Parasitism Rates Research Articles

Density-dependent fitness and mass-rearing of Habrobracon hebetor (Say) (Hymenoptera: Braconidae) incorporating life table variability

The ectoparasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is an important natural enemy insect deployed for controlling lepidopteran larvae in warehouses and fields. However, there is limited information on mass-rearing methods of H. hebetor. This study investigated the effects of different Ephestia elutella (Hübner) (Lepidoptera: Pyralidae) and parasitic egg densities on the fitness and mass-rearing efficiency of H. hebetor, aiming to determine the optimal conditions for developing an economically viable and sustainable mass-rearing system for this parasitoid. Our results showed that the average number of eggs laid per host dropped below 7.54 eggs when the number of hosts exceeded five. H. hebetor exhibited significantly increased preadult survival rate (67.41%-81.00%), female and male body size (2224.55-2379.83 μm, 2213.39-2324.65 μm), fecundity (443.98-492.43 eggs), net reproductive rate (R0=154.57-216.67 offspring), intrinsic rate of increase (r=0.2776-0.3223 d-1), net paralyzed rate (C0=72.37-93.17 larvae), and net parasitism rate (Z0=43.55-55.04 larvae) at a density of 5-15 eggs per host than at 20 eggs per host. Meanwhile, considering rearing costs and production rate, a density of 5-15 eggs per host proved to be the most economical for mass-rearing H. hebetor, achieving a daily harvest rate of 10,000 newly emerged female adults. Therefore, for an efficient mass-rearing system for H. hebetor, maintaining a density of 5-15 eggs per host is recommended considering variability in life table and discarding aged individuals (after 36 days old). In summary, providing 5-10 5th instar larvae of E. elutella per day per pair of male and female parasitoid wasps is advised for effective mass-rearing of H. hebetor.

Molecular Detection of Haemonchus spp Parasite in Human in Babylon Province, Iraq

Stool samples of 100 human were collected the diagnosis of Haemonchus worm in Babylon province usied Microscopic examination by PCR assay. The human were classified into sub-groups according to age, locality and sex in order to study association of these risk factors with rate of infection. The results showed, by using (PCR) based on detection 18srRNA gene to Haemonchus worm human stool samples that the persons was infected with this worm , and the infection rate was (32%) The rate of positive cases, infection was the highest in Western Hamza district and it was (40%), followed Al-Musayyab district was (34.61%), and the rate in Al-Qassim a District was (30%), whereas in Al Mahaweel district it was (20.83%), The present study showed no significant impact of geographical variation. The infection rate of Haemonchus worm for human in age group (41-60) was (43.75%) while in age group (21-40) was (38.46%), in age group (11-20) was (26.66%), and in age group (< 10 years) was (20%), and the statistical analysis reveals that there was no significant (P>0.05) difference in the infection rate of parasite between age intervals. This current study concluded the rate of infected male with Haemonchus worm was (40%) and females was (27.69%) Through the above, we found that the percentage of infection in females was greater than males, when results statistical analyzed showed there are no significant effect in infected rate at (P>0.05) on sex. The study is the first in lraq to diagnosis the presence of Haemonchus worm in human in Iraq.

Molecular methods for the detection and identification of parasitoids within larval wheat midges.

Three species of cecidomyiid midges (Diptera: Cecidomyiidae) cause significant yield losses on wheat in Europe: Sitodiplosis mosellana (Géhin), Contarinia tritici (Kirby) and Haplodiplosis marginata (von Roser). Eggs and young larvae may be parasitised by a complex of hymenopteran parasitoids belonging to the Pteromalidae and Platygastridae families which contributes to natural pest control. We have developed molecular tools for detecting and identifying seven parasitoid species previously encountered in Belgium inside individual wheat midge larvae. Barcode DNA sequences from COI, 18S and 28S genes were obtained from the midges and parasitoid species. Each of the three genes allowed all the species to be distinguished although 18S was the only one displaying a barcoding gap, both between parasitoids and midges, and at the species level. Based on the 18S gene, we developed a TaqMan assay to assess parasitism in midge larvae, regardless of the midge and parasitoid species. Next, two group-specific PCR primer pairs were generated, allowing the separate amplification of midge DNA or parasitoid DNA in parasitised individuals and subsequent identification by Sanger sequencing. Finally, species-specific primers were designed to identify six parasitoid species by simple PCR amplification. These tools were successfully applied to assess the parasitism rate of S. mosellana larvae in seven Belgian fields.

