Keywords: Moths
Homing gene drive strains for genetic suppression of agricultural insect pests
35331Yadav, Amarish K.; Tarrand, Ariel E.; Scott, Maxwell J., Entomologia Generalis, 45:1577 - 1590. 2025-12-04 14:52:03.
Agricultural insect pests cause substantial losses in crop productivity each year. Genetic-based strategies provide economical and environmentally friendly ways to limit pests that reproduce sexually. In contrast to conventional genetic methods (e.g. SIT), homing gene drives (HGDs) are potentially capable of suppressing or modifying an entire pest population in a short period of time after releasing a small number of HGD insects. The advent of CRISPR/Cas gene editing tools has simplified the engineering of gene drives, and the progress made on HGDs in various insects in the recent past is encouraging. However, to date HGDs have been developed and evaluated in only a few agricultural pest species. These drives have been designed to suppress populations by targeting genes essential for female development or fertility. Homing gene drive relies on homology directed repair (HDR) of the Cas9-mediated double-stranded DNA break in germ cells. Consequently, the use of other DNA repair pathways such as non-homologous end joining (NHEJ) and micro-homology mediated end joining (MMEJ) can retard homing. Further, establishment of functional resistant alleles through these end-joining pathways is one of the major challenges associated with HGDs. Development of HGDs in some pest species is challenging due to the technical difficulties of making transgenics. Identification and characterization of germline-specific promoters and other regulatory elements to achieve precise HDR (in early meiosis) can facilitate efficient homing. In this review, we highlight the recent progress made towards developing HGDs in agricultural insect pests with insights gained from studies in model organisms (e.g. Drosophila melanogaster).
CRISPR/Cas9 Genome Editing in the Diamondback Moth: Current Progress, Challenges, and Prospects
34556Asad, M., Chang, Y., Liao, J., & Yang, G., International Journal of Molecular Sciences, 26:1515. 2025-03-04 11:34:07.
The development of site-specific genome-editing tools like CRISPR (clustered regularly interspaced short palindromic repeat) and its associated protein, Cas9, is revolutionizing genetic engineering with its highly efficient mechanism, offering the potential for effective pest management. Recently, CRISPR/Cas9 gene-editing has been extensively utilized in the management of the diamondback moth, Plutella xylostella (L.), a highly destructive pest of vegetable crops, for different purposes, such as gene function analysis and genetic control. However, the progress related to this gene-editing tool in P. xylostella has not yet been summarized. This review highlights the progress and applications of CRISPR/Cas9 in uncovering the genes critical for development, reproduction, and insecticide resistance in P. xylostella. Moreover, the progress related to the CRISPR/Cas9 gene drive for population suppression and modifications has also been discussed. In addition to the significant progress made, challenges such as low germline editing efficiency and limited homology-directed repair remain obstacles to its widespread application. To address these limitations, we have discussed the different strategies that are anticipated to improve the efficiency of CRISPR/Cas9, paving the way to it becoming a pivotal tool in sustainable pest management. Therefore, the present review will help researchers in the future enhance the efficiency of the CRISPR/Cas9 system and use it to manage the diamondback moth.
Loss-of-function in testis-specific serine/threonine protein kinase triggers male infertility in an invasive moth
32506Wei, Z., Wang, Y., Zheng, K. et al., Communications Biology, 7. 2024-10-08 09:10:05.
Genetic biocontrol technologies present promising and eco-friendly strategies for the management of pest and insect-transmitted diseases. Although considerable advancements achieve in gene drive applications targeting mosquitoes, endeavors to combat agricultural pests have been somewhat restricted. Here, we identify that the testis-specific serine/threonine kinases (TSSKs) family is uniquely expressed in the testes of Cydia pomonella, a prominent global invasive species. We further generated male moths with disrupted the expression of TSSKs and those with TSSKs disrupted using RNA interference and CRISPR/Cas9 genetic editing techniques, resulting in significant disruptions in spermiogenesis, decreased sperm motility, and hindered development of eggs. Further explorations into the underlying post-transcriptional regulatory mechanisms reveales the involvement of lnc117962 as a competing endogenous RNA (ceRNA) for miR-3960, thereby regulating TSSKs. Notably, orchard trials demonstrates that the release of male strains can effectively suppress population growth. Our findings indicate that targeting TSSKs could serve as a feasible avenue for managing C. pomonella populations, offering significant insights and potential strategies for controlling invasive pests through genetic sterile insect technique (gSIT) technology.
Male-killing virus leads to more female moths
28365Anonymous, Nature, 2023-11-07 09:51:08.
Keisuke Nagamine at Minami Kyushu University in Miyazaki, Japan, and his colleagues have identified another virus that kills male embryos of the tobacco caterpillar, Spodoptera litura. Female moths infected with the virus produced an equal number of male and female embryos, but almost no male embryos survived. The virus doesn’t share male-killing genes with other known male-killing viruses or bacteria, suggesting that these mechanisms evolved independently.
Male-killing virus in a noctuid moth Spodoptera litura
28367K. Nagamine, Y. Kanno, K. Sahara, T. Fujimoto, A. Yoshido, Y. Ishikawa, M. Terao, D. Kageyama and Y. Shintani, Proceedings of the National Academy of Sciences, 120:e2312124120. 2023-11-06 09:56:12.
