Fly Pests Research Articles

EFIKASI DAN EFEKTIVITAS FORMULASI DAUN MELADA (Piper colubrinum Link) SEBAGAI ATRAKTAN HAMA LALAT BUAH (STUDI KASUS PERTANAMAN CABAI)

Fruit flies ( Bactrocera spp.) represent a group of Plant Pests that can inflict both qualitative and quantitative losses. The utilization of chemical pesticides and the scarcity of Methyl Eugenol continue to pose significant challenges in agriculture. The abundant availability of Melada plants presents an opportunity for the development of an economically viable and environmentally friendly biological attractant. Encapsulation technology based on Maltodextrin and Gum Arabic (MD-GA) formulated with powdered simplicia of Melada leaves F1(02:10), F2(05:10), F3(10:10), and F4(12:10) is employed to enhance the slow-release resistance of volatile compounds. The surface oil content of the four formulations ranges from 0.3% to 9.6%. The encapsulation efficiency value for the four formulations ranges from 70% to 85%. The loading capacity value ranges from 0.7% to 1.3%. The yield value of microcapsule characteristics ranges from 63% to 82%. Morphological analysis reveals a decrease in the number of particles along with the combination of treatment formulations. The size of the microcapsules for the four formulations falls within the range of 201.2 µm–252.6 µm. The effectiveness of the resulting attractant can lure 19-185 fruit flies. The diversity of the fruit fly pest population obtained includes the Bactrocera umbrosa and Bactrocera melastomatos species. The total value of the best formulation for the four treatments ranged from 0.3% to 0.5%. The optimization of the best biological attractant application with high development potential lies in the encapsulation formulations F3 and F4.

Modelling time-temperature-dependent mortality of pest flies in cold storage to support the management of trade-related biosecurity risks

AbstractCold treatment with rigorous regulatory oversight is often mandated to manage horticultural trade-related biosecurity threats, such as invasive, cold-sensitive fruit flies (Diptera: Tephritidae). Cold treatment schedules, developed through rigorous laboratory experiments, require a set temperature and duration to ensure at least a probit 8.7 (99.99%) mortality rate, regardless of infestation likelihood. This threshold is costly to demonstrate for each pest and commodity combination and the resultant treatment may be harmful to fruit quality. Moreover, these stringent schedules do not account for cold-induced mortality already occurring in commercial supply chains. We developed a predictive temperature-dependent mortality function using 28 published cold treatment studies of pest fly species to support more flexible and proportionate use of cold treatment. The daily mortality rate was unaffected by the duration of cold exposure (0–20 days). The mortality rate varied primarily by pest species (10 species) and developmental stage (eggs and larval stages), and to a lesser extent by temperature (0–7 °C) and host (13 fruit types). Our model mostly predicted fewer days to meet probit 9.0 mortality compared to empirical results from large-scale studies, suggesting these studies can be overly conservative. By leveraging previous empirical studies, our model enables estimation of temperature-dependent daily mortality for unstudied pest developmental stage host–temperature combinations, which can then be empirically validated through targeted studies. It is hoped these results will shift cold treatment usage from highly regulated, fixed temperature treatments with a target mortality rate requirement to a more flexible approach that accounts for existing commercial supply chain practices and infestation likelihood in produce.

PSLBI-27 Rumen microbiome dynamics in feedlot steers receiving free-choice garlic-infused mineral supplements

