Search Results (61)

In 2024 and 2025, researchers investigated the breeding ecology of the Twite Linaria flavirostris in riparian shrubland habitats at an elevation of 3400 m in the northeastern Qinghai–Tibet Plateau. This species lays eggs from late June to mid-July, capitalizing on the region’s brief warm season. Nests are typically open-cup structures built in Hippophae spp. shrubs. The population predominantly exhibits monogamous mating, with a mean clutch size of 4.7 ± 0.49 (3~5). Incubation is performed solely by the female and lasts 11.52 ± 1.65 days. Both parents provision the nestlings, and the nestling period lasts 12.43 ± 2.39 days. Morphological measurements of nestling body mass and external organs all fit well to the Logistic growth curve equation. By fledging, tarsus length and bill length reach over 90% of adult values, conferring substantial terrestrial mobility. However, flight-related feathers, primaries and rectrices, remain markedly underdeveloped compared to adults, resulting in extremely poor flight capability; further post-fledging development is thus required. Based on reproductive outcomes from this single breeding season, a total of 121 eggs were laid, of which 81 successfully hatched, and ultimately 79 fledglings survived to leave the nest. The overall hatching success was 66.94%, fledging success (among hatchlings) was 97.53%, and overall offspring survival (from eggs to fledglings) was 65.29%. The apparent nesting success rate was 76.0%, based on a total of 50 nests monitored over two years. Daily nest survival rates were estimated using Mayfield’s method and program MARK, resulting in nest success probabilities of 0.587 and 0.219, respectively. Comparing populations across different geographic regions, the results indicate that Twites breeding in environments with higher levels of environmental stress produce smaller clutch sizes and larger eggs, and exhibit a prolonged nestling period. This life-history strategy likely represents an evolutionary adaptation to spatially variable environmental conditions. Full article

The spongy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), is one of the most destructive defoliators, primarily of oak forest ecosystems, causing severe ecological and economic damages. The present study evaluated the effectiveness of the mating disruption method against L. dispar populations in an oak-dominated forest in Greece. Field experiments were conducted for three consecutive years (2022–2024) in two forest areas: a treated area, where a flowable pheromone gel was applied, and an untreated control area. The L. dispar male flight activity was monitored using pheromone-baited traps. Egg cluster counts were assessed during winter to evaluate reproductive success. The obtained results revealed a significant reduction in male trap captures in the treated area, following the mating disruption application in 2023 and 2024, compared to the control area. Additionally, the egg cluster counts decreased significantly in the mating disruption area, reaching reductions of 94.8% and 99.2% during the winters of 2023–2024 and 2024–2025, respectively, compared to the winter of 2022–2023 (before the mating disruption application). These results demonstrate that mating disruption, an environmentally friendly strategy for sustainable forest pest management, can effectively reduce L. dispar populations under Mediterranean environmental conditions. Full article

This paper addresses the limitations of genetic algorithms in solving the Flexible Job-Shop Scheduling Problem (FJSP) including slow convergence, susceptibility to local optima, and sensitivity to parameter settings. The paper proposes an Improved Genetic Algorithm based on Reinforcement Learning (IGARL). First, a hybrid population selection mechanism that combines the Queen Bee Mating Flight (QBMF) strategy with the Tournament Selection (TS) method is introduced. This mechanism significantly accelerates convergence by optimizing the population structure. Second, a dynamic population update strategy based on tunnel vision, termed the Solution Space Diversity Awakening (SSDA) strategy, is developed. When the population becomes trapped in local optima, this strategy intelligently triggers random perturbations and introduces high-potential individuals to enhance the algorithm’s ability to escape local optima and promote population diversity. Third, a novel multi-Q-table reinforcement learning framework is embedded within the iterative process to dynamically adjust key genetic algorithm parameters (such as selection, mutation, and crossover rates) and enable multi-dimensional performance evaluation, thereby effectively guiding the search toward better solutions. Experimental results demonstrate that the IGARL algorithm achieves a 10% to 60% improvement in convergence speed on Brandimarte benchmark instances, with solution quality significantly surpassing that of the basic genetic algorithm. Moreover, the fluctuation of the average optimal solution remains within 20%, indicating strong stability and robustness. Full article