A female-biased sex ratio is considered advantageous for the cytoplasmic elements that inhabit sexually reproducing organisms. There are numerous examples of bacterial symbionts in the arthropod cytoplasm that bias the host sex ratio toward females through various means, including feminization and male killing. Recently, maternally inherited RNA viruses belonging to the family Partitiviridae were found to cause male killing in moths and flies, but it was unknown whether male-killing viruses were restricted to Partitiviridae or could be found in other taxa. Here, we provide compelling evidence that a maternally inherited RNA virus, Spodoptera litura male-killing virus (SlMKV), selectively kills male embryos of the tobacco caterpillar Spodoptera litura, resulting in all-female broods. SlMKV injected into uninfected S. litura can also be inherited maternally and causes male killing. SlMKV has five genomic segments encoding seven open reading frames, has no homolog of known male-killing genes, and belongs to an unclassified group of arthropod-specific viruses closely related to Tolivirales. When transinfected into larvae, both male and female recipients allow SlMKV to proliferate, but only males die at the pupal stage. The viral RNA levels in embryonic and pupal male killing suggest that the mechanism of male killing involves the constitutive expression of viral products that are specifically lethal to males, rather than the male-specific expression of viral products. Our results, together with recent findings on male-killing partiti-like viruses, suggest that diverse viruses in arthropods tend to acquire male killing independently and that such viruses may be important components of intragenomic conflict in arthropods.
Mating Competitiveness of Irradiated Lobesia botrana (Lepidoptera: Tortricidae) in Male-Only and Both Sex Release Strategies under Laboratory Cage Conditions
24324G. Saour, A. Hashem and I. Jassem, Insects, 14. 2022-12-23 09:03:18.
This laboratory study explored the concept of whether irradiated male-only releases are more or equally efficient as releases of both irradiated males and females in the context of using the sterile insect technique/inherited sterility (SIT/IS) for the management of the European grapevine moth Lobesia botrana. The current study examined the mating competitiveness of 150-Gy-treated L. botrana male and female moths or 150-Gy-treated male moths only, with untreated moths in laboratory cages. Our results showed that the release of both sexes significantly increased the competitiveness value (C) and the biological efficiency index (BE) as compared with male-only release, and this was independent of the male to untreated male ratio. Moreover, a single release of 150-Gy-treated and untreated males and females at a 1:1:10:10 ratio (untreated male:untreated female: treated male:treated female) significantly reduced egg hatch, and the number of first-generation offspring (F1) was small. The emergence of F2-moths per untreated F1 male and female moth was low, but these undesired fertile moths should be eliminated in order to achieve effective control. The results presented herein provide useful information on the impact of 150-Gy-treated male-only, versus releases of both treated males and females on untreated moths, which is essential to managing L. botrana populations with SIT/IS.
A Wolbachia factor for male killing in lepidopteran insects
24016S. Katsuma, K. Hirota, N. Matsuda-Imai, T. Fukui, T. Muro, K. Nishino, H. Kosako, K. Shoji, H. Takanashi, T. Fujii, S.-i. Arimura and T. Kiuchi, Nature Communications, 13:6764. 2022-11-14 12:59:35.
Bacterial symbionts, such as Wolbachia species, can manipulate the sexual development and reproduction of their insect hosts. For example, Wolbachia infection induces male-specific death in the Asian corn borer Ostrinia furnacalis by targeting the host factor Masculinizer (Masc), an essential protein for masculinization and dosage compensation in lepidopteran insects. Here we identify a Wolbachia protein, designated Oscar, which interacts with Masc via its ankyrin repeats. Embryonic expression of Oscar inhibits Masc-induced masculinization and leads to male killing in two lepidopteran insects, O. furnacalis and the silkworm Bombyx mori. Our study identifies a mechanism by which Wolbachia induce male killing of host progeny.
Sterility of Cydia pomonella by X ray irradiation as an alternative to gamma radiation for the sterile insect technique
23463J.-H. Zhang, N. Li, H.-Y. Zhao, Y.-Q. Wang, X.-Q. Yang and K.-M. Wu, Bulletin of Entomological Research, 2022-08-06 09:27:59.
The codling moth Cydia pomonella is a major pest of global significance impacting pome fruits and walnuts. It threatens the apple industry in the Loess Plateau and Bohai Bay in China. Sterile insect technique (SIT) could overcome the limitations set by environmentally compatible area-wide integrated pest management (AW-IPM) approaches such as mating disruption and attract-kill that are difficult to suppress in a high-density pest population, as well as the development of insecticide resistance. In this study, we investigated the effects of X-ray irradiation (183, 366, 549 Gy) on the fecundity and fertility of a laboratory strain of C. pomonella, using a newly developed irradiator, to evaluate the possibility of X-rays as a replacement for Cobalt60 (60Co-γ) and the expanded future role of this approach in codling moth control. Results show that the 8th-day is the optimal age for irradiation of male pupae. The fecundity decreased significantly as the dosage of radiation increased. The mating ratio and mating number were not influenced. However, treated females were sub-sterile at a radiation dose of 183 Gy (20.93%), and were almost 100% sterile at a radiation dose of 366 Gy or higher. Although exposure to a radiation dose of 366 Gy resulted in a significant reduction in the mating competitiveness of male moths, our radiation biology results suggest that this new generation of X-ray irradiator has potential applications in SIT programs for future codling moth control.