Abstract Garlic (Allium sativum) in its dehydrated or distillate (garlic oil) form has been used as a feed additive owing to its insecticidal, antimicrobial, and organoleptic properties. Commercial mineral mixtures have been formulated to contain a low proportion of dehydrated garlic powder as a strategy to deter pest flies and increase mineral intake in cattle. As an antimicrobial, garlic powder has the potential to alter the rumen microbiome, with possible implications for feed digestibility and the growth performance of beef cattle. This study evaluated the effect of short-term feeding of a garlic-mineral mixture in feedlot steers receiving high-grain diets. Four groups of twenty steers [total = 80, ~14 mo old, body weight (BW) = 599 ± 32 kg] were randomly assigned to either a 5% garlic-mineral (5DGP) or plain mineral supplement (MS). The individual feed and mineral intakes of the steers were measured with an automatic feeding system. Feed and mineral supplements were tracked in different bunks for each group. Baseline rumen fluid samples were collected from all steers at the end of an acclimatization period before administering the trial supplements. Rumen samples were later collected from 10 steers in each group with the greatest mineral supplement intake over the trial period. Total DNA and RNA were extracted from all rumen samples and subjected to metagenomic and metatranscriptomic sequencing, respectively. None of the bacterial species with an overall relative abundance of greater than 0.1% were differentially abundant between the two supplement treatments, nor did the rumen microbial community structures differ between the two groups (PERMANOVA: R2 = 0.02, P = 0.43). Regardless of the dietary supplement, the rumen microbiome of the steers was dominated by uncultured Prevotella spp. (in addition to Prevotella lacticifex) as well as the uncharacterized UBA2810 sp900317945 and UBA2810 sp002351705. Overall, these results show that a 5DGP can be effectively administered to cattle without significantly disrupting the rumen microbiome.

Gut fungal diversity across different life stages of the onion fly Delia antiqua

A significant number of microorganisms inhabit the intestinal tract or the body surface of insects. While the majority of research on insect microbiome interaction has mainly focused on bacteria, of late multiple studies have been acknowledging the importance of fungi and have started reporting the fungal communities as well. In this study, high-throughput sequencing was used to compare the diversity of intestinal fungi in Delia antiqua (Diptera: Anthomyiidae) at different growth stages, and effect of differential fungi between adjacent life stages on the growth and development of D. antiqua was investigated. The results showed that there were significant differences in the α and β diversity of gut fungal communities between two adjacent growth stages. Among the dominant fungi, genera Penicillium and Meyerozyma and family Cordycipitaceae had higher abundances. Cordycipitaceae was mainly enriched in the pupal and adult (male and female) stages, Penicillium was mainly enriched in the pupal, 2nd instar and 3rd instar larval stages, and Meyerozyma was enriched in the pupal stage. Only three fungal species were found to differ between two adjacent growth stages. These three fungal species including Fusarium oxysporum, Meyerozyma guilliermondii and Penicillium roqueforti generally inhibited the growth and development of D. antiqua, with only P. roqueforti promoting the growth and development of female insects. This study will provide theoretical support for the search for new pathogenic microorganisms for other fly pests control and the development of new biological control strategies for fly pests.Graphical Three fungal species were found to differ between two adjacent growth stages. These three fungal species including Fusarium oxysporum, Meyerozyma guilliermondii and Penicillium roqueforti generally inhibited the growth and development of D. antiqua, with only P. roqueforti promoting the growth and development of female insects.

REFUGIA BLOG TO INCREASE THE DIVERSITY OF NATURAL ENEMIES THAT FUNCTION AS CONTROL OF FRUIT FLY PESTS BACTROCERA DORSALIS IN MALANG ORANGE GROVES IN MALANG ORANGE GROVES GARDEN

Bactrocera dorsalis is a pest that attacks horticultural fruit crops, especially oranges. Control of fruit fly pests can be done by engineering the blog refugia habitat which attracts the presence of natural enemies so that it can stabilize the ecosystem and be more sustainable for the environment. The aim of this research is toanalyzing the application of habitat engineering to the Bactrocera dorsalis fruit fly population and natural enemy diversity, fruit fly population fluctuations, and Farmers' perceptions of pest controlfruit flies that attack oranges. This research was conducted on former rice fields and moorland in Krajan Hamlet, Sumbersekar Village, Dau District, Malang Regency. The method used was survey sampling by placing refugia plants in tumpeng sari, 4 fruit fly traps were placed in each field, the trapped fruit flies and natural enemies were observed every morning, afternoon and evening every week 10 times. The results showed an increase in the diversity of natural enemies in the 2 fields planted with refugia, abiotic factors and host plants influenced fluctuations in fruit fly populations. In orange orchards, 2 rainfall factors influence the rise and fall of fruit fly populations. Farmers' perceptions are relatively high in their approval of controlling fruit fly pests using refugia plants which has been proven through validity and reliability tests on the results of the questionnaire.

