Glyphosate is a broad-spectrum, systemic herbicide that has attracted concern over its non-target effects, environmental persistence, and the presence of residues in food. The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a major invasive pest of maize that can be controlled by application of its homologous nucleopolyhedrovirus (SfMNPV), an occluded virus in the family Baculoviridae. We examined the effects of a glyphosate-based herbicide on S. frugiperda growth and survival and on virus occlusion bodies (OBs) exposed to product label-recommended concentrations of the herbicide. Larval growth, time to pupation, pupal weight, duration of the pupal stage and sex ratio were not affected by exposure to the herbicide (1% v/v solution) applied to the surface of semi-synthetic diet. Exposure to 1-2% herbicide solution had no effect on the median lethal concentration (LC50) of OBs, the susceptibility of second instar larvae to virus infection, or the production of OBs in virus-killed larvae. Virus acquisition did not vary significantly when larvae fed on virus-sprayed maize plants at 1 and 6 days after they had been treated with herbicide, compared to healthy plants. Finally, the presence of 2% herbicide solution did not influence the persistence of OBs in non-sterilized soil samples over a 6-week greenhouse experiment. Although the laboratory and greenhouse experiments indicated that the glyphosate-based herbicide tested was unlikely to influence the transmission or persistence of SfMNPV OBs, future studies should verify these findings across a range of field conditions, soil types and different herbicide formulations.

The Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) is an important pathogen of the fall armyworm and is used as the basis for biological insecticides. In this study, we examined the relationship between the size–frequency distribution of SfMNPV occlusion bodies (OBs) and their insecticidal characteristics when collected at the end of the replication cycle. Exposure of OBs to 40%, 70%, and 90% (wt/wt) glycerol had no effect on OB pathogenicity. Glycerol density gradient (50–100%) centrifugation was used to separate OBs into two fractions. OBs recovered from the upper fraction of the gradient had a significantly smaller median cross-sectional area than those harvested from the lower fraction. These fractions also differed significantly in their size–frequency distributions. The OB concentration–mortality response of S. frugiperda second instars did not differ significantly between the two fractions or with non-centrifuged OBs. The median survival time was similar for insects inoculated with OBs from the upper and lower fractions but was significantly shorter in insects inoculated with non-centrifuged OBs. The proportion of mature OBs (67–71%) and the number of viral genome copies (1.33–1.40 × 108 copies/µL) did not differ significantly between the upper and lower OB fractions. These findings suggest that altering the size–frequency distribution by density gradient centrifugation is not a useful technique for selecting large OBs with high insecticidal activity as part of the baculovirus insecticide production process. Future studies should evaluate a range of OB size separation techniques to determine their effects on OB insecticidal characteristics.

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.

The presence of Silba adipata in countries outside its native range has raised increasing concern among fig (Ficus carica L.) producers due to its growing economic importance. Information on this lonchaeid remains scarce and is frequently fragmented across regional reports, technical documents, and isolated scientific studies. The lack of consolidated and reliable knowledge on S. adipata, together with its sporadic impacts on figs and frequent confusion with closely related species, has hindered the development of effective and sustainable management strategies. Here, we provide a comprehensive synthesis of the current geographic distribution of S. adipata and its expansion into new areas, addressing diagnostic aspects and potential misidentifications reported in the literature that have the potential to confound distribution records and assessments of its pest status. We critically review current knowledge of the biology, ecology, and behavior of S. adipata, together with existing and emerging management and control approaches, including cultural practices, monitoring tools, mass trapping strategies, and biological- and chemical-based tactics. The strengths and limitations of these approaches are discussed in the context of their applicability to fig production systems. Advancing the management of S. adipata requires not only accurate species identification and evaluation of conventional control methods, but also a deeper understanding of its ecology and sexual behavior. Addressing these knowledge gaps will be essential for the development of innovative, effective, and environmentally sustainable management strategies for this emerging pest.