Development of CRISPR/Cas9-Mediated Gene-Drive Construct Targeting the Phenotypic Gene in Plutella xylostella
23265M. Asad, D. Liu, J. Li, J. Chen and G. Yang, Frontiers in Physiology, 13:938621. 2022-07-20 13:03:05.
The gene-drive system can ensure that desirable traits are transmitted to the progeny more than the normal Mendelian segregation. The clustered regularly interspersed palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) mediated gene-drive system has been demonstrated in dipteran insect species, including Drosophila and Anopheles, not yet in other insect species. Here, we have developed a single CRISPR/Cas9-mediated gene-drive construct for Plutella xylostella, a highly-destructive lepidopteran pest of cruciferous crops. The gene-drive construct was developed containing a Cas9 gene, a marker gene (EGFP) and a gRNA sequence targeting the phenotypic marker gene (Pxyellow) and site-specifically inserted into the P. xylostella genome. This homing-based gene-drive copied ∼12 kb of a fragment containing Cas9 gene, gRNA, and EGFP gene along with their promoters to the target site. Overall, 6.67%-12.59% gene-drive efficiency due to homology-directed repair (HDR), and 80.93%-86.77% resistant-allele formation due to non-homologous-end joining (NHEJ) were observed. Furthermore, the transgenic progeny derived from male parents showed a higher gene-drive efficiency compared with transgenic progeny derived from female parents. This study demonstrates the feasibility of the CRISPR/Cas9-mediated gene-drive construct in P. xylostella that inherits the desired traits to the progeny. The finding of this study provides a foundation to develop an effective CRISPR/Cas9-mediated gene-drive system for pest control.
Toward a CRISPR-Cas9-Based Gene Drive in the Diamondback Moth Plutella xylostella
24426X. Xu, T. Harvey-Samuel, H. A. Siddiqui, J. X. D. Ang, M. E. Anderson, C. M. Reitmayer, E. Lovett, P. T. Leftwich, M. You and L. Alphey, The CRISPR Journal, 5:224-236. 2022-04-01 10:25:39.
Promising to provide powerful genetic control tools, gene drives have been constructed in multiple dipteran insects, yeast, and mice for the purposes of population elimination or modification. However, it remains unclear whether these techniques can be applied to lepidopterans. Here, we used endogenous regulatory elements to drive Cas9 and single guide RNA (sgRNA) expression in the diamondback moth (DBM), Plutella xylostella, and test the first split gene drive system in a lepidopteran. The DBM is an economically important global agriculture pest of cruciferous crops and has developed severe resistance to various insecticides, making it a prime candidate for such novel control strategy development. A very high level of somatic editing was observed in Cas9/sgRNA transheterozygotes, although no significant homing was revealed in the subsequent generation. Although heritable Cas9-medated germline cleavage as well as maternal and paternal Cas9 deposition were observed, rates were far lower than for somatic cleavage events, indicating robust somatic but limited germline activity of Cas9/sgRNA under the control of selected regulatory elements. Our results provide valuable experience, paving the way for future construction of gene drives or other Cas9-based genetic control strategies in DBM and other lepidopterans.
Fall armyworms with offspring-killing gene tested on farms in Brazil
21020M. Le Page, New Scientist, 2022-03-15 06:46:51.
Fall armyworms genetically modified to wipe out wild populations of the pests have been released in corn fields in São Paulo State in Brazil in the first farm trial of the new technology. The test was a success and is now being expanded, says Oxitec, the UK-based company that created the modified armyworms. Fall armyworms (Spodoptera frugiperda) are in fact moth caterpillars. They get their name from the fact that they multiply very fast and feed on many plants. Swarms of armyworms can devastate everything from lawns to crops in just days. They are native to the Americas, but in recent years have spread across Africa, Asia and Australia, reducing harvests of some crops by up to half. Conventional control methods aren’t working well because some strains have evolved resistance to many pesticides. “There is a lot of interest in new solutions to this pest,” says Neil Morrison at Oxitec. “Growers are struggling to control it through insecticidal means.” For its method of control, Oxitec took a strain of fall armyworm that is still susceptible to pesticides and modified males so that their female offspring can survive only in the presence of a specific chemical. In other words, the males carry a gene that kills all their female offspring in the wild.
New tech fights fall armyworm by letting offspring die
20568V. Ouma, Sci Dev Net, 2022-03-01 09:43:19.