Tri‐Trophic Interactions of Cabbage Cultivars, a Generalist Aphid, Myzus persicae (Sulzer) and the Braconid Diaeretiella rapae McIntosh

ABSTRACTThe tri‐trophic interactions among five cabbage (Brassica oleracea var. capitata) cultivars—Copenhagen Market (CM), Red Acre (RA), Vertus Savoy (VS), Sugarloaf (SL) and Danish Ballhead (DBH)—a generalist aphid, Myzus persicae (Sulzer) and its parasitoid, Diaeretiella rapae McIntosh, were assessed. Copenhagen Market, known for its reported aphid resistance, recorded the fewest aphids (9.11 per plant; F = 6.50; df = 4, p < 0.01), followed closely by Red Acre (11.83 per plant), which was statistically similar. Upon aphid attack, all cultivars produced plant volatiles that influenced the attraction of the parasitoid, D. rapae. Copenhagen Market consistently showed a higher response across cultivar combinations, attracting 62.59%–67.50% of parasitoids. It also recorded a higher parasitisation rate (39.9%; F = 5.94; df = 4/20, p < 0.01) in a multiple‐choice test. The results indicate that cabbage cultivars employ both constitutive and induced resistance, as aphid‐resistant cultivars were also found to be more attractive to parasitoids. In addition to plant odour cues, factors such as plant colour, texture and host aphid kairomones can influence the orientation and parasitisation by D. rapae.

Preference for host larval stages and density-dependent parasitism of Psyttalia parasitoid species in Bactrocera fruit flies

The study examined host preferences among three Psyttalia parasitoids (P. ponerophaga, P. concolor, and P. fletcheri) regarding the larval stages of two Bactrocera fruit flies (B. cucurbitae and B. oleae). All parasitoids preferred the third instar larvae, followed by the second and first instars. Psyttalia fletcheri had the highest parasitism rate on B. cucurbitae, while P. ponerophaga was most effective on B. oleae. The highest parasitism rates were observed at the host-parasitoid ratio (400:20) for both P. fletcheri on B. cucurbitae and P. ponerophaga on B. oleae. These results highlight the importance of understanding host-parasitoid dynamics for effective fruit fly management.

Using Egg Parasitoids to Manage Caterpillars in Soybean and Maize: Benefits, Challenges, and Major Recommendations

The use of egg parasitoids in Augmentative Biological Control (ABC) is a highly effective strategy within the integrated pest management (IPM) of lepidopteran defoliators. Safer than chemical insecticides, these natural antagonists have demonstrated significant efficacy. Trichogramma pretiosum and Telenomus remus, known for their high parasitism rates, are the most extensively used and studied parasitoids for controlling economically important lepidopterous in crops such as soybean and maize. Brazil, a leading adopter of crops expressing Bacillus thuringiensis (Bt) proteins, faces growing field-evolved resistance to Cry proteins in soybean and maize. This resistance, particularly of Rachiplusia nu in soybean and Spodoptera frugiperda in maize, has become more prominent in recent years, increasing insecticide use. Therefore, this article reviews the current status of egg parasitoids adoption in ABC against lepidopteran pests, emphasizing the role of Tr. pretiosum and the potential of Te. remus as sustainable alternatives to chemical insecticides to manage pests in both non-Bt and Bt crops. Additionally, we provide recommendations for using these parasitoids in ABC programs and discuss the challenges that must be addressed to optimize the adoption of biocontrol agents in ABC programs for maximum benefit.