Avocado (Persea americana Miller), a crop of major economic importance in Mexico, is threatened by several quarantine pests, and recent reports have suggested that the lance fly Neosilba batesi (Diptera: Lonchaeidae) may be responsible for significant yield losses. To clarify the role of this species, we surveyed avocados from six localities in Veracruz State on the Gulf coast of Mexico and identified lance flies using both morphological and molecular tools. None of the symptoms previously attributed to N. batesi infestation in Hass avocado were observed in any of the fruits inspected across the six localities. However, 90 fruits displayed clear signs of borer attack by Conotrachelus spp. or other primary pests, and 64 of these damaged fruits (60%) yielded lance flies. Hass avocados were rarely infested and hosted only N. batesi, whereas creole avocados (P. americana var. drymifolia) were hosts to N. batesi, N. glaberrima, N. recurva, and N. flavitarsis and an undescribed species (Neosilba sp.3) that was detected by analysis of the COI gene sequences of males. Additionally, Lonchaea cristula was reported for the first time emerging from creole avocado. Each avocado yielded an average of between 2.3 and 21.0 adult lance flies. Infestation was more frequent and numerous in fruits collected from the ground than in those harvested directly from trees, supporting the idea that lance flies preferentially exploit pre-damaged or fallen fruits. Indeed, lonchaeid eggs were frequently observed deposited on the periphery or inside oviposition holes created by other pests. Overall, our results indicate that Neosilba spp. act as secondary invaders in Veracruz, with no evidence of N. batesi behaving as a primary pest in this region. None of the avocados were infested by species of Tephritidae and none of the Neosilba species we identified appear to pose a threat to avocado production in Mexico. This study highlights the value of combining morphological and molecular tools for species identification and underscores the importance of differentiating between primary and secondary invaders in the context of avocado pest management.

The black fig fly, Silba adipata McAlpine (Diptera: Lonchaeidae), is a monophagous invasive pest of fig crops. Its recent detection in Mexico has highlighted the urgent need for control strategies. However, efforts to study and manage this pest are constrained by a limited understanding of its basic biology and an inability to rear this insect in the laboratory. Some species of flies are reproductively immature at adult emergence and require specific nutrients for the development of reproductive structures. Given this, we examined the development of ovaries and testes in response to different adult diets, ovary maturation in relation to access to figs and ultraviolet (UV) light exposure and behavioral responses to fig latex. Dietary protein (hydrolyzed yeast) was essential for egg maturation. The highest prevalence of sexual maturity in females was observed at age 21 days and was not influenced by UV light or access to figs. Male testes size decreased over time irrespective of the adult diet. The consumption of latex increased when protein was not available, although the sexes differed in their response to latex over time. These findings help overcome a critical barrier to the laboratory colonization of S. adipata by demonstrating that protein-supplemented diets are essential for sexual maturation. However, the lack of information on the specific role of fig latex in the diet and the absence of sexual behavior during the experiments highlight key knowledge gaps. Future research should focus on identifying those stimuli that promote copulation and oviposition to understand the complete life cycle of this pest under controlled conditions.

Baculoviruses can naturally regulate lepidopteran populations and are used as biological insecticides. The genetic diversity of these viruses affects their survival and efficacy in pest control. For nucleopolyhedroviruses, occlusion-derived virions and the occlusion body facilitate the transmission of groups of genomes, whereas this is not the case for granuloviruses. We review the evidence for baculovirus genetic diversity in the environment, in the host insect, and in occlusion bodies and virions. Coinfection allows defective genotypes to persist through complementation and results in the pseudotyping of virus progeny that can influence their transmissibility and insecticidal properties. Genetic diversity has marked implications for the development of pest resistance to virus insecticides. We conclude that future research is warranted on the physical segregation of genomes during virus replication and on the independent action of virions during infection. We also identify opportunities for studies on the transmission of genetic diversity and host resistance to viruses.

A distinctive species of Neosilba Waddill & Weems, namely Neosilba flavitarsis sp. nov is described from specimens reared from cultivated figs in Mexico. DNA sequencing confirms that the species belongs in the genus Neosilba and it is placed in a phylogenetic tree with other close relatives.

In the original publication [...].

Nucleopolyhedroviruses of lepidopteran larvae (Alphabaculovirus, Baculoviridae) form the basis for effective and highly selective biological insecticides for the control of caterpillar pests of greenhouse and field crops and forests. Horizontal transmission is usually achieved following the release of large quantities of viral occlusion bodies (OBs) from virus-killed insects. In the present review, I examine the evidence for productive midgut infection in different host species and the resulting transmission through the release of OBs in the feces (frass) of the host. This has been a neglected aspect of virus transmission since it was initially studied over six decades ago. The different host–virus pathosystems vary markedly in the quantity of OBs released in feces and in their ability to contaminate the host’s food plant. The release of fecal OBs tends to increase over time as the infection progresses. Although based on a small number of studies, the prevalence of transmission of fecal inoculum is comparable with that of recognized alternative routes for transmission and dissemination, such as cannibalism and interactions with predators and parasitoids. Finally, I outline a series of predictions that would affect the importance of OBs in feces as a source of inoculum in the environment and which could form the basis for future lines of research.

