Applied Entomology and Zoology最新文献

Portions of the sodium channel gene were sequenced for a strain of Neoseiulus womersleyi (Schicha) (Acari:Phytoseiidae) showing resistance to a pyrethroid. The results revealed that the strain had M918L and S1539T. The compositions of phytoseiid mite species inhabiting apple orchards in Iwate prefecture, northern Japan, were also examined in 2023 and 2024 using quantitative sequencing, species-specific PCR, and nucleotide sequencing. Results revealed the most dominant species in the apple orchards as Typhlodromus vulgaris Ehara (Acari:Phytoseiidae), followed by N. womersleyi. Also observed were Neoseiulus makuwa (Ehara) (Acari:Phytoseiidae), Scapulaseius okinawanus (Ehara) (Acari:Phytoseiidae), Amblyseius tsugawai Ehara (Acari:Phytoseiidae), and Amblyseius andersoni (Chant) (Acari:Phytoseiidae), but their relative proportions were low. Nucleotide sequencing of the individually amplified sodium channel gene fragments showed M918L as distributed widely in N. womersleyi and showed L925V/M distributed in T. vulgaris in some apple orchards. These results indicate that indigenous phytoseiid mite species in apple orchards might have reduced sensitivity to pyrethroids.

Based on previous studies, parasites manipulate host behavior. In particular, Wolbachia has often been shown to manipulate the life history and reproductive traits of the host. Wolbachia is generally transmitted vertically in the maternal line of host populations, but it can also be transmitted horizontally from infected prey to predators. Hence, Wolbachia may manipulate its hosts to increase their predation risk. Nevertheless, the impact of Wolbachia infection on the predator avoidance behavior of the host remains unknown. Therefore, this study aimed to investigate the effect of Wolbachia removal on tonic immobility as their antipredator behavior in Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), which is known to be infected by Wolbachia. Results indicated that the duration of the tonic immobility of T. confusum remarkably increased after Wolbachia removal. This study is the first to reveal that antibiotic treatment of T. confusum can prolong tonic immobility duration in its later generations, which may result from host manipulation to increase the probability of the horizontal transmission of Wolbachia.

The generalist feeding habit of the eri silkworm, Samia ricini (Donovan) (Lepidoptera: Saturniidae) enables it to utilize a wide range of host plants with diverse phytochemical compositions, has made understanding its dietary preferences and adaptations complex. In this study, we evaluated the phenotypic responses of the yellow plain strain of S. ricini reared on four diets: castor (Ricinus communis), cassava (Manihot esculenta), tree of heaven (Ailanthus altissima), and the artificial diet Silkmate L4M. Our results demonstrated that diet was the most influential factor shaping phenotypic traits, with additional influences from sex and season, highlighting the complex interplay of these factors in determining eri silkworm life-history characteristics. S. ricini performed best when reared solely on castor when compared with other diets, reinforcing its status as the primary diet. To circumvent suboptimal performance provided by A. altissima, we shifted larvae from castor to A. altissima at the fifth instar and observed minimal compromise in survivability, suggesting a commercially viable strategy and broader diet options for eri silkworm by utilizing this plant. Transcriptomic analysis of fifth instar larvae fed on castor showed significant enrichment in gene pathways associated with metabolic activity, whereas larvae fed on A. altissima or cassava exhibited reduced expression in pathways related to lipid and energy metabolism, correlating with their lower performance and survivability. Our results support the strategic integration of A. altissima to enhance sustainability and facilitate extended eri silkworm rearing seasons, particularly in temperate regions.

The chrysanthemum lace bug, Corythucha marmorata (Uhler) (Hemiptera: Tingidae), is an invasive agricultural pest. A logistic regression model to estimate the distribution of C. marmorata was developed based on both vegetation and meteorological information, and the potential distribution area was mapped for effective pest management in northern Honshu Island, Japan. Deciduous broadleaf forests and urban areas had significant negative and positive effects, respectively, and no interaction was statistically significant between vegetation and meteorological information on the probability of presence. Comparing the degree of influence between variables indicated that their distribution was limited mainly by vegetation rather than the average daily minimum temperatures in January, probably related to the environment for establishing the major host plant, tall goldenrod Solidago altissima L. (Asterales: Asteraceae). The accuracy of the prediction model was 65.2% and indicated that the surveyed area included both established and progressive invasion areas. The accuracy dramatically improved in the established area (94.4%) but declined in the progressing area (34.3%). The percentage of data correctly predicted as present was 98.8%, whereas the specificity of the percentage of absent data correctly predicted as absent was 11.3%. Based on the valuation index results, our model could estimate the presence of C. marmorata with high reliability.

Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is a zoophytophagous mirid predator that has recently been commercialised for augmentation biological control in Japanese greenhouses. This predator species is expected to control both Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Thrips palmi Karny (Thysanoptera: Thripidae) on vegetables grown in greenhouses throughout Japan. Studies on the predatory efficacy of N. tenuis are essential for assessing the effectiveness in terms of biological control in greenhouses. The voracity (the daily maximum predation) of N. tenuis for B. tabaci and T. palmi of different stages and the functional response to the density of B. tabaci nymphs were assessed in a controlled environment. Nesidiocoris tenuis nymphs and females exhibited high voracity for both B. tabaci nymphs and T. palmi larvae. Females reached peak voracity at 462.4 ± 72.8 on B. tabaci first-/second-instar nymphs. The voracity of N. tenuis nymphs increased with the development and that of fifth instar nymphs were not significantly different from females. Nesidiocoris tenuis females reached peak voracity (61.9 ± 5.2) on T. palmi second-instar larvae and both the fourth-instar nymphs and females of N. tenuis showed higher voracity for T. palmi second-instar larvae than for T. palmi adults. Moreover, the N. tenuis females exhibited a type III functional response to the density of B. tabaci first-/second-instar nymphs. The voracity and the functional response will be used as input to a prey–predator models for the quantitative evaluation of biological control by N. tenuis in greenhouses.