Relative efficacy of anti-Plasmodium vivax malaria combination drugs in preventing transmission to two major Anopheles mosquitos in the first few days of treatment

ObjectivesThe World Health Organization recommends three drug anti-malarial combinations: cloroquine+primaquine, artesiminin+primaquine, and cloroquine+tafenoquine. These combinations aim to eradicate Plasmodium by disrupting its life cycle within the human body. We evaluated the effect of these medications on the vectorial competence of two main vectors in the New World. Methods: We recruited patients diagnosed with malaria vivax from a primary care in Manaus, Amazonas. To determine how different treatments affected vectors, we collected blood samples prior treatment at the hospital and at six intervals over the next 68h at the patient's homes. These samples were used to infect Anopheles darlingi and Anopheles aquasalis. To assess the potential for Plasmodium transmission by bite to a new human host, we analyzed the infection intensity, infection rate, and presence of parasites in the salivary gland of the mosquitoes. Results: The results show the infection of the mosquitoes fed with the patient's bloods during the first days of treatment with all three drug combinations. However, the cloroquine+tafenoquine combination was the least effective while artesiminin+primaquine was the most effective. Conclusion: In the first few days of treatment, two main vectors continue to spread malaria vivax from patients, potentially contributing to the ongoing transmission in malaria-endemic regions.

Secretory Proteins Are Involved in the Parasitism of Melon by Phelipanche aegyptiaca During the Attachment Stage.

Parasitic plants represent a significant challenge in global agriculture, with Broomrape (Orobanche/Phelipanche spp.) being a notable example of a holoparasitic species that targets the roots of host plants. This study employed comparative transcriptomics to investigate the mechanisms underlying the parasitism of P. aegyptiaca on melon, focusing on both resistant and susceptible interactions. The findings indicate that the critical phase of P. aegyptiaca parasitism occurs during the post-attachment stage. It is suggested that peptidases may play a role in the development of invasive cells, while cell wall-degrading enzymes (CWDEs) are likely involved in cell wall modification and degradation, and transferases, elicitors, and effectors may play a role in immune regulation. In this study, 25 tobacco rattle virus (TRV) recombinant vectors were successfully constructed and functionally validated using a host-induced gene silencing assay to explore the functions of candidate-secreted effector proteins. The results revealed that silencing Cluster-107894.0, Cluster-11592.0, and Cluster-12482.0 significantly decreased the parasitism rate of P. aegyptiaca on Nicotiana benthamiana. Notably, Cluster-107849.0 encodes a cellulase with hydrolase activity, Cluster-11592.0 encodes a periodic-dependent kinase inhibitor with phosphoprotein activity, and Cluster-12482.0 encodes a glucan 1,3-β-glucosidase with hydrolase activity. These findings potentially offer a novel theoretical framework and justification for understanding host-parasite plant interactions, and suggest new avenues for developing crop varieties resistant to parasitic infestation.

Demographic toxicology of insect growth regulators on the nontarget ectolarval parasitoid Habrobracon hebetor

Habrobracon hebetor Say (Hymenoptera: Braconidae) is one of the most important parasitoids of many pyralid moths, including the olive leaf moth, Palpita unionalis Hubner (Lepidoptera: Pyralidae). The widespread use of insecticides threatens natural enemies. Assessing the side effects of insecticides on nontarget organisms supports the rational use of insecticides during field application. The present study evaluates the lethal and sublethal effects of three insect growth regulators (IGRs), novaluron, methoxyfenozide, and pyriproxyfen, on P. unionalis and the demographic toxicology of these IGRs on its parasitoid H. hebetor. The LC50 values of these IGRs on P. unionalis were 0.97, 0.176, and 0.00009 ppm, respectively, indicating that pyriproxyfen was the most toxic. When H. hebetor adults were exposed to these LC50 levels under laboratory conditions to determine possible side effects. The IGRs did not affect the paralysis and parasitism rates of the parasitoid nor the sex ratio of its offspring. IGR treatments slightly reduced hatching rates and immature survival by 15–25%, indicating moderate effects on the early developmental stages of H. hebetor. The longevity and fecundity of treated females were each reduced to < 50% of their respective values in untreated females. Additionally, some demographic parameters of the parasitoid were significantly affected by the IGRs. Nevertheless, despite these observed effects, the positive net reproductive rate (R0 > 0) and intrinsic rate of increase (rm > 1) of H. hebetor indicated an exponential population increase that reflects the compatibility of the IGRs with the parasitoid. Our results demonstrated that the tested IGRs could be categorized as relatively harmless compounds to the parasitoid. Following these laboratory assessments, field studies will be required to confirm the effects of the tested IGRs on H. hebetor as well as other nontarget organisms.

