Oviposition Substrate Research Articles

Beauveria bassiana associated with a novel biomimetic hydrogel to control Aedes albopictus through lure and kill ovitraps.

Within the framework of sustainable and effective control methods for Aedes albopictus, two different conidial suspensions, BbCS-1 and BbCS-2 (respectively without and with nutrients), were used as solvents for the biopolymers water-soluble 2-hydroxyethylcellulose (HEC) and sodium alginate (SA). In this way, two different classes of hydrogels were prepared for each polymer (previously shown to attract tiger mosquito oviposition) to produce HEC-based and SA-based Bb/Gel systems with and without nutrients. The aim was to achieve a long-lasting and cost-effective lure-and-kill oviposition substrate useful for lethal ovitraps. Beauveria bassiana (Bb) survival and growth in the different Bb/Gel systems were monitored for 24 days. Following the growth assay, 24-day-old Bb/Gel systems were tested against Ae. albopictus eggs through a hatching test to evaluate their lethal effect. Gel systems enhance Bb's longevity (up to 24 days) more effectively than standard liquid conidial suspensions, proving that tested HEC- and SA-based hydrogels are not toxic for Bb (biocompatibility) and create a microenvironment suitable to sustain prolonged fungal growth. In particular, the results indicate that gel system based on hydroxyethylcellulose is a suitable delivery substrate for supporting the activity of Bb and is simultaneously effective against Ae. albopictus eggs through a combined mechanism of mechanical effect and fungal action (CM > 90%). The efficacy of Bb gel systems was assessed according to its properties in favouring the growth and vitality of Bb as well as in reducing the Ae. albopictus hatching eggs rate. Further studies, in semi-field and field conditions, will be useful to evaluate the efficacy of Bb/Gel systems on adults in terms of attraction, oviposition, mortality, and potential autodissemination to propose a new tool in precision pest management. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of oviposition substrates for laboratory rearing of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

Abstract Cotton (Gossypium sp.) is the one of the major commercial fibre crops cultivated across the country. The yield is severely affected by insect pests and diseases. Pink bollworm, Pectinophora gossypiella (Saunders, 1844) is one of the major insect pests threatening the cultivation of cotton. The major constraint limiting cotton production is resistance, which prevails to date due to the indiscriminate use of the insecticides and noncompliance of the refugia. Hence the status of the pest needs to be ascertained periodically to initiate timely and dynamic management tactics. For conducting laboratory screening, a higher number of individuals is the prime requirement, which is facilitated through mass-rearing techniques. We have evaluated different oviposition substrates like paper and muslin cloth for enhancing the recovery of eggs. Our results are quite promising and the use of black muslin cloth has shown a recovery of eggs on par with natural substrate (cotton twig). Adoption of the artificial substrate has huge potential in rearing techniques and avoids drawbacks like tissue drying, carry-over of diseases and reusability.

Validation of Diets with Tomato Pomace in Complete Cycle Breeding of Tenebrio molitor (L.) (Coleoptera: Tenebrionidae).

By-product-based diets have the potential to improve the environmental and economic sustainability of Tenebrio molitor (Linnaeus, 1758) production. However, evaluations of the efficacy of new diets are generally focused on larval performance, while the effect on adults is poorly understood. This aim of this study was to evaluate diets enriched with tomato pomace over a complete breeding cycle. The results showed that when used as an oviposition substrate, all the tested diets, including tomato pomace (T), outperformed the control bran-yeast diet (WY, 95:5 ratio), possibly due to the presence of cholesterol and linoleic acid. The adults fed with the bran-tomato pomace-brewer's spent grain diet (WTB, 50:27:23 ratio), the bran-tomato pomace-yeast diet (WTY, 50:41:9 ratio), and the bran-tomato pomace diet (WT, 50:50 ratio) produced significantly more larvae than those fed with the WY diet. The WTB diet (despite being yeast-free) performed similarly to the WY control diet during the subsequent larval growth phase, making it suitable for the entire production cycle. In conclusion, the results show that tomato pomace can be used a valid by-product in the formulation of efficient diets for the breeding of T. molitor and also provide an alternative to expensive yeast.

Wooden tongue depressors as oviposition substrate for the detection of container-breeding Aedes species in ovitraps – Do we miss something?

Wooden tongue depressors as oviposition substrate for the detection of container-breeding Aedes species in ovitraps – Do we miss something?

