this topic is about weevil, there are heaps of different sorts in the species so we will generalise it a little bit. so we will go with the vine weevil a common pest in the garden that once established can be quite hard to eradicate as they have a nocturnal habit and the grub is a ground dweller. to go along with that they dont seem to have many natural predators like some other pests.
the adult vine weevil are all female reproducing by reproducing by parthogenesis which means they dont need a mate, the are flightless, but are extremely good walkers, if one is spotted place a white piece of material under the leaf as any disturbance they will drop to the ground and are quite hard to find.
the presence of vine weevil can be identified by semi circular notches eaten from the edge of the leave in, mostly on evergreen shrubs which can include but most definately not limited to azalea, camellia and rhododendron etc.
this damage to the leave is not fatal but obviously unsightly, it is also a good indication that there is most likely eggs in the potting medium that will end up hatching in autumn.
the major damage these grubs create is under the soil were they will chew through roots ravenously. this will quickly kill a tree in no time if the infestation is severe especially in potted culture.
first signs of the presences of the grubs are yellowing leaves, poor growth and wilting that isnt responding to watering. generally by this time it can be to late if the infestation is severe, rescue may be possible by obviously bare rooting and removing the grubs and eggs with a pressure spray of water, then repotted and extremely good after care.
control and iradication
there are a few methods of control and iradication in contact, biological and physical. biologically they have a natural predator in the centipede which eats both eggs and larvae, it is also possible to introduce nematodes, these are a biological control that is introduced into the soil, the nematode Steinernema kraussei is a microscopic eel worm that will kill the larvae, it is also capable of tolerating tempratures down to 5 degrees celcius. these are best used when the larvae are hatching between august and november, and then another application about three months later when the larvae will be active with the warmth, this will hopefully break the weevils life cycle.
simple traps can be made to catch the elusive adult as they are nocturnal, simply roll a piece of corrugated card board up as this will give the adult weevil a place to hide in during the day, daily destruction of the cardboard will give best results.
contact insecticides will work but being such an elusive pest that is nocturnal it can be hard unless you want to sit outside with a torch and then spray them when spotted.
if you have any experiences or information to add, or questions for discussion please feel free to do so here as i am trying to build a data base on pest and disease for beginners and experienced alike
jamie
information written by me.
pictures sourced from various sites.
taking the top half of trees of since 2005! 