Preliminary observations on the physiology and behavior of Sytretomorpha szaboi Papp

Sytretomorpha szaboi Papp (Hymenoptera: Braconidae) is a parasitic wasp that specializes in parasitizing the Apis cerana and is widely distributed in the Eastern Ocean region, particularly in southern China and northern India. The parasitization rate of this parasitic wasp can reach as high as 20%, which poses a significant threat to the health of bee colonies. This study reports the results of observations of S. szaboi in Chongqing, China. Current research on the physiology and behavior of S. szaboi is limited; thus, this report provides a valuable contribution to the existing body of knowledge on this type of parasitic wasp. Consequently, during the summers of 2023 and 2024, we observed the physiological and behavioral characteristics of S. szaboi and their hosts in the field at the Bee Breeding Center of Chongqing, along with additional incubated observations conducted in the laboratory.

Effects of Free and Nanoencapsulated Benznidazole in Acute Trypanosoma cruzi Infection: Role of Cholinergic Pathway and Redox Status

Background/Objectives: The Trypanosoma cruzi infection promotes an intense inflammatory process that affects several tissues. The cholinergic system may exert a regulatory immune response and control the inflammatory process. This study aimed to evaluate the comparative effect of free and nanoencapsulated benznidazole in acute T. cruzi infection to assess hematological, biochemical, and oxidative status triggered by the cholinergic system. Methods: For this, fifty female Swiss mice were distributed in eight groups, i.e., uninfected and infected animals under four treatment protocols: untreated (control—CT); vehicle treatment (Eudragit L 100—EL-100); benznidazole treatment (BNZ); and nanoencapsulated benznidazole treatment (NBNZ). After eight treatment days, the animals were euthanized for sample collection. Results: The peak of parasitemia was at day 7 p.i., and the BNZ and NBNZ controlled and reduced the parasite rate but showed no efficacy in terms of total elimination of parasites analyzed by RT-PCR in both infected groups. The infection promotes significant anemia, leukopenia, and thrombocytopenia, which the BNZ improves. There was an increase in AChE activity during infection, leading to a pro-inflammatory response and an increase in M1 and M2 mACh receptors in the BNZ group, showing that the treatment interacted with the cholinergic pathway. In addition, a pro-oxidative response was characterized in the infection and mainly in the infected BNZ and NBNZ groups. The histopathological analysis showed significative splenomegaly and inflammatory infiltrate in the heart, liver, and spleen. Conclusions: The administration of the BNZ or NBNZ reverses hematological, hepatic, and renal alterations through cholinergic signaling and stimulates a pro-inflammatory response during acute T. cruzi infection.

Effect of individual quick freezing treatment and cold storage on the host egg (Lepidoptera: Saturniidae) quality for the production of the parasitoid Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae)

