The Butterflies of Iowa

Problems for Future Research

Problems for Future Research uch work remains to be done on all aspects of the butterflies of Iowa. Reading through the species accounts will give you an excellent idea of appropriate problems in need of solution. Not a single species is completely known in terms of its total biology and natural history. In this chapter, we have listed some questions under general headings that could result in significant contributions not only within the state but also to the science of lepidopterology. These issues are generally restricted to questions that may be answered by field and natural history observations. Laboratory and sophisticated problems which require expensive scientific apparatus are not included (though they are very important ), simply because the general collector and naturalist may not have such specialized equipment. Taxonomic Problems Even in an area as well known as Iowa, some taxonomic problems remain which must be solved before we can truly say that we understand the systematic positions of our butterflies . Most of these concern the less-studied groups, the Lycaenidae and Hesperiidae, simply because few have taken the time and effort to study the relationships between closely related taxa. Perhaps the most puzzling taxonomic problem is in the “persius group” of the Duskywings . Many species show superficial resemblances in wing characters, and it is often difficult to identify a specimen correctly by matching it with photographs of determined species. Specimens from Iowa include both the Wild Indigo Duskywing (Erynnis baptisiae ) and the Columbine Duskywing (E. lucilius). The larval food plants of both—false indigo, a prairie plant, and columbine, a forest plant—occur commonly in Iowa, especially in the northeastern part of the state. The problem is that the two Duskywings often occur together. Some specimens from that area can easily be assigned to each type, but as many as a third show characteristics of both. Could each be reared on the other’s food plant? What would the adults look like? Genetic studies will probably solve this issue or create more questions. M 34 | a n i n t r o d u c t i o n t o i o wa b u t t e r f l i e s The Persius Duskywing (Erynnis persius) has been taken both east and (more commonly ) west of Iowa. Several specimens from within our borders have been recorded as this species; however, most also have proven to be E. baptisiae upon examination of the genitalia. Still, there is no reason to exclude persius, because its lupine food plant occurs in Iowa. Series of bred specimens carefully documented in regard to food plants and other habitat data would go far toward determining which “persius group” members occur in Iowa. As with all taxonomic problems, definitive studies must include specimens from throughout the range of the species; they cannot be solved on the basis of Iowa populations alone. Study of the Satyridae involves some pressing problems. What is the taxonomic and biological relationship between diverse populations of Satyrodes eurydice eurydice and S. eurydice fumosa? Are the differences that we see in Iowa and Minnesota due to genetics or to environment? The relationship between S. eurydice and S. appalachia leeuwi also needs study. Secondarily, does the last-named butterfly occur in Iowa? Similarly, the extreme variation of Common Wood-nymphs (Cercyonis pegala) requires much study at the population level to ascertain whether proper taxonomic discrimination has been made. Life-history Problems It is safe to say that we need to know much more about the life cycles and life history of all our butterflies. Not only do we need detailed morphological studies on each stage, but ecological and biological data are also lacking for most species. In particular, do we need intensive studies of single populations? Single populations exhibit many features not shown by the individuals in them. For instance, they have birth rates and death rates, sex ratios, and a host of statistical parameters that involve the population as a whole. The patterns of variability of these traits, both within and between populations, document evolutionary pathways and help explain why complex life cycles have developed. Also, comparative data might help explain why there is diversity not only among individuals within the same population but among the different species in the same area. At the base of these variables is the factor of adaptability. After the purely descriptive phase of recording life-cycle data, including morphological, physiological, behavioral, and genetic features, we should study how they might better adapt the...