Livestock Pests Research Articles

The cost of the production and release of male Aedes aegypti mosquitoes sterilised by irradiation.

Classic vector control tools do not sustainably reduce Aedes populations or prevent the surge of arboviruses. The sterile insect technique (SIT) by irradiation relies on mass-rearing and release of male insects that will not produce viable offspring. It has been successfully integrated into controlling agricultural and livestock pests. Experiments are conducted to determine the effectiveness of the approach for suppressing Aedes aegypti and curbing dengue transmission. Detailed implementation cycle costs have not been reported yet. To detail the costs of producing and releasing male A. aegypti mosquitoes sterilised by irradiation. We carried out a cost analysis during a SIT pilot trial in Havana. We took a provider perspective and used microcosting. From the cost function, we subsequently calculated costs for base case variations in production volume and mosquito release rate per hectare. The setup expenses to establish the capacity to produce and release 450,000 mosquitoes weekly amounted to 155,452.00 and 2456.40 USD in capital means and training, respectively. The average number of sterile mosquitoes released per hectare per week during the trial was 1500, utilising 17% of the installed capacity. Including capital depreciation, the average cost per 10,000 sterile male mosquitoes released was 110.12 USD. When producing at 85% capacity, this reduces nearly threefold, to 41.06 USD. At that production level, releasing 500 or 4500 sterile male mosquitoes per hectare costs on average 2.70 or 16.54 USD per hectare covered. In densely populated areas with 500 inhabitants per hectare, this corresponds to 0.28 or 1.72 USD per inhabitant per year. Our cost estimates for SIT by irradiation are within the range of estimates reported for alternative mass-rearing and release methods to control Aedes populations, and the approach appears competitive with insecticide-based interventions. The cost-effectiveness in different contexts remains to be investigated.

Radiating South

Abstract From the 1960s to the 1990s, the US Department of Agriculture led a campaign across North America to eradicate a notorious livestock pest known as the screwworm. It did so by breeding flies in factories, sterilizing them with radiation, and scattering them from the air. Based on original multisite archival research, this article examines the overlooked role of Mexico in what was a flagship application of the “sterile male technique.” It argues that three main factors shaped this role: Mexico's long-term projects of agricultural and atomic modernization; diplomatic leverage provided by a shared border; and an earlier tradition of bilateral cooperation and conflict over animal disease that stretched back to the 1940s. The analysis deepens our understanding of how Mexico shaped science and agriculture at home and abroad. It also helps explain why this particular project of atomic agriculture succeeded on the scale it did.

Determinants of coping strategies among agropastoralists in Kitui and Isiolo counties, Kenya

Agropastoralists in Kenya’s Arid and Semi-arid Lands (ASALs) face various shocks that threaten their livelihoods and expose them to significant health and economic risks. While existing studies often focus on climate-related shocks, they frequently overlook other challenges faced by these communities. A comprehensive understanding of how agropastoralists manage diverse shocks is essential to developing effective vulnerability reduction strategies. This study examined the major shocks experienced by agropastoral households in Kenya’s ASALs, their primary coping strategies, and the determinants informing the choice of the strategies adopted. Using cross-sectional data from 371 households in Isiolo (203) and Kitui (168) counties, this study applied descriptive analysis and multivariate probit (MVP) models to assess coping strategies and influencing factors. From 2016 to 2021, households faced shocks, such as droughts, livestock pests and diseases, crop pests, theft, and intercommunal conflicts. Regional variations were observed: crop pests were common in Kitui, whereas Isiolo experienced higher theft and conflict rates. Coping strategies include income diversification, asset sales, increased farm labor, and reduced food expenditure. Severe droughts and conflicts led to migration, while floods caused extreme measures such as withdrawing children from school. Key factors influencing coping strategies include household demographics, farm characteristics, and market proximity. Households with more adults, higher literacy, or greater income from crops and livestock are less likely to adopt costly strategies. This study recommends integrated interventions to enhance resilience to both climate and non-climate shocks.

Black flies (Diptera: Simuliidae) in the Galapagos Islands: Native or adventive?