BackgroundThe augmentative release of the parasitoid species Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae) is essential for managing the recent invasion of litchi stink bugs (Tessaratoma papillosa (Drury)) (Hemiptera: Tessaratomidae) in Taiwan. The mass release program in the spring targets this univoltine pest’s reproduction cycle. Low-temperature storage for the host eggs and parasitoids is required to maximize the production for the annual release program. This study aimed to enhance the shelf life of Samia cynthia (Lepidoptera: Saturniidae) eggs using the combination of refrigeration and individual quick freezing (IQF) as a storage treatment. Storage of A. japonicus in the IQF-treated S. cynthia eggs was evaluated to determine the optimal production process during the short preparation window before the release.ResultsThe influences of cold storage and IQF treatment on the host eggs were evaluated for different storage durations. The host quality was determined according to the emergence rate and female ratio of A. japonicus. The study’s results demonstrated that the host quality of S. cynthia eggs did not change significantly compared to the control group after 28 d of refrigeration at 7 °C. IQF treatment extended S. cyathia’s shelf life to 5 months without significantly affecting the host quality. Applying IQF at different developmental stages of the host eggs affected the parasitism rates of A. japonicus. Significantly higher emergence rates of A. japonicus were recorded in the eggs treated during the initial development (D0 to D2). However, storing parasitoids in the IQF-treated eggs under the current storage condition for one month at 12 °C significantly impacted the parasitoid’s emergence rate.ConclusionsThe results of this study highlight the potential benefits of the individual quick freezing technique. This technique didn’t alter the egg quality of S. cynthia, a crucial factor for the mass production of A. japonicus. The IQF treatment extends the shelf life of the host eggs to 5 months when stored at − 20 °C, a significant improvement compared to the 4-week shelf life without IQF treatment. This technology offers a promising and efficient approach for the mass production of A. japonicus and supports field releases. The treatment allowed for the stockpiling of host eggs during the off-season, which can help expedite the mass production of A. japonicus to fit an eight-week production window.

Host adaptability of Microplitis manilae (Hymenoptera: Braconidae) in Noctuidae.

Biological control is an effective and sustainable method of integrated pest management. Microplitis manilae (Hymenoptera: Braconidae) is a common internal parasitoid wasp of the order Lepidoptera. To determine a suitable host species for the reproduction of parasitoids, it is essential to assess host suitability and parasitic potential of the parasitized pests. Herein, we investigated host selection and exploitation of M. manilae. We evaluated the parasitic efficacy of M. manilae in 4 pest species in the Spodoptera and Mythimna genera of the Noctuidae family. The results indicated that the parasitism rate of M. manilae on 3 species in the Spodoptera genus is higher than on Mythimna separata in the Mythimna genus, with M. manilae exhibiting a higher parasitism rate and shorter development duration on Spodoptera litura compared to other species. The parasitism rate for 1st instars hosts was 86.67 ± 0.04%, while the development duration was 14.1 ± 0.03 days. However, when parasitizing the 3rd instar of Spodoptera frugiperda, parasitoids showed a higher sex ratio, of 0.71 ± 0.05. Additionally, M. manilae had parasitic effect on M. separata, providing a new choice for its parasitism. The results identify the optimal host, which could enhance and reproduction rate and survival rate of M. manilae, thus facilitating their large-scale propagation. Understanding the parasitic effects of M. manilae on pests can further its field application, also plays a major role in promoting the development of biological control technologies and sustainable agricultural production.

Impact of Zinnia elegans Cultivation on the Control Efficacy and Distribution of Aphidius colemani Viereck (Hymenoptera: Braconidae) against Aphis gossypii Glover (Hemiptera: Aphididae) in Cucumber Greenhouses.

This study aimed to evaluate the enhancement of A. gossypii control by A. colemani when Z. elegans was planted as a companion crop in cucumber greenhouses. The density and spatial distribution of A. gossypii and parasitized mummies were investigated across three treatment plots: (1) the simultaneous application of A. colemani and cultivation of Z. elegans (parasitoid-zinnia plot); (2) the application of A. colemani alone (parasitoid plot); and (3) a control plot (no application of both). A. gossypii maintained low densities in the parasitoid-zinnia plots, while its densities in the parasitoid plots initially decreased but rapidly increased thereafter. The spatial distribution patterns of A. gossypii and parasitized mummies showed similar trends across treatments. However, the parasitism rate of A. gossypii exhibited random distribution in parasitoid and control plots, while showing uniform distribution in the parasitoid-zinnia treatment. These results supported the idea that cultivating Z. elegans alongside cucumber could enhance the effectiveness of A. colemani as a biocontrol agent against A. gossypii, highlighting the importance of such companion planting in pest management strategies.

