Plant-feeding phlebotomine sand flies, vectors of leishmaniasis, prefer <i>Cannabis sativa</i>

Abstract

Blood-sucking phlebotomine sand flies (Diptera: Psychodidae) transmit leishmaniasis as well as arboviral diseases and bartonellosis. Sand fly females become infected with <i>Leishmania</i> parasites and transmit them while imbibing vertebrates' blood, required as a source of protein for maturation of eggs. In addition, both females and males consume plant-derived sugar meals as a source of energy. Plant meals may comprise sugary solutions such as nectar or honeydew (secreted by plant-sucking homopteran insects), as well as phloem sap that sand flies obtain by piercing leaves and stems with their needle-like mouthparts. Hence, the structure of plant communities can influence the distribution and epidemiology of leishmaniasis. We designed a next-generation sequencing (NGS)-based assay for determining the source of sand fly plant meals, based upon the chloroplast DNA gene ribulose bisphosphate carboxylase large chain (<i>rbcL</i>). Here, we report on the predilection of several sand fly species, vectors of leishmaniasis in different parts of the world, for feeding on <i>Cannabis sativa</i> We infer this preference based on the substantial percentage of sand flies that had fed on <i>C. sativa</i> plants despite the apparent "absence" of these plants from most of the field sites. We discuss the conceivable implications of the affinity of sand flies for <i>C. sativa</i> on their vectorial capacity for <i>Leishmania</i> and the putative exploitation of their attraction to <i>C. sativa</i> for the control of sand fly-borne diseases.