Journal of Applied Entomology最新文献

Peach (Prunus persica [L.] Batsch) is an important speciality fruit crop in the United States. Peach is self-compatible, but bee pollination enhances fruit sets and diverse populations improve pollination efficiency. However, the bee diversity and abundance in peach orchards in South Carolina are unknown. To understand this, we sampled bees during peach tree bloom at two locations in South Carolina—the Clemson University Musser Fruit Research Center (MFRC) and a peach farm in Ridge Spring, South Carolina. Overall, a total of 651 bees were collected from peach orchards, of which Bombus (37%) and Apis (32%) were the most dominant genera, followed by Eucera (14%), Andrena (8%) and Habropoda (5%). Diversity indices indicate higher species richness and diversity at the Ridge Spring farm than at MFRC. Dominant species at the MFRC were Apis mellifera (36.77%), Bombus bimaculatus (29.1%), B. griseocolis (12%) and Eucera hamata (8%). In contrast, the Ridge Spring farm was dominated by A. mellifera (24.17%), Habropoda laboriosa (12%), Andrena barbara (12%), E. atriventris (11.72%) and B. bimaculatus (11.35%). In comparing the effectiveness of sampling methods, blue vane traps (BVTs) captured more bees than aerial sweep netting. Furthermore, BVTs predominantly captured larger-sized bees, while smaller-sized bees were more frequently collected using sweep netting. Throughout peach bloom, differences in bee abundance were observed over time as well. Our study sheds light on the bee diversity and abundance in South Carolina peach orchards, revealing variations between locations. This knowledge of bee diversity and abundance will provide baseline information on bee communities in peach orchards and will help develop suitable pollinator conservation programs.

The bird cherry-oat aphid (Rhopalosiphum padi) and the grain aphid (Sitobion miscanthi) are two destructive wheat pests that have caused severe economic losses in China's main wheat-producing regions. Although previous studies have focused mainly on the population dynamics of wheat pests in wheat fields, little is known about the trans-sea migration of both wheat aphid species in eastern China. Here, we conducted 10 years of monitoring from 2012 to 2021 to determine aerial migration patterns utilizing a suction trap on Beihuang Island (BH), a small island in the centre of the Bohai Strait that serves as a seasonal insect migratory pathway in eastern Asia. We also simulated the migration trajectories of these pests using the HYSPLIT model. Overall, a total of 6362 alatae S. miscanthi and 335 alatae R. padi were captured, and both wheat aphid species exhibited regular patterns of comigration across the sea from late April to late October each year. There were significant interannual and seasonal differences in the migratory numbers of both wheat aphids. Notably, the average daily humidity was the most important meteorological factor affecting migration biomass. The seasonal migration trajectories simulated using the HYSPLIT model revealed different source areas for both wheat aphid species, which mostly originated in Northeast, North and East China. Accordingly, our study provides valuable insights into the occurrence and migration route of wheat aphids in eastern Asia, helps fine-tune forecasting and early warning systems, and thereby guides integrated pest management of wheat aphids in eastern Asia.

The white grub, Diaprepes abbreviatus L. (Coleoptera: Curculionidae), is a significant pest of yam tubers and the second cause of tuber rot in Haiti. Larval feeding inflicts severe damage to tubers, leading to notable losses due to decreased tuber quality, reduced marketability and increased susceptibility to secondary parasites and pathogens. This study examined the influence of planting and harvesting dates on the vulnerability of yam tubers to white grub infestation and the resulting tuber quality across 24 farmers' fields. At harvest, we assessed the level of tuber infestation, white grub density and the tuber quality index. The results indicated that 85% of grub populations were found in fields planted on the traditional date. In addition, 69.5% of tuber damage occurred in early-planted fields with fewer tubers damaged (30%) when harvested early. In contrast, in fields planted 30 days after the traditional date, the harvest date did not affect tuber infestation and damage by the pest. Overall, both planting and harvest dates impacted the quality grade of yam tubers. Delayed planting by 30 days and early harvesting (34th–38th week after planting) improved the marketability of yams. These findings highlight the importance of optimising planting and harvest schedules to better manage white grub infestation and enhance the marketability of yam tubers.

