Human-biting behavior of Leptoconops irritans (Diptera: Ceratopogonidae) in a touristic area of the Balearic Islands (Spain)

Abstract

Biting gnats of genus Leptoconops Skuse 1889 are small blood-feeding insects recognized as highly irritating diurnal pests in certain regions around the globe. In Europe, their presence is poorly documented, except in France and Italy. Following reports of human discomfort in a touristic area of Menorca, Balearic Islands (Spain), a small-scale study was conducted to identify the biting species and assess their preferred biting sites using a human-landing assay along a habitat gradient in a coastal dune area. Leptoconops irritans (Noé, 1905) was identified based on morphological features and DNA barcoding. This species reached high densities (average rates of 3.3 landings/min), particularly near coastal dune vegetation. No statistically significant differences were found among the four main body site landings of L. irritans (F3,6.023 = 1.80, p = 0.250): head (n = 91, 53.8%), lower extremities (n = 39, 23.1%), upper extremities (n = 37, 21.8%) and other covered areas (n = 2, 0.2%). Landing preferences varied among the three volunteers and bites progressed differently. This study represents the second documented case of Leptoconops gnats causing human discomfort in Spain. We hope this research stimulates further interest in this understudied genus, which has been largely overlooked across much of Europe.