The life system of the yellow-headed fireworm, Acleris minuta (Robinson) (Lepidoptera: Tortricidae)

A resident population of the yellow-headed fireworm, Acleris minuta (Robinson) (Lepidoptera: Tortricidae), is established in the commercial nurseries of southwestern Iowa. This species sporadically reaches pest status causing considerable damage to rosaceous and ericaceous plantings;A conceptual life system model has been constructed to explain the bionomics of A. minuta populations. The conceptual model consists of an ovipositional subsystem, a developmental subsystem for larval instars 1-4, a developmental subsystem for larval instars 5, 6, & 7 under a summer and winter color morph scheme, and an overwintering subsystem;Acleris minuta is a multivoltine pest with 4 discrete generations in southwestern Iowa. The adult moths are seasonally dimorphic. Adults from the first 3 generations emerge as orange moths, while adults from the fourth generation emerge as gray moths. Orange moths are capable of mating on day 1 post emergence between the hours of 0500 - 0800 CDST. Gray moths which emerge in the fall are not capable of mating even if environmental conditions are favorable. Apparently, both males and females overwinter and mate in the spring;Larval development proceeds through 5 stadia, 6 stadia, or 7 stadia. Reduced growth rates caused by nutrient deficiencies and other adverse environmental conditions increase the frequencies of supernumerary molts. The 6 and 7 instar modes of development are more prevalent during the fourth generation;Laboratory and ecological life tables have been constructed. Ten species of parasitoids caused significant mortality during 1977 and 1978

Biological Evaluation of Tree Survivorship within the Lowman Fire Boundary, 1989-1993

In 1989, the Lowman fire burned 47,600 acres in the South Fork Payette River drainage near the town of Lowman, Idaho. Impact plots were installed to monitor tree survivorship and causes of mortality. Eighty two percent of the ponderosa pine and 52 percent of the Douglas-fir monitored in this study survived the fire. Trees which died from fire had an average crown scorch of 74 percent and trees which died from beetles had an average crown scorch of 48 percent. The data set compiled during this study was used to validate a probability of mortality equation developed by Reinhardt and Ryan (1988). This equation accurately classified trees as dead or alive 83 percent of the time. Marking guidelines for both Douglas-fir and ponderosa pine based upon DBH and percentage of the crown volume scorched could be developed using this equation

Instar development of the Douglas-fir tussock moth in relation to field temperatures /

"July 1993."Shipping list no. 94-0274-M.Distributed to depository libraries in microfiche.Includes bibliographical references (p. 4)Mode of access: Internet