Project description:Although the use of airborne molecules as infochemicals is common in terrestrial plants, it has not been shown to occur in an ecologically relevant context in marine seaweeds. Like terrestrial plants, intertidal plants spend part of their lives emersed at low tide and release volatile organic compounds (VOCs) into the air when they are grazed or physiologically stressed. We hypothesized seaweeds could use airborne VOCs as infochemicals and respond to them by upregulating a keystone defensive metabolite, dimethylsulfoniopropionate (DMSP). We conducted laboratory and field experiments in which Ulva fenestrata was exposed to airborne dimethyl sulfide (DMS), a volatile antiherbivore and antioxidant metabolite released when the seaweed is grazed or physiologically stressed. In the laboratory, U. fenestrata exposed to DMS had 43-48% higher DMSP concentrations, relative to controls, 6-9 days after exposure. In the field, U. fenestrata 1 m downwind of DMS emitters had 19% higher DMSP concentrations than upwind seaweeds after 11 days. To our knowledge, this is the first demonstration of a marine plant using an airborne molecule released when damaged to elicit defensive responses. Our study suggests that the ability to detect airborne compounds has evolved multiple times or before the divergence of terrestrial plants and green algae.
Project description:Meliponiculture, the keeping of domesticated stingless bees such as Geniotrigona thoracica (Smith, 1857) (Hymenoptera: Apidae), is an increasingly popular agricultural industry in Malaysia. This study reports the soldier fly (Diptera: Stratiomyidae) species of the genus Hermetia colonizing stingless bee colonies in Malaysia. The larvae were reared in the laboratory to the adult stage and identified through molecular and morphological approaches. Hermetia illucens (Linnaeus, 1758) and Hermetia fenestrata de Meijere, 1904 (Diptera: Stratiomyidae) were identified from the sample provided. Earlier records of stratiomyids in stingless bee nests were misidentified as H. illucens. This paper represents the first identified record of H. fenestrata colonizing a "spoiled" stingless bee colony. In addition, adult and larval morphological differences between both species and the roles of both species in bee nest decomposition are discussed.
