Abstract of Block 50 City of Holland

An abstract of Block 50, City of Holland Mich SE44 of Sec. 29… .https://digitalcommons.hope.edu/vrp_1840s/1275/thumbnail.jp

Seed Predation by Acanthoscelides Submuticus and A. Pallidipennis (Coleoptera: Bruchidae) in False Indigo in the Northern Great Plains

False indigo (Amorpha fruticosa L.) is a native North American leguminous shrub frequently found on shores of lakes and banks of rivers and streams in eastern and central United States and is present in 46 of the 48 contiguous states. It is planted for wildlife habitat, streambank erosion control, and ornamental purposes. Over several years, 16 collections of mature pods of false indigo were obtained from shorelines of four lakes and one cultivated planting in the northern Great Plains to determine frequency of pod predation by bruchid beetles. Frequency of pod predation by Acanthoscelides submuticus (Sharp) varied significantly among locations, among years, and among plants within locations. Out of a total of 5,000 pods examined from 15 different collections, 41% were infested by A. submuticus. Acanthoscelides pallidipennis (Motschoulsky) occurred in only one of the 16 collections, but it infested 60% of those pods. The range in pod predation frequencies for A. submuticus ranged from 70% for a collection at Oakwood Lake, South Dakota, to 7% for a collection from a cultivated planting at Bismarck, North Dakota. The parasitoids Dinarmus acutus Thomson and Lyrcus incertus (Ashmead) were reared from pods infested with A. submuticus. Acanthoscelides submuticus is a new host record for D. acutus. Although pod predation by A. submuticus showed considerable spatial and temporal variation, it ultimately resulted in a significant loss of viable seed production in three natural populations of false indigo along shorelines of lakes in the northern Great Plains

Seed Predators of Canada Milk-Vetch and Their Parasitoids

Canada milk-vetch (Astragalus canadensis L.), North America’s most widespread species of Astragalus, is important for herbivores and granivores in natural ecosystems but suffers heavy seed losses to bruchids and curculionids. Our objectives were: (1) compile a species inventory and describe life histories of insects associated with seed production in Canada milk-vetch, and (2) determine frequencies of pod predation and primary parasitism in Canada milk-vetch. The seed predators were Acanthoscelides perforatus (Horn) and Tychius liljebladi Blatchley. Frequency of pod predation varied between two plant populations (46 and 70%) and between A. perforatus (37 %) and T. liljebladi (21 %). The primary parasitoids were two exotics [Dinarmus acutus Thomson and Eupelmus vesicularis (Retzius)] and two natives [Eurytoma tylodermatis Ashmead and an unidentified chalcid (Pteromalidae)]. Parasitism rates were 10% for T. liljebladi and 22% for A. perforatus. The seed predators had similar niches. Larvae of both species fed on the same food source (occasionally inside the same pod), and adults of both species were active on the plants concurrently. However, A. perforatus overwintered as full-grown larvae inside the pods, whereas larvae of T. liljebladi exited pods in late July and overwintered as pupae in the soil. This research identified a unique community of insects composed, in part, of two seed predators that utilized the same food source and two exotic and two native parasitoids. More research is needed to determine the stability of this insect community in response to variation in production at the first trophic level

Fates of Ovules in Groundplum Milk-Vetch (Astragalus Crassicarpus Nutt.) in South Dakota