Microbiomes of Two Pest Fly Species of Pennsylvania Mushroom Houses.

Mushroom cultivation vastly improves the yield of mushrooms under optimized, controlled conditions, but may be susceptible to opportunistic colonization by pest species that can establish themselves, as well as the pathogens and pests they may transmit. Here, we describe our investigation into the bacterial communities of adult Lycoriella ingenua (Diptera: Sciaridae) and Megaselia halterata (Diptera: Phoridae) collected from button mushroom (Agaricus bisporus) production houses in Pennsylvania. We collected adult flies and sequenced the hypervariable v4 region of the bacterial 16S rRNA using the Illumina MiSeq. The most abundant bacterial genus detected in both species was Wolbachia, but phylogenetic analysis revealed that the infections are from different clades. Future studies include the characterization of Wolbachia infections on fly behavior and biology, comparison of microbial diversity of fly species colonizing wild mushrooms, and other microbiota that may contribute to the success of certain pest fly species.

Shaping the Microbial Landscape: Parasitoid-Driven Modifications of Bactrocera dorsalis Microbiota

Koinobiont endoparasitoids regulate the physiology of their hosts through altering host immuno-metabolic responses, processes which function in tandem to shape the composition of the microbiota of these hosts. Here, we employed 16S rRNA and ITS amplicon sequencing to investigate whether parasitization by the parasitoid wasps, Diachasmimorpha longicaudata (Ashmaed) (Hymenoptera: Braconidae) and Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae), induces gut dysbiosis and differentially alter the gut microbial (bacteria and fungi) communities of an important horticultural pest, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). We further investigated the composition of bacterial communities of adult D. longicaudata and P. cosyrae to ascertain whether the adult parasitoids and parasitized host larvae share microbial taxa through transmission. We demonstrated that parasitism by D. longicaudata induced significant gut perturbations, resulting in the colonization and increased relative abundance of pathogenic gut bacteria. Some pathogenic bacteria like Stenotrophomonas and Morganella were detected in both the guts of D. longicaudata-parasitized B. dorsalis larvae and adult D. longicaudata wasps, suggesting a horizontal transfer of microbes from the parasitoid to the host. The bacterial community of P. cosyrae adult wasps was dominated by Arsenophonus nasoniae, whereas that of D. longicaudata adults was dominated by Paucibater spp. and Pseudomonas spp. Parasitization by either parasitoid wasp was associated with an overall reduction in fungal diversity and evenness. These findings indicate that unlike P. cosyrae which is avirulent to B. dorsalis, parasitization by D. longicaudata induces shifts in the gut bacteriome of B. dorsalis larvae to a pathobiont-dominated community. This mechanism possibly enhances its virulence against the pest, further supporting its candidacy as an effective biocontrol agent of this frugivorous tephritid fruit fly pest.

Fly into the light: eliminating Drosophila melanogaster with chlorophyllin-based Photodynamic Inactivation

Fruit flies spoil crops in agricultural settings. As conventional pesticides may generate negative off-target effects on humans or the environment, existing treatment methods need eco-friendly and safe alternatives. Photodynamic Inactivation (PDI) is based on the photosensitizer-mediated and light-induced overproduction of reactive oxygen species in targets. We here explore the potential of PDI for the control of fruit fly pests. Drosophila melanogaster serves as well-established model organism in this study. Two distinct experimental approaches are presented: the feed assay, in which fruit flies are provided with sodium magnesium chlorophyllin (Chl, approved as food additive E140) along with sucrose (3%) as their food, and the spray assay, where the photosensitizer is sprayed onto the insects. We show that PDI based on Chl can induce moribundity rates of Drosophila melanogaster of more than 99% with 5 mM Chl and LED illumination (395 nm, 8 h incubation in the dark, radiant exposure 78.9 J/cm2) with the feed assay. If the radiant exposure is doubled to 157.8 J/cm2, 88% of insects are killed by PDI based on 1 mM Chl. The photoactive compound is also effective if presented on strawberries without addition of sucrose with somewhat lower moribundity (71% at 5 mM Chl). Spraying Chl onto insects is less effective than feeding the photosensitizer: 5 mM Chl resulted in 79.5% moribundity (drug to light interval 8 h, radiant exposure 78.9 J/cm2), but if 5 h of sun light (532 J/cm2) and overnight (14 h) dark incubation is used for activation of Chl, more than 95% of insects are killed. As conclusion, Chl serves as effective photoinsecticide against Drosophila melanogaster if a drug to light interval of 8 h is maintained. Feeding the photoactive compound together with sucrose is more effective than spraying it onto insects and increasing the radiant exposure allows for lowering the photosensitizer concentration. Photodynamic Inactivation might therefore represent an eco-friendly addition to the farmers armamentarium against (semi-transparent) insects.Graphical abstract

