Journal of economic entomology最新文献

The arrangement of crop hosts in the landscape plays a role in polyphagous pest exposure to multiple chemical applications that can affect resistance selection. Stink bugs are a group of polyphagous pest species that utilize both crop and noncrop hosts throughout the growing season, leading to insecticide exposure in different crops. The spatiotemporal arrangement of common crop hosts creates a mosaic of host patches that are infested by stink bugs during the growing season in eastern North Carolina. This study explored the relationship between stink bug insecticide susceptibility and landscape composition in that region. Stink bug populations were collected from 35 locations from 2022 to 2024 in eastern North Carolina. A glass-vial bioassay procedure was used to evaluate bifenthrin susceptibility of Euschistus servus Say (brown stink bug), Chinavia hilaris Say (green stink bug), and Nezara viridula L. (southern green stink bug). We then used a geospatial approach to explore the relationship between insecticide susceptibility of stink bug species and landscape-level availability of host crops where bifenthrin is commonly used. Our results showed that in bifenthrin susceptibility differed among stink bug populations. Species level susceptibility was not consistently related to the abundance and frequency of their host crops. Stink bug susceptibility to bifenthrin reported here will provide the baseline data in future resistance monitoring programs.

Highbush blueberry (Vaccinium corymbosum L.) depends on insect pollinators, but frequently experiences pollination deficits, which limit crop yield and quality. Understanding the relationship between pollinator traits and pollination efficiency and their relative importance for pollen transfer, can provide valuable insights into how different foraging strategies influence pollination success. This study aimed to determine the influence of bee foraging behavior, specifically whether bees forage inside or outside the corolla, on pollination efficiency and fruit production in highbush blueberry. Fieldwork was carried out in 5 commercial blueberry orchards in southern Chile over 2 yr, where we recorded 893 flower visits from 16 species of bees. We classified pollinators into 2 behavioral groups: inside flower foragers (smaller-bodied native bees that enter the corolla) and outside flower foragers (larger-bodied bees that forage from the flower exterior). Using a single-visit pollination test and generalized linear mixed models, we quantified fruit set, fruit weight, and seed set by the 2 different foraging behaviors. Our results indicate that inside flower foragers significantly increased fruit set compared to unvisited flowers and outside flower foragers. However, outside flower foragers contributed more to fruit weight and seed set, highlighting a trade-off between pollination quantity and quality. This suggests that foraging behavior, rather than species identity alone, can serve as a predictive functional trait for pollination efficiency in blueberries. The behavior of foraging inside/outside the flower can serve as a functional trait to evaluate pollination efficiency, providing a new perspective beyond traditional species-level taxonomic identification.

This study evaluates the antennal responses and behavioral preference of 3 strains of the German cockroach (Blattodea: Ectobiidae), Blattella germanica (L.) (S, D, and E), against 6 commercial essential oil-based formulations (Essentria, EcoVia, Excite-R, ER-22, Garscentria, and Orange Guard) and 8 individual components using electroantennography (EAG) and a two-choice olfactometer bioassay. Significant strain-specific differences in antennal sensitivity were observed, with strain E displaying the highest sensitivity, followed by strain D, while strain S demonstrated the least. Notably, Essentria elicited the strongest antennal responses and was least preferred by all strains at all concentrations, except for strain S at lower concentrations. EcoVia, Excite-R, and Orange Guard exhibited increased avoidance of the treatment only at the highest tested concentration (1,000 µg/µL), with EcoVia prompting higher treatment avoidance in strains D and E, Excite-R in strain E, and Orange Guard in strain S. In contrast, ER-22 demonstrated a significant increase in treatment avoidance for strain S at 1,000 µg/µL and for strain D even at 1 µg/µL. Garscentria did not significantly alter preference in any strain. A positive correlation between antennal responses and the level of treatment avoidance was observed, particularly for Essentria, suggesting that antennal sensitivity may predict olfactory-driven behavioral choices. These findings provide critical insights into the behavioral and physiological dynamics of strain-specific pest responses, emphasizing the importance of tailored approaches in pest management strategies.

