Page 22 - Griffin Gazette Q4 2017
P. 22

By Rick Yates,    fatal. Equally problematic, adult fungus  larvae are not directly damaging to plants.
                          GGSPro Technical   gnats and shoreflies are known to spread   Habitat Management
                          Services Manager  root and crown rot diseases in their travels.  Habitat modification and sanitation is the
                          Fungus  gnats  and  Proper identification of fungus gnats and  first line of defense against fungus gnats
                          shoreflies  are  a shoreflies is important for control; some  and shoreflies. Fungus gnats lay their eggs
                          nuisance,  there's  differences in chemical and biological control  in cracks and crevices in the soil media. In
                          no  debating that.  options need to be accounted for. Adult  greenhouses this most often occurs on the
                          They make insect- fungus gnats are dark, delicate-looking flies,  surface  of  the  soil  but  can  occur  in  drain
                          leery   customers  similar in appearance to mosquitoes, with  holes  in  the  sides  and  bottom  of  pots  as
                          uncomfortable  and  slender legs and long segmented antennae.  well. Constantly moist soil media, and the
                          they  leave  their  Their wings are clear with a distinctive “Y”  algae it encourages, make a suitable habitat
        calling cards (fecal matter) on the foliage  shaped vein. Fungus gnat larvae have a  for fungus gnat larvae. Shoreflies live in
        of otherwise beautiful plant material. More  shiny black head and an elongated, whitish- consistently damp areas with abundant
        than one grower has inhaled these tiny  to-clear, legless body. Shorefly adults more  algae. The larval stage feeds on algae and
        flies while hard at work in the greenhouse.  closely resemble miniature house flies.  the pupal stage is semi-aquatic, partially
        Yuck…. That's not where the list of offenses  Compared  to  fungus  gnats, shoreflies  are  submerged in water.
        ends. Fungus gnats are a major pest of  stronger fliers and have shorter legs and   Moisture management, including improved
        greenhouse crops, but don’t often get  antennae. Shoreflies have  five distinctive   drainage and taking steps to limit algae,
        the attention they deserve. Direct plant  clear to white spots on their wings. Shorefly   can pay dividends in terms of creating a
        damage occurs through larvae feeding  larvae are also clear to white, but lack a   less favorable habitat for pest development.
        on roots, in stems, and occasionally on  distinct head capsule. The pupal stage is   Power washing and use of approved
        foliage, especially leaves in contact with the  dark brown and has an interesting “fork”   cleaners, such as Strip-it Pro, can be used
        growing media. For seedlings and cuttings  structure on one end.  While shorefly adults   to remove organic matter from surfaces
        in propagation, the damage is sometimes  are able to spread plant pathogens, the
                                                                                between crops. After a thorough cleaning,

         Table 1:
         Product           Active            MOA        Fungus      Shoreflies  Comments
         Name(s)           Ingredient                    Gnats
         Adept             Diflubenzuron      15           X            X      IGR, sprench, 21 days of control
         Citation          Cyromazine         17           X            X      IGR, sprench, vegetable transplants

         Distance          Pyriproxyfen       7C           X            X      IGR, sprench, soil surface spray, 21 days,
         Fulcrum                                                               Distance- fruiting vegetables
         Gnatrol WDG       BT- israelensis    11A          X                   Make 3 applications 1 wk apart
         Pylon             Chlorfenapyr       13           X                   Soil surface spray only, 7-14 days
         Safari            Dinotefuran        4A           X            X      Soil drench, vegetable transplants

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