Invertebrate iridescent viruses (IIVs, family Iridoviridae) are icosahedral double-stranded DNA viruses that infect a wide range of invertebrates, particularly in humid and aquatic environments. During field trials in Chiapas, southern Mexico, larvae of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), displayed an unexpected lavender iridescence, leading to the discovery of novel IIV isolates from this major agricultural pest. Restriction endonuclease analysis revealed evident diversity among isolates from individual infected larvae. Although one field experiment yielded inconclusive results, a second experiment revealed a positive association between IIV disease and SfMNPV infection, compared to a negative association with the prevalence of parasitoids, and no association with entomopathogenic nematodes (probably Hexamermis sp.). These findings require further investigation to determine the distinct ecological routes through which the virus may transmit across host species. IIV infection of S. frugiperda was also identified in Veracruz State, Mexico, and northern Argentina, revealing a previously unrecognized geographic and host range for these viruses. The genomic and evolutionary features of the three isolates from S. frugiperda were compared with those of two other lepidopteran isolates from Helicoverpa zea (IIV30C obtained from CSIRO) and Anticarsia gemmatalis (AgIIV). Genome sizes ranged between 196.1 and 205.4 kbp (~28% GC content), with several large inversions, and were rich in tandem repeats. The average amino acid identity of the complete genomes and phylogenetic analyses of 26 core gene sequences placed all five isolates within the genus Chloriridovirus, closely related to IIV22 and IV22a isolated from blackflies (Diptera) in Wales and a previously sequenced isolate of IIV30 from the USA. We conclude that these lepidopterans are all infected by closely related strains of the virus species Chloriridovirus simulium1 across their native geographical range. These findings highlight the unexpected ecological breadth and evolutionary adaptability of IIVs.

The black fig fly, Silba adipata, and a complex of Neosilba species have emerged as major fig pests in Veracruz, Mexico. To assess infestation patterns and species composition, we sampled figs during one production cycle (March-October 2024) in two plantations. A total of 1647 S. adipata (821 females, 826 males) and 1250 Neosilba spp. (628 females, 622 males) emerged from samples. One species, Neosilba recurva, is described as new based on the characteristics of the male genitalia and COI sequencing. Neosilba spp. outnumbered S. adipata in the preharvest period, after which S. adipata became dominant. S. adipata emerged ~14 days earlier than Neosilba spp. Infestation by S. adipata caused uniform fig reddening, while Neosilba spp. produced patchy redness near larval exit holes. Approximately 65% of figs were lost to lonchaeid infestation preharvest. Based on male genitalia, we identified Neosilba batesi and N. recurva sp. nov. (that together comprised 64% of samples), as well as Neosilba sp.1 (26%) and N. glaberrima (10%), but COI sequences revealed greater diversity. Neosilba batesi formed a clade that did not match a Floridan sequence. Neosilba glaberrima clustered near N. pendula from Brazil, but another sequence diverged, suggesting the presence of an additional, undescribed species, Neosilba sp.2? Neosilba recurva and Neosilba sp.1, together with the newly described N. flavitarsis from Veracruz, formed distinct genetic branches, supporting their specific status.