Invasive species are a threat to ecosystems worldwide, but determining if a species is adventive or native is not always straightforward. The black flies that inhabit the Galapagos Islands, long known as Simulium ochraceum, are blood-feeding pests of humans and livestock. They first came to the attention of residents in 1989, suggesting a recent arrival. Earlier colonization, however, has been suggested, based largely on polymorphic genetic loci. To address questions of origin, provenance, and length of residency, we conducted a macrogenomic analysis of the polytene chromosomes of the S. ochraceum complex from seven sites in the Galapagos Islands and 30 sites in mainland Ecuador, Central America, and the Caribbean. Among 500 analyzed larvae, we discovered 88 chromosomal rearrangements representing 13 cytoforms, at least seven of which are probably full species. All evidence points to a single, cohesive cytoform with full species status in the Galapagos, conspecific with mainland populations, and widely distributed in the Neotropical Region. It has an identical, nearly monomorphic banding sequence with 10 novel fixed inversions and a subtle but unique Y-linked chromosomal rearrangement across all populations sampled in the Galapagos, the mainland, and the Caribbean. We recalled the name Simulium antillarum from synonymy with S. ochraceum and applied it to the Galapagos black flies, and we established that wolcotti is a junior synonym of antillarum. The time(s) and mode(s) of arrival of S. antillarum in the Galapagos remain uncertain, although the wide geographic distribution, including islands in the Caribbean, suggests that the species is an adept colonizer. Regardless of how long it has been in the archipelago, S. antillarum might have assumed a functional role in the streams of San Cristobal, but otherwise has had a detrimental effect on humans and livestock and potentially on the unique birds and mammals of the Galapagos Islands.

Deltamethrin exposure caused renal inflammation and renal fibrosis via upregulating endoplasmic reticulum stress-mediated TXNDC5 level in mice

Deltamethrin (DLM) is a type II pyrethroid insecticide that is extensively applied to agriculture, veterinary medicine and livestock pest control. Excessive accumulation of DLM in the body can lead to nephrotoxicity, but the precise toxic mechanism remains obscure. Therefore, we established in vivo models of DLM-exposed mice for 30 days and in vitro models of DLM-exposed renal tubular epithelial cells of mice. The results revealed adverse effects on renal function in mice exposed to excessive DLM, manifested as endoplasmic reticulum (ER) swelling, local inflammatory infiltration in renal tissue and increased collagen fibers, suggesting renal inflammation and fibrosis, etc. Subsequently, in vivo experiments, we found that DLM exposure increased expression levels of endoplasmic reticulum stress (ERS)-related factors, significantly upregulated the expression of TXNDC5, and enhanced the colocalization of GRP78 with TXNDC5. Notably, DLM exposure also strengthened the co-localization of TXNDC5 with NF-κB p65 and TGF-β1, upregulated the expression levels of TLR4/MYD88/NF-κB and TGF-β/SMAD2/3 pathways, alongside inflammation and fibrosis-related factors, these changes exhibited a dose-dependent effect. Meanwhile, in vitro experiments, the results of ERS, inflammation, and fibrosis-related factor expression levels were consistent with those observed in vivo. In conclusion, our results demonstrated that TXNDC5 might played a certain role in DLM-induced nephrotoxicity. Specifically, DLM exposure could trigger ERS, increase TXNDC5 expression, and promote TLR4/MYD88/NF-κB and TGF-β/Smad2/3 pathways, leading to renal inflammation and fibrosis in mice. These discoveries not only deepen our understanding of DLM toxicity but also provide valuable avenues for exploring mitigation strategies and therapeutic interventions.

Highlights of veterinary entomology, 2023: beyond the barnyard: exploring the wild side of veterinary entomology.

Due to economic and food security concerns, veterinary entomology has traditionally focused on livestock pests and ectoparasites. However, recognizing the significant environmental changes of the Anthropocene era, there is a need to broaden the scope to include pests and ectoparasites of wildlife. This review highlights key studies from 2023 that go beyond the barnyard and represent this expanded focus. Key areas explored include the development and application of unique methodologies, the impact of arthropods on behavior, and the effects of anthropogenic and environmental influences on pests, ectoparasites, and hosts. By adopting a broader perspective, veterinary entomologists can develop new collaborations and better understand the complex interactions between pests, ectoparasites, and a diverse array of nonhuman vertebrates. This comprehensive understanding is essential for advancing global health and biodiversity conservation.