IPM approaches based on pheromone-based techniques for the management of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), are of great interest. We evaluated the effectiveness of mating disruption (MD) experiments against T. absoluta using a biodegradable pheromone dispenser (Isonet-T TT BIOX234) in greenhouse-grown tomatoes over two years in southern Italy. A base treatment alternating the most used insecticides for the pest, i.e., the farmer treatment schedule (FTS), was assigned as a reference, and two MD dispenser densities (i.e., 300 and 500 dispensers/ha) were compared with the MD commercial product Isonet T at 1000 units/ha. We conducted two trials on crops at a density of 37,000 plants/ha. Pest flights were monitored in summer–autumn 2023 and 2024 with pheromone-baited Delta traps. The FTS ensured a generally low level of T. absoluta attacks (about 1 leaflet/leaf and 1/300 fruits). Even so, mating disruption resulted in further appreciable reductions in the presence and attacks of the target pest: 89%, 76% and 52% fewer catches; 61%, 45% and 37% fewer mined leaflets; and 76%, 59% and 54% fewer attacked fruits, for Isonet-T TT 500, Isonet-T TT 300 and Isonet T 1000, respectively. Overall, MD biodegradable dispensers could be a valuable tool for controlling T. absoluta in greenhouse-grown tomatoes, while also reducing plastic waste in the agricultural setting. Full article

This study investigated the effects of preheat hardening on the egg-laying capacity of honeybee queens and the flight performance of their daughter workers. A honeybee queen was confined in a cage with a two-section frame for 12 h. Then, 48 h old eggs from one section were incubated for 15 min at 41 °C and 70% relative humidity (RH). The queens (n = 12) raised in this section were named the pre-heat-treated queens (pH-TQs). Eggs from the second section were exposed to 34.5 °C and 70% RH for 15 min, and the queens raised in this section were named the non-heat-treated queens (nH-TQs) (n = 12). After mating, both groups were introduced to queenless hives in order to produce workers. The results show that, during the study period (2021 and 2022), the colonies headed by the pH-TQs reared significantly more brood cells and worker adults (especially during the summer), collected and stored more pollen, had less tendency to rear drone brood, and constructed fewer swarm cells than the colonies headed by the nH-TQs. Preheat hardening can be a promising method for improving honeybee workers’ reproductive potential and adaptability, allowing for better adaptation to environmental changes, thus compensating for the mass fatalities of honeybees globally. Full article

Mosquitoes detect sound with their antennae, which transmit vibrations to mechanosensory neurons in Johnston’s organ. However, their auditory system is exposed to low-frequency noise such as convective and thermal noise, as well as noise induced by flight, which could impair sensitivity. High-pass filters (HPFs) may mitigate this issue by suppressing low-frequency interference before it is transformed into neuronal signals. We investigated HPF mechanisms in Culex pipiens mosquitoes by analyzing the phase–frequency characteristics of the primary sensory neurons in the Johnston’s organ. Electrophysiological recordings from male and female mosquitoes revealed phase shifts consistent with high-pass filtering. Initial modeling suggested a single HPF; however, experimentally obtained phase shifts exceeding –90° required revising the model to include two serially connected HPFs. The results showed that male mosquitoes exhibit stronger low-frequency suppression (~32 dB at 10 Hz) compared to females (~21 dB), with some female neurons showing negligible filtering. The estimated delay in signal transmission was ~7 ms for both sexes. These findings suggest that HPFs enhance noise immunity, particularly in males, whose auditory sensitivity is critical for mating. The diversity in female neuronal tuning may reflect broader auditory functions in addition to mating, such as host detection. This study provides indirect evidence for HPFs in mosquito hearing and highlights sex-specific adaptations in auditory processing. The proposed dual-HPF model improves our understanding of how mosquitoes maintain high auditory sensitivity in noisy environments. Full article