Insights into the evolution of herbivory from a leaf-mining fly.

Herbivorous insects and their host plants comprise most known species on Earth. Illuminating how herbivory repeatedly evolved in insects from non-herbivorous lineages is critical to understanding how this biodiversity is created and maintained. We characterized the trophic niche of Scaptomyza flava, a representative of a lineage nested within the Drosophila that transitioned to herbivory ~10-15 million years ago. We used natural history studies to determine if S. flava is a true herbivore or a cryptic microbe-feeder, given that the ancestral character state for the family Drosophilidae is likely microbe-feeding. Specifically, we quantified oviposition substrate choice and larval viability across food-types, trophic-related morphological traits, and nitrogen isotope and sterol profiles across putatively herbivorous and non-herbivorous drosophilids. The results of these studies show that S. flava is an obligate herbivore of living plants. Paired with its genetic model host, Arabidopsis thaliana, S. flava is a novel and powerful system for exploring mechanisms underlying the evolution of herbivory, a complex trait that enabled the exceptional diversification of insects.

Season-long comparison of trap lures for integrated management of the navel orangeworm (Lepidoptera: Pyralidae) in almond and pistachio

Monitoring navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae) using pheromone lures is now complicated by the use of mating disruption. Two commercially available lures that are minimally affected by mating disruption use either natural ovipositional substrates (Bait lures) or a combination of phenyl propionate (PPO), a volatile chemical that attracts both sexes and pheromone lures (Combo lures). We compared the season-long trap capture for these two lures in a sterile insect technique (SIT) demonstration project in Fresno County, California, 2020–2023. A total of 194,233 males (96.52%) were caught using Combo lures and 7006 (3.48%) caught using Bait lures, while 95,947 females (48.83%) were caught using Combo lures and 100,532 (51.17%) caught using Bait lures. Capture of A. transitella was 2.3-fold higher in pistachio (278,492) than in almond (119, 316), and within a commodity, there was a moderate correlation in female capture between the two lures; correlation was stronger during the period leading up to July 21 (Julian date 202). For Bait lures, 48.7% of the trap catch in almond occurred by July 21 and 87.1% of the trap catch occurred in pistachio by July 21. For Combo lures, 38.9% of the trap catch in almond occurred by July 21 while 54.6% of the catch occurred in pistachio. Bait lures became less effective after July 21, likely due to diminished attractiveness as new crop nuts split in August through October. Our data indicate that Combo lures are preferable when the goal is consistent season-long capture of A. transitella in almond and pistachio.

Host plant preference of Lygus hesperus (Hemiptera: Miridae) in 4 field crops: potato, alfalfa, carrot, and pea.

The western tarnished plant bug, Lygus hesperus (Knight), has emerged as a pest of potatoes (Solanum tuberosum L.) in the Lower Columbia Basin of Oregon and Washington. This species is generally found infesting several other field-grown crops in the region; however, their host preference is poorly understood. Thus, greenhouse cage experiments were conducted to evaluate L. hesperus host preference by simultaneously presenting adults with 4 host plants: potato, alfalfa, Medicago sativa L., carrot, Daucus carota L., and pea, Pisum sativum L. In addition, an oviposition test was conducted. The results indicated that L. hesperus actively chose as a host and as an oviposition substrate among the 4 host plants. We found a significantly higher number of adults on alfalfa and potato plants over carrot or pea plants at 6 h, 24 h, and 48 h after adults were released into the cage. However, 96 h after release, more L. hesperus were found in alfalfa. In addition, female L. hesperus strongly preferred potato and alfalfa plants as an oviposition substrate over carrot and pea plants at 96 h after release.

Colonization pattern and thermal needs of immature phases of Sarcophaga argyrostoma (Diptera: Sarcophagidae): Significance for estimating postmortem interval