Effects of Changing Weather Patterns on Household Food Availability in Bukiro Sub County Mbarara District

Changing weather patterns and their variables are already negatively impacting food security by damaging crops, reducing yields, and increasing the prevalence of pests and diseases. These pests and diseases contend with crops for sunlight, water, and nutrients, further diminishing agricultural yields and creating issues for crops that were previously unexposed to these threats. Climate-related disruptions in food distribution and transportation, both internationally and domestically, have a substantial impact on not just safety and quality but also access to food. Prolonged dry spells followed by heavy and stormy rains cause interruptions in food production and transportation, reducing farmers' ability to get their grains to market and potentially affecting food prices. This study assessed farmers’ perceptions of effects of changing weather patterns on food security and their coping strategies towards effects of weather changing patterns in smallholder households in Bukiro Sub County, Mbarara District. A sample of 100 smallholder farmers were randomly selected from four parishes of Bukiro sub county and studied using questionnaire and observations. Key informants Interviews were also conducted with nine technical workers and three opinion leaders. Software STAT 26 and Ms excel version 2016 were used to do data analysis. The study found out that changing weather patterns through its variables specifically heavy and stormy rains, late of set of rains, and prolonged dry spells had significant effects on food security. The perceived effects of changing weather patterns established were drying up of water sources (83.8%), decreased land for crop growing (82.4%), reduction in crop yields (77.7%), drying of pastures for animals (67.4%), drying of crops (58.1%), and occurrence of crop and livestock pests and diseases at (56.6%). Also, the perceived weather changing variabilities were late onset of rains (60.1%), prolonged dry spells were responded at 17.6%, and heavy and stormy rains 22.3%. From the study finding farmers clearly perceived that changing weather patterns had negative effects smallholders’ agricultural production systems impacting negatively on food security

Antennal transcriptome analysis reveals sensory receptors potentially associated with host detection in the livestock pest Lucilia cuprina

BackgroundLucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) is the main causative agent of flystrike of sheep in Australia and New Zealand. Female flies lay eggs in an open wound or natural orifice, and the developing larvae eat the host’s tissues, a condition called myiasis. To improve our understanding of host-seeking behavior, we quantified gene expression in male and female antennae based on their behavior.MethodsA spatial olfactometer was used to evaluate the olfactory response of L. cuprina mated males and gravid females to fresh or rotting beef. Antennal RNA-Seq analysis was used to identify sensory receptors differentially expressed between groups.ResultsLucilia cuprina females were more attracted to rotten compared to fresh beef (> fivefold increase). However, males and some females did not respond to either type of beef. RNA-Seq analysis was performed on antennae dissected from attracted females, non-attracted females and males. Transcripts encoding sensory receptors from 11 gene families were identified above a threshold (≥ 5 transcript per million) including 49 ATP-binding cassette transporters (ABCs), two ammonium transporters (AMTs), 37 odorant receptors (ORs), 16 ionotropic receptors (IRs), 5 gustatory receptors (GRs), 22 odorant-binding proteins (OBPs), 9 CD36-sensory neuron membrane proteins (CD36/SNMPs), 4 chemosensory proteins (CSPs), 4 myeloid lipid-recognition (ML) and Niemann-Pick C2 disease proteins (ML/NPC2), 2 pickpocket receptors (PPKs) and 3 transient receptor potential channels (TRPs). Differential expression analyses identified sex-biased sensory receptors.ConclusionsWe identified sensory receptors that were differentially expressed between the antennae of both sexes and hence may be associated with host detection by female flies. The most promising for future investigations were as follows: an odorant receptor (LcupOR46) which is female-biased in L. cuprina and Cochliomyia hominivorax Coquerel, 1858; an ABC transporter (ABC G23.1) that was the sole sensory receptor upregulated in the antennae of females attracted to rotting beef compared to non-attracted females; a female-biased ammonia transporter (AMT_Rh50), which was previously associated with ammonium detection in Drosophila melanogaster Meigen, 1830. This is the first report suggesting a possible role for ABC transporters in L. cuprina olfaction and potentially in other insects.Graphical

