the mycorrhizal treatment was 98.89%. In the combination treatment of mycorrhizae with some organic mulch, reached health index of shallot bulbs by 100%.

The influence of agent density for biological control of young Brazilian peppertree (Schinus terebinthifolia) with the Brazilian peppertree thrips (Pseudophilothrips ichini)

ABSTRACT Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), is an invasive tree in the Southeastern United States, Texas, California, and Hawaii. The Brazilian peppertree thrips, Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae), is a recently approved biological control agent for use within the US. The thrips have since been released in the field and are expected to reduce Brazilian peppertree performance. Pseudophilothrips ichini is likely to impact young trees but the impacts may vary based on thrips population size and tree age. To better understand the factors contributing to agent impact on young trees and P. ichini population growth, we measured the effect of P. ichini density (0, 4, 10, and 20 thrips) and tree age (3-, 4-, and 6-month-old plants), on tree performance and P. ichini productivity in the laboratory. Brazilian peppertree height and the number of growing tips were reduced across all age groups. However, the negative impact was more pronounced on the youngest trees, which had a reduction in the relative change in height of 171% and a 100% reduction in the number of growing tips. Pseudophilothrips ichini production was positively correlated with tree height (r = 0.44) and biomass (r = 0.56), but thrips relative production was similar across tree age. Results indicate that P. ichini have a great capacity for population increase regardless of starting density. Field studies are needed to corroborate these findings and identify barriers to agent success. This work aims to refine expectations of the impacts to Brazilian peppertree caused by P. ichini.

Overwintering diapause and survival of western Leucotaraxis argenticollis, a promising biological control agent for Adelges tsugae, in the eastern United States

Successful use of biological control agents can be improved with a thorough understanding of the life history, survival, diapausing strategy, and synchrony with the host in the introduced range. Introduction of a novel organism can be influenced by abiotic factors that can impact the interactions with their target prey. Leucotaraxis argenticollis (Zetterstedt) and Le. piniperda (Malloch) (Diptera: Chamaemyiidae) are two species of predatory fly showing promise in the biological control program to manage the invasive hemlock woolly adelgid, Adelges tsugae (Annand)(Hemiptera: Adelgidae), in eastern North America. Field releases of these Leucotaraxis spp. began in 2015, but little is known about their potential for survival or how they overwinter. In an effort to explore Le. argenticollis establishment potential, laboratory reared puparia were observed at seven sites, across a latitudinal gradient, on the east coast and one site on the west coast (native range) of North America from July 20, 2020, to June 1, 2021. Leucotaraxis piniperda puparia were included at five sites and observed to be diapausing in a different stage or using a different cue. Adult Le. argenticollis emerged in spring 2021, after successfully overwintering as puparia, with a subset emerging in summer-fall 2020 at all observation sites. Results suggest that 1) the interaction of mean daily fall maximum temperatures and relative humidity has the most impact on survival, 2) mean daily minimum fall temperatures influence induction/maintenance of diapause, and 3) mean average daily fall temperatures and relative humidity impact survival to spring emergence. Substantial variation in survival and facultative diapause of Le. argenicollis was observed along a latitudinal gradient, potentially influencing predator establishment, supporting the need for continued research.