Groundplum milk-vetch (Astragalus crassicarpus Nutt.) is a native legume found on gravelly to sandy prairie uplands throughout central North America. The large and fleshy fruits, or pods, of this species were consumed by indigenous people and European settlers, and are cached by rodents. Our previous research on native legumes of the northern Great Plains indicated seed predation by insects, notably bruchid beetles belonging to the genus Acanthoscelides Schilsky, was a dominant factor determining viable seed production in natural and artificial plant assemblages. However, although we have studied the reproductive biology of several species of Astragalus L., none had fleshy pods. Therefore, the objective of this study was to quantify the factors influencing viable seed production in natural populations of GPMV in South Dakota. Mature pods were collected from two natural populations on the South Dakota State University Oak Lake Field Station during July 2000 and from one natural population on the Grand River National Grassland near Lodgepole, SD, in July 2003. Pods were dissected and number of ovules that: 1) produced viable seed, 2) were unfertilized, 3) produced aborted seed, and 4) produced seeds that were predated by larvae of the bruchid beetle Acanthoscelides fraterculus (Horn) (Coleoptera: Chrysomelidae: Bruchinae) were recorded for each of the two valves of individual pods. Our results indicated average seed set, i.e., percent of ovules that produced viable seed not predated, was about 55%, averaged across populations. Unfertilized ovules were 42% of the total. Predation by the bruchid beetle occurred in about 2% of the developed seeds, with aborted seed making up the rest of the ovule total. About 35% of pods infested contained larvae, or adults that were immured within the pod while attempting to exit, presumably due to the thick and leathery layers of the ovary wall. Predispersal seed predation was a relatively minor factor in the reduction of viable seed set in GPMV in South Dakota

Native Grass and Legume Biology and Establishment

https://openprairie.sdstate.edu/oak-lake_presentations/1000/thumbnail.jp

Fates of Ovules in Groundplum Milk-Vetch (Astragalus crassicarpus Nutt.) in South Dakota

Groundplum milk-vetch (Astragalus crassicarpus Nutt.) is a native legume found on gravelly to sandy prairie uplands throughout central North America. The large and fleshy fruits, or pods, of this species were consumed by indigenous people and European settlers, and are cached by rodents. Our previous research on native legumes of the northern Great Plains indicated seed predation by insects, notably bruchid beetles belonging to the genus Acanthoscelides Schilsky, was a dominant factor determining viable seed production in natural and artificial plant assemblages. However, although we have studied the reproductive biology of several species of Astragalus L., none had fleshy pods. Therefore, the objective of this study was to quantify the factors influencing viable seed production in natural populations of GPMV in South Dakota. Mature pods were collected from two natural populations on the South Dakota State University Oak Lake Field Station during July 2000 and from one natural population on the Grand River National Grassland near Lodgepole, SD, in July 2003. Pods were dissected and number of ovules that: 1) produced viable seed, 2) were unfertilized, 3) produced aborted seed, and 4) produced seeds that were predated by larvae of the bruchid beetle Acanthoscelides fraterculus (Horn) (Coleoptera: Chrysomelidae: Bruchinae) were recorded for each of the two valves of individual pods. Our results indicated average seed set, i.e., percent of ovules that produced viable seed not predated, was about 55%, averaged across populations. Unfertilized ovules were 42% of the total. Predation by the bruchid beetle occurred in about 2% of the developed seeds, with aborted seed making up the rest of the ovule total. About 35% of pods infested contained larvae, or adults that were immured within the pod while attempting to exit, presumably due to the thick and leathery layers of the ovary wall. Predispersal seed predation was a relatively minor factor in the reduction of viable seed set in GPMV in South Dakota

\u3cem\u3eEucosma giganteana\u3c/em\u3e (Riley) and \u3cem\u3eSliphium perfoliatum\u3c/em\u3e L., Morphological Variation in an Insect-Plant Association in Eastern South Dakota

Silphium perfoliatum L., cup plant, has potential as a new multi-purpose crop. It is pollinator-friendly and has biodiversity enhancement, conservation, economic, and medical potential. In eastern South Dakota, S. perfoliatum can produce more than 20 Mg (million grams) ha-1 of biomass and 0.09 Mg ha-1 of seed in agronomic plantings. The giant eucosma moth, Eucosma giganteana (Riley), is a major pest of agronomic S. perfoliatum in the region. We provide a summary of this insect and its association with its host. Our experimental objectives were to determine if the frequency of rhizome occupation by late instar larvae and if their final prepupal size were influenced by plant genetic or environmental effects. In October 2009, several individual plants from each of 32 half-sib families were removed from the field. Rhizomes, proaxes, and shoots were examined for the presence of larvae. Each larva was counted and measured for total length, width, thoracic tergite length, head length, and head width. Significant differences were found among half-sib families and between locations for frequency of shoot infestation, degree of crown and rhizome feeding, number of larvae per shoot, and larval morphometrics. The parasitoid Bracon cf. mellitor Say (Hymenoptera: Braconidae) was found parasitizing larvae feeding in floral meristems, but no parasitism was found in larvae in the crown or rhizomes

