The distribution of two strains of Leptoglossus zonatus  (Hemiptera: Coreidae): Is this species invasive?

The leaffooted bug, Leptoglossus zonatus (Hemiptera: Coreidae), has a broad distribution in the Western Hemisphere. This insect feeds on many host plants, including economically important crops such as maize and almonds. In California, this species is considered an occasional pest on almonds. In recent years, L. zonatus has been more abundant. Previous collections of L. zonatus from California found the presence of two genetically divergent strains (2%). One strain was found throughout the Central Valley and another occurred at the Southern region of the Central Valley. The strain which occurred primarily at the southern region of the valley matched a haplotype from Brazil. The purpose of this study was to determine the distribution of the two strains of L. zonatus, and consider whether California might have an invasive strain of L. zonatus. L. zonatus specimens were obtained from the national insect collection at UNAM in Mexico City. Specimens were used to sequence mitocondrial DNA COI. Sequences were compared with existing sequences from California and Brasil. A maximum likelihood tree was produced. The number of haplotypes, haplotype diversity and other measures of genetic diversity were determined for each of the three groups, and for insects which comprised strain 1 and 2 of L. zonatus. A map of the distribution of the two strains was produced. Genetic diversity was considered when determining whether or not this species may be invasive in California. Results will be discussed.