The biological control for fruit flies in Brazil has been extended with the introduction of the parasitoid Diachasmimorpha longicaudata (Ashmead, 1905) (Hymenoptera: Braconidae) and native parasitoids, such as Doryctobracon brasiliensis (Szepligeti, 1911) (Hymenoptera: Braconidae), which show great potential for control. Among the main pest species of fruit flies, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) and Ceratitis capitata (Wiedemann, 1830) (Diptera: Tephritidae) have a wide geographic distribution in the South American continent. The objectives of this study were to evaluate the functional response of D. brasiliensis to the density of A. fraterculus larvae and to model the parasitism rates of D. longicaudata and D. brasiliensis on A. fraterculus and that of D. longicaudata when exposed to C. capitata. The experiments were conducted to evaluate the parasitism rate, and the data were subjected to statistical analysis, verifying the probability distribution. The parasitism rate of D. brasiliensis ranged from 82.2% to 35% when 5 and 30 larvae were offered to each female, respectively. The results revealed a type II functional response, indicating that the parasitism rate reached a saturation point as the larval density increased. In A. fraterculus, the average number of larvae parasitized by D. longicaudata females was higher than that of C. capitata at nearly all host densities. The highest percentage of parasitism (55%) was observed at the density of 3 larvae per parasitoid, similar to what was recorded for C. capitata. The results obtained support the biological control program for fruit flies in Brazil, optimizing laboratory rearing and field release.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) can cause extensive damage to many cultivated stone and small fruits. Larvae feed and develop inside the fruits, which deteriorate and rot, leading to high economic losses. Concern about this pest has motivated research into many possible control methods. However, at present the main control strategies are based on the application of insecticides, some of which may pose risks to human health and the environment. Therefore, research is needed to find more secure strategies to control this pest. Here, 2 natural compounds (kaolin, azadirachtin) and 2 insect growth regulators (pyriproxyfen, cyromazine) with safer ecotoxicological properties than conventional pesticides were evaluated for the control of D. suzukii in cherries. In no choice assays, kaolin showed a strong effect reducing female activity, so the adult offspring production in treated cherries was almost completely inhibited (96% reduction), whereas azadirachtin showed a lesser nonsignificant effect (47% reduction). Pyriproxyfen completely prevented the immature development both in treated cherries exposed to D. suzukii females and in cherries previously exposed to the females and subsequently treated (100% reduction), and with cyromazine only a few adult flies were produced in both cases (99% and 93% reduction, respectively). In choice assays, the adult offspring reduction indices were 100% for kaolin, pyriproxyfen and cyromazine. Additionally, a residue analysis showed that pyriproxyfen and cyromazine were present in the pulp of the treated cherries and in the flies exposed to them. Kaolin, pyriproxyfen and cyromazine could be considered for the control of D. suzukii in cherry orchards.

Mythimna separata is a major migratory agricultural pest in China, with its number of generations varying significantly along latitudinal gradients, posing a serious threat to grain production and security. To address the current lack of fundamental temperature-response data for predicting outbreaks in third-generation occurrence areas, this study systematically investigated the developmental characteristics of this pest under naturally fluctuating temperature conditions. Three complete generations were observed during the April-October 2021 study period, with each generation's developmental progression showing a significant correlation with temperature variations. The second generation developed fastest during the high-temperature period in July, completing its life cycle in only 48.2 d. When the temperature reached approximately 25 °C, the developmental duration shortened significantly, but the larval survival rate decreased. Fifth-instar larvae exhibited the strongest environmental adaptability, with starvation tolerance lasting up to 281.4 h. This study provides guidelines for predicting M. separata occurrence in third-generation breeding areas under natural conditions.