Members of Sarcophagidae are necrophagous and are commonly found on decaying carcasses; and their developmental forms are important indicators for the approximation of lowest postmortem interval (PMImin). This work describes the biological characteristics of Sarcophaga argyrostoma from Tehran, Iran. Various temperature regimes were applied to estimate the thermal summation constant (k) and thermal requirements for development of S. argyrostoma. Five growth proceedings, containing 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion, were investigated under eight fixed temperature regimes (6–30 °C). The effects of fly age, freshness, and availability of oviposition substrate on oviparity and viviparity was studied. At 6 °C, no development occurs, and at 8 °C only the first ecdysis occurs. At temperatures between 10 and 30 °C, all immature stages proceeded to the adult stage, and thus immature development was analyzed at these six remaining temperatures. The development phases needed minimum (Dz ± SE) 5.4(0.4), 8.5(0.26), 5.3(0.44), 3.8(0.1), and 6.6 (0.6)°C to attain one of the succeeding developmental occasion, correspondingly. The approximated K for those five occasions were 15.04 ± 1.12, 12.62 ± 0.65, 140.36 ± 4.35, 14.59 ± 0.6, and 222.8 ± 4.18°-day (DD) accordingly. When the food substrate is available and fresh, the female prefers to lay eggs, no matter how old she is. However, the chance of ovoviviparity increased when no oviposition substrate was available. The truth that S. argyrostoma able to either larviposit or to lay eggs encompasses serious consequences for the precise estimation of the PMImin, as the existence of larvae resulting from eggs laid on the carcass could add hours (based on ambient temperature) to the PMImin.

Identification of Mosquito Eggshell Proteins from Aedes aegypti by Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS) Proteomic Analysis.

The insect eggshell is a multifunctional structure with several important roles, including generating an entry point for sperm via the micropyle before oviposition, serving as an oviposition substrate attachment surface, and functioning as a protective layer during embryo development. Eggshell proteins play major roles in eggshell tanning and hardening following oviposition and provide molecular cues that define dorsal-ventral axis formation. Precise eggshell formation during ovarian follicle maturation is critical for normal embryo development and the synthesis of a defective eggshell often gives rise to inviable embryos. Therefore, simple and accurate methods for identifying eggshell proteins will facilitate our understanding of the molecular pathways regulating eggshell formation and the mechanisms underlying normal embryo development. This protocol describes how to isolate and enrich eggshells from mature oocytes of Aedes aegypti mosquitoes and how to extract their eggshell proteins for liquid chromatography with tandem mass spectrometry (LC-MS/MS) proteomic analysis. Although this methodology was developed for studying mosquito eggshells, it may be applicable to eggs from a variety of insects. Mosquitoes are ideal model organisms for this study as their ovarian follicle development and eggshell formation are meticulously regulated by blood feeding and their follicles develop synchronously throughout oogenesis in a time-dependent manner.

Evaluating Egg-Laying Preference of Individual Aedes aegypti Mosquitoes.

Egg-laying behavior in insects has a dramatic impact on their fitness, controlling their extent and distribution across ecosystems. Thus, understanding the cues that guide mosquito egg laying is an important goal. Measuring mosquito egg-laying preference is critically important for understanding the sensory and neural mechanisms guiding adaptive breeding decisions. Here, we present a method for ascertaining the egg-laying preference of individual Aedes aegypti mosquitoes in small chambers with two distinct oviposition substrate choices. This assay is best suited for medium- to high-throughput analysis of egg-laying preference to liquids containing distinct contact chemosensory cues, such as differing salinities. We discuss all steps of the process from assay construction and setup to data acquisition and analysis.

Fatty acids derived from oviposition systems guide female black soldier flies (Hermetia illucens) toward egg deposition sites.

The black soldier fly, Hermetia illucens, comes with big promises for industrial purposes since its larvae feed polyphagously on a broad spectrum of organic substrates. However, research focusing on adult flies is scarce, which is inconsistent with their reproductive relevance within the rearing cycle. In particular, directed oviposition is a challenge in artificial systems. Currently, decomposing organic matter is commonly used as oviposition substrate, which has extensive potential for improvement in view of the lack of standardization and the risk of microbial contamination. Here, we identified three fatty acids and one fatty acid methyl ester derived from the surface of old oviposition sites and targeted to elucidate their effect on preference behavior and oviposition site selection using Y-olfactometry and prepared oviposition sites, respectively. Exposure to tetradecanoic acid attracted gravid females and stimulated oviposition most strongly, while decanoic acid demonstrated a repulsive effect. Females kept in mixed-sex populations were attracted by tetradecanoic acid, resulting in a higher egg mass found in the compound box (3.0-11.4 fold), a ≥ 2.3 fold reduction of nonspecifically deposited eggs, and the highest total egg mass. Conversely, decanoic and dodecanoic acid caused females to lay a greater proportion of eggs nonspecifically outside both boxes. Our data suggest that fatty acids, especially tetradecanoic acid, are important cues for oviposition site selection in black soldier flies. In order to achieve a directed oviposition behavior, the role of further short- and long-chain fatty acids as attractants should be examined.