Comparative Responses of Two Major Cucurbit Pests, Zeugodacus cucurbitae and Zeugodacus tau to Phenylbutanoid Male Lures.

Zeugodacus cucurbitae and Z. tau are two major fruit fly pests of cucurbitaceous plants in the tropical and subtropical regions. The former species has a broader host range and wider world distribution than the latter. With global climate change, Z. tau shows great potential for geographical expansion with several invasion records in recent years. Males of both species are attracted to cue lure (CL) (and raspberry ketone (RK), a deacetyl derivative of CL), a common male lure used in fruit fly population detection, monitoring and control programs. Males of both species are also known to respond to zingerone (ZN), which are produced by some rainforest orchids. Previous studies have shown that fruit fly-male lure interactions are unique to species and lure types, and significantly impact the success of a lure-based fruit fly control program. We seek to compare the attraction of Z. cucurbitae and Z. tau males to CL, RK and ZN via Probit behavioral assays. Our results showed that CL is more attractive to Z. cucurbitae and Z. tau males than RK, while ZN is a poor lure for both species. Attraction Z. tau to CL is slightly lower than Z. cucurbitae, but the former is at least 1.71 times less attractive to RK than the latter. Together with published information on species' sexual development, our current study indicates a lure-based control program via male annihilation technique for Z. tau will be more challenging than Z. cucurbitae and should incorporate other integrated pest management strategies for a desirable outcome.

All-you-can-eat buffet: A spider-specialized bat species (Myotis emarginatus) turns into a pest fly eater around cattle.

Determining the dietary spectrum of European insectivorous bats over time is the cornerstone of their conservation, as it will aid our understanding of foraging behavior plasticity in response to plummeting insect populations. Despite the global decline in insects, a restricted number of arthropod pest species thrive. Yet past research has overlooked the potential of European bats to suppress pests harmful to woodlands or livestock, in spite of their economic relevance. Here we investigated the diet composition, its breeding season variations and pest consumption of an insectivorous bat species (Myotis emarginatus), at the northern edge of its range (Wallonia, Belgium). We also explored the prey ecology to gain insight into the hunting strategies and foraging habitats of this bat species. We used DNA metabarcoding to amplify two COI markers within 195 bat droppings collected in June, July and August, thereby identifying 512 prey taxa predominated by Diptera, Araneae and Lepidoptera. Overall, in 97% of the samples we detected at least one of the 58 potential pest taxa, 41 of which targeting trees. The June samples were marked by a diet rich in orb-weaver spiders, in accordance with the archetypal diet of M. emarginatus bats. However, during the highly energy demanding July-August parturition and lactation period, roughly 55% of the dropping samples contained two cattle fly pests (Stomoxys calcitrans and Musca domestica). Moreover, among the 88 Diptera species preyed upon by M. emarginatus in July and August, these flies accounted for around 50% of the taxa occurrences. This plasticity-the switch from a spider-rich to a fly-rich diet-seems providential considering the dramatic ongoing drop in insect populations but this involves ensuring bat-friendly cattle farming. Our results revealed that bats widely consume pest entomofauna, thereby highlighting their potential role as allies of forest managers and farmers.

