monarch-esa-petition-final_61585

As explained elsewhere in this petition (see Threats- Overutilization), upon listing the monarch
butterfly, petitioners request that the Service implement measures that promote the continuance
of activities that benefit monarch conservation such as citizen tagging and monitoring, scientific
research, classroom rearing, education, and other activities that are beneficial for monarch
conservation (see Appendix B).
Petitioners also recognize the valuable role that the native seed industry plays, and will continue
to play, in propagating milkweed seed and plants to facilitate monarch habitat recovery. Take of
monarch caterpillars, eggs, and pupae routinely occurs as part of normal milkweed production
activities. Should the Fish and Wildlife Service list the monarch butterfly as a threatened species
under the ESA, we strongly recommend that the agency recognize the valuable role that
milkweed producers will play in monarch habitat recovery and streamline the permitting process
for incidental take permits for milkweed producers, so that the listing will not hinder milkweed
production efforts.
FACTOR FIVE: OTHER FACTORS AFFECTING THE MONARCH’S CONTINUED
EXISTENCE
Several other factors also threaten the monarch butterfly including increased pesticide use, global
climate change, severe weather events, the spread of invasive species, and mortality at solar
energy facilities.
Pesticides
Monarchs face threats at all life stages from pesticides used throughout their range. The term
“pesticides” encompasses herbicides, insecticides, fungicides, nematocides, rodenticides, and all
of the other biocides. Impacts of pesticides on monarchs can occur from indirect and direct
effects, and from lethal and sub-lethal injuries (e.g., Kohler and Triegskorn 2013).
Monarchs are harmed from widespread loss and degradation of habitat as a result of herbicide
use that kills host milkweeds and alters nectar plant quality and abundance (e.g., Pleasants and
Oberhauser 2012). As discussed in detail in the Modification and Curtailment of Habitat or
Range section of this petition, use of glyphosate on genetically engineered, Roundup Ready corn
and soybeans has been identified as the major cause of the precipitous drop in monarch numbers
over the last 15 years, and this threat to the population continues as new areas are converted to
corn and soybeans for biofuels, in addition to upcoming threats from the imminent introduction
of new genetically engineered, herbicide-resistant crops (see discussion in Loss and Curtailment
of Habitat and Range section of this petition).
Larvae and adults, and under some circumstances, eggs and pupae, of monarch butterflies can be
killed or impaired by exposure to pesticides via contact from overspray, drift of spray particles
and vapor, runoff, dust, and through ingestion of pesticide-contaminated food and water.
Pesticides also have “inert” ingredients, many of which are also toxic to butterflies (Stark et al.
2012).
Monarch ESA Petition 89