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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #429682
Research Project: Development and Implementation of Biological Control Programs for Natural Area Weeds in the Southeastern United States

Location: Invasive Plant Research Laboratory

Title: A non-destructive method for sex identification in a tubuliferan thrips

Author
item Foster, Brianna
item Dray Jr, Forrest
item Halbritter, Dale

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Accurately determining the sex of thrips while they are still alive is nearly impossible in some species and this poses a problem for conducting experiments in which the ratios of females to males affects the outcome. Previously, to correctly determine the sex of these species, thrips needed to be killed and have their exoskeletons partially dissolved and examined under a microscope. This was done after experiments were completed to confirm whether the live estimates of sex ratios at setup were accurate. Here, we devised an accurate method to determine the sex of the thrips species Pseudophilothrips ichini while the thrips are alive. Thrips were temporarily immobilized on a chilled metal plate and their undersides were examined using a digital microscope with imagery displayed on a laptop screen. This allowed us to determine the sexes without harming them, thereby ensuring accurate sex ratios for setting up experiments. We confirmed this method was accurate by using the microscope method to verify sexes after the experiment concluded.

Technical Abstract: Accurate sex identification of the biological control agent Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae) is a useful tool for colony management and experimental applications, particularly in this haplodiploid species where sex ratios are prone to fluctuation. Yet destructive methods of sex identification limits specimen usage prompting the need for a sex identification method for live thrips. In this study we present a new live sexing protocol for P. ichini involving temporary immobilization on a chilled stage and examination via a digital microscope. We compared the new protocol to the existing destructive sex identification method using an individual-level comparison and a population-level sex ratio comparison. Despite susceptibility to male-biased error, the live-sexing protocol represents a practical alternative to the destructive method of sex identification for P. ichini, and this new method offers promise for adaptation to other species of thrips.