Open Access
The role of Chrysoperla carnea (Steph.) (neuroptera: Chrysopidae) as a potential dispersive agent of noctuid baculoviruses
(MDPI, 2020) Gutiérrez Cárdenas, Oscar Giovanni; Adán, Ángeles; Beperet Arive, Inés; Medina, Pilar; Caballero Murillo, Primitivo; Garzón, Agustín; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Baculoviruses (BV) are highly effective against lepidopteran pests of economic importance such as Spodoptera exigua. The combined use of entomopathogens and macrobiological control agents requires the study of their relationships. Laboratory bioassays were developed to evaluate the interactions between the multiple nucleopolyhedroviruses of S. exigua (SeMNPV) and Autographa californica (AcMNPV), and the predator Chrysoperla carnea. The microscopic examination of predator’s excreta (larval drops and meconia) after the ingestion of BV-infected S. exigua revealed the presence of viral occlusion bodies (OBs). The reinfection of S. exigua larvae with BVs-contaminated excreta by using OBs water suspensions or by direct application both yielded high mortality values but different speed-of-kill results. Meconia killed before in suspensions due to their higher viral load and larval excretion drops did so in direct application due to their liquid nature and their easiness of consumption. The prey-mediated ingestion of SeMNPV and AcMNPV triggered slight effects in C. carnea, which were probably derived from the food nutritional quality. Chrysoperla carnea larvae did not discriminate between healthy and BV-infected S. exigua, while a preference was shown for S. exigua (healthy or infected) vs. Macrosiphum euphorbiae. Our findings present C. carnea, and particularly its larvae, as a promissory candidate for BV dispersion in the field.
Open Access
Harnessing Chelonus inanitus for efficient Spodoptera spp. management: learning about production to explore roles in baculovirus transmission
(Elsevier, 2025-03-01) Dáder, Beatriz; Morel, Ariel; Muñoz Labiano, Delia; Caballero Murillo, Primitivo; Medina, Pilar; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Control of Spodoptera spp. (Lepidoptera: Noctuidae) crop pests has traditionally relied on heavy insecticide use. Baculoviruses (BV) from the genera Alphabaculovirus and Betabaculovirus offer effective, species-specific alternatives for managing their outbreaks. Joint use of BVs with natural enemies, such as parasitoids, could further enhance control of Spodoptera spp. by contributing to virus dispersion. In a series of experiments, we studied the optimal host age and parasitization duration of the endoparasitoid Chelonus inanitus L. (Hymenoptera: Braconidae) for parasitoid production, as well as the parasitoid preference and mechanical transmission of Spodoptera exigua and Spodoptera littoralis multiple nucleopolyhedroviruses (SeMNPV and SpliMNPV). We found that parasitoid progeny production was significantly lower when parasitized eggs were either too young (24 h) or too old (96 h), highlighting the importance of host egg age. Additionally, there was an increasing trend in parasitoid offspring production with longer parasitization exposure times, particularly at 6 and 24 h compared to shorter durations. Chelonus inanitus did not discriminate between SpliMNPV-contaminated and non-contaminated eggs, but had a remarkable preference for SeMNPV-contaminated eggs. The parasitoid effectively dispersed BVs, not only from BV-treated eggs to heathy ones by parasitization, but also, and even more efficiently, by the sole contact with a contaminated surface without eggs. Understanding complex BV-parasitoid interactions is crucial for developing integrated pest management strategies that maximize the efficacy of both parasites.
Open Access
The parasitoid hyposoter didymator can transmit a broad host range baculovirus in a two host system
(MDPI, 2023) Morel, Ariel; Leigh, Brendan; Muñoz Labiano, Delia; Caballero Murillo, Primitivo; Medina, Pilar; Dáder, Beatriz; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Hyposoter didymator (Thunberg) (Hymenoptera: Ichneumonidae) and baculovirus (BV) might be used jointly to provide effective control of the Spodoptera genus. The literature has mostly covered the safe compatibility between natural enemies and BV-based insecticides, but research on the potential dispersal of BV by natural enemies is lacking. Thus, the goal of this manuscript was to ascertain if H. didymator was able to disperse the broad host range of Autographa californica nucleopolyhedrovirus (AcMNPV) to Spodoptera littoralis and Spodoptera exigua in choice and non-choice conditions and whether the preference of the parasitoid by one of these noctuids could mediate this dispersion. It was previously needed to improve the rearing of the parasitoid in the laboratory, concerning the optimal host age and length of parasitization, parasitoid competition, and influence of parasitization on the longevity of females. The best rearing conditions for S. littoralis are collective parasitization of mature L3 larvae for 24 h, after at least one day of copulation. Hyposoter didymator transmits AcMNPV to both lepidopterans, but its efficiency is mediated by host preference and the pathogenicity of the BV in each host. In this particular case, H. didymator as well as AcMNPV showed a clear preference towards S. exigua.
