This study investigated flight activity to develop forecasting methods for adult Eysarcoris aeneus（Scopoli）entry into rice fields. We examined the effects of temperature（30°C and 25°C）and food on flight muscle development and flight activity. Flight muscle weights were significantly higher at 25°C than at 30°C. At both temperatures, most males maintained their flight muscles as they aged. Female flight muscle weights decreased at both temperatures due to histolysis, with a more rapid reduction at 30°C than at 25°C in younger females. Oviposition rates showed no significant differences between the two temperatures. The rapid histolysis of female flight muscles at 30°C likely reflects higher maintenance costs at this temperature than at 25°C, thereby influencing the duration of female flight activity. Additionally, given the developmental transition of the flight muscles, flight activity may differ between male and female E. aeneus. Under feeding conditions, the number of flying individuals within 30 days after eclosion was higher at 30°C（16 individuals）than at 25°C（5 individuals）and higher in females（20 individuals）than in males（1 individual）. Females began flying an average of 5.7 days after eclosion at 30°C, compared with 11.8 days at 25°C. These findings demonstrate that temperature influences the number of flying individuals and the duration of flight activity in E. aeneus, especially in adult females. Food availability was essential for flight muscle development in adults after eclosion. Under 25°C conditions, removing food significantly increased the number of flying individuals compared with feeding conditions, with no significant differences observed between males and females. This indicates that unfavorable feeding conditions enhance E. aeneus activity. In conclusion, temperature and food interact to influence the flight activity of E. aeneus, affecting the timing and number of adults entering rice fields.

To clarify the effect of ambient temperature on the abundance of the two pecky rice bug species Niphe elongata and Cletus punctiger in organic rice paddy fields, we studied the relationships between the abundance of these species and temperatures recorded from November to April in Yamaguchi Prefecture, Japan, in 2022 and 2023. The periods during which temperature affected the abundance of both species were determined. Our analyses revealed that the abundance of N. elongata was significantly and positively related to the average minimum temperature in mid-April, suggesting that the low temperatures after the diapause termination may be associated with N. elongata mortality. The abundance of C. punctiger was significantly and positively related to the average maximum temperature in mid-March, suggesting that the higher temperature soon after the diapause termination makes it possible for overwintered C. punctiger adults to feed on host plants from earlier in the season. The heading period of rice was also observed to affect both species’ abundance in paddy fields. These results may allow us to estimate the abundance of both species based on the temperature before the start of rice cultivation and the rice heading period.

The sugar beet cyst nematode（SBCN）, Heterodera schachtii Schmidt（Rhabditida: Hoplolaimidae）, was first detected in Japan in 2017 and has since been officially controlled using chemical nematicides. Resistant cultivars and cultural practices against SBCN have been investigated, and two radish cultivars have been selected as a trap crop available in Japan. However, there is limited information on the ecology of the SBCN population in Japan. Among its various ecological traits, hatching is particularly important because of its direct impact on the effectiveness of cultural control measures and the survival period of the nematode. In this study, we conducted long-term hatching tests using field-collected SBCN cysts to explore the hatching dynamics of the nematode. Hatching of SBCN second-stage juveniles（J2）continued for 28 weeks, with approximately 85% of J2 emerging within 8 weeks. Our results indicate that the hatching of SBCN under field conditions can continue for a long time.

Paddy grains with a slight gap between the lemma and palea are vulnerable to rice leaf bugs, Stenotus rubrovittatus（Matsumura）and Trigonotylus caelestialium（Kirkaldy）（Hemiptera: Miridae）. This study aimed to determine the vulnerable paddy rate that can reduce pecky rice damage. Field data were collected from 2021 to 2023 in Joetsu City, Japan. Logistic models were constructed using data from 76 fields to estimate the probability of damage incidence; a relatively good model was selected. The selected model was used to assess the probability of ＞0.7% damaged grain incidence with two explanatory variables: percentage of vulnerable paddies and total number of rice leaf bug adults and larvae collected by sweeping at the full-heading stage. Using data from 113 fields, the selected model was evaluated and was reproducible for the ＜10% and 10–50% grades but not for the 50–90% and ＞90% grades. The model indicated that low vulnerable paddy incidence（＜13.3%）reduces the probability to ＜10% damage incidence under low bug density conditions（≤3.4 rice leaf bugs/20 sweepings）. Although moderately effective（reducing damage to ≤0.7%）, the low incidence of vulnerable paddy may help control damage, especially in late-heading rice fields.

A camera-trapping system developed for photographing perching Sympetrum dragonflies using passive photosensors is expected to support the biodiversity monitoring and evaluation of rice paddy fields. However, considerable time and labor was required in order to visually check the massive number of captured photographs to determine whether the dragonflies were correctly captured in them. In this study, automatic image classification using a deep-learning artificial-intelligence （AI）model was applied to the photographs captured by camera traps set in rice paddy fields in eastern Fukushima prefecture. The results show that the AI model can accurately detect and classify photographs containing a Sympetrum dragonfly, and that the estimated detection frequency based on the AI image classification is associated with the relative density of Sympetrum dragonflies directly observed in the fields. This suggests that automation by combining camera trapping and AI image classification is promising for monitoring Sympetrum dragonflies in the study area.

Stem borers are important insect pests that cause serious damage to trees by their larvae boring into the interior of trees. Although chemical control using aerosol spray insecticides is recommended for stem-boring insect pests, the chemicals often do not reach the larvae hidden in complicated pores, thereby reducing their extermination effectiveness. Because the pores are semi-closed spaces, volatile insecticides are expected to reach the larvae hidden deep within the complex pores. Therefore, we conducted a model test to demonstrate the effectiveness of extermination of the stem boring moth larvae, Endoclita excrescens（Butler）（Lepidoptera: Hepialidae）, hiding deeply in the holes where the insecticide spray cannot be directly reached using AITC containing agents, which have insecticidal effects and high volatility, and the non volatile insecticide containing clothianidin and fenpropathrin. The results showed that the AITC preparation had a significantly higher extermination effect on moth larvae than the non-volatile insecticidal preparation or the control（no insecticide preparation）. This suggested that volatile insecticides could effectively exterminate borer insect pests in areas that cannot be reached by chemical solutions.

Alternative control measures such as spiracle blockers can reduce the frequency of pest population exposure to pesticides and delay resistance development; however, population decline may in itself cause resistance allele fixation through genetic drift. We conducted a release experiment with two-spotted spider mites, Tetranychus urticae Koch, in strawberry fields in Shizuoka and Nara prefectures to examine the influence of spiracle blockers （sorbitan fatty acid esters） on the frequency of the etoxazole resistance allele （CHS1; I1017F）. F2 adult females from resistant and susceptible strains crossed at a 1 : 9 ratio were introduced, followed by two consecutive control rounds using either a spiracle blocker or etoxazole at their registered concentrations. Resistance allele frequencies were measured via quantitative PCR. The resistance allele frequency increased in Shizuoka only after using etoxazole but increased to approximately 80% in Nara after the first round regardless of the control measure used. The population density dropped to one mite per compound leaf after the first round, suggesting a genetic bottleneck. The estimated initial allele frequency in the F2 population was 6%, and etoxazole was effective only once, highlighting the need for risk avoidance （e.g., switching to other control measures） when resistance alleles are still rare.