Effects of High-Temperature Stress on Biological Characteristics of Coccophagus japonicus Compere.

The parasitoid, Coccophagus japonicus Compere (Hymenoptera: Aphelinidae) is a dominant natural enemy of Parasaissetia nigra Nietner (Hemiptera: Coccidae), an important pest of rubber trees. Much of Chinese rubber is cultivated in hotter regions such as Yunnan and Hainan, exposing applied parasitoids to non-optimal temperatures. Therefore, C. japonicus must adapt to avoid temperature-related impacts on survival and population expansion. In this study, we monitored the survival rate, developmental duration, parasitism rate, and fecundity of C. japonicus during short-term exposures to 36 °C, 38 °C, and 40 °C for 2, 4, and 6 h, as well as continuous exposures to 32 °C and 34 °C for 3 days. The results show that short-term exposure to high-temperature stress leads to decreased survival rate of C. japonicus larvae and pupae, with survival rates declining as temperature and duration increase. High-temperature stress also delayed insect development, reduced mature egg production, shortened the body length of newly emerged females, and decreased female lifespans. Moreover, continuous high-temperature stress was found to significantly impact the development and reproduction of C. japonicus. Compared with the CK (27 °C), 3 d of continuous exposure to 34 °C prolonged developmental duration, shortened the body length and lifespan of newly emerged females, reduced survival rate and single female fecundity, and significantly decreased offspring numbers and parasitism rates. Temperatures of 36 °C, 38 °C, and 40 °C decreased the mortality time of adult females to 28.78, 16.04, and 7.91 h, respectively. Adverse temperatures also affected the insects' functional response, with 8 h of stress at 36 °C, 38 °C, and 40 °C causing the control efficiency of C. japonicus on P. nigra. This level of stress in the parasitoids was found to reduce the immediate attack rate and search effect, prolong processing time, and attenuate interference between small prey. Parasitoid efficiency was lowest following exposure to 40 °C. In this study, we determined the range of high temperatures that C. japonicus populations can tolerate under short- or long-term stress, providing guidance for future field applications.

Identification and Occurrence of the Dominant Parasitic Wasp Therophilus festivus of Larval Grapholita molesta

The oriental fruit moth, Grapholita molesta, is one of the most destructive orchard pests worldwide. Due to its behavior of boring into twigs and fruits, controlling the pest at the larval stage using insecticides is challenging. We studied the enemy species at the larval stage of G. molesta from seven fruit-growing areas by sampling peach shoots and fruits bored by its larvae. The occurrence and biological characteristics of the dominant enemy were verified using field investigation and laboratory experiments. The results showed that the dominant enemy species of larval G. molesta was identified as Therophilus festivus. The larval, cocoon, and pupal stages of T. festivus could not survive at 35 °C. The developmental durations of these three stages at 20 °C were significantly longer than those at 25 °C and 28 °C. Consecutive years of investigation in Xinxiang, China, indicated that T. festivus can parasitize G. molesta larvae collected at each generation. The parasitism rates in June (45.16%), July (63.50%), and August (48.37%) were significantly higher than those in April (15.27%). Most field research in China has focused on the release of parasitoids to control G. molesta eggs. Our study establishes a foundation for the control of G. molesta larvae using T. festivus.

Pre-emptive augmentative biological control of Spodoptera frugiperda in Europe using Trichogramma spp.

