Heterorhabditis amazonensis for biological control of fungus gnats Bradysia difformis in Daisy gerberas

Fungus gnats (FG) have been reported in Venezuelan greenhouses recently. Bradysia difformis Frey (Diptera, Mycetophilidae) was found attacking Daisy gerbera plants [Gerbera sp. L. (Asterales: Asteraceae)] and many other crops in the country causing serious damages. Heterorhabditis amazonensis Andalo et al. (Rhabditida: Heterorhabditidae), was used to assess the mortality of larvae and adults of FG, number of invader nematodes per larvae and to compare the mortality of FG using nematodes and/or ciromazine under laboratory conditions. In a commercial flower farm, different doses of these nematodes were applied for eight weeks to control FG. The results showed 95% of mortality of the B. difformis larvae under laboratory conditions and performed better in the field when 50,000 nematodes were applied in every pot as a base dose to initiate a control programme. According to our results, H. amazonensis has the potential to become a regular organism for controlling fungus gnat larvae in tropical greenhouses.