Arthropod Predator Occurrence and Performance of Geocoris uliginosus (Say) on Pest-Resistant and Susceptible Turfgrasses
Abstract Interactions between host plant resistance and biological control may be advantageous or disadvantageous for pest management. Turfgrass cultivars have rarely been tested for extrinsic resistance characteristics such as occurrence and performance of beneficial arthropods on plants with resistance to known turf pests. Among six turfgrass cultivars tested, the bigeyed bug, Geocoris uliginosus (Say) nymphs varied in ability to reduce numbers of fall armyworm, Spodoptera frugiperda (J. E. Smith), larvae. The six grasses tested (Sea Isle 1 and 561-79 seashore paspalum, Paspalum vaginatum Swartz; TifSport and TifEagle bermudagrass, Cynodon dactylon [L.] x C. transvaalensis [Burtt-Davy]; and Cavalier and Palisades zoysiagrass Zoysia japonica von Steudel and Z. matrella [L.] Merrill) represented a range in resistance to S. frugiperda. In the laboratory, the greatest reduction in S. frugiperda larvae by a low density of G. uliginosus occurred on the resistant Cavalier zoysiagrass. A 7-fold difference in weight of 10-d-old larvae between those feeding on susceptible versus resistant grasses suggested that on the resistant grass larvae remained for a longer period in a size range susceptible to predation. Results of laboratory studies were not directly translated to the field, in which a diverse predatory arthropod community varied in composition depending on turfgras cultivar. In the field, the greatest reduction in S. frugiperda larvae by a low density of G. uliginosus occurred on Sea Isle 1 and 561-79 seashore paspalum grass. In the field, vacuum samples indicated that predaceous Heteroptera were most abundant in paspalum grasses and bermudagrasses, while Carabidae, Staphylinidae, and Araneae were more common in zoysiagrasses. In contrast, pitfall traps indicated that carabids were more common in bermudagrasses, Araneae and Staphylinids were similar among grass taxa, and Cicindellidae were most common in paspalum grasses and bermudagrasses. Predation was never significantly decreased on resistant turfgrass cultivars in any of the experiments described in this work, indicating no negative tritrophic interactions.
Functional Response of the Tiger Beetle Megacephala carolina carolina (Coleoptera: Carabidae) on Twolined Spittlebug (Hemiptera: Cercopidae) and Fall Armyworm (Lepidoptera: Noctuidae)
Abstract The functional response of the tiger beetle Megacephala carolina carolina L. (Coleoptera: Carabidae) was determined on adult twolined spittlebug, Prosapia bicincta (Say) (Hemiptera: Cercopidae), and fourth instars of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), in single-prey and two-prey systems. In the laboratory, M. carolina carolina demonstrated a type II functional response for P. bicincta and S. frugiperda in both single- and two-prey systems. Search efficiency of M. carolina declined for both prey as the initial number of prey increased. Of the total prey consumed, M. carolina carolina killed significantly more S. frugiperda than P. bicincta in the single-prey system (8.0 and 4.5, respectively) and the two-prey system (5.0 and 2.0, respectively). Estimates of attack coefficient, a, were not significantly different for P. bicincta and S. frugiperda in the single-prey (0.07 and 0.02) and two-prey systems (0.04 and 0.06), respectively. The handling time, Th, was significantly greater for P. bicincta (5.02 and 10.64 h) than for S. frugiperda (2.66 and 4.41 h) in single- and two-prey systems, respectively. Estimations of attack coefficient and handling time in the single-prey system were used to predict prey preference of M. carolina carolina. No strong prey switching response was observed. M. carolina carolina showed no preference for either prey. However, in the presence of S. frugiperda, the functional response of the predator for P. bicincta was reduced. M. carolina carolina is a potential predator of one or more turfgrass pests and should be considered in conservation efforts.
History, criminology and the ‘use’ of the past
This article considers why, despite an apparent congruence of subject matter and methodologies, the disciplines of sociological criminology and criminal justice history are not more closely aligned. It contends that intellectual traffic between the two fields is not usually limited by institutional barriers, nor is it a legacy of the disciplinary antipathy which existed between history and sociology in Britain during the mid-twentieth century. Rather, it is due to the different ‘purposes’ with which sociological criminologists and criminal justice historians imbue their work and to the differing disciplinary perceptions of the relationship between the past, present and future which result from this. These different ‘purposes’ are traced via a consideration of the paths of development of the two disciplines from the 1940s. The article concludes by proposing an arena for future collaboration between criminal justice historians and sociological criminologists.