Oviposition preference for spherical surfaces is shared among multiple Drosophila species except D. melanogaster (Diptera: Drosophilidae)

AbstractOviposition preference for spherical substrates has been reported in some insects but not in Drosophila species until the recent finding that Drosophila suzukii preferentially lays eggs on spherical surfaces with a smaller radius, whereas D. melanogaster does not. This finding raised two questions: (i) Was this trait specifically acquired in D. suzukii or lost in D. melanogaster? (ii) In the latter case, is it due to the long‐term laboratory culture using oviposition substrates with flat surfaces? To answer these questions, we examined the oviposition preference of three Drosophila species using the stocks recently established from wild individuals. As with D. suzukii, D. simulans and D. takahashii showed significant preference for spherical surfaces with a smaller radius, suggesting that this trait is shared by multiple Drosophila species. In contrast, D. melanogaster did not show any preference for either smaller or larger radii, showing that the preference already has been lost in the natural population of D. melanogaster. It may be possible that the loss of oviposition preference for spherical surfaces is involved in the evolutionary process of D. melanogaster becoming a human commensal.

Soil moisture reduces egg mortality during wildfires in the Madeiran green bush-cricket

AbstractThe increasing frequency of fires is a major threat to biodiversity around the world, further facilitated by global warming. Fires usually affect insect populations directly, but insect eggs may partly be protected from wildfires when oviposited into the ground. Madeira belongs to the Macaronesian islands which experience wildfires annually. The Madeiran Green Bush-Cricket (Psalmatophanes barretoi) is endemic to the island and listed on the IUCN Red List as Vulnerable with wildfires being named as the major threat to the species. However, it remains unclear whether the eggs of P. barretoi may be partly protected from fires due to the oviposition substrate (soil). It also remains unknown whether increased temperature alone or increased drought are more important drivers of mortality when fires are approaching or surpassing an oviposition site. We hypothesized that drought might have a significant effect on mortality when heat levels remain slightly below or above mortal temperatures. Therefore, we tested the effects of temperature and drought on egg survival in two laboratory experiments by incubating eggs at different temperatures (49 °C, 55 °C) for six hours with and without water replacement. Our results show that the combination of drought and heat affected egg mortality significantly stronger than heat alone. As a result, we conclude that egg mortality is strongly mediated by soil desiccation and that eggs might be buffered from fire effects in moist habitats or after increased rainfall.

Life history of Laccophilus dikinohaseus Kamite, Hikida, and Satô, 2005 (Coleoptera: Dytiscidae) and its preferences for oviposition substrates

We describe the life history of Laccophilus dikinohaseus Kamite, Hikida, and Satô, 2005 using laboratory rearing-based methods to contribute to future ex situ and in situ conservation. At 26 °C, each developmental stage had the following duration: egg, 6–7 days; first-instar, 3–5 days; second-instar, 3–5 days; third-instar in water, 7–18 days; landing to leaving the pupal chamber, 9–11 days; and total duration of the immature stages, 30–44 days. The total larval period was significantly longer than those of L. yoshitomii Watanabe and Kamite, 2018, L. kobensis Sharp, 1873, and L. hebusuensis Watanabe and Kamite, 2020. The maximum complete lifespan (egg to adult death) and adult lifespan (exiting the pupal chamber to adult death) were 792 and 762 days, respectively, indicating that L. dikinohaseus can live for more than two years after the adults exit the pupal chamber. Laccophilus dikinohaseus laid eggs not only in aquatic plants but also in driftwood and withered plants, suggesting a diverse oviposition substrate availability. This is the first study on the immature stages of L. dikinohaseus and lifespan of Laccophilus. We propose in situ conservation measures for L. dikinohaseus based on its findings.

The Transmission Patterns of the Endosymbiont Wolbachia within the Hawaiian Drosophilidae Adaptive Radiation.

