Revision of the Elusive Harvestmen Genus Discocyrtulus Roewer, 1927 (Opiliones: Laniatores: Gonyleptidae): Investigating the Presumed Northeastern Brazilian Discocyrtus-Like Relatives

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  Revision of the Elusive Harvestmen Genus Discocyrtulus Roewer, 1927 (Opiliones: Laniatores: Gonyleptidae): Investigating the Presumed Northeastern Brazilian Discocyrtus-Like Relatives ABSTRACT A maximum parsimony analysis based on morphological characters (23 taxa; 98 characters; 1951 scorings) was conducted to test the monophyly of Discocyrtulus Roewer, 1927, and to assess its phylogenetic relationships within Gonyleptidae. The results recover the species currently assigned to Discocyrtulus as phylogenetically distant from Pachylinae sensu stricto and nested instead within Discocyrtus sensu stricto +, forming a clade together with Discocyrtus moraesianus Mello-Leitão, 1923. Accordingly, Discocyrtulus is removed from Pachylinae Sørensen, 1884, and left without subfamilial assignment. As a result, Discocyrtulus now comprises Discocyrtulus crenulatus (Roewer, 1913) comb. nov. , Discocyrtulus marginalis Roewer, 1929, and Discocyrtulus moraesianus (Mello-Leitão, 1923) comb. ...

Harshing the Vibes: Behavioural Responses to Predation and Deterrent Vibrational Playback in Scolypopa Australis (Hemiptera: Ricaniidae)

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Harshing the Vibes: Behavioural Responses to Predation and Deterrent Vibrational Playback in Scolypopa Australis (Hemiptera: Ricaniidae)

ABSTRACT

The use of substrate borne vibrational playback to control insect pests is a rapidly growing line of research targeting many problematic species. Among the control approaches currently being tested, vibrational deterrent playbacks that aim to prevent feeding and to drive pests away from the target area are comparatively under-explored. In experiments involving an introduced pest of New Zealand orchards, the passion vine hopper (PVH, Scolypopa australis), we investigated PVH anti-predator behaviour and alarm call responses and the potential use of alarm calls as vibration-based deterrent stimuli. We used laser-Doppler vibrometry and video recordings to assess the vibrational and behavioural responses of PVH to the presence of a predator (Maratus griseus jumping spider), serendipitously discovering a new female call possibly involved in mate rejection. In our tests, we did not find evidence of any vibrational alarm calls in PVH, which showed a significantly reduced rate of general vibration-based signalling and reduced propensity to call overall compared to control recordings. Instead, PVH responded to a predator threat with a rapid jumping escape response in 87.5% of attacks. We also tested the efficacy of three deterrent vibrational playbacks on driving PVH movement away from a source point, finding that a broad-band white noise playback spanning 301–688 Hz induced significant movement away from the playback source compared with silent controls. As preliminary proof of concept, we hope these results will assist in developing successful vibrational deterrence for PVH.

MacDougall, M. S., Nelson, X. J., & Stringer, L. D. Harshing the Vibes: Behavioural Responses to Predation and Deterrent Vibrational Playback in Scolypopa Australis (Hemiptera: Ricaniidae). Journal of Applied Entomology. https://doi.org/10.1111/jen.13412