Host–pathogen interaction between the African fig fly, Zaprionus indianus, and its external mycobiome under laboratory conditions

AbstractThe African fig fly, Zaprionus indianus Gupta (Diptera: Drosophilidae), is an ecologically diverse pest species that interacts with and feeds on various microbial pathogens including bacteria and yeast found in decomposing fruits. However, the interaction of Z. indianus with its microbial community and microbial pathogens is obscure. To determine the presence of fungal pathogens, we collected wild Z. indianus from the northwestern part of the Indian subcontinent. Based on molecular identification and phylogenetic analysis, Debaryomyces hansenii (Zopf) Lodder & Kreger‐van Rij (isolate ziha1) was the most commonly observed fungus associated with Z. indianus. Furthermore, we identified two more opportunistic fungal pathogens: Aspergillus flavus Link (isolate zias2), and Pichia kudriavzevii Boidin, Pignal & Besson (isolate zibd3). The interaction of isolated fungi with Z. indianus was evaluated in terms of larval mortality, adult emergence, and fecundity. Debaryomyces hansenii ziha1 resulted in 90% emergence rate for adults, and did not cause significant mortality in the larval stage. In contrast, A. flavus zias2 and P. kudriavzevii zibd3 showed a significant reduction in fecundity and caused 99% and 74% larval mortality of Z. indianus, respectively. In the laboratory oviposition preference assay, mated females of Z. indianus preferred D. hansenii ziha1 supplemented food with a positive oviposition index compared to the uninfected control and compared to food infected with P. kudriavzevii zibd3 or A. flavus zias2. These findings underscore Z. indianus' potential to act as a reservoir for both symbiotic and pathogenic fungal species, some of which may be further harnessed for effective fruit fly pest control strategies.

A review on natural phenylbutanoid attractants: Occurrence, distribution, and role in nature, especially in relation to Dacini fruit fly behavior and pollination.

The natural occurrence, distribution (within a plant) and roles of four phenylbutanoid compounds (anisyl acetone, cue-lure, raspberry ketone and zingerone) are elucidated for the Asia-Pacific and Oceania regions. These phenylbutanoids may act individually or in combination to attract true fruit fly males belonging to a tribe Dacini of subfamily Dacinae (Diptera: Tepritidae). Of special interest are the mutualistic interactions between the Dacini fruit fly males and the tropical daciniphilous (attracting exclusively Dacini fruit flies) orchids - leading to cross pollination for the orchids and enchanced mating success for the flies. When offered to male flies, anisyl acetone and cue-lure are generally converted to raspberry ketone. Upon consumption, raspberry ketone and zingerone are individually sequestered in the male rectal (pheromonal) gland unchanged. Attracted male flies readily imbibe the phenylbutanoid(s) in the floral synomone to compliment the endogenously synthesized male sex pheromonal components - to enhance attraction of conspecific females during courtship as well as attract conspecific males to form 'leks'. The phenylbutanoid(s) may also act as an allomone to deter vertebrate predators, especially geckos, besides possessing antimicrobial and antioxidant activities. Cue-lure, raspberry ketone and zingerone are important attractants/lures used in pest surveillance and mass trapping under the integrated pest management (IPM) program against quarantine Dacini fruit fly pest species, particularly Bactrocera tryoni and Zeugodacus cucurbitae.

Integrated parasite management (IPM) and the pasture ecosystem: Optimizing outcomes for cattle, insect biodiversity, and soil health

Concerns over the negative environmental impacts of livestock parasiticide treatments and the widespread development of resistance has precipitated a move towards integrated parasite management (IPM). However, within the pasture ecosystem management strategies are likely to impact multiple processes in complex ways. This study investigates the impacts of IPM strategies on pest flies, gastrointestinal nematode (GIN) parasites, beneficial dung insects, and soil health. Twenty-nine grazing dairy farms participated in the study, representing different chemical and nonchemical parasite management and grazing strategies (continuous, rotational, or management intensive rotational (MIG)). Cattle managed using rotational grazing and MIG had significantly lower FEC than continuously grazed cattle. Farms using chemical parasiticides had significantly fewer pest flies, however farms releasing parasitoid wasps as biological control also had reduced abundances. Dung inhabiting beetle abundance was significantly correlated with reduced pest flies and GIN. Beneficial insects were negatively impacted on farms that used parasiticides. Continuously grazed pastures had higher beneficial insect abundances only on farms that did not use chemical parasiticides. Pastures managed under MIG had lower soil bulk density and higher active carbon compared to continuous grazing. There were positive associations between soil health and tunneling dung insects (Onthophagus spp. dung beetles). Finding optimal strategies will be context dependent, however the results of this study indicate that grazing strategies can control gastrointestinal parasites and improve soil health outcomes, natural enemies such as parasitoid wasps and dung inhabiting beetles can suppress pest fly populations, and the impacts of chemical control strategies may be mitigated through thoughtful implementation.