The production of viable nucleopolyhedrovirus in the feces of infected lepidopteran larvae represents a poorly understood route for virus transmission prior to host death. In the present study, we examined the presence of viable virus in the feces of fourth-instar Spodoptera frugiperda larvae infected with the Nicaraguan isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV-NIC). Feces production increased in samples taken at 2 to 6 days post-inoculation but was significantly lower in infected insects compared to controls. Second instars experienced 3.9 to 68.3% of polyhedrosis disease following consumption of feces collected at 2–5 days post-inoculation, which subsequently fell to 29.1% in the 6-day sample. Calibration of the insect bioassay using OB-spiked samples of feces indicated that the concentration of OBs varied between 5.4 × 102 and 4.4 × 105 OBs/100 mg of feces in infected fourth instars. Quantitative PCR analysis of fecal samples indicated the presence of 0 to 7629 copies/mg feces following amplification targeted at the polyhedrin gene. However, no correlation was detected between qPCR estimates of virus concentration and time of sample collection or the quantity of feces collected. The qPCR estimates were positively correlated with the prevalence of lethal infection observed in the insect bioassay, but the correlation was weak and several samples did not amplify. Calibration of the qPCR assay using OB-spiked samples of feces provided estimates that were 5- to 10-fold lower than the insect bioassay, indicating inhibition of the amplification reaction or loss of material during processing. In a greenhouse experiment, 2.5–48.3% of second-instar larvae acquired lethal infection following a 24 h period of feeding on maize plants on which fourth instar larvae had deposited their feces at 3 days and 4 days post-infection, respectively. These findings highlight the potential of OB-contaminated feces as a source of biologically significant quantities of inoculum for virus transmission prior to the death of infected insects and represent an additional contribution to the biological control of lepidopteran pests by these pathogens.

The black fig fly, Silba adipata (Diptera: Lonchaeidae), is an invasive pest recently introduced to Mexico, where it has rapidly spread across fig-producing regions. Despite its economic importance, effective monitoring strategies remain poorly studied. The present study evaluated the response of S. adipata adults to visual (color) and olfactory (attractant) cues under laboratory and field conditions in fig orchards. No significant color preferences were observed in laboratory choice tests using nine colors or in field trials using traps of four different colors. In the laboratory, traps containing 2% ammonium sulfate solution, torula yeast + borax, or Captor + borax, captured similar numbers of flies, whereas CeraTrap® was less attractive. Traps containing 2% ammonium sulfate were more effective than 2% ammonium acetate, though attraction was comparable when ammonium acetate was diluted to 0.2% or 0.02%. In the field, torula yeast + borax and 2% ammonium sulfate mixed with fig latex outperformed the 2% ammonium sulfate solution alone, although seasonal variation influenced trap performance. A high proportion of field-captured females were sexually immature. Torula yeast + borax attracted high numbers of non-target insects and other lonchaeid species, which reduced its specificity. In contrast, traps containing fig latex mixtures showed higher selectivity, although some S. adipata adults could not be sexed due to specimen degradation. These findings highlight the value of torula yeast pellets and 2% ammonium sulfate plus fig latex for monitoring this pest, but merit validation in field studies performed over the entire crop cycle across both wet and dry seasons. Future studies should evaluate other proteins, ammonium salt combinations and fig latex volatiles in order to develop effective and selective monitoring or mass trapping tools targeted at this invasive pest.

The radish fly, Delia planipalpis Linnaeus (Diptera: Anthomyiidae), is an emerging pest of broccoli and brassicaceous crops (Brassicaceae). The fly oviposits close to the stem of broccoli plants, and larvae feed within the stem and then pupate in the soil. Due to D. planipalpis ’s recent appearance as a pest, no insecticides are registered for its management in Mexico. This study evaluated the efficacy of 13 synthetic and biological insecticides against different developmental stages through laboratory bioassays. Neonicotinoid-based products were highly toxic to the larvae, especially when applied via root irrigation, with thiamethoxam, clothianidin, and imidacloprid showing systemic activity. Thiamethoxam- and spinetoram-based products were also effective when applied to the stem oviposition site as a spray. A clothianidin-based product demonstrated moderate ovicidal activity, and bifenthrin had moderate residual activity against adult flies. A pyriproxyfen-based product effectively suppressed adult emergence. Products based on spirotetramat, neem (Meliaceae), and Tagetes (marigold) (Asteraceae) extracts and the microbial insecticide Bacillus thuringiensis var. israelensis (Bacillaceae) were ineffective against this pest. Spinosad and Sterneinema feltiae (Rhabditida: Steinernematidae) were not highly effective but could be used together with other control strategies in organic production. Neonicotinoids, spinetoram, and pyriproxyfen are promising options to validate in field trials for the management of D. planipalpis in broccoli.

Drought events are expected to limit crop productivity in the context of current climate change. Drought is also likely to affect multitrophic interactions such as those involving plants, phytophagous insects and their natural enemies. We designed a two-phase experiment to test the effect of water availability and fertilizer treatment on the interaction between maize, the fall armyworm and its nucleopolyhedrovirus pathogen. Plants grown in soil with high irrigation and mineral fertilization had the highest shoot and root dry weight. Furthermore, plant nitrogen levels were higher in plants with fertilization and a low irrigation scheme compared to other treatments. Low irrigation of maize plants reduced virus-induced mortality of armyworm larvae. Insects did not feed on plants with high irrigation and without fertilization. We conclude that water stress and plant nutrition can affect virus performance and thereby affect the efficiency of biological control and pest management, especially as water and nutrient limitation will likely increase under climate change.

