How do I update the list of a Realtime RecyclerView when I insert a record in SQLite

I have an activity with a ViewPager and within three fragments and from the third fragment I have a small form and below a recyclerview that contains the data I keep in the form above, what I try to do is that when I save a record the recyclerView it is updated in real time, but I have not managed it for weeks with this problem. I attach an image so you have an idea of what I say. link I'm using

This is the Fragment

public class TarifaFragment extends Fragment implements View.OnClickListener{

EditText edtTarifa;
TextView tvFecha;
ImageButton imgbtnFecha;
Button btnCrearTarifa;

// objeto helper para gestionar operaciones con la base de datos
DBHelper conn;

// Recycler para cargar la lista de registros almacenados en la base de datos
RecyclerView recyclerTarifas;
ArrayList<Tarifa> listaTarifas;
TarifaAdapter adapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_tarifa, container, false);

    // inicializar el bojeto conexion
    conn = new DBHelper(getActivity());
    listaTarifas = new ArrayList<>();

    imgbtnFecha = (ImageButton) rootView.findViewById(R.id.imgbtnFecha);
    imgbtnFecha.setOnClickListener(this);
    tvFecha = (TextView)rootView.findViewById(R.id.tvFechaTarifa);
    edtTarifa = (EditText)rootView.findViewById(R.id.edtTarifa);
    btnCrearTarifa = (Button)rootView.findViewById(R.id.btnCrearTarifa);
    btnCrearTarifa.setOnClickListener(this);
    recyclerTarifas = (RecyclerView)rootView.findViewById(R.id.recyclerTarifa);
    // setear el layout para el recyclerView
    recyclerTarifas.setLayoutManager(new LinearLayoutManager(getActivity()));

    ConsultarListaTarfias();
    adapter = new TarifaAdapter(listaTarifas);
    recyclerTarifas.setAdapter(adapter);

    return rootView;
}

private void ConsultarListaTarfias()
{
    SQLiteDatabase db = conn.getReadableDatabase();
    Tarifa tarifa = null;

    Cursor cursor = db.rawQuery("SELECT * FROM "+Utils.NOMBRE_TABLATARIFA+" ORDER BY tarifaId DESC",null);
    while(cursor.moveToNext())
    {
        tarifa = new Tarifa();
        tarifa.setId(cursor.getInt(0));
        tarifa.setTarifa(cursor.getString(1));
        tarifa.setFecha(cursor.getString(2));

        listaTarifas.add(tarifa);
    }
}

public void InsertarTarifa()
{
    SQLiteDatabase db = conn.getWritableDatabase();
    ContentValues values = new ContentValues();

    String tarifa = edtTarifa.getText().toString();
    String fechaTarifa = tvFecha.getText().toString();

    values.put(Utils.CAMPO_CANTIDADTARIFA,tarifa);
    values.put(Utils.CAMPO_FECHATARIFA,fechaTarifa);

    if(!(tarifa.equals("")) && !(fechaTarifa.equals("")) && !(fechaTarifa.equals("Fecha")))
    {
        long resultado = db.insert(Utils.NOMBRE_TABLATARIFA,Utils.CAMPO_TARIFAID,values);

        if(resultado != 0)
        {
            Log.i("Registro Creado",""+resultado);

            final SweetAlertDialog dialogo = new SweetAlertDialog(getActivity(),SweetAlertDialog.SUCCESS_TYPE);
                    dialogo.setTitleText("EXITO!")
                    .setContentText("REGISTRO CREADO CORRECTAMENTE")
                    .setConfirmText("CONTINUAR")
                    .setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
                        @Override
                        public void onClick(SweetAlertDialog sweetAlertDialog) {
                            dialogo.dismiss();
                        }
                    })
                    .show();
            tvFecha.setText("Fecha");
            edtTarifa.setText("");
        }
    }

    else
    {
        final SweetAlertDialog dialogo = new SweetAlertDialog(getActivity(),SweetAlertDialog.ERROR_TYPE);
        dialogo.setTitleText("ERROR!")
                .setContentText("TODOS LOS CAMPOS SON REQUERIDOS")
                .setConfirmText("CONTINUAR")
                .setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
                    @Override
                    public void onClick(SweetAlertDialog sweetAlertDialog) {
                        dialogo.dismiss();
                    }
                })
                .show();
    }
    db.close();
}

@Override
public void onClick(View v) {
    switch (v.getId())
    {
        case R.id.tvFechaTarifa:
            CrearDialogoFecha(v,getActivity(),getActivity().getFragmentManager());
            break;

        case R.id.imgbtnFecha:
            CrearDialogoFecha(v,getActivity(),getActivity().getFragmentManager());
            break;

        case R.id.btnCrearTarifa:
            InsertarTarifa();
            break;
    }
}

}

This is the Adapter code

public class TarifaAdapter extends RecyclerView.Adapter<TarifaAdapter.ViewHolderTarifa> {

ArrayList<Tarifa> listaTarifas;

public TarifaAdapter(ArrayList<Tarifa> listaTarifas)
{
    this.listaTarifas = listaTarifas;
}

@Override
public ViewHolderTarifa onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview_tarifas,null,false);
    return new ViewHolderTarifa(view);
}

@Override
public void onBindViewHolder(ViewHolderTarifa holder, int position) {
    Tarifa tarifa = this.listaTarifas.get(position);
    //tarifa.getMySpecialStatus();
    holder.tvTarifa.setText("Q."+listaTarifas.get(position).getTarifa());
    holder.tvFechaTarifa.setText(listaTarifas.get(position).getFecha());
}

@Override
public int getItemCount() {
    return listaTarifas.size();
}

public void update(ArrayList<Tarifa> modelList){
    this.listaTarifas.clear();
    for (Tarifa model: modelList) {
        this.listaTarifas.add(model);
    }
    notifyDataSetChanged();
}

public void replaceItem(ArrayList<Tarifa> lista)
{
    this.listaTarifas.clear();
        if(lista != null)
        {
            this.listaTarifas.clear();
            this.listaTarifas.addAll(lista);
        }
        else
        {
            this.listaTarifas = lista;
        }
        notifyDataSetChanged();
}

public class ViewHolderTarifa extends RecyclerView.ViewHolder {
    TextView tvTarifa, tvFechaTarifa;

    public ViewHolderTarifa(View itemView) {
        super(itemView);

        tvTarifa = (TextView)itemView.findViewById(R.id.tvTarifa);
        tvFechaTarifa = (TextView)itemView.findViewById(R.id.tvFechaTarifa);
    }
}

}