Scientists have developed a new technology that could control the devastating fall armyworm crop pest by releasing genetically-controlled males that suppress populations as subsequent offspring cannot survive, a study says. The fall armyworm, Spodoptera frugiperda, which was detected in Sub-Saharan Africa for the first time in 2016, could lead to one-third maize yield losses in some countries and up to US$6.3 billion loss annually, according to the study published in the journal BMC Biotechnology. The gene technology developed by Oxitec, a UK-based biotechnology company that genetically modifies insects to assist in insect control, enables production of male-only cohorts of the friendly fall armyworm that when released into farmer fields will mate with pest female fall armyworms, and their female offspring cannot survive, resulting in fewer pests on the crops and therefore less damage
Self-limiting fall armyworm: a new approach in development for sustainable crop protection and resistance management
20232C. E. Reavey, A. S. Walker, S. P. Joyce, L. Broom, A. Willse, K. Ercit, M. Poletto, Z. H. Barnes, T. Marubbi, B. J. Troczka, D. Treanor, K. Beadle, B. Granville, V. de Mello, J. Teal, E. Sulston, A. Ashton, L. Akilan, N. Naish, O. Stevens, N. Humphreys-Jo, BMC Biotechnology, 22:5. 2022-01-27 09:04:56.
Here, we describe the first germline transformation of the fall armyworm and the development of a genetically engineered male-selecting self-limiting strain, OX5382G, which exhibits complete female mortality in the absence of an additive in the larval diet. Laboratory experiments showed that males of this strain are competitive against wild-type males for copulations with wild-type females, and that the OX5382G self-limiting transgene declines rapidly to extinction in closed populations following the cessation of OX5382G male releases. Population models simulating the release of OX5382G males in tandem with Bt crops and non-Bt ‘refuge’ crops show that OX5382G releases can suppress fall armyworm populations and delay the spread of resistance to insecticidal proteins
Putting the sterile insect technique into the modern integrated pest management toolbox to control the codling moth in Canada
19363Nelson, C., Esch, E., Kimmie, S., Tesche, M., and Philip, H. Arthur, S., AREA-WIDE INTEGRATED PEST MANAGEMENT: Development and Field Application, 2021-11-29 16:38:40.
The Okanagan-Kootenay Sterile Insect Release (OKSIR) programme, in southern British Columbia, Canada, has been successfully applying the Sterile Insect Technique (SIT) as part of a sustainable areawide integrated pest management (AW-IPM) programme to control the codling moth Cydia pomonella L. in pome fruits in the region for over 20 years. Chemical, cultural and biological techniques that complement the SIT are also integrated into orchard and regional pest management plans by the programme and/or individual growers. The AW-IPM programme is supported by close monitoring of codling moth populations in orchards and adjacent urban properties; enforcing suppression of codling moth infestations in orchards and urban areas; removing derelict orchards, wild host trees and poorly managed host trees; and increasing public awareness and education. Successful collaboration between the OKSIR programme, the pome fruit industry, area residents and various government organizations has reduced codling moth populations by 94%, relative to pre-programme levels, and codling moth damage to less than 0.2% of fruit, in more than 90% of the orchards in the programme area. Local pesticide sales indicate a 96% reduction in the amount of active ingredient used against the codling moth since 1991. Implementing the SIT through an innovative social approach to local community-centred area-wide pest management has posed many challenges and created many learning opportunities. The codling moth mass-rearing facility in Osoyoos, British Columbia, has the capacity to produce 780 million sterile codling moths annually, but only a portion of that is used seasonally to treat 3400 hectares (ha) of pome fruit made up of small orchards intermixed with residential areas in the Okanagan Valley. As a result of climate change and increasing global trade, destructive insect pests are migrating to new habitats throughout the world. These new threats must be managed in ways that protect both the agrifood industries and the natural environments in which the industries operate. The OKSIR programme is an effective and easily transferred model to meet these challenges, especially as a supplement to other biological control methods. The programme is also a compelling model of success that can encourage other regions to use the SIT in their pest management toolbox to combat codling moth infestations across multiple local community jurisdictions using environment-friendly, cost-effective methods based on proven technology. The OKSIR programme is exploring the sale of surplus sterile moths, egg sheets or possible virus production as an opportunity to offset costs of incorporating additional area-wide approaches to combat other invasive pests.
Towards CRISPR/Cas9-based gene drive in the diamondback moth Plutella xylostella
18867X. Xu, T. Harvey-Samuel, H. Siddiqui, J. Ang, M. A. E. Anderson, C. Reitmayer, E. Lovett, P. T. Leftwich, M. You and L. Alphey, bioRxiv, 2021.10.05.462963. 2021-10-05 19:03:11.
Promising to provide powerful genetic control tools, gene drives have been constructed in multiple dipterans, yeast and mice, for the purposes of population elimination or modification. However, it remains unclear whether these techniques can be applied to lepidopterans. Here, we used endogenous regulatory elements to drive Cas9 and sgRNA expression in the diamondback moth, (Plutella xylostella), and test the first split-drive system in a lepidopteran. The diamondback moth is an economically important global agriculture pest of cruciferous crops and has developed severe resistance to various insecticides, making it a prime candidate for such novel control strategy development. A very high level of somatic editing was observed in Cas9/sgRNA transheterozygotes, although no significant homing was revealed in the subsequent generation. Although heritable, Cas9-medated germline cleavage, as well as maternal and paternal Cas9 deposition was observed, rates were far lower than for somatic cleavage events, indicating robust somatic but limited germline activity of Cas9/sgRNA under the control of selected regulatory elements. Our results provide valuable experience, paving the way for future construction of gene drive-based genetic control strategies in DBM or other lepidopterans.Competing Interest StatementThe authors have declared no competing interest.