Drosophila suzukii is an invasive pest of many fruit crops worldwide. Employing the Sterile Insect Technique (SIT) could mitigate D. suzukii population growth and crop damage. This study evaluated the efficacy of SIT on commercial fruit, by (1) validating the quality of irradiated sterile males (male mating competitiveness, courtship, and flight performance) in the laboratory, and (2) assessing population suppression and fruit damage reduction in commercial raspberry fields. Treatment with SIT was compared to the grower’s standard chemical insecticide program throughout the season. The principal metrics of efficacy were trap counts of wild adult female D. suzukii in crops and larvae per fruit during harvesting. These metrics together with monitoring of border areas allowed targeting of high-pressure areas with higher releases of sterile males, to maximise efficacy for a given release number. The sterile male D. suzukii were as competitive as their fertile non-irradiated counterparts in laboratory mating competitiveness and flight performance studies while fertility egg-to-pupae recovery was reduced by 99%. In commercial raspberry crops, season-long releases of sterile males significantly suppressed the wild D. suzukii population, compared to the grower standard control strategy; with up to 89% reduction in wild female D. suzukii and 80% decrease in numbers of larvae per harvested fruit. Additionally, relative fruit waste (i.e., percentage of harvested fruits rejected for sale) at harvest was reduced for early, mid and late harvest crops, by up to 58% compared to the grower standard control. SIT has the potential to provide an effective and sustainable strategy for managing D. suzukii in raspberries, increasing marketable yield by reducing adult populations, fruit damage and waste fruit. SIT could therefore serve as a valuable tool for integrated pest management practices in berry production systems. Full article

Agroforestry systems are essential in sustainable land use in the face of the growing global food demand and climate change. The southern region of Bahia, Brazil, is one of the places in the world where the tree species is particularly in abundance, primarily in cocoa agroforestry systems, contributing to biodiversity conservation. Understanding their reproductive patterns is crucial for the survival and sustainability of these trees. This study dealt with Lecythis pisonis (Sapucaia) trees by applying microsatellite markers for mixed-mating mode and paternity analyses for pollen dispersal. In particular, it was found that Lecythis pisonis offspring are produced through outcrossing, as the case may be, while random crossings and no nearby tree fertilization are the remaining factors that play a crucial role in myriad genetic diversity inversions. This phenomenon was indicated by paternity in nine offspring, with full siblings being from the same parents. The average distance of pollen flow was 6 km, which is why the pollinator, the bee Xylocopa frontalis, has a flight range aligning with distance. These data show the influence of habitat fragmentation, the function of Cabruca, and the conservation strategy. Full article

Background/Objectives: Anadenanthera colubrina (popularly known as angico; in this study: Acol) is a bee-pollinated tree with gravity-dispersed seeds that occurs in dry tropical forests (SDTF), one of the most fragmented tropical ecosystems. In this study, we analyzed the resilience of 30 Acol Forest fragments of Ribeirão Preto, São Paulo, Brazil, and the flow of pollinators among these fragments based on the flight ranges of Apis mellifera (6 km) and Trigona spinipes (8 km). Additionally, we investigated genetic diversity, spatial genetic structure (SGS), and phenology across generations of one Acol population (AcolPM), located in the urban fragment M103 in the “Parque Municipal Morro de São Bento” (a municipal park in Ribeirão Preto). Methods: We mapped Acol fragments using geospatial data, with relief and slope analysis derived from digital terrain modeling. We created a flow diagram based on the pollinator’s flight ranges and calculated betweenness centrality. We amplified DNA from AcolPM individuals using 14 SSR molecular markers. Results: Notably, 17 of the 30 fragments occurred on slopes > 12%, terrain unsuitable for agriculture or construction, indicating that the presence of A. colubrina may serve as an indicator of territorial transformations. The AcolPM population (Fragment M103) emerged as a key node among the angicais, connected by the native pollinator T. spinipes, being fundamental for regional gene flow. In this focal population, we observed a slight but significant inbreeding (Fis, Fit, p < 0.01) and an SGS up to ~17 m. Genetic diversity was intermediate (He ≈ 0.62), and PCoA, Fst, and AMOVA values suggest low generational isolation, with most genetic variation within generations. This highlights AcolPM as a promising source for seed collection for reforestation. Phenological observations showed that fructification occurs between September and October, at the beginning of the rainy season. Conclusions: We concluded that Acol resilience is linked to the species’ mixed-mating system and pollinator dynamics-driven connectivity, allowing for the maintenance of genetic diversity in fragmented landscapes, as well as its natural tendency to form dense angicais clusters in non-arable slopes. We reaffirmed A. colubrina as a valuable species for restoration and urban climate resilience, providing cooling shade to humans and wildlife alike while offering refuge and food for local insects and birds in a warming landscape. Full article