Open Access
Synergy of lepidopteran nucleopolyhedroviruses AcMNPV and SpliNPV with insecticides
(MDPI, 2020) Dáder, Beatriz; Aguirre Sánchez, Eduardo; Caballero Murillo, Primitivo; Medina, Pilar; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The joint use of baculoviruses and synthetic insecticides for integrated pest management requires the study of the additive, synergistic or antagonistic effects among them on pest mortality. Droplet bioassays were conducted with Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) and seven insecticides (azadirachtin, Bacillus thuringiensis, cyantraniliprole, emamectin, metaflumizone, methoxyfenozide and spinetoram) on Spodoptera exigua and Spodoptera littoralis. The lethal concentrations LC50 and LC95 were calculated through probit regressions. Then, the sequential feeding of insecticides and nucleopolyhedroviruses was studied. Larvae were provided with the LC50 of one insecticide, followed by the LC50 of one nucleopolyhedrovirus 24 h later. The inverse order was also conducted. The insecticide LC50 and LC95 were higher for S. littoralis than for S. exigua. AcMNPV showed greater toxicity on S. exigua than SpliNPV on S. littoralis. Emamectin showed synergy with AcMNPV when the chemical was applied first, and metaflumizone and AcMNPV were synergistic regardless of the order of application, both from the first day of evaluation. SpliNPV was synergistic with azadirachtin and emamectin when it was applied first, but synergy was reached after 12–13 days. Excellent control is possible with the LC50 of azadirachtin, emamectin and metaflumizone in combination with nucleopolyhedroviruses, and merits further study as a means of controlling lepidopteran pests.
Open Access
A novel use of Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) as inoculative agent of baculoviruses
(Wiley, 2023) Gutiérrez Cárdenas, Oscar Giovanni; Adán, Ángeles; Medina, Pilar; Caballero Murillo, Primitivo; Garzón, Agustín; Muñoz Labiano, Delia; Institute for Multidisciplinary Research in Applied Biology - IMAB
Background: Alphabaculoviruses are Lepidoptera-specific virulent pathogens that infect numerous pests, including the Spodoptera complex. Due to their low environmental persistence, the traditional use of Alphabaculoviruses as bioinsecticides consist in high-rate spray applications with repeated treatments. Several abiotic and biotic factors can foster its dispersion, promoting their persistence in the agroecosystem. Amongst biotic factors, predatory arthropods can disperse the viruses by excretion after preying on infected individuals. Therefore, this study focused on promoting predator's ingestion of nucleopolyhedrovirus (NPV)-treated diets, and the later exposition of the insect host to leaf surfaces contaminated with predator excreta. The virus–host–predator system studied was Spodoptera littoralis nucleopolyhedrovirus (SpliNPV), Spodoptera littoralis (Boisduval) and Nesidiocoris tenuis (Reuter). The infective potential of N. tenuis feces and the retention time of SpliNPV were assessed under laboratory conditions after feeding on treated diets (sucrose solution and Ephestia kuehniella eggs). Results: Mortality of S. littoralis larvae was lower via N. tenuis excretion than in positive control (spray application) in the first infection cycle, together with a delay in host death. In the second infection cycle, both SpliNPV-treated diets triggered 100% mortality. Both diets allowed the transmission of SpliNPV, with a faster excretion via sucrose solution compared to E. kuehniella eggs. SpliNPV remained in N. tenuis digestive tract and was viable after excretion at least for 9 days for both diets. Conclusions: This study demonstrated the potential of the predator N. tenuis as inoculative agent of baculoviruses, representing a new alternative that, along with inundative applications, might contribute to improve pest management strategies.