Interpretation of gypsy moth frontal advance using meteorology in a conditional algorithm.

Area of Science:

• Ecology
• Invasive Species Biology
• Atmospheric Science

Background:

• The gypsy moth (Lymantria dispar) is an invasive species in North America, spreading through local growth and long-distance jumps.
• Anthropogenic movement and short-distance atmospheric transport are known spread mechanisms, but empirical data suggest alternative long-range dispersal methods.

Purpose of the Study:

• To investigate the potential role of atmospheric transport events in the long-range dispersal of the gypsy moth across Lake Michigan.
• To explain the simultaneous appearance of new gypsy moth populations on the western shore of Lake Michigan in the mid- to late-1990s.

Main Methods:

• A synoptic climatology model was developed and parameterized.
• Population dynamics data from 1996 to 2007 were integrated with the climatology model.
• The model was used to assess the association between atmospheric transport events and gypsy moth population spread.

Main Results:

• Vigorous cyclones can generate strong easterly winds capable of transporting gypsy moth early instars across Lake Michigan.
• A correlation was found between specific atmospheric transport events and the spread of gypsy moth populations.
• The model demonstrated the potential for these storms to explain the observed spread across Lake Michigan.

Conclusions:

• Atmospheric transport events, particularly those associated with strong cyclonic winds, play a significant role in the invasion dynamics of the gypsy moth.
• This mechanism provides a plausible explanation for the rapid, long-range dispersal of gypsy moths across significant geographical barriers like Lake Michigan.
• The findings serve as a model for understanding long-range dispersal mechanisms in other invasive species.