Sex comparison of oxidative stress, mitochondrial dysfunction, and apoptosis triggers induced by single-dose Abamectin in albino rats

Abamectin (AB) is widely used in agriculture and has been employed as an insecticide, nematicide, and livestock pest control agent. However, it may also pose a serious threat to mammals. The primary purpose of this research was to compare the sex variations between male and female rats during exposure and to assess the risk of toxicity of abamectin, which are still largely unknown. The twenty albino rats were divided randomly into four groups (n = 5): 1) the male control group; 2) the male treatment group treated with AB (1 mg/kg B.W.); 3) the female control group; and 4) the female treatment group treated with AB (1 mg/kg B.W.). AB administration caused a drop in body weight in females more than males with showing oxidative stress in both sexes of animals, as characterized by an increase in MDA content and a decrease in glutathione (GSH) content and superoxide dismutase (SOD) activity. Reported sex-specific effects suggested that females are more susceptible from males in brain tissues for alteration of antioxidant markers while females' liver and kidney tissues showed more level of lipid peroxidation than males. In addition, mitochondrial dysfunction was associated with a significant decrease in NADH dehydrogenase (Complex I) and a significant decrease in mitochondrial ATPase, which led to apoptosis and histopathological alterations in the targeted tissues, indicating that females are higher sensitive than males to these biological events. In brief, the results of this study led to female rats are generally more sensitive than male rats to neurobehavioral and hepatic complications associated with abamectin treatment. Further evaluation should be performed to determine the adverse outcome pathways involved and to determine the effects of sex on improving the risk assessment of abamectin in both sexes.

Variable gut pH as a potential mechanism of tolerance to Bacillus thuringiensis subsp. israelensis toxins in the biting midge Culicoides sonorensis.

Toxins of Bacillus thuringiensis subsp. israelensis (Bti) are safer alternatives for controlling dipteran pests such as black flies and mosquitoes. The biting midge Culicoides sonorensis (Diptera: Ceratopogonidae) is an important pest of livestock in much of the United States and larval midges utilize semi-aquatic habitats which are permissive for Bti product application. Reports suggest that Bti products are ineffective at killing biting midges despite their taxonomic relation to black flies and mosquitoes. Here, we investigate the toxicity of a Bti-based commercial insecticide and its active ingredient in larval Culicoides sonorensis. A suspected mechanism of Bti tolerance is an acidic larval gut, and we used a pH indicator dye to examine larval Culicoides sonorensis gut pH after exposure to Bti. The lethal concentration to kill 90% (LC90) of larvae ofthe commercial product (386 mg/L) was determined to be almost 10 000 times more than that of some mosquito species, and no concentration of active ingredient tested achieved 50% larval mortality. The larval gut was found to be more acidic after exposure to Bti which inhibits Bti toxin activity. By comparison, 100% mortality was achieved in larval Aedes aegypti at the product's label rate for this species and mosquito larvae had alkaline guts regardless of treatment. Altering the larval rearing water to alkaline conditions enhanced Bti efficacy when using the active ingredient. We conclude that Bti is not practical for larval Culicoides sonorensis control at the same rates as mosquitos but show that alterations or additives to the environment could make the products more effective. © 2024 Society of Chemical Industry.

Climate Change-Related Drivers of Migration in East Africa: An Integrative Review of the Literature

Despite the growing academic concern and policy interest in climate change drivers of migration, scientific evidence on the topic remains contested, with divergent claims of positive and negative contributions of climate change on human migration and displacement. This review seeks to assess the climate change-related drivers of migration with a focus on three East African countries: Tanzania, Kenya, and Uganda. They are among the most vulnerable countries in Africa, with one of the most mobile populations. The study used the available literature on climate change and migration as the data source. About 22 research articles on climate change and migration were sourced from the Web of Science and Scopus databases and critically reviewed. The review generally indicates that climate change effects such as frequent drought and flood disasters, livestock pests, and crop diseases influence migration and displacement in the region. On the other hand, rising sea levels pose imminent risks that can cause migration if adaptation measures are not taken. The review has also revealed that responses to drought or livestock and crop diseases, be it localized adjustment or out-migration, are determined by households' adaptive capacity. For rapid onset climate events such as floods, the most vulnerable are the less fortunate living in poorly constructed structures in flood-prone zones. This review proposes strengthening the climate policy framework by mainstreaming climate change migration in East African nations’ adaptation plans. It also calls for promoting alternative livelihood activities as an adaptation strategy in areas prone to climate change to lessen human-forced migration and displacement.