Persistent Spodoptera frugiperda rhabdovirus infection in Sf9 cells is not restricted by Wolbachia wMelPop-CLA and wAlbB strains and is targeted by the RNAi machinery
18362R. Parry, H. de Malmanche and S. Asgari, Virology, 563:82-87. 2021-09-08 14:28:58.
The endosymbiotic bacterium Wolbachia pipientis confers RNA virus refractoriness in Drosophila and Aedes mosquitoes. Questions remain about the Wolbachia-virus restriction phenotype and how extensive this phenomenon may be within other arthropods. Here, we generated two Spodoptera frugiperda cell lines stably transinfected with two strains of Wolbachia, wAlbB and wMelPop-CLA. Despite the high density of Wolbachia in stably infected Sf9 cells, RT-PCR indicated the presence of the negative-sense RNA virus Spodoptera frugiperda rhabdovirus (SfRV) in Wolbachia-infected and uninfected cell lines. No differences in the replication of SfRV between Sf9 and Wolbachia-infected cells was found. RNA-Seq analysis of the parental Sf9 cells supported SfRV's presence in these cells with abundant 20 nt virus-derived small RNAs indicating active replication of SfRV in these cells. Overall, this study supports a growing body of evidence that Wolbachia does not restrict negative-sense RNA viruses and generates an in vitro model to examine Lepidoptera-Wolbachia virus interactions.
CRISPR/Cas9-based functional characterization of the pigmentation gene ebony in Plutella xylostella
18155X. Xu, T. Harvey-Samuel, J. Yang, M. You and L. Alphey, Insect Molecular Biology, 2021-08-20 17:59:44.
Abstract Body pigmentation is an important character of insects in adapting to biotic and abiotic environmental challenges. Additionally, based on the relative ease of screening, several genes involved in insect melanisation have been used in classic genetic studies or as visual markers in constructing transgenic insects. Here, a homolog of the Bombyx mori melanisation-inhibiting gene ebony, associated with the conversion of dopamine to N-?-alanyl dopamine, was identified in a global pest, Plutella xylostella. The CRISPR/Cas9 system was applied to generate multiple Pxebony knockout alleles which were crossed to produce a Pxebony knockout strain, showing darker pigmentation in larvae, pupae and adults, compared with wildtype. Interestingly, we observed that Pxebony heterozygotes displayed an intermediate darkened phenotype, indicating partial dominance between the knockout and wildtype alleles. The fitness costs of Pxebony-deficiency were also assessed in the mutant strain, indicating that embryo hatchability and larval survival were significantly reduced, while the eclosion rate was not obviously affected. Our work provides a potential target for exploring CRISPR-based genetics-control systems in this economically important pest lepidopteran.
British Firm Develops ‘Friendly’ Fall Armyworm To Save Crops
17176J. Choubey, Zenger, 2021-05-14 19:57:00.
The genetically modified fall armyworm, a pest that has invaded farms across Asia, Africa, and the Americas, has been developed by U.K-based biotechnology firm Oxitec to reduce the species’ population. The fall armyworm, or Spodoptera frugiperda, is a lepidopteran pest belonging to the family of butterflies and moths. It feeds on leaves, stems, and the reproductive parts of plants. The pest is causing significant damage to economically important cultivated grasses like maize, rice, sorghum, sugarcane, and wheat, along with 75 other crop species. Oxitec is collaborating with Bayer, a German multinational pharmaceutical and life sciences company, for the technology.
Bliotech firm behind CRISPR mosquitoes is working on other gene-hacked creatures
17217D. Robitzski, Futurism, 2021-05-14 16:08:11.
Brazil’s regulatory agency CTNBio gave Oxitec and Bayer the approval they needed to launch a field test of the gene-hacked armyworm — technically a caterpillar — on commercial crops, so there may be genetically altered bugs crawling across corn farms in the area soon. For years, Brazilian farmers have been trying to control fall armyworms with chemical pesticides. But as the pests grew to resist the sprays — which were already difficult to time in a way that actually impacted the nocturnal insect — they had to spray more and more harmful chemicals in the environment, according to Zenger‘s reporting. If Oxitec’s technology works — there’s reason to doubt that its similar mosquito tech does what the company claims — then that excessive pesticide spraying may be able to stop. “Our technology potentially reduces the need for additional pesticides in the long term,” Oxitec head of agricultural programs Neil Morrison said, according to Zenger. “Besides reducing populations of the pest, it also has the potential to slow the resistance development to insecticides and biotechnology enhanced crops.”
Next gen insect control
16960E. Unglesbee, Progressive Farmer, 2021-05-04 14:58:12.
Dubbed "self-limiting" insects by their makers, a UK-based biotechnology company called Oxitec, these insects are genetically modified (GM) with an inserted gene that permits only male offspring to survive. Once released into a pest community, the GM insects gradually lower the population, accomplishing a new type of pest control. Then, rather politely, they die off themselves. "After we stop releasing the self-limiting males, the gene declines in a population over a short period of time and within a few generations, disappears," Neil Morrison, head of agriculture programs for Oxitec, told DTN. "It's a gene that prevents survival of half its carriers -- the females -- so it's essentially programmed to decline and disappear quite rapidly." Sound too sci-fi to be real? It's actually happening right now, in the Florida Keys. After gaining EPA and state regulatory approval for the project last year, Oxitec is working with the Florida Keys Mosquito Control District to deploy the country's first largescale release of Oxitec's self-limiting Aedes aegypti mosquitoes.