The effects of volatile organic compounds (VOCs) from tobacco and Myzus persicae (Sulzer) (Homoptera, Aphididae) on the host-searching behavior and fecundity of Aphidoletes aphidimyza Rondani (Diptera, Cecidomyiidae), a key aphid predator, were investigated. The olfactory responses of A. aphidimyza adults to VOCs from healthy tobacco plants (HTPs), mechanically damaged tobacco plants (MDTPs), aphid-damaged tobacco plants without aphids (A-DTPs), aphid-carrying tobacco plants (A-CTPs), honeydew (H), and M. persicae (MPs) were assessed by electroantennography (EAG) and behavioral bioassays. A. aphidimyza exhibited significant differences in their preferences for different odor sources, as follows: A-CTPs > A-DTPs > MDTPs > HTPs > H > MPs. Their fecundity varied significantly following exposure to different VOCs from the tobacco-aphid system, being highest for A-CTPs and A-DTPs, which exceeded those of the other odor sources. Gas chromatography-mass spectrometry (GC-MS) identified 18 highly abundant VOCs from 6 odor sources. EAG revealed that the females detected these compounds in a concentration-dependent manner, exhibiting the strongest responses to n-hexanol, benzaldehyde, methyl salicylate, hexanoic acid, cis-3-hexenol, (E)-beta-farnesene, and (E)-6,10-dimethyl-5,9-undecadien-2-one, which elicited significant EAG responses at varying concentrations. Exposure to 50 μl/ml n-hexanol, cis-3-hexenol, (E)-beta-farnesene, 0.1 μl/ml methyl salicylate, hexanoic acid, or (E)-6,10-dimethyl-5,9-undecadien-2-one significantly increased the fecundity of A. aphidimyza. A 10:0.1:0.1:50:10:0.1 mixture of n-hexanol: methyl salicylate: hexanoic acid: cis-3-hexenol:(E)-beta-farnesene:(E)-6,10-dimethyl-5,9-undecadien-2-one (M3) significantly enhanced the behavioral responses and fecundity of A. aphidimyza, compared to those associated with individual VOCs or the blank control. These findings indicate that M3 elicited positive chemotactic responses in adult A. aphidimyza, and holds significant potential for precise aphid control using A. aphidimyza.

Euschistus quadrator Rolston (Hemiptera: Pentatomidae) is a polyphagous pest of row crops in the southern United States. In Louisiana, it is part of a complex of stink bug pests of soybean but historically has been a minor component. However, recent reports suggest E. quadrator is becoming more numerous. To address this, studies were conducted to: (i) mine past survey data to determine the extent and importance of E. quadrator, (ii) determine current E. quadrator age-specific population dynamics in relationship to soybean crop phenology, (iii) conduct assays to determine supercooling points (SCP) for adults, and (iv) conduct age-stage, two-sex life table studies to understand the survival and reproductive capabilities of E. quadrator on soybean. Over the 12-year survey period, E. quadrator and E. servus were the most numerous brown species. From 2008 to 2010, E. servus was the most dominant of the two species. In 2015, a switch occurred with E. quadrator becoming the most dominant. Nymphs and adults of E. quadrator were found throughout R2 to R7, indicating visitation, egg deposition, and eclosion throughout soybean reproductive stages. However, E. quadrator adults were significantly less numerous at R2 to R4 stages and significantly more numerous at the R5 to R7 stages. The SCP of E. quadrator was -9.9 ± 0.2 °C. Life table studies proved E. quadrator can successfully utilize soybean as a food source and will maintain population growth. In summary, this research enhances current knowledge of E. quadrator and provides a foundation for creating models to estimate population growth in the field.

Chile pepper, Capsicum annuum L. (Solanales: Solanaceae) yield in New Mexico is threatened by a multitude of factors, including beet curly top virus (BCTV) vectored by the beet leafhopper, Neoaliturus tenellus (Baker), and competition with annual weeds. Early-season weeds in chile pepper can be reduced by either barley, Hordeum vulgare L. or brown mustard, Brassica juncea (L.) Czern. cover crops; however, the potential of attracting N. tenellus should be factored into cover crop selection. In this study, dual choice tests were carried out between a brown mustard cultivar ('Caliente Rojo') and two barley cultivars ('Stockford' and 'Valor'). In a subsequent no-choice test, viruliferous N. tenellus were caged onto individual leaves of barley and brown mustard, and plant tissue was stained and examined for the presence of sheaths, punctures, and eggs. N. tenellus demonstrated a nine times greater acceptance of brown mustard than either barley cultivar. In no-choice tests, viruliferous N. tenellus successfully produced sheaths on brown mustard four times more than N. tenellus trapped on barley. N. tenellus survival was lower on Stockford barley than both Valor barley and brown mustard. No eggs were laid on either barley cultivar, indicating its unsuitability as an oviposition host. This research indicates that barley is less likely than brown mustard to sustain N. tenellus populations with the capacity to transmit BCTV to subsequently planted chile pepper. Accordingly, farmers attempting to manage early season chile pepper weeds with cover crops, while minimizing potential habitat for N. tenellus, should select barley rather than brown mustard.