The zoophytophagous mirid Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an important biological control agent that primarily acts against small insect pests of tomato (Solanum lycopersicum L., Solanales: Solanaceae). In Japan, biological control programs in vegetable greenhouses are primarily implemented using N. tenuis and cleome (Cleome hassleriana Chod., Brassicales: Cleomaceae), which is a suitable banker plant for maintaining this mirid. However, the preference of N. tenuis for crop or banker plant remains unclear. Here, we assayed the plant preference of N. tenuis between tomato and cleome using three colonies—individuals reproduced on Crassula ovata (Mill.) Druce (Saxifragales: Crassulaceae), tomato, and cleome. Moreover, we evaluated the effect of temporary (24 h) plant experience on the preference of N. tenuis. The plant preference was assayed by a dual-choice test using potted plants. The results showed that individuals reproduced on C. ovata showed equal preference for tomato and cleome, suggesting that N. tenuis has no innate preference for either of these plants. In contrast, individuals reproduced on tomato or cleome had a strong preference for the plant species on which they were grown. Furthermore, individuals who were temporarily exposed to a plant were more likely to prefer that plant. Our findings demonstrate that the preference of N. tenuis between tomato and cleome changes reversibly through learning, indicating that plant preference may be artificially manipulated. This study can help develop effective release strategies for N. tenuis, leading to improved banker plant systems for biological control.

Ostrinia Hübner (Lepidoptera: Crambidae) is a moth genus that includes major agricultural pests and has been used as a model for studies such as chemical ecology and reproductive manipulation by its symbionts. The presence or absence of abdominal hair tufts and the morphology of the mid tibiae (small, medium, or large) in males both represent major interspecific and intraspecific differences in this genus. In this study, we generated hybrids between two Ostrinia species (O. furnacalis and O. scapulalis) with different abdominal hair and mid-tibial phenotypes to explore their hereditary modes. The ratios of abdominal hair phenotypes in F2 and backcrossed individuals indicated that a single dominant locus on an autosome determines the presence of abdominal tufts in males. After 23 rounds of backcrossing to O. furnacalis (lacking abdominal tufts), where only individuals with abdominal tufts were selected as male parents in each generation, males with abdominal tufts also exhibited enlarged, grooved mid tibiae, whereas those without abdominal tufts did not. According to these results, the two traits are most likely governed by the same locus, or tightly linked genomic regions, in Ostrinia moths. This study is the first to clarify the genetic association between abdominal hair and mid-tibial traits, thus providing insights into understanding the evolution of a male-specific novelty in the genus.

Some maternally inherited endosymbionts are known to cause Cytoplasmic incompatibility (CI), in which uninfected females cannot or seldom produce offspring by mating with infected males. Mortality by CI may vary depending on the bacterial strain, the host’s genotype, or the host’s age. Mesenetia is an alphaproteobacterial endosymbiont infecting the coconut hispine beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), a serious pest of the coconut palm. This bacterium was discovered in the Pacific clade B. longissima, which causes 100% CI mortality. The Mesenetia infection in the other Asian clade, which is considered more invasive than the Pacific clade, was then discovered; however, the CI was unknown. We investigated the CI ability of Mesenetia infecting the Asian clade using different ages of hosts originally collected in Japan. The effects of the host’s age on bacterial density were also investigated with qPCR. The results of crossing tests showed that infected males caused CI with approximately 70% mortality with uninfected females in all age groups: 21–30, 30–40, 60–70, or 90–100-day-old males. CI mortality did not differ among the males’ ages. Infected females rescued CI caused by infected males in all age groups: 15–20, 30–40, 60–70, or 90–100-day-old females. Results of qPCR showed that, in males, bacterial density did not diverge according to age in the testis, hindleg, foregut, midgut, and hindgut. In females, aged insects tended to have higher bacterial density than younger ones in the ovary and, to a lesser extent, in the hindgut.

Mirid bugs include polyphagous predators, which are used for augmentative biological control in the greenhouses to manage whiteflies, thrips and lepidopteran pests around the world. Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), which is indigenous to Japan, has recently been commercialised to control whiteflies and thrips. This predator species is expected to control both Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Thrips palmi Karny (Thysanoptera: Thripidae) on greenhouse-grown cucumbers in Japan. To examine the suppressive effects of N. tenuis against these two pest species, occurring in cucumbers, it is essential to clarify the prey selection between them. In this study, we examined the preference of N. tenuis between B. tabaci and T. palmi on cucumber leaf discs under controlled conditions. Nesidiocoris tenuis female adults preferred T. palmi larvae over B. tabaci nymphs. Preference for T. palmi larvae was weakest when the density ratio of B. tabaci to T. palmi presented to the N. tenuis female was highest. Neither the nymphal developmental stage of B. tabaci, nor predation experience in either prey species prior to the experiment, significantly affected prey selection. Nesidiocoris tenuis has excellent predatory characteristics for the control of T. palmi when it co-occurs with B. tabaci on cucumbers in greenhouses.