Armyworm meets Friendly moth
17066M. Francisco, Nature Biotechnology, 39:532-532. 2021-05-01 14:11:25.
The fall armyworm moth, a pest so named for its caterpillar’s invasive and destructive behavior, may now have to contend with a ‘Friendly’ foe. UK-based Oxitec and agbiotech giant Bayer have jointly developed a genetically modified variety to combat the fall armyworm (Spodoptera frugiperda), an insect pest causing severe destruction to corn, rice and sorghum crops in more than 100 countries. Brazil has approved field trials of the GM ‘Friendly’ fall armyworm moths. The technology, originally developed at Oxford University, uses male self-limiting fall armyworm moths. When males are released into infested areas, the moths mate with wild females, but as they produce no female offspring in the next generation, this reduces the population of crop-eating caterpillars. The approach is species specific, is self-limiting in the environment, and has no impact on beneficial insects such as bees. Oxitec has successfully used the technology with mosquitoes to control dengue and Zika in Brazil, and is currently releasing Friendly mosquitoes in the Florida Keys as part of a US Environmental Protection Agency trial. Though some groups remain opposed to the technology, most experts agree that GMOs must be part of an integrated pest management solution, in addition to rotating crops, encouraging the growth of a pest’s natural predators, and using pesticides selectively to mitigate resistance buildup.
Oxitec Receives Landmark Biosafety Approval for New Fall Armyworm Control Solution
16810Oxitec, Oxitec, 2021-04-15 16:03:00.
Approval of Oxitec’s Friendly™ fall armyworm technology by the Brazilian government’s regulatory agency CTNBio confirms that it is safe for people, animals and the environment. Oxitec’s Friendly™ fall armyworm is a new, safe, and sustainable solution to one of the world’s most devastating crop pests. CTNBio’s decision is a significant step towards deployment on commercial corn fields in Brazil. This is the world’s first commercial biosafety approval of an agricultural Friendly™ insect solution, following the regulatory approval in Brazil for Oxitec’s Friendly™ Aedes aegypti mosquito in 2020
Operational Parameters for the Aerial Release of Sterile Codling Moths Using an Uncrewed Aircraft System
17762E. D. Esch, R. M. Horner, D. C. Krompetz, N. Moses-Gonzales, M. R. Tesche and D. M. Suckling, Insects, 12:2/13/2021. 2021-02-13 14:52:13.
The codling moth is a serious pest of apples in most regions of the world where this fruit is produced. The sterile insect technique is one strategy used to control this pest and is employed as part of an area-wide integrated pest management program for the codling moth in British Columbia, Canada. Modified fixed wing aircraft are the most common method for the release of sterile insects in large area-wide pest management programs. However, aerial release with a full-size aircraft can be prohibitively expensive. We evaluated the use of small, uncrewed aircraft systems (UASs) for the release of sterile codling moths. Sterile codling moths released from greater altitudes were more broadly distributed and drifted more in strong winds, compared to those released from lower altitudes. Most of the released insects were recaptured in a 50 m wide swath under the release route. Recapture rates for aerially released insects were 40–70% higher compared to those released from the ground. UASs provide a promising alternative to ground release and conventional aircraft for the release of sterile codling moths.
Combined Effects of Mating Disruption, Insecticides, and the Sterile Insect Technique on Cydia pomonella in New Zealand
15958R. M. Horner, P. L. Lo, D. J. Rogers, J. T. S. Walker and D. M. Suckling, Insects, 11:23. 2020-11-27 18:11:55.
We aimed to supplement these tactics with the sterile insect technique (SIT) to further suppress the codling moth on orchards. SIT involves mass rearing and sterilizing codling moth and then releasing them onto orchards where they mate with wild insects resulting in no offspring. We released sterile insects onto seven orchards using unmanned aerial vehicles and ground releases. Six years of the program saw significant drops (90-99%) in wild moth populations. The SIT is an excellent tactic for reducing moth populations in export apple orchards.
Can a Genetically Modified Bug Combat a Global Farm Plague?
14470E. Nitler, Wired, 2020-09-24 17:24:48.
Executives from the US-owned, but UK-based, firm Oxitec and its multinational partner Bayer announced today that they have developed a fall armyworm that has a self-limiting gene introduced into the male of the species.
Recessive Z-linked lethals and the retention of haplotype diversity in a captive butterfly population
11972I. J. Saccheri, S. Whiteford, C. J. Yung and A. E. van't Hof, Heredity, 2020-05-13 18:21:56.
Sex chromosomes are predicted to harbour elevated levels of sexually antagonistic variation due to asymmetries in the heritability of recessive traits in the homogametic versus heterogametic sex.
Genetically engineered moths may save kale chips
7357C. Poku, BIOtechNOW, 2020-02-07 21:49:10.