BackgroundFall armyworm, Spodoptera frugiperda, is a highly invasive pest of maize and other crops worldwide. It has recently been detected in Europe, and it is urgent to test and develop new sustainable control methods adapted to the European context and market. Trichogramma spp. are egg parasitoids that are sometimes used as biological control agent against S. frugiperda in other continents. However, a major issue using Trichogramma spp. against this pest is that females cannot reach all eggs in an egg mass, which is usually composed of one to three layers of eggs, often covered with scales and hair. Three European Trichogramma species were tested for their ability to parasitize egg masses with one to three layers and with or without hair and scale cover.MethodsTrichogramma brassicae, T. dendrolimi and T. cacoeciae were offered five types of S. frugiperda egg masses: one-layer without hair; one-layer with hair; two-layers without hair; two-layers with hair; three-layers with hair. For each treatment, an egg mass laid on paper was placed in a small vial saturated with females, to be sure that all reachable eggs would be parasitized. For each egg mass, the number of eggs in each layer was counted. Fifteen replicates were made per treatment, as well as 10 control vials without Trichogramma sp. Parasitism rates were calculated for each egg mass.ResultsThere were significant differences in the ability of parasitoid species to oviposit through hair and scales and to reach the lower egg layers. Trichogramma dendrolimi was the most efficient species and T. cacoeciae the least. Depending on the number of egg layers and hair and scales, parasitism rates by T. brassicae, T. dendrolimi and T. cacoeciae varied between 99 and 41%, 100 and 43% and 100 and 28%, respectively.ConclusionsThe assays confirmed that Trichogramma females cannot easily oviposit through thick layers of hair and scales but overall parasitism rates were higher than found previously. Important variations between species were found, and more Trichogramma sp. and other local natural enemies should be tested pre-emptively before S. frugiperda has invaded Europe.

Reproductive ecology and egg parasitism of the Samoan swallowtail butterfly

AbstractWe investigated the reproductive ecology and effects of egg parasitism on the Samoan swallowtail butterfly (Papilio godeffroyi), which survives only on Tutuila Island, American Samoa, after having disappeared from the much larger islands of Upolu and Savai‘i in independent Samoa. During monthly surveys of its only known host plant, Micromelum minutum, across eight sites in 2013 and 2014, we collected eggs, eggshells, larvae, pupae, and pupal exuviae. Live specimens were reared under laboratory conditions to determine reproductive outcomes, developmental rates, and sex ratios, as well as parasitoid attack frequencies, brood sizes, and sex ratios. Sixty‐six of 448 (14.7%) eggs produced larvae, 47 of which became adults. The sex ratio was approximately even overall and within each developmental stage. Eggs were slightly larger on individual host trees and in host tree stands that yielded more eggs per unit of foliage, indicating that ovipositing females responded to some features of host trees and stands. Eggs hatching female or male larvae were similar in size, and the sexes developed at similar rates. A newly described species of parasitoid wasp, Ooencyrtus pitosina (Encyrtidae), emerged from 73.6% of 382 butterfly eggs that failed to hatch in the laboratory (62.7% of 448 eggs overall). Forty‐one other eggs contained dead parasitoid larvae. An additional, unidentified Ooencyrtus wasp species emerged from a single P. godeffroyi egg. No parasitoids were reared from P. godeffroyi larvae or pupae. Of 656 P. godeffroyi eggshells collected in the field and examined in the laboratory, 62.2% showed signs of having been parasitized by O. pitosina. There was no evidence that parasitism rates were density‐dependent. O. pitosina brood sizes ranged from 1 to 5, with the sex ratio skewed toward females (2.40 F:1.00 M). Larger parasitoid broods were associated with slightly larger host eggs, indicating that female wasps may adjust brood size according to host egg size or that fewer wasp larvae are able to complete development in smaller eggs. Techniques used to rear both P. godeffroyi and O. pitosina in the laboratory could be applied to a captive‐rear, wild‐release program, which may facilitate reestablishment of the species in Samoa.

Detection of the carcinogenic liver fluke, Opisthorchis viverrini: comparison of two coprological methods versus the automatic feces analyzer.