Volatiles of essential oils and yeast derivatives influence mating behaviour of Anastrepha fraterculus males under field cage conditions

AbstractThe sterile insect technique (SIT) is used for the management of tephritid fruit fly pests. The South American fruit fly, Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), is one potential pest to be targeted by means of SIT. The success of SIT depends, to a large extent, on the sexual performance of sterile males. Various approaches have been evaluated with the aim of improving their sexual performance. These include the exposure to plant‐derived compounds and/or the provision of protein sources in the adults' diet capable of stimulating male mating success. The present study aimed to determine whether exposure to volatiles of Citrus limon (L.) Burm. F. (Rutaceae) essential oil and limonene confers a mating advantage to A. fraterculus laboratory males fed two distinct dietary regimes when competing with wild males for wild females under field cage conditions. Dietary regimes were, one, with non‐hydrolysed brewer's yeast and sugar (1:3 ratio), and the other with brewer's yeast hydrolysate enzymatic and sugar (1:12 ratio). The effect was evaluated in four variables associated with mating success: number of copulas obtained, latency to mate, copula duration, and copula location. Exposure to volatiles did not affect the number of matings achieved, irrespective of the diet given to the males. When laboratory males were fed with brewer's yeast hydrolysate, the effect of volatile exposure was shown in latency to mate, copula duration, and copula location. When the laboratory males were fed with non‐hydrolysed brewer's yeast, the effect of volatile exposure was shown only in copula duration. Laboratory males fed brewer's yeast hydrolysate achieved the same number of matings as wild males, whereas laboratory males fed non‐hydrolysed brewer's yeast had lower performance.

The landscape of fear in cattle farms? How the presence of barn swallow influences the activity of pest flies

Abstract Insectivorous birds are key suppliers of crucial ecosystem services, especially important for pest control in agricultural systems, and are globally decreasing at a fast rate. Among them, the declining barn swallow Hirundo rustica is particularly linked to cattle farms, where it is impacted by changes in livestock husbandry practices. The presence of swallows in cattle sheds might contribute to control insect pests, but such an effect had never been explored. With this work, we evaluated the potential control effect exerted by barn swallow on economically relevant pest insects, filth flies. To assess whether swallows inside the cattle sheds influence the activity rate of pest flies (especially Musca domestica and Stomoxys calcitrans), we assessed the relative abundance of swallows and flies over 16 weeks in nine different cattle farms in Non valley (Trentino, North‐east Italy), either occupied or not by nesting swallows. From April 2022 to August 2022, we collected weekly data on the activity rate of flies by placing eight white spot cards inside each of nine cattle sheds and counting the deposition of faecal and regurgitation spots by flies. Simultaneously, we collected weekly data regarding swallow occurrence, brood size, number and age of chicks. We applied generalised linear mixed effect models on the activity rate of flies, with spot card and farm as nested random effects, to account for potential random variability between cards and farms. We then assessed through model selection the effect of number of cows, number of swallows, and temperature or week alternatively. Temperature and week were modelled also in interaction with the number of swallows. Fly activity rate followed a seasonal trend with a peak in July, which was markedly lower where swallows were present. Moreover, the positive relationship between flies and temperature was lessened when swallows were abundant. Synthesis and applications. Barn swallows are effective biological control agents for lowering pest fly activity in livestock farms. Farmers were actively involved in swallow conservation within their sheds, also with a shared memorandum‐of‐intent. Harnessing the ecosystem services supplied by farmland birds could bring positive outcomes for people and biodiversity.

Overexpression of miR-927-5p suppresses stalky expression and negatively reduces the spermatid production in Zeugodacus cucurbitae.