Anastrepha fruit flies (Diptera: Tephritidae) are important pests of several crops in the Americas. Alkaline hydrolysis of proteins represents a potential source of novel attractants. Previous studies revealed a higher response by Anastrepha obliqua (Macquart) to alkaline hydrolyzed torula yeast compared with other attractants. Under field conditions, captures of Anastrepha fraterculus (Wiedemann), Anastrepha ludens (Loew), and Anastrepha serpentina (Wiedemann) were significantly higher in traps baited with alkaline hydrolyzed torula yeast than in traps baited with acid hydrolyzed protein (Captor) + borax. Fly attraction to alkaline hydrolyzed torula yeast varied with species but was higher in the 1st week and decreased after 2 or 3 weeks of use in the field. The release of ammonia gas from alkaline hydrolyzed torula yeast and CeraTrap was reduced after 3 weeks, but CeraTrap remained effective in the capture of flies whereas alkaline hydrolyzed torula yeast did not. No improvement in fly captures was observed for aged alkaline hydrolyzed torula yeast when 1% ammonium acetate was added to traps. The addition of propylene glycol or benzalkonium chloride did not improve trap captures over time. Although CeraTrap has advantages in attractiveness and durability, the attraction, simplicity, and low cost make alkaline hydrolyzed torula yeast a promising attractant when compared with the standard Captor + borax in short-term monitoring programs targeted at Anastrepha pests.

Alphabaculoviruses are lethal dsDNA viruses of Lepidoptera that have high genetic diversity and are transmitted in aggregates within proteinaceous occlusion bodies. This mode of transmission has implications for their efficacy as biological insecticides. A Nicaraguan isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV-NIC) comprising nine genotypic variants has been the subject of considerable study due to the influence of variant interactions on the insecticidal properties of mixed-variant occlusion bodies. As part of a systematic study on the replication and transmission of variant mixtures, a tool for the accurate quantification of a selection of genotypic variants was developed based on the quantitative PCR technique (qPCR). First, primer pairs were designed around a region of high variability in four variants named SfNic-A, SfNic-B, SfNic-C and SfNic-E to produce amplicons of 103–150 bp. Then, using cloned purified amplicons as standards, amplification was demonstrated over a dynamic range of 108–101 copies of each target. The assay was efficient (mean ± SD: 98.5 ± 0.8%), reproducible, as shown by low inter- and intra-assay coefficients of variation (<5%), and specific to the target variants (99.7–100% specificity across variants). The quantification method was validated on mixtures of genotype-specific amplicons and demonstrated accurate quantification. Finally, mixtures of the four variants were quantified based on mixtures of budded virions and mixtures of DNA extracted from occlusion-derived virions. In both cases, mixed-variant preparations compared favorably to total viral genome numbers by quantification of the polyhedrin (polh) gene that is present in all variants. This technique should prove invaluable in elucidating the influence of variant diversity on the transmission and insecticidal characteristics of this pathogen.

The radish fly, Delia planipalpis (Meigen), is an emerging pest that infests broccoli in Mexico. Females oviposit near the stem of broccoli plants or in the inflorescence. Effective monitoring systems are necessary for the development of integrated pest management programs against this insect. Laboratory and field experiments were performed to determine the fly's responses to stick traps and water pan traps. Both yellow and blue sticky traps captured significantly more males than females. Yellow traps captured higher numbers of D. planipalpis than blue traps, but with a lower capture of Delia platura (Stein) and other non-target insects. Sticky traps or yellow water pan traps captured similar numbers of D. planipalpis in broccoli crops, but water pan traps captured significantly more females than sticky traps. The addition of the host attractant allyl isothiocyanate significantly increased the capture of flies when used in sticky traps but not in water pan traps. Sticky traps or water pan traps could be used for surveillance of D. planipalpis. Water pan traps require more servicing time as specimens need to be dried before identification. In contrast, sticky traps allow rapid identification of insects, but some insects become damaged on the sticky surface.