Roadside Surveys

• The majority of the milkweed (asperula) was found in the Edward's Plateau and Cross-timbers.
• The lowest number of milkweed was in the South Texas Plains.
• We are evaluating the relationship between abundance and precipitation.

Site-Specific Surveys

• Compared to roadside locations, there is more milkweed in the site specific locations.

Seed Viability and Germination

• Viability is not an issue.
• Germination is not an issue for most milkweed species.
• Most milkweed species have the photosynthetic characteristics of heliophytes.

Light Level Responses

• Significant differences in transpiration rates were at the highest and lowest light intensities tested.
• Significant differences in stomatal conductance were at the highest and lowest light intensities tested.

Patch Size

• There is not an optimum spacing or density of milkweed for monarch reproductive success.

Nectar Density

• Only under extremely high densities of nectar plants do you see increases in monarch success.
• Tropical milkweed will increase monarch success in the spring.

Best Management Practices

• Disturbance seems to increase the number of milkweed stems, but the effect is short-term.

Fire Ant Mounds

• All larval stages of monarchs are preyed upon by red imported fire ants.