The melon fly, Zeugodacus cucurbitae Coquillett, is one of the major pests attacking Cucurbitaceae crops. Identifying critical genes or proteins regulating fertility is essential for sustainable pest control and a research hotspot in insect physiology. MicroRNAs (miRNAs) are short RNAs that do not directly participate in protein translation, but instead function in post-transcriptional regulation of gene expression involved in male fertility. We found that miR-927-5p is highly expressed in the testes and investigated its function in spermatogenesis in Z. cucurbitae. Fluorescence in situ hybridization (FISH) showed miR-927-5p in the transformation and maturation region of the testis, and overexpression of miR-927-5p reduced the number of sperms by 53%. In continuation, we predicted 12 target genes of miR-927-5p using bioinformatics combined with transcriptome sequencing data, and found that miR-927-5p targets the new gene Stalky in insects, which was validated by quantitative real-timePCR, RNA pull-down and dual luciferase reporter assays. FISH also confirmed the co-localization of miR-927-5p and the transcript Stalky_1 in the testis. Moreover, silencing of Stalky_1 by RNA interference reduced the number of sperms by 32% and reduced sperm viability by 39% in physiologically mature male adults. Meanwhile, the silencing of Stalky_1 also resulted in low hatchability. Our work not only presents a new, so far unreported mechanism regulating spermatogenesis by miR-927-5p targeting a new unknown target, Stalky, which is providing new knowledge on the regulatory network of insect spermatogenesis, but also lays a foundation for the development of SIT against important tephritid fly pests. © 2024 Society of Chemical Industry.

Direct and indirect host‐related volatile compounds attract a fruit fly parasitoid, Diachasmimorpha longicaudata

AbstractFruit fly pests (Diptera: Tephritidae) are a serious problem for fruit production and for local and international trade. Biological control is increasingly included as a pest control tool within integrated pest management (IPM) programmes, seeking to reduce pesticides and improve fruit quality. Ceratitis capitata Wiedemann, the Mediterranean fruit fly (medfly), is probably the most damaging fruit fly pest, with a global distribution and more than 200 host species. The solitary larval endoparasitoid Diachasmimorpha longicaudata Ashmead (Hymenoptera: Braconidae) is a biocontrol agent widely used against Tephritidae fruit fly pests. Previous studies showed that female wasps locate host larvae using visual, mechanical, and chemical cues. Here, we investigated the chemical basis of female parasitoid attraction to cues that guide D. longicaudata to the host, and thus unveil volatile organic compounds that might be used in IPM programmes. Female orientation to chemical cues was tested in a Y‐tube olfactometer, where attraction to C. capitata‐infested oranges, oranges with residues of larval activity, oranges infected with a green mould, and overripe oranges was confirmed. Volatiles from all these types of fruit were collected and used in gas chromatography‐electroantennographic detection (GC‐EAD) and GC‐mass spectrometry (MS) analyses. These studies allowed us to identify six candidate compounds that were present in all treated oranges but not in the control fruit (ripe and uninfested oranges): D‐limonene, acetophenone, linalool, nonanal, decanal, and eugenol. Electroantennography (EAG) showed that acetophenone, nonanal, and decanal triggered dose‐dependent responses, suggesting a relevant role in the process of host finding. Although responses to D‐limonene, linalool, and eugenol were independent of the dose, they could be involved in host location in areas with high probability of host presence. The fact that these six compounds are shared by the four behaviourally attractive sources opens new possibilities for the development of novel tools to improve biocontrol programmes.

A comparison of vertical and horizontal trap orientations for attracting male Bactrocera spp. as fruit fly pest

Fruit flies, such as Bactrocera spp., are significant agricultural pests focusing on crop yields in Indonesia. One way of environmentally friendly control is the application of attractants to the trap. This study aims to ascertain the trap model that efficiently captures Bactrocera spp. This survey was conducted in Malang’s Dau Subdistrict between December 2022 to February 2023. The traps used were modified Steiner traps, namely plastic bottle traps with vertical and horizontal models. Any traps were baited with 0.125 milliliters of methyl eugenol, which was dripped on cotton and suspended inside the trap. To determine the effective trap model for capturing fruit flies, the study randomly installed vertical (3 pieces) and horizontal (3 pieces) traps in each citrus orchard. The findings within the Friedman testing analysis suggested that the attraction of fruit flies to vertical and horizontal trap models had significant differences. Horizontal traps had 58% effectiveness compared to vertical traps. The types of fruit flies in the vertical model are Bactrocera dorsalis, B. carambolae, and B. umbrosa. Meanwhile, in the horizontal model, B. umbrosa was absent. Modifying this trap model increases the ability as a potential fruit fly trap and a fruit fly pest monitoring tool.