The melon fly, Bactrocera cucurbitae, poses a severe threat to the country’s agricultural productivity, particularly in the cultivation of cucurbitaceous crops. This study was conducted to determine the ideal irradiation dose to be used to set up a Sterile Insect Technique (SIT)-based strategy to control B. cucurbitae outbreaks in Sri Lanka. A B. cucurbitae colony was established and maintained under standard laboratory conditions. Male pupae (100 pupae per treatment) were exposed to different radiation doses, namely 0 (control), 50, 60, 70, 80, 90, 100, and 110 Gy. The effect of irradiation on selected performance parameters such as survival, flight ability, fecundity, fertility, and adult longevity was evaluated under laboratory conditions. In addition, mating competitiveness was evaluated for irradiated male B. cucurbitae. Significant differences were observed in percentage pupal survival, flight ability, and fertility rates (p < 0.05) at a 95% level of confidence. Further, the 50% and 75% adult longevity periods of irradiated B. cucurbitae males significantly decreased with the increasing irradiation dosage (p < 0.05). B. cucurbitae exposed to 70 Gy radiation reported a mean pupal survival rate of 94.0 ± 1.25, flight ability of 93.3 ± 1.88, and fertility 0.2 ± 0.05%, along with a mean longevity of 38 ± 1.5 days until 50% reduction in the population. The competitiveness of B. cucurbitae exposed to 70 Gy with respect to wild males was 0.56 under laboratory conditions, which reduced up to 0.5 in semi-field settings. The 70 Gy dose could be recommended as the optimal radiation dose for the production of sterile B. cucurbitae males with an acceptable level of fitness and sterility to be used in SIT-based melon fly control programmes in Sri Lanka. Full article

The Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae: Lamiinae), is a serious pest of over 43 species of hardwood trees in North America, China and Europe. The development of an effective lure and trap for monitoring A. glabripennis has been hindered by the fact that mate finding involves a rather complex series of behaviors and responses to several chemical (and visual), cues. Adults (female-biased) locate a tree via host kairomones. Research has demonstrated that female contact pheromone components are precursors that undergo abiotic oxidation to yield attractive volatile components. Males also produce a pheromone to attract other adults nearby before the final step of recognition by males to the female-produced trail and contact pheromones. Our research aimed to identify new female-produced components from ozone and UV-treated A. glabripennis body washes and test them for behavioral activity using laboratory and field assays. The ozone and UV treatment of virgin female extract yielded sixteen aldehydes, nine of which were found in trace amounts. All sixteen aldehydes elicited antennal responses (GC-EAD) in both males and females, although responses were clearer and more distinct with standards of hexanal, heptanal, octanal, nonanal, decanal, undecanal and dodecanal. Olfactometer assays showed that males were highly attracted to a blend of these seven aldehydes. Females did not show any attraction to the blend in olfactometer assays. Despite low population levels during field tests in 2018 in China, traps containing the aldehyde blend detected A. glabripennis on a weekly basis over 6 weeks and caught significantly more adults (mainly males) than control ‘flight intercept panel’ traps. Field tests in China in 2019 that used the aldehyde blend along with a three-component host blend lure also caught significantly more males (nearly 5×) than blank control traps. Full article