Physiology, ecology, and evolution of a successful colonizer: the horned dung beetle, Euoniticellus intermedius

AbstractInsects are intentionally introduced to various regions out of their native ranges to perform fundamental functions, such as pest control, and some keep dispersing from introduction sites to become cosmopolitan and even invasive. The African horned dung beetle, Euoniticellus intermedius (Reiche) (Coleoptera: Scarabaeidae), has been intentionally introduced on multiple continents to bury cattle dung and control livestock pests, but has naturally dispersed and became very abundant at various latitudes and elevations out of its native and original introduction ranges. This beetle has been considered invasive, but there is no direct evidence of its effects on displacing native species. As it is highly fecund, E. intermedius has been an important model in experimental studies performed in nature and in the laboratory in multiple fields. In evolutionary biology, it serves as a model for sexual selection, given the sexual dimorphism characterized by the presence of a horn in males which is correlated with individual condition and strength, and which is absent in females. In ecotoxicology, it has been studied regarding physiological mechanisms of responses to contaminants, population declines, and evolutionary responses to challenging toxic conditions. Given its importance in burying dung in cattle pastures, experiments have also determined environmental conditions that limit this ecological function. Despite being unique in its tolerance to a wide variety of stressors and environments, this species is sensitive to current conditions of global change, including warming and pollution. We identify the most promising questions to be solved in physiology, ecology, and evolution, for which E. intermedius would be an ideal study system.

Transgenerational effects of pyriproxyfen in a field strain of Musca domestica L. (Diptera: Muscidae).

Musca domestica L. (Muscidae: Diptera) is a human and livestock pest especially in tropical and sub-tropical areas. Different insecticides have been used to control this pest that pose serious harmful effects on humans and the environment. The current study was planned to investigate the effects of two concentrations (LC25 and LC50) of pyriproxyfen on biological and population parameters of a field strain of M. domestica. The exposed parents (F0) and their progeny (F1) were studied to examine the transgenerational effects. The results indicated that preadult duration was higher in control (13.68 days) compared to LC50 treated individuals (12.44 days). The male and female longevity was relatively lower in the LC25 treated population i.e. 24.62 and 26.62 days, respectively. The adult pre-oviposition period (APOP) and total pre-oviposition period (TPOP) values were higher in the LC25 treated individuals than those of control. Moreover, oviposition days and fecundity were reduced in the treated individuals as compared to the control treatment. A gradual decrease in the net reproductive rate (R0) was observed (8.46-14.07 per day) while the value of R0 was significantly higher in control. The results suggested that pyriproxyfen can be effectively utilized and incorporated in the management programs of M. domestica.

Use of the Proboscis Extension Response Assay to Evaluate the Mechanism of House Fly Behavioral Resistance to Imidacloprid.

The house fly, Musca domestica L., is a significant human and livestock pest. Experiments used female adult house flies glued onto toothpicks for controlled exposure of their tarsi alone (tarsal assay) or their tarsi and proboscis (proboscis assay) with a sucrose solution containing imidacloprid at either a low (10 µg/mL) or high (4000 µg/mL) concentration. Proboscis extension response (PER) assays were used to characterize the response of imidacloprid-susceptible and behaviorally resistant house fly strains to contact with sucrose solutions containing either a low or high concentration of imidacloprid. In each assay, 150 female flies from each fly strain were individually exposed to sucrose solutions containing either a low or high concentration of imidacloprid by deliberate contact of the fly tarsi to the test solution. The PER for each fly was subsequently recorded at 0, 2, and 10 s following the initial tarsal contact. A significant and rapid reduction in PER was observed only for the behaviorally resistant fly strain and only following contact by the flies' proboscis with the sucrose solution containing the high imidacloprid concentration. The results suggest that chemoreceptors on the fly labellum or internally on the pharyngeal taste organs are involved in the detection of imidacloprid and discrimination of the concentration, resulting in an avoidance behavior (proboscis retraction) only when imidacloprid is at sufficient concentration. Further research is needed to identify the specific receptor(s) responsible for imidacloprid detection.