Sea salt kale chips, bacon brussels sprouts, and buffalo cauliflower wings are under threat. Environmental activists will have you believe the biggest threat to our food system is pesticides. That’s not true, in fact, it’s insects—the very reason most pesticides are necessary. Insects are such a dangerous issue that Somalia recently declared a state of emergency as an “unprecedented” swarm of locusts is raising alarms about famine. Climate change has led to a rampant increase in bugs like locusts and moths, that threaten our food, and mosquitoes and ticks, that threaten people. A recent CNN article explains that diamondback moths are one of the most damaging insects because of their high reproduction rate and resistance to most insecticides.
Genetically engineered moths have been released into the wild to wipe out pests
7360K. Rogers, CNN, 2020-02-03 21:55:17.
Genetically modified diamondback moths designed to wipe out wild pest populations were released in fields for the first time in New York state. Diamondback moths are migratory pests found in the Americas, Europe, New Zealand and Southeast Asia, but especially in areas where crops can be grown yearround. In these parts -- where it's not too hot nor too cold -- are where diamondback moths cause the greatest problems, including billions of dollars in damages to cruciferous crops such as cabbage, broccoli, cauliflower and canola. They're one of the most damaging insects because of their high reproduction rate and resistance to most insecticides.
Genetically modified butterflies could herald a new era in crop protection
7245Science News,, Science News, 2020-02-01 16:02:30.
New study highlights successful test including field release of genetically modified butterflies. Scientists believe this success could pave the way for an effective and sustainable approach to pest control in crops. The butterfly in question is the cruciferous moth ( Plutella xylostella ), or cabbage moth, a species of moth (butterfly) of the family Plutellidae. The agricultural industry has been trying for decades to find organic and environmentally friendly ways to fight the cruciferous moth, a species largely resistant to insecticides.
World’s First Genetically Modified Moths Released to Nature
7248M. Cage, SOMAG News, 2020-01-30 16:07:06.
There are many insect species that harm agricultural products in the world. One of them is diamond moths. Genetically modified moths were used to control these moths, which are harmful to many plants. Plutella xylostella or also known as diamond moths; One of the most harmful and destructive insects for plants such as cauliflower, cabbage, broccoli and canola. This creature, which is also very resistant to pesticides, causes great damage to the plants it dips. Especially in China, this insect seriously undermines the growing of cabbage, one of the country’s most important crops.
GMO diamondback moth shows promise as sustainable pest control tool in first ever open-field release
7262Cornell University, Genetic Literacy Project, 2020-01-29 16:35:41.
A newly published study reports a successful, first-ever open-field release of a self-limiting, genetically engineered diamondback moth, stating that it paves the way for an effective and sustainable approach to pest control. The diamondback moth, also known as Plutella xylostella, is highly damaging to brassica crops such as cabbage, broccoli, cauliflower and canola. This new strain of diamondback moth, developed by Oxitec Ltd, is modified to control pest diamondback moth in a targeted manner. The study showed the engineered strain had similar field behaviors to unmodified diamondback moths, with results offering promise for future protection of farmers’ brassica crops.
Scientists have released genetically modified moths
7259N. Kumar, The Times Hub, 2020-01-29 16:32:32.
In the US, the researchers decided to test emerging from genetic modification Diamondback moth, placing it in field conditions. The work was conducted by experts from new York, representing Cornell University.
GM Insects on the Horizon
7256E. Unglesbee, Progressive Farmer, 2020-01-29 16:22:18.
Diamondback moths would do well to be wary of potential mates in the years to come. Scientists recently completed the first successful field testing of a genetically modified (GM) "self-limiting" insect in the U.S., using this species. When the GM male diamondback moths are released and mate with wild female moths, they pass on a gene that causes all female offspring from the match to die in the early larval stages.
Male moths genetically modified to kill females released in the wild
7253M. Le Page, New Scientist, 2020-01-29 16:14:01.
Genetically modified male diamondback moths designed to wipe out pest populations have been released in New York state. The field trial shows that these GM moths, whose female offspring die soon after hatching, could help control this major crop pest. Oxitec, the British biotechnology company behind the trial, has already carried out field trials of this method for controlling mosquitoes that spread diseases such as dengue. However, the moth field trial is the first for a crop pest, the company says.
First Field Release of a Genetically Engineered, Self-Limiting Agricultural Pest Insect: Evaluating Its Potential for Future Crop Protection
7251A. M. Shelton, S. J. Long, A. S. Walker, M. Bolton, H. L. Collins, L. Revuelta, L. M. Johnson and N. I. Morrison, Frontiers in Bioengineering and Biotechnology, 7:1-15. 2020-01-29 16:10:21.
