Diversity of Flower-visiting Bees and their Pollen Loads on a Wildflower Seed Farm in Montana

During a two-year survey on a wildflower seed farm in southcentral Montana, we collected ∼50 species of bees from 18 genera in sweep samples on cultivated wildflowers and weeds. The two cultivated plant species most intensively sampled attracted different assemblages of bee visitors. Slender white prairie clover (Dalea candida) attracted 27 species, 94% of visitors being Apis mellifera (73%), Lasioglossum spp., Colletes phaceliae, and Bombus spp. Prairie coneflower (Ratibida columnifera) attracted 20 species, the majority being Halictus rubicundus and three Melissodes species; only 3% of visitors to this plant were A. mellifera, despite the fact that the coneflower field was closer to an apiary than were the prairie clover fields. Other apparently non-random plant-bee associations included A. mellifera onOnobrychis viciaefolia, Bombus spp. on Astragalus cicer, and Halictus ligatus and aMelissodes sp. on Symphyotrichum chilensis. Analysis of pollen loads suggests high flower constancy for A. mellifera, Bombus spp., and many of the native solitary bee species foraging on cultivated plants. The low numbers of honey bees on certain plants suggest that native, non-managed bees of such genera as Bombus, Melissodes, Halictus, and Lasioglossum may be critical for plant species for which honey bees show relatively low preference (especially when highly-preferred species such as D. candida are abundant)

Increased area of a highly suitable host crop increases herbivore pressure in intensified agricultural landscapes

Landscape simplification associated with agricultural intensification has important effects on economically important arthropods. The declining cover of natural and semi-natural habitats, in particular, has been shown to reduce natural-enemy attack of crop pests, but also in some cases reduced crop colonization by such pests. In this study, we examined the influence of changes in two elements of landscape composition, natural grassland cover and cover of a highly suitable crop host, on infestation by a generalist insect pest in wheat, and parasitism of this pest by its dominant natural enemies. Surprisingly, we found no significant influences of increasing natural grassland habitat, at either local or landscape scales, on infestation by the wheat stem sawfly, Cephus cinctus, or parasitism of this pest by the native parasitoid wasps, Bracon cephiand Bracon lissogaster. In contrast, we found significant increases in levels of C. cinctus infestation with increasing wheat cover at the landscape scale. This pattern was consistent across six study regions spanning three states in the northern Great Plains of North America, despite large differences in cropping systems and pest population densities across regions. Regional variation in pest infestation was best explained by long-term averages in precipitation, with higher C. cinctus infestation rates found in drier regions. Results suggest that landscape-mediated variation in pest pressure in this system is better explained by a direct response of pest insects to increasing cover of a highly suitable crop rather than an indirect response via reductions in natural enemies as natural habitat declines. The implication is that habitat diversification at the landscape scale could play a role in suppressing agricultural pest populations via reductions in area of suitable crop hosts

Spring Wheat Production and Associated Pests in Conventional and Diversified Cropping Systems in North Central Montana

The primary focus of this study was to determine impacts of diversification and intensification of the spring wheat–fallow system on spring wheat production, pests, and pest interactions at the field scale

Kansas blister beetles (Coleoptera: Meloidae): historical and alfalfa field survey results

Call number: LD2668 .T4 ENTM 1987 B56Master of ScienceEntomolog

Yield, Pests, and Water Use of Durum and Selected Crucifer Oilseeds in Two-Year Rotations