The evolution of endosymbionts and their hosts can lead to highly dynamic interactions with varying fitness effects for both the endosymbiont and host species. Wolbachia, a ubiquitous endosymbiont of arthropods and nematodes, can have both beneficial and detrimental effects on host fitness. We documented the occurrence and patterns of transmission of Wolbachia within the Hawaiian Drosophilidae and examined the potential contributions of Wolbachia to the rapid diversification of their hosts. Screens for Wolbachia infections across a minimum of 140 species of Hawaiian Drosophila and Scaptomyza revealed species-level infections of 20.0%, and across all 399 samples, a general infection rate of 10.3%. Among the 44 Wolbachia strains we identified using a modified Wolbachia multi-locus strain typing scheme, 30 (68.18%) belonged to supergroup B, five (11.36%) belonged to supergroup A, and nine (20.45%) had alleles with conflicting supergroup assignments. Co-phylogenetic reconciliation analysis indicated that Wolbachia strain diversity within their endemic Hawaiian Drosophilidae hosts can be explained by vertical (e.g., co-speciation) and horizontal (e.g., host switch) modes of transmission. Results from stochastic character trait mapping suggest that horizontal transmission is associated with the preferred oviposition substrate of the host, but not the host's plant family or island of occurrence. For Hawaiian Drosophilid species of conservation concern, with 13 species listed as endangered and 1 listed as threatened, knowledge of Wolbachia strain types, infection status, and potential for superinfection could assist with conservation breeding programs designed to bolster population sizes, especially when wild populations are supplemented with laboratory-reared, translocated individuals. Future research aimed at improving the understanding of the mechanisms of Wolbachia transmission in nature, their impact on the host, and their role in host species formation may shed light on the influence of Wolbachia as an evolutionary driver, especially in Hawaiian ecosystems.

Identification and functional characterization of female antennae-biased odorant receptor 23 involved in acetophenone detection of the Indian meal moth Plodia interpunctella.

The Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae), a globally distributed storage pest, relies on odors that are emitted from stored foods to select a suitable substrate for oviposition. However, the molecular mechanism underlying the chemical communication between P. interpunctella and its host remains elusive. In this study, 130 chemosensory genes were identified from the transcriptomes of 7 P. interpunctella tissues, and the quantitative expression levels of all 56 P. interpunctella odorant receptor genes (PintORs) were validated using real-time quantitative polymerase chain reaction. The functional characteristics of 5 PintORs with female antennae-biased expression were investigated using 2-electrode voltage clamp recordings in Xenopus laevis oocytes. PintOR23 was found to be specifically tuned to acetophenone. Acetophenone could elicit a significant electrophysiological response and only attracted mated females when compared with males and virgin females. In addition, molecular docking predicted that the hydrogen bonding sites, TRP-335 and ALA-167, might play key roles in the binding of PintOR23 to acetophenone. Our study provides valuable insights into the olfactory mechanism of oviposition substrate detection and localization in P. interpunctella and points toward the possibility of developing eco-friendly odorant agents to control pests of stored products.

Invasive Aedes mosquitoes in an urban—peri-urban gradient in northern Spain: evidence of the wide distribution of Aedes japonicus

BackgroundThe expansion of invasive mosquitoes throughout Europe has increased in recent decades. In northern Spain, Aedes albopictus was detected for the first time in 2014, and Aedes japonicus was detected in the three Basque provinces in 2020. This study aimed to evaluate the distribution of these mosquito species and their association with factors related to urbanization.MethodsIn 2021, a total of 568 ovitraps were deployed in 113 sampling sites from 45 municipalities with > 10,000 inhabitants. Oviposition substrate sticks were replaced each fortnight and examined for Aedes eggs from June to November. Aedes eggs were counted, and the eggs from a selection of positive oviposition sticks, encompassing at least one stick from each positive ovitrap, were hatched following their life cycle until the adult stage. When egg hatching was not successful, PCR targeting the COI gene and sequencing of amplicons were carried out.ResultsEggs were detected in 66.4% of the sampling sites and in 32.4% of the ovitraps distributed in the three provinces of the Basque Country. Aedes albopictus and Ae. japonicus were widespread in the studied area, confirming their presence in 23 and 26 municipalities, respectively. Co-occurrence of both species was observed in 11 municipalities. The analysis of the presence of Aedes invasive mosquitoes and the degree of urbanization (urban, suburban, peri-urban) revealed that Ae. albopictus showed a 4.39 times higher probability of being found in suburban areas than in peri-urban areas, whereas Ae. japonicus had a higher probability of being found in peri-urban areas. Moreover, the presence of Ae. albopictus was significantly associated with municipalities with a higher population density (mean = 2983 inh/km2), whereas Ae. japonicus was associated with lower population density (mean = 1590 inh/km2).ConclusionsThe wide distribution of Ae. albopictus and Ae. japonicus observed confirmed the spread and establishment of these species in northern Spain. A new colonization area of Ae. japonicus in Europe was confirmed. Due to the potential impact of Aedes invasive mosquitoes on public health and according to our results, surveillance programs and control plans should be designed considering different urbanization gradients, types of environments, and population density.Graphical