Alternative, biologically-based approaches for pest management are sorely needed and one approach is to use genetically engineered insects. Herein we describe a series of integrated field, laboratory and modeling studies with the diamondback moth, Plutella xylostella, a serious global pest of crucifers. A “self-limiting” strain of Plutella xylostella (OX4319L), genetically engineered to allow the production of male-only cohorts of moths for field releases, was developed as a novel approach to protect crucifer crops. Wild-type females that mate with these self-limiting males will not produce viable female progeny. Our previous greenhouse studies demonstrated that releases of OX4319L males lead to suppression of the target pest population and dilution of insecticide-resistance genes. We report results of the first open-field release of a non-irradiated, genetically engineered self-limiting strain of an agricultural pest insect. In a series of mark-release-recapture field studies with co-releases of adult OX4319L males and wild-type counterparts, the dispersal, persistence and field survival of each strain were measured in a 2.83 ha cabbage field. In most cases, no differences were detected in these parameters. Overall, 97.8% of the wild-type males and 95.4% of the OX4319L males recaptured dispersed <35 m from the release point. The predicted persistence did not differ between strains regardless of release rate. With 95% confidence, 75% of OX4319L males released at a rate of 1,500 could be expected to live between 3.5 and 5.4 days and 95% of these males could be expected to be detected within 25.8–34.9 m from the release point. Moth strain had no effect on field survival but release rate did. Collectively, these results suggest similar field behavior of OX4319L males compared to its wild-type counterpart. Laboratory studies revealed no differences in mating competitiveness or intrinsic growth rates between the strains and small differences in longevity. Using results from these studies, mathematical models were developed that indicate release of OX4319L males should offer efficacious pest management of P. xylostella. Further field studies are recommended to demonstrate the potential for this self-limiting P. xylostella to provide pest suppression and resistance management benefits, as was previously demonstrated in greenhouse studies.
Identification and characterisation of a Masculinizer homolog in the diamondback moth Plutella xylostella
5607Harvey-Samuel, T., V. C. Norman, R. Carter, E. Lovett and L. Alphey, Insect Molecular Biology, 2019:2019. 2019-12-17 16:09:12.
Recently, a novel sex-determination system was identified in the silkworm (Bombyx mori) in which a piRNA encoded on the female-specific W chromosome silences a Z-linked gene (Masculinizer) which would otherwise initiate male sex-determination and dosage compensation. Masculinizer provides various opportunities for developing improved genetic pest management tools. A pest lepidopteran in which a genetic pest management system has been developed, but which would benefit greatly from such improved designs, is the diamondback moth, Plutella xylostella. However, Masculinizer has not yet been identified in this species. Here, focusing on the previously described ?masculinizing? domain of B. mori Masculinizer, we identify P. xylostella Masculinizer (PxyMasc). We show that PxyMasc is Z-linked, regulates sex-specific alternative splicing of doublesex and is necessary for male survival. Similar results in B. mori suggest this survival effect is possibly through failure to initiate male dosage compensation. The highly conserved function and location of this gene between these two distantly related lepidopterans suggests a deep role for Masculinizer in the sex-determination systems of the Lepidoptera.
Peri-Urban Community Attitudes towards Codling Moth Trapping and Suppression Using the Sterile Insect Technique in New Zealand
17774G. Paterson, G. L. W. Perry, J. T. S. Walker and D. M. Suckling, Insects, 10. 2019-10-09 15:21:37.
New, more socially-acceptable technologies are being developed to suppress horticultural pests, because suppression is technically difficult with current technologies, especially in urban areas. One technique involves the release of sterile insects to prevent offspring in the next generation. This technology involves aerial or ground release systems, but this could also create issues for the public. This study investigated community perceptions of a recently-introduced response to codling moth control in New Zealand—Sterile Insect Technique (SIT). Community attitudes to SIT were examined in Hastings, New Zealand, in April, 2018. Eighty-six detailed interviews were undertaken with a random sample of households. This community was very willing (98% agreement) to host a sex pheromone trap in their gardens, and condoned regular visits to monitor traps. Attitudes to SIT were very positive (98% in favor). Once explained, the concept of using unmanned aerial vehicles to deliver sterile insects was also acceptable (98%) to the community. Use of unmanned aerial vehicles to release sterile insects during a hypothetical incursion response of an exotic fruit fly was also supported at 98% by respondent householders. Investigation of community attitudes can be valuable to guide practitioners in determining suitable technologies before an area-wide programme is launched.
Twenty-five Years of Research Experience with the Sterile Insect Technique and Area-Wide Management of Codling Moth, Cydia pomonella (L.), in Canada
13154H. M. A. Thistlewood and G. J. R. Judd, Insects, 10:292. 2019-09-10 14:21:45.
The advent of novel genetic methods has led to renewed interest in the sterile insect technique (SIT) for management of insect pests, owing to applications in mass rearing and in the production of sterile offspring without use of irradiation. An area-wide management programme for codling moth, Cydia pomonella, has employed the SIT and other management practices over a large area (3395 to 7331 ha) of orchards and neighbouring urban, public, or First Nations lands in British Columbia, Canada, for 25 years. This project is the first to employ the SIT for C. pomonella, and the longest-running application of area-wide techniques for its control, anywhere. It was derived from basic research and applied trials from the 1960s onwards. Many biological challenges were overcome, and lessons learnt, in transferring from small- to large-scale applications of mass rearing and the SIT, with particular regard to Lepidoptera. Research has proven essential to identifying, if not resolving, issues that threaten the implementation and success of any such programme. The major challenges encountered, and the resulting research, are reviewed, as well as future directions. Recommendations are given for application of the SIT as part of any area-wide management programme for C. pomonella.
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