The navel orangeworm, Amyelois transitella, is the principal pest of pistachio and almond in California. The timing of the insecticide application is challenging because there is no model that predicts when pistachio is vulnerable to infestation. Sixteen years of pistachio flight data from Madera and Fresno counties (541,892 adults) were analyzed to determine if there was a consistent starting point each year for flights that overlap pistachio vulnerability. This effort was complicated by changes in trap lures over this period, as unmated females were replaced by a combination lure consisting of the synthetic pheromone and phenyl propionate, which is needed because mating disruption suppresses pheromone lure trap capture. There were two additional complications: the increased degree day accumulation during the growing season and the three-fold hectarage expansion of pistachio. A biofix at 944.4 degree days °C from the beginning of the year was identified from the dataset, which was consistent across all years in both counties. Using the biofix, subsequent flight peaks occurred at 277.78 degree day °C intervals (generation time on new crop pistachios), corresponding to three weeks in the field. This biofix can be used to improve the timing of field scouting, which in turn will improve the timing of insecticide application. Full article

The biological characteristics of Lymantria xylina Swinhoe (Lepidoptera: Erebidae), a moth that threatens coastal forests in Fuzhou, China, are closely linked to its spread risk. To characterize these traits, we primarily investigated emergence, reproductive, and flight behaviors. Our findings show that females typically emerge, mate, and copulate during specific times of day. The peak hours of emergence, courtship, and copulation are 13:00–14:00, 19:00–21:00, and around 0:00, respectively. The starting time of oviposition was concentrated before dawn and during the daytime. They preferentially lay eggs on columnar objects, including artificial ones. On average, females laid 361 eggs, lived for 4.5 days, and weighed 0.74 g. Non-ovipositing females were observed to fly for short distances, especially during the evening. Field observations suggest that these females can potentially travel up to 184.5 m in total and 34.5 m continuously. While this indicates a theoretical risk of long-distance dispersal, our findings suggest that the overall risk is limited. These results contribute to our understanding of the biology and dispersal potential of L. xylina. Full article

Lygus pratensis (Linnaeus) is an important agricultural pest with a strong ability to move and spread between hosts. However, L. pratensis’ flight potential and factors affecting its flight ability are unclear. We used the insect flight information system (flight mill) to determine the effects of temperature, humidity, age, sex, and mating on L. pratensis’ flight ability in an artificial climate chamber. Temperature and relative humidity significantly affected L. pratensis’ flight ability; however, low and high temperature, as well as low humidity, were unsuitable, and the optimal flight environment was 20–28 °C and 60–75% RH. Lygus pratensis’ flying ability initially increased and then decreased with age and was highest at 10 days old (flight rate: 71.43%; total flight distance: 18.63 ± 1.89 km; total flight time: 6.84 ± 0.60 h). At 15 days old, flight speed was the highest (3.36 ± 0.18 km h⁻¹). Sex had little effect on L. pratensis’ flying ability; it was marginally stronger for females than males, but the difference was insignificant. Mating increased female flying ability but decreased that of males, but the difference was insignificant. Overall, L. pratensis had strong flight dispersal ability, was largely unaffected by sex and mating, and optimal flight conditions were mild temperature and humidity. This knowledge provides a scientific basis for L. pratensis outbreak prediction, prevention, and control. Full article

Lymantria xylina Swinhoe (Lepidoptera: Erebidae) is a potentially invasive pest, similar to Lymantria dispar asiatica Vnukovskij and Lymantria dispar japonica Motschulsky (Lepidoptera: Erebidae). To evaluate its potential for spread and flight distance related to egg deposition on vessels at ports, we employed a flight mill to assess the flight capabilities of its adults under varying conditions. Our findings revealed that females primarily flew short distances and ceased flying after 3:00 AM, whereas males covered much longer distances throughout the day. Sex, age, and flight duration significantly influenced flight ability. Females exhibited weaker flight capability than males, and their ability declined with increasing age or flight duration. Notably, 1-day-old moths displayed the strongest flight ability, with average flight distances of up to 3.975 km for females and 8.441 km for males. By the fifth day, females no longer flew, and males experienced reduced flight ability. After continuous hanging for 16 h, females lost most of their flight capacity, while males remained capable of flight even after 32 h. Additionally, female flight ability decreased significantly after mating, possibly due to factors such as egg-carrying capacity, weight, and load ratio. This study provides a foundation for assessing the risk of long-distance dispersal of L. xylina via ocean-going freighters, considering female moths’ phototactic flight and oviposition. Full article