Cool-season oilseed crops are potential feedstock for biofuel production, but few studies have compared oilseed-durum (Triticum durum Desf.) rotations on yield, quality, water use, and pests associated with crops. We conducted an experiment under dryland conditions during 2007 to 2010 near Culbertson, MT, comparing crop productivity, water balance, and key weed and arthropod pests of 2-yr oilseed-durum rotations under zero tillage. Rotations included durum with three Brassicaceae sp., camelina [Camelina sativa (L.) Crantz], crambe (Crambe abyssinica Hochst. ex R.E. Fries), and canola-quality Brassica juncea L., and fallow. Over 4 yr, B. juncea had the highest seed and oil yields of crucifer entries. Water use was similar among oilseed crops, averaging 286 mm. Water use was similar for durum following oilseeds, averaging 282 mm, 72 mm less than for durum following fallow. Durum following fallow averaged 775 kg ha−1 greater grain yield than durum following oilseeds due to higher water availability and use. Camelina had greater weed biomass at harvest and lower densities of Plutella xylostella L. than other oilseeds. Durum in rotation with crambe had higher weed density and biomass at harvest than durum following B. juncea or fallow. Brassica juncea generally performed better than crambe or camelina, but each oilseed crop had several positive attributes. Oilseed-durum rotations can be used for biofuel feedstock and grain production, but long-term sustainability of 2-yr rotations on crop yields and pest management requires further study

MF918

Randall A. Higgins, Sue L. Blodgett and Andrew W. Lenssen, “Alfalfa weevil management in Kansas: II. Non-chemical controls,” Kansas State University, April 1989

Milkweed (Asclepias syriaca) plant detection using mobile cameras

Milkweed (Asclepias spp.) are host plants of monarch butterflies (Danaus plexippus). It is important to detect milkweed plant locations to assess the status and trends of monarch habitat in support of monarch conservation programs. In this paper, we describe autonomous detection of milkweed plants using cameras mounted to vehicles. For detection, we used both aggregated channel features (ACF) for running the detectors on embedded computing platforms with central processing unit and faster region‐based convolutional neural network (Faster R‐CNN) with a ResNet architecture‐based detector that is suitable for graphics processing unit optimized processing. The ACF‐based model produced 0.89 mean average precision (mAP) on the training dataset and 0.29 mAP on the test dataset, whereas the ResNet‐based Faster R‐CNN model provided 0.98 mAP on training and 0.44 mAP on the test dataset. The detections were used to calculate approximate densities of milkweed plants in geo‐referenced locations based on global positioning system point correspondences of recorded images. Probability‐of‐count distributions are compared for the actual milkweed plant locations near roadsides. This is one of the first examples of using automated milkweed plant detection and density mapping using a vehicle‐mounted camera

farmers knowledge and practices in the management of insect pests of leafy amaranth in kenya

Abstract Amaranth (Amaranthus L.) species are grown for their grain or leaves and contribute to farmers' livelihoods and nutritional food security. Leafy amaranth (LA) is consumed widely as a vegetable in Kenya. An assessment of current farmers' knowledge of pest management practices provides information about future educational needs. Six-hundred LA farmers were interviewed, focus group discussions with farmers, and interviews with key informants were completed in four Kenyan counties. The majority (71%) of survey respondents grew LA on less than 0.25 acre (<0.1 ha) and 59.2% were female. Constraints of LA production differed by counties surveyed. Farmers indicated insects and birds were important in Kiambu and Kisumu counties, whereas in Vihiga and Kisii, capital, markets, and land area for production were important. Farmers stated and ranked importance of the insects they observed during LA production. Eighty-seven percent stated aphids (Hemiptera: Aphididae), as a major pest and 96.8% ranked aphids as the number-one insect pest of LA in all four counties. Two other pests of LA included cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) (0.8%) and spider mites, Tetranychus spp (Trombidiformes; Tetranychidae) (0.7%). Forty-two percent of all LA farmers managed aphids, with 34% using synthetic insecticides and 8% using nonsynthetic methods. Biological controls and host-plant resistance were not mentioned. Educational programs that train farmers about integrated pest management (IPM) in LA production are needed. Future research should determine successful IPM strategies for aphids on LA to reduce insecticide use and improve sustainability and nutritional food security for small-landholder farmers and consumers

Monarch Butterflies Show Differential Utilization of Nine Midwestern Milkweed Species

Monarch butterfly overwintering numbers have declined over the past 20 years. Restoring habitat that includes milkweeds, the only host plants for larval monarch butterflies, is necessary to increase monarch numbers within the breeding range. The value of different milkweed species for restoration will depend, in part, on the extent to which they are utilized