Olfactory receptors in Bactrocera species for sustainable fruit fly management: A review and future perspectives

AbstractMolecular studies on odorant receptors (ORs), odorant‐binding proteins (OBPs) and the functioning of the receptor and pheromone signal transduction in fruit fly Bactrocera species have expanded exponentially during the past few decades. OBPs contribute to the sensing of the olfactory system (OS) via the transduction of odorants through the sensillum lymph. However, ORs, a family of G‐protein‐coupled receptors in Bactrocera and various other species, exhibit heightened responsiveness to multiple chemical odours such as hormones, sensory stimuli and neurotransmitters. The apparent mechanism involves a combinatorial code encompassing both peripheral and antennal lobe processing, facilitating the reception of sexual pheromones and environmental cues. The OS is specifically designed to recognize and process information from volatile chemical signals, and these chemical signals play an important function in various flies. Insects rely on these chemicals to navigate and comprehend their surroundings. A mature insect OS is composed of two pairs of sensillae‐covered palps, antennae and two primary pairs of olfactory appendages on the anterior head. It has been shown that chemosensory gene families contribute in odour perception. These include various neuroreceptor families, such as OBPs, chemosensory proteins and sensory neuron membrane proteins. Additionally, there are three divergent chemoreceptors, namely ORs, ionotropic receptors and gustatory receptors. Methods based on systematic biology, molecular biology and bioinformatics tools have rapidly emerged to investigate the insect communication systems and provide new insights for the management of many agricultural pest. Several aromatic compounds, including semiochemicals and pheromones, have been employed to defend crops and animals from destructive fruit flies and other invasive and frugivorous species. To promote the expansion of the cropping system, the utilization of phytochemical lures can be convenient for sustainable agriculture production and enhance food security. Hence, this review examined the state of the art in chemical communication of insects with a focus on fruit fly pest species to identify OS and their semiochemical receptors, protein receptors and chemosensory receptors (CSRs), as well as their practical applications for biological control and integrated pest management are highlighted.

Metarhizium spp. isolates effective against Queensland fruit fly juvenile life stages in soil.

Queensland fruit fly, Bactrocera tryoni, Froggatt (Diptera: Tephritidae) is Australia's primary fruit fly pest species. Integrated Pest Management (IPM) has been adopted to sustainably manage this polyphagous species with a reduced reliance on chemical pesticides. At present, control measures are aimed at the adult stages of the fly, with no IPM tools available to target larvae once they exit the fruit and pupate in the soil. The use of entomopathogenic fungi may provide a biologically-based control method for these soil-dwelling life stages. The effectiveness of fungal isolates of Metarhizium and Beauveria species were screened under laboratory conditions against Queensland fruit fly. In bioassays, 16 isolates were screened for pathogenicity following exposure of third-instar larvae to inoculum-treated vermiculite used as a pupation substrate. The best performing Metarhizium sp. isolate achieved an average percentage mortality of 93%, whereas the best performing Beauveria isolate was less efficient, with an average mortality of 36%. Susceptibility to infection during different development stages was investigated using selected fungal isolates, with the aim of assessing all soil-dwelling life stages from third-instar larvae to final pupal stages and emerging adults. Overall, the third larval instar was the most susceptible stage, with average mortalities between 51-98% depending on the isolate tested. Moreover, adult mortality was significantly higher when exposed to inoculum during pupal eclosion, with mortalities between 56-76% observed within the first nine days post-emergence. The effect of temperature and inoculum concentration on insect mortality were assessed independently with candidate isolates to determine the optimum temperature range for fungal biological control activity and the rate required for application in field conditions. Metarhizium spp. are highly efficacious at killing Queensland fruit fly and have potential for use as biopesticides to target soil-dwelling and other life stages of B. tryoni.