Parasitoids of \u3ci\u3eChionaspis Pinifoliae\u3c/i\u3e (Homoptera: Diaspididae) in Iowa

Three parasitoids (Hymenoptera: Encyrtidae: Aphelininae), Aphytis diaspidis, Coccobius varicornis, and Marietta pulchella, were recovered from field collections of the pine needle scale, Chionaspis pinifoliae, on Pinus sylvestris in central Iowa. Parasitoid mean time (± SEM) to emergence from overwintered scale mummies occurred at 46.6 (4.6) and 23.9 (1.3) days for C. varicornis and M. pulchella, respectively, using a 16L:8D photoperiod and a corresponding temperature regime of 22°C and 18°C. Growing-season parasitism level on field-collected female C. pinifoliae was 15%; parasitoid community composition was 86% A. diaspidis, 12% C. varicornis, and 2% M. pulchella

Phenology and Infestation Patterns of the Cottonwood Twig Borer (Lepidoptera: Tortricidae) in Iowa

Cottonwood twig borer, Gypsonoma haimbachiana (Lepidoptera: Totricidae), phenology and infestation patterns on Populus spp. were examined over a 2-year period in Iowa. Weekly sampling of infested shoots during the host growing season verified the existence of five instars. Head capsule size increased nonlinearly from the first to the fifth instar and corresponded to a concomitant geometric increase in the volume of larval feeding galleries. The sampling indicated that the cottonwood twig borer had two generations per year in Iowa. Corresponding with the two generations, two peaks of larval abundance were observed; one in the second week of June and the other in the first week of August. Greater volume of feeding galleries occurred in the early season generation compared with the late season generation. Sampling of infested shoots revealed that more than 80% of infested terminals contained only one active attack (freshly bored hole in tree terminal with frass present); more than 88% of feeding galleries contained only one larva; and more than 80% of the larvae were found in the first active attack nearest the terminal apex. These data were compared with results published on the phenology and attack patterns of the cottonwood twig borer in the southern United States

Technology benefits and ground test facilities for high-speed civil transport development

The advanced technology base necessary for successful twenty-first century High-Speed Civil Transport (HSCT) aircraft will require extensive ground testing in aerodynamics, propulsion, acoustics, structures, materials, and other disciplines. This paper analyzes the benefits of advanced technology application to HSCT concepts, addresses the adequacy of existing groundbased test facilities, and explores the need for new facilities required to support HSCT development. A substantial amount of HSCT-related ground testing can be accomplished in existing facilities. The HSCT development effort could also benefit significantly from some new facilities initially conceived for testing in other aeronautical research areas. A new structures testing facility is identified as critically needed to insure timely technology maturation

Maternal Linguistic Input to Toddlers with Slow Expressive Language Development

Maternal speech styles to children between 20 and 34 months of age who were slow to acquire expressive language were compared to those of mothers with normally speaking toddlers. Aspects of the mothers\u27 speech examined included use of various sentence types (declaratives, negative, questions, etc.); the mother\u27s lexical contingency with regard to the child\u27s utterance; mother\u27s use of pragmatic functions such as requests, comments, and conversational devices; and the mother\u27s use of topic management. Results revealed that mothers of toddlers with slow language development are different from mothers of normal speakers only in their frequency of use of lexical contingency devices, specifically, expansion and extension. However, the proportion of expansions and extensions relative to the number of child utterances is not different, indicating that when late talkers give their mothers something to expand, the mothers do so, but that the late talkers do not give their mothers as much speech to work with as do the normal toddlers. Implications of these findings for parent training are discussed