ants and Hemorrhage

Reflex bleeding is an effective defensive mechanism against predators. When attacked, some insects emit hemolymph, which coagulates, quickly entangling their aggressor. Bleeding occurs at weak intersegmental membranes or through dedicated organs, which can be associated or not with glandular cells. Here, we describe the behavior and morphological structures involved in reflex bleeding in the larvae of the ladybird, Diomus thoracicus, which are intranidal parasites of the ant Wasmannia auropunctata. The larvae are tolerated by the ants thanks to odor mimicry, but some rare aggressive ant behaviors were observed that trigger reflex bleeding both at a pair of thoracic tubercles and a pair of posterodorsal abdominal humps. No glandular structure was found in association with these emission points, which suggests that the material emitted was hemolymph only. A 3D reconstruction suggested that reflex bleeding seems to be controlled by muscles whose contraction increases the internal hydrostatic pressure and pushes the hemolymph into a funnel-like structure with an opening to the outside. In D. thoracicus, the morphological structures involved in reflex bleeding are among the most complex and prominent described to date.

Topics: Adaptation, Physiological; Animals; Ants; Coleoptera; Hemolymph; Hemorrhage; Larva

Topics: Alcoholic Intoxication; Animals; Ants; Autopsy; Bites and Stings; Cause of Death; Fatal Outcome; Feeding Behavior; Hemorrhage; Humans; Male; Middle Aged; Postmortem Changes

We describe a case of Vibrio fluvialis hemorrhagic cellulitis and cerebritis following multiple fire-ant stings and wading in brackish water. A high index of suspicion is required for diagnosis of this specific pathogen and concordant infection. This is, to our knowledge, the first report of this type of wound infection.

Topics: Animals; Ants; Bites and Stings; Cellulitis; Fatal Outcome; Hemorrhage; Humans; Male; Meningitis, Bacterial; Middle Aged; Vibrio; Vibrio Infections; Water Microbiology