scholarly journals Seasonal Captures of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) and the Effects of Habitat Type and Tree Species on Detection Frequency

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Nicole F. Quinn ◽  
Elijah J. Talamas ◽  
Tracy C. Leskey ◽  
J. Christopher Bergh

Trissolcus japonicus, an important egg parasitoid of Halyomorpha halys in Asia, was first detected in the USA in 2014. To evaluate the effect of habitat and the seasonality of T. japonicus detections in the USA, yellow sticky traps were placed in the canopy of Ailanthus altissima growing at the edge of isolated patches of trees, windbreaks, and woodlots in northern Virginia in 2018 and 2019. In both years, captures occurred from May to September, and peaked in July and August. While T. japonicus was detected in all habitats, there was not a consistent effect of habitat type on capture frequency. To evaluate tree species effects on T. japonicus captures, in 2017 and 2018, yellow sticky traps deployed in the canopy of A. altissima bordering apple orchards were paired with a nearby trap in one of several wild tree species along a common woods edge. In 2019, these traps were deployed in A. altissima, black walnut, and black locust growing in the same windbreaks. No consistent association between captures of T. japonicus or native parasitoids of H. halys and the tree species sampled was observed among years. Results are discussed in relation to the ecology and sampling optimization of T. japonicus.

2019 ◽  
Vol 112 (4) ◽  
pp. 1997-2000 ◽  
Author(s):  
N F Quinn ◽  
E J Talamas ◽  
T C Leskey ◽  
J C Bergh

Abstract Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest that has established in much of the United States. Adventive populations of an effective Asian egg parasitoid of H. halys, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), have been detected in several states, including Virginia, and its geographic range is expanding. Documenting changes in its distribution and abundance have thus become key research priorities. For these specific purposes, surveillance of T. japonicus over large geographic areas using sentinel H. halys egg masses may not be optimally efficient, and examination of alternative sampling tactics is warranted. In 2016, sentinel H. halys egg masses were deployed as vertical transects in the canopy of female Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) in Virginia. A brief follow-up study in 2016 using yellow sticky traps deployed in the same trees yielded captures of T. japonicus, leading to a comparison of vertical transects of sentinel eggs and yellow sticky traps in 2017. Both methods yielded T. japonicus detections only in the middle and upper tree canopies, whereas other known H. halys parasitoids were detected in the lower, middle, or upper canopies. Based on this information, a method for deploying yellow sticky traps in the middle canopy of H. halys host trees was assessed in 2017, yielding T. japonicus captures. A comparison of estimated time inputs revealed that traps were more efficient than sentinel eggs in this regard. Results are discussed in relation to the utility of each sampling method to address specific questions about the range expansion and ecology of T. japonicus.


Author(s):  
A. D. Chalfoun

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 877
Author(s):  
Rachel M. Durben ◽  
Faith M. Walker ◽  
Liza Holeski ◽  
Arthur R. Keith ◽  
Zsuzsi Kovacs ◽  
...  

The North American beaver (Castor canadensis Kuhl) and cottonwoods (Populus spp.) are foundation species, the interactions of which define a much larger community and affect a threatened riparian habitat type. Few studies have tested the effect of these interactions on plant chemistry and a diverse arthropod community. We experimentally examined the impact of beaver foraging on riparian communities by first investigating beaver food preferences for one cottonwood species, Fremont cottonwood (P. fremontii S. Watson), compared to other locally available woody species. We next examined the impact of beaver foraging on twig chemistry and arthropod communities in paired samples of felled and unfelled cottonwood species in northern Arizona (P. fremontii) and southwestern Colorado (narrowleaf cottonwood, P. angustifolia James, and Eastern cottonwood, P. deltoides W. Bartram ex Marshall). Four major patterns emerged: (1) In a cafeteria experiment, beavers chose P. fremontii six times more often than other woody native and exotic species. (2) With two cottonwood species, we found that the nitrogen and salicortin concentrations were up to 45% greater and lignin concentration 14% lower in the juvenile resprout growth of felled trees than the juvenile growth on unfelled trees (six of seven analyses were significant for P. fremontii and four of six were significant for P. angustifolia). (3) With two cottonwood species, arthropod community composition on juvenile branches differed significantly between felled and unfelled trees, with up to 38% greater species richness, 114% greater relative abundance and 1282% greater species diversity on felled trees (six of seven analyses with P. fremontii and four of six analyses with P. angustifolia were significant). The above findings indicate that the highest arthropod diversity is achieved in the heterogenous stands of mixed felled and unfelled trees than in stands of cottonwoods, where beavers are not present. These results also indicate that beaver herbivory changes the chemical composition in 10 out of 13 chemical traits in the juvenile growth of two of the three cottonwood species to potentially allow better defense against future beaver herbivory. (4) With P. deltoides, only one of five analyses in chemistry was significant, and none of the four arthropod community analyses were significant, suggesting that this species and its arthropod community responds differently to beaver. Potential reasons for these differences are unknown. Overall, our findings suggest that in addition to their impact on riparian vegetation, other mammals, birds, and aquatic organisms, beavers also may define the arthropod communities of two of three foundation tree species in these riparian ecosystems.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 840
Author(s):  
Barbara Bittau ◽  
Maria Luisa Dindo ◽  
Giovanni Burgio ◽  
Giuseppino Sabbatini-Peverieri ◽  
Kim Alan Hoelmer ◽  
...  

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6 °C (86.5%) compared to −24 °C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6 °C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16 °C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance.


2011 ◽  
Vol 40 (4) ◽  
pp. 873-879 ◽  
Author(s):  
Hamaseh Aliakbarpour ◽  
Che Salmah Md. Rawi

1989 ◽  
Vol 4 (2) ◽  
pp. 52-54 ◽  
Author(s):  
David L. Verbyla ◽  
Richard F. Fisher

Abstract Forest habitat types have been purported to be useful indicators of site quality. This is generally true for habitat types with different dominant tree species. However, few have studied the site indicator value of habitat types with the same dominant tree species. We measured site index (base age 25) from 172 randomly selected plots within the ponderosa pine (Pinus ponderosa) zone of the Dixie National Forest, Utah. The range of site index within any one habitat type was broad. Poor sites occurred on all five habitat types. However, the best sites occurred only on the Pinus ponderosa/Symphoricarpos oreophilus and Pinus ponderosa/Quercus gambelii habitat types. Therefore, habitat type may be useful in predicting the best sites, but only if other site information is used in addition to habitat type. West. J. Appl. For. 4(2):52-54, April 1989.


2020 ◽  
Vol 149 ◽  
pp. 104324 ◽  
Author(s):  
Sean M. Boyle ◽  
Donald C. Weber ◽  
Judith Hough-Goldstein ◽  
Kim A. Hoelmer

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