Liver fluke infection, particularly Opisthorchis viverrini, poses a significant public health risk in Thailand, where it is closely associated with cholangiocarcinoma and contributes to substantial mortality in the northeastern region. Diagnosis of this condition employs various parasitological approaches. This research aims to compare the diagnostic accuracy of three parasitological techniques: the Kato Katz technique (KKT), the formalin-ethyl acetate concentration technique (FECT), and the Fully Automatic Feces Analyzer (FAFA) for O. viverrini identification. A total of 455 fecal specimens were collected from rural areas across five provinces in northeastern Thailand. The specimens were processed according to each method and examined through microscopy for KKT and FECT, and by utilizing an artificial intelligence-based machine for FAFA. Data analysis was conducted to assess parasitic infection rates and observe diagnostic accuracy. The results revealed a parasitic infection rate of 19.34%, with the majority of infections attributed to O. viverrini (18.02%), followed by Strongyloides stercoralis (0.88%). FECT exhibited the highest positive detection of O. viverrini eggs (16.48%), followed by FAFA (10.55%), and KKT (8.57%), respectively. Statistical analysis indicated sensitivity and specificity values for O. viverrini detection by KKT (100% and 89.21%), FECT (98.67% and 97.63%), and FAFA (97.92% and 91.15%). The positive predictive value, negative predictive value, and kappa were reported for FECT (89.16%, 99.73%, 0.92), FAFA (56.63%, 99.73%, 0.67), and KKT (45.78%, 100%, 0.58). Additionally, the preparation time for KKT, FECT, and FAFA was 30, 15, and 10 min, respectively. In conclusion, this study highlights FECT, KKT, and FAFA as comparably sensitive in diagnosing O. viverrini. The FAFA machine emerges as a potentially valuable tool for detecting O. viverrini and other parasitic infections, showcasing promise for clinical use. The findings provide valuable insights into the diagnostic landscape and underscore the potential of FAFA in enhancing efficiency and accuracy in parasitological assessments.

Assessing the effects of imidacloprid exposure on the microbiota of Binodoxys communis (Hymenoptera: Braconidae) and gene expression

Imidacloprid is a potent neonicotinoid insecticide that exerts control over cotton aphids. Binodoxys communis is the predominant parasitic threat to cotton aphids, serving as a crucial biological means to control cotton aphids. Imidacloprid has been Sprayed to control cotton aphids, but it also causes toxic effects on the natural enemies of cotton aphids, such as parasitic wasps, Binodoxys communis. However, the sublethal impact of imidacloprid on parasitic antagonists has remained unclear. This study sought to investigate the sublethal effects of imidacloprid on B. communis at the biological phenotype and transcriptional level, as well as the impact of imidacloprid on the microbial composition in the B. communis. Our research indicated that the sublethal dosages of imidacloprid imparted significant biologic adverse impacts on B. communis, including extended larval and pupal stages, as well as reduced parasitism and emergence rates. Following treatment with imidacloprid, transcriptomic analysis identified 1263 significantly differentially expressed genes. These differentially expressed genes were predominantly annotated in metabolic routes, and the annotated genes mainly belong to the fatty acid metabolism pathway, the carbon metabolism pathway, and protein processing in the endoplasmic reticulum pathway. 16S rDNA sequencing results showed significant changes in the composition of the microbial community in B. communis after exposure to imidacloprid. A total of 14 bacteria exhibiting the highest abundance in parasitic wasps were found, and the microbiota abundance of Akkermansia, Bacteroides, Streptomyces, Helicobacter, and Prevotellaceae UCG_001 was noticeably reduced, while Lactobacillus, Escherichia Shigella, Ligilactobacillus, Lachnospiraceae, Rikenellaceae RC9_gut_group, Erysipelatoclostridium, Acinetobacter, Enterococcus, and Aquabacterium were significantly elevated. By evaluating the enrichment pathways of microbial functions, it was found that the microbial functions with significant changes in proportion were mainly annotated to the carbon, fatty acid, and amino acid (aa) metabolic pathways, which was consistent with the transcriptome sequencing results. This finding mirrored transcriptome analysis results. According to transcriptomics analysis and 16S rDNA sequencing data, imidacloprid limits changes in metabolic pathways of B. communis, including fatty acid metabolism, impacting the development and parasitic competence of B. communis. Accordingly, the gene expression linked to detoxification and the cytochrome P450 gene family was significantly elevated at 1 h and significantly declined after three days.