Evaluating Materials to Serve as Removable Oviposition Substrates for Lycorma delicatula (Hemiptera: Fulgoridae) Under Field Conditions

Evaluating Materials to Serve as Removable Oviposition Substrates for Lycorma delicatula (Hemiptera: Fulgoridae) Under Field Conditions

Oviposition substrate location by the invasive woodwasp Sirex noctilio: the combined effect of chemical cues emitted by its obligate symbiont Amylostereum areolatum and different host-tree species.

Sirex noctilio is an invasive forest wasp that affects pines and can result in severe economic losses. The use of semiochemicals offers an opportunity to develop sensitive and specific capturing systems to mitigatenegative impacts. Previous research showed that female S. noctilio would use volatiles emitted by its fungal symbiont, Amylostereum areolatum, but little is known about how these modulate behaviour when combined with pine-wood emissions. Our aim was to understand the relevance of fungal volatiles grown on artificial media and wood from two hosts trees, Pinus contorta and Pinus ponderosa, on behavioural and electroantennographic responses of wasp females. Because background odours can modify an insect's response towards resource-indicating semiochemicals, we propose that the behaviour towards the symbiont (resource) will be modulated by host pine emissions (background odours). Olfactometric assays showed that both host species with fungus were attractive when contrasted against air (P. contorta versus Air, χ2 = 12.19, P < 0.001; P. ponderosa versus Air, χ2 = 20.60, P < 0.001) and suggest a clear hierarchy in terms of female preferences towards the tested stimuli, with response highest towards the fungus grown on P. contorta (olfactory preference index: 5.5). Electrophysiological analyses indicate that females detect 62 volatile compounds from the tested sources. Results indicate a strong synergy between symbiont and host semiochemicals, suggesting that the pine species could play a fundamental role in the interaction. Further understanding of the chemical basis of this, could guide the development of specific and attractive lures, in order to maximize attraction of wasps in surveillance programmes. © 2023 Society of Chemical Industry.

Coconut oil derived five-component synthetic oviposition deterrent for oriental fruit fly, Bactrocera dorsalis.

Bactrocera dorsalis, oriental fruit fly (OFF), is one of the most destructive agricultural pests. Although bait sprays can effectively control OFF, resistance development has been a concern. We evaluated the oviposition deterrent activity of coconut free fatty acids (CFFA), a mixture of eight coconut oil-derived fatty acids known to repel hematophagous insects and deter their feeding and oviposition, against OFF females. In laboratory 72-h two-choice assays using guava-juice infused-agar as an oviposition substrate, CFFA deterred OFF oviposition in a dose-dependent manner with the greatest reduction of 87% at 20 mg dose compared to the control. When the eight CFFA components were tested individually, four compounds (caprylic, capric, oleic, and linoleic acids) significantly reduced OFF oviposition ('negative-compounds'), two (lauric and myristic acids) had no effect ('neutral-compounds'), and two (palmitic and stearic acids) stimulated OFF oviposition ('positive-compounds'). In two-choice tests, the 'negative-compounds' blend failed to elicit the same level of oviposition reduction as CFFA at equivalent concentrations found in CFFA. Adding the two 'neutral-compounds' recovered the oviposition deterrence similar to CFFA. Subsequent subtraction tests showed that four 'negative-compounds' plus lauric acid was as effective as CFFA in reducing OFF oviposition in guava-juice agar. This five-component key-deterrent blend also reduced OFF oviposition by 95 and 72% on papaya and tomato fruit, respectively. CFFA acts as an oviposition deterrent for OFF. Given that CFFA compounds are generally regarded as safe for humans and the environment, CFFA and its bioactive components have potential use in behavioral control strategies against OFF. © 2023 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.