Semiochemical based integrated livestock pest control.

The role of arthropods as livestock pests has been well established. Besides their biting habits causing nuisance in animals; they are important vectors for transmission of economically important livestock diseases worldwide. Various pests and vector control managemental programs that also make use of chemicals have variable success rates. Consequently, insecticide/acaricide resistance has been reported against most of the commonly used chemicals along with increased concern for environment and demand for clean and green, residue-free animal products. This calls for an urgent need to develop novel, alternate, effective strategies/technologies. This lays the foundation for the use of semiochemicals as alternatives along with other biological control agents. Current knowledge on semiochemical use in livestock is refined and limited; however, it has been widely exploited in the agricultural sector to control plant and food crop pests, surveillance, and monitoring. Semiochemicals have an added advantage of being natural and safe; however, knowledge of extraction and quantification by using assays needs to be explicit. Expertise is required in behavioral and electrophysiological studies of arthropods and their interactions with the host and environment targeting specific semiochemicals for promising results. A thorough prior understanding on aspects such as mechanism of action, the stimulus for the release, the effecter/target species, response produced, application methods, dose and concentration is required to develop any successful pest/vector control program. The current review provides essential and frontline information on semiochemicals and their potential applications in the livestock sector along with future challenges and interventions.

Identification and functional analysis of Cochliomyia hominivorax U6 gene promoters.

The New World screwworm, Cochliomyia hominivorax, is an obligate parasite, which is a major pest of livestock. While the sterile insect technique was used very successfully to eradicate C. hominivorax from North and Central America, more cost-effective genetic methods will likely be needed in South America. The recent development of CRISPR/Cas9-based genetic approaches, such as homing gene drive, could provide a very efficient means for the suppression of C. hominivorax populations. One component of a drive system is the guide RNA(s) driven by a U6 gene promoter. Here, we have developed an in vivo assay to evaluate the activity of the promoters from seven C. hominivorax U6 genes. Embryos from the related blowfly Lucilia cuprina were injected with plasmid DNA containing a U6-promoter-guide RNA construct and a source of Cas9, either protein or plasmid DNA. Activity was assessed by the number of site-specific mutations in the targeted gene in hatched larvae. One promoter, Chom U6_b, showed the highest activity. These U6 gene promoters could be used to build CRISPR/Cas9-based genetic systems for the control of C. hominivorax.

First report of filarial nematodes in the genus Onchocerca infecting black flies (Diptera: Simuliidae) in Iran

Black flies are blood-sucking insects of public health importance, and they are effective vectors of pathogens and parasites, such as filarial nematodes of the genus Onchocerca. Our previous surveys have shown that individuals of Simulium turgaicum are annoying pests of humans and livestock in the Aras River Basin of Iran. In the present study, adult black flies of S. turgaicum were trapped from different ecotopes of five villages in Khoda-Afarin County, Iran. By using a sensitive nested PCR assay and targeting the nuclear 18S rDNA-ITS1 marker, filarial infections were found in 38 (1.89%) of 2005 black flies. Homology exploration of 360 bp of the sequences indicated that the filarial worms are members of the family Onchocercidae, with maximum alignment scores of 93–95%. Phylogenetic analysis showed that two Iranian Onchocerca isolates were clustered in the O. fasciata–O. volvulus lineage and were well separated from other filarial nematodes. Both the entomological evidence (empty abdomen of the specimens) and climatologic data (adequate accumulated degree days for development) suggest that the filarial DNA was probably that of infective larvae of vertebrates. This is the first report of an infection by Onchocerca species in S. turgaicum and the first record of onchocercids in black flies in Iran; however, more research is required to demonstrate transmission of these filarial worms by black flies in nature.

New insights into immune genes and other expanded gene families of the house fly, Musca domestica, from an improved whole genome sequence.