The diamondback moth (DBM), Plutella xylostella (L.), is responsible for extensive losses in brassicas' production, with its control heavily relying on the use of insecticides. The imbricated brassica's leaves on the stem provide a suitable habitat for the ring-legged earwig, Euborellia annulipes (Lucas), to attack DBM larvae and pupae. The study focused on the combination of the earwig with indoxacarb and cyantraniliprole against DBM, as these insecticides target chewing and sucking sap pests infesting Brassica crops, respectively. These insecticides were tested against adult earwigs, 5th instar nymphs and predation upon DBM. When exposed to the recommended rates, the survival rates for nymphs were 74%, 100% and 96% in the cyantraniliprole, indoxacarb and control groups, respectively, and over 90% for adults. When 5th instar earwig nymphs were exposed to cyantraniliprole, they took 16.3 days to develop compared to indoxacarb (3.4 days) or the control group (3.2 days). Furthermore, females exposed to cyantraniliprole required more time to initiate oviposition and produced fewer eggs in the first egg batch. Despite that, the egg-hatching rate was greater than 80% in all treatments. Female earwigs confined to indoxacarb- or cyantraniliprole-treated or untreated leaves and DBM larvae maintained similar survival but lower consumption of DBM larvae when exposed to cyantraniliprole. The findings revealed that cyantraniliprole weakened the potential of the ring-legged earwig to control DBM. On the other hand, indoxacarb was harmless to the earwig and showed additive mortality for the pest. Therefore, indoxacarb seems compatible with E. annulipes, while cyantraniliprole has a sublethal effect that slows down development and reproduction.

Knowledge about cold tolerance of non-native biological control agents is critical to avoid permanently establishing them in new temperate areas outside of their native range. The cold tolerance of the predatory mites, Amblydromalus limonicus and Iphiseius degenerans, was investigated in the laboratory to assess their establishment potential in northern Europe, particularly Sweden. The lethal time of I. degenerans (the number of days until 100% mortality was reached) declined steeply from 5°C to 0°C and was almost zero at −5°C. The lethal time of A. limonicus did not differ between 5°C and 0°C, but was reduced at −5°C. For both species, LTime₅₀ (the number of days until 50% of the mites died) was longer for fed than for unfed mites. The lethal temperature of A. limonicus (the temperature at which 100% mortality was reached) was −17.75°C, whereas most I. degenerans died at −8.5°C. LTemp₅₀ (the temperature at which 50% of the mites died) was lower for A. limonicus (−9.8°C) than for I. degenerans (−0.1°C). Collectively, these findings suggest that I. degenerans is unlikely to establish in Sweden but that A. limonicus is more cold tolerant. This highlights the risk associated with releasing A. limonicus in Sweden due to concerns about potential establishment.

Diapause is a vital survival strategy for insects, enabling them to conserve energy and endure adverse conditions. Understanding how diapause affects insect phenology and population dynamics is crucial for the effective management of insect pests. Predictive pest phenological models can be invaluable tools for providing essential information to support management strategies. This study presents a modelling framework to incorporate diapause into phenological models when biological information on variables regulating and functions describing diapause induction and termination are lacking or limited. In our framework, insect phenology is divided into a set of phases characterized by specific events (diapause induction and termination) and processes (development of diapausing and post-diapausing biological stages). The phenology is simulated by a stage-structured model based on the Kolmogorov equation, and the temperature-dependent development rate functions are described by the Brière functional form. Our modelling framework was tested on a case study involving the prediction of the phenology of the codling moth, (Cydia pomonella L. 1758). Model calibration and validation were performed using four time-series adult trap catch data collected in the Emilia Romagna Region from 2021 to 2023. The calibration procedure allowed obtaining realistic parameters related to the temperature threshold triggering diapause termination and the development rate function of post-diapausing larvae and pupae. Model validation proved successful in simulating both the initial emergence and the overall phenological patterns of adults across the three observed generations. The methodological framework proposed here aims to facilitate the introduction of diapause in phenological models improving also their predictive abilities. The model may serve as an accurate and knowledge-based tool for planning and implementing pest monitoring and control actions based on the realistic predictions provided by the model on the phenological status of the pest.

Studies of oriental fruit moth (OFM), Grapholita molesta (Busck), and codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae), both important pests of pome fruit, evaluated the addition of low-intensity light-emitting diode (LED) to delta traps baited with 3 commercial monitoring lures. Studies were conducted in 9 orchards treated with and without sex pheromone mating disruption for one or both species. OFM was monitored with a two-part pheromone/kairomone lure (OFM Combo Dual), while CM was monitored with either a two-part kairomone lure (CM Dual 4 K) or a sex pheromone lure (CM PH). Both pests were monitored with or without the addition of three types of a low power LED light with peak intensity at 395 (UV-A), 458 (blue), and 516 (green) nm. The UV-A LED was found to be the most effective among the three lights for OFM. Unexpectedly, traps with the OFM Combo Dual lure plus UV-A LED caught similar numbers of CM as traps baited with the CM Dual 4 K and CM PH lures alone. They also caught other pest species, such as oblique banded leafroller (OBLR), Choristoneura rosaceana (Harris), and peach twig borer (PTB), Anarsia lineatella (Zeller). Interestingly, in different trials the OFM Combo Dual combined with UV-A LED light caught significantly more OFM and/or CM females compared to the OFM Combo Dual lure without light, opening the perspective for a female-oriented monitoring and for a “female removal” management approach of these pests. The development of inexpensive, dual-modality traps adding a light stimulus to a pheromone/kairomone lure may reduce monitoring costs in orchards with multiple moth pests, improving the trapping efficiency.