Seed Set and Seed-Insect Interactions in Natural and Cultivated Populations of Purple Prairie Clover

Purple prairie clover (Dalea purpurea Vent.) is a common native legume on dry prairies throughout the central USA and Canada. Seed set in natural populations can be very low, and the reason(s) are not well known. Our objectives were: 1) determine seed set in natural and cultivated populations of purple prairie clover in eastern SD, and 2) identify seed predators and parasitoids associated with natural and cultivated populations. Collection of inflorescences occurred on the South Dakota State University Oak Lake Field Station (OLFS), and from a cultivated population in McCrory Gardens at Brookings, SD. At OLFS, normal seed set was 10% compared with 60% for the McCrory Gardens population. Frequency of unfertilized ovules was about 25%, and seed predation was 55% at OLFS compared with 24% unfertilized ovules and 23% seed predation at McCrory Gardens. The most common seed predators were Kissingeria capitone (Kissinger) and an unidentified midge, Contarinia sp. (Cecidomyiidae). The bruchid beetle Acanthoscelides seminulum (Horn) had much lower seed predation rates. The most common parasitoid reared from beetle larvae was Lyrcus incertus (Ashmead). The chalcidoid wasps Baryscapus sp. and Aprostocetus marylandensis (Girault) attacked midge larvae. A few individuals of Bracon sp. and Inostemma sp., hosts unknown, were also collected from immature inflorescences. This study identified a previously unknown guild of insects associated with inflorescences in purple prairie clover and revealed reasons for a paucity of viable seed production in natural populations

Teacher Turnover: Examining Exit Attrition, Teaching Area Transfer, and School Migration

The purposes of this research were to quantify trends in three components of teacher turnover and to investigate claims of excessive teacher turnover as the predominant source of teacher shortages. Attrition and teaching area transfer rates were comparable in special and general education and increased substantially from 1991-1992 to 2000-2001. School migration was stable over years, but higher in special than general education. Although annual turnover was high and increased to 1 in 4 teachers (25.6%) by 2000-2001, teacher attrition was lower than in other occupations. Evidence suggests that retention is unlikely to increase without dramatic improvements in the organization, management, and funding of public schools. Until then, an increased supply of qualified teachers is needed to reduce teacher shortages

Biomass Production of Monocultures and Mixtures of Cup Plant and Native Grasses on Prime and Marginal Cropland

To date, most candidate systems for producing herbaceous cellulosic biomass have been composed of monocultures of perennial or annual grasses. Ecosystem goods and services provided from these biomass feedstock production systems could be increased dramatically with mixing of one or more forb species that would increase biodiversity and provide habitat for pollinators. Cup plant (Silphium perfoliatum L.) is featured with many desirable characteristics, such as high biomass potential, adaptation to marginal soils, and attractiveness to pollinators, desirable in a dicot species to grow in mixtures with perennial warm-season grasses. The objective of this study was to compare cup plant, switchgrass (Panicum virgatum L.), and prairie cordgrass (Spartina pectinata Link) monocultures to their mixtures for biomass production on prime and poorly drained marginal crop land for two years in both South Dakota and Wisconsin. In Wisconsin, monocultures of prairie cordgrass and cup plant and their mixture produced more biomass (8.1 Mg·ha-1) than the switchgrass monoculture and switchgrass/cup plant mixture (5.3 Mg·ha-1) on both prime and marginal land. While in South Dakota, drought and meristem destruction by the cup plant moth (Eucosma giganteana Riley) caused large reductions in biomass production (1.7 Mg·ha-1) in both years, with the switchgrass/cup plant mixture on marginal land having the highest yield (2.1 Mg·ha-1). Our study showed binary mixtures of cup plant and native warm-season grasses have great potential for increasing biodiversity and other ecosystem goods and services, relative to monocultures, for sustainable biomass feedstock production on poorly drained marginal land in the northcentral USA