The house fly, Musca domestica, is a pest of livestock, transmits pathogens of human diseases, and is a model organism in multiple biological research areas. The first house fly genome assembly was published in 2014 and has been of tremendous use to the community of house fly biologists, but that genome is discontiguous and incomplete by contemporary standards. To improve the house fly reference genome, we sequenced, assembled, and annotated the house fly genome using improved techniques and technologies that were not available at the time of the original genome sequencing project. The new genome assembly is substantially more contiguous and complete than the previous genome. The new genome assembly has a scaffold N50 of 12.46 Mb, which is a 50-fold improvement over the previous assembly. In addition, the new genome assembly is within 1% of the estimated genome size based on flow cytometry, whereas the previous assembly was missing nearly one-third of the predicted genome sequence. The improved genome assembly has much more contiguous scaffolds containing large gene families.To provide an example of the benefit of the new genome, we used it to investigate tandemly arrayed immune gene families. The new contiguous assembly of these loci provides a clearer picture of the regulation of the expression of immune genes, and it leads to new insights into the selection pressures that shape their evolution.

The use of RNA interference for the management of arthropod pests in livestock farms.

Pest management in farm animals is an important action to contain economic damage to livestock production and prevent transmission of severe diseases to the stock. The use of chemical insecticides is still the most common approach followed by farmers; however, avoiding possible toxic effects on animals is a fundamental task for pest control measures compatible with animal well-being. Moreover, legal constraints and insurgence of resistance by target species to the available insecticidal compounds are increasingly complicating farmers' operations. Alternatives to chemical pesticides have been explored with some promising results in the area of biological control or the use of natural products as sprays. The application of RNA interference techniques has enabled the production of new means of pest control in agriculture, and it is opening a promising avenue for controlling arthropod pests of livestock. Transcript depletion of specific target genes of the recipient organisms is based on the action of double-strand RNAs (dsRNA) capable of impairing the production of fundamental proteins. Their mode of action, based on the specific recognition of short genomic sequences, is expected to be highly selective towards non-target organisms potentially exposed; in addition, there are physical and chemical barriers to dsRNA uptake by mammalian cells that render these products practically innocuous for higher animals. Summarising existing literature on gene silencing for main taxa of arthropod pests of livestock (Acarina, Diptera, Blattoidea), this review explores the perspectives of practical applications of dsRNA-based pesticides against the main pests of farm animals. Knowledge gaps are summarised to stimulate additional research in this area.

Species diversity and daily infestation patterns of Haematophagus flies in cattle farms at Tanah Bumbu District, South Kalimantan Province, Indonesia

Abstract. Hairani B, Hadi UK, Supriyono. 2023. Species diversity and daily infestation patterns of Haematophagus flies in cattle farms at Tanah Bumbu District, South Kalimantan Province, Indonesia. Biodiversitas 24: 2995-3003. Blood-sucking flies act as livestock pests and vectors of zoonotic diseases. This study aims to know the species diversity of blood-sucking flies, relative abundance, frequency, and dominance of species and their correlation to weather parameters on beef cattle farms with three different ecosystems in the Tanah Bumbu District, South Kalimantan, Indonesia. The research was conducted from August to October 2022 on 6 beef cattle farms in Tanah Bumbu District with different types of ecosystems, namely forest, non-forest, and coastal areas. The flies was collected by using sweep nets, NZI traps. and Vavoua traps. Blood meal activity was measured by counting flies infestation on the cow's body. The results showed that there were 11 species of blood-sucking flies, i.e., Stomoxys calcitrans Linnaeus 1758, S. sitiens Rondani 1873, S. indicus Picard 1908, S. bengalensis Picard 1908, Haematobia exigua Meijere 1903, Therioplectes sp., Chrysops fixissimus Walker 1856, Tabanus optatus Walker 1856, T. striatus Fabricius 1787, T. rubidus Wiedemann 1821, and Hippobosca sp. The S. calcitrans population appears to be dominat in each type of ecosystem. The peak of blood-sucking fly infestations on the body of beef cattle in each ecosystem occurred at 10AM-2PM. In addition, the environmental temperature and humidity were significantly correlated to fluctuations in blood-sucking fly infestations in each ecosystem, and the light intensity was significantly correlated to the population of H. exigua in coastal ecosystems, while the wind velocity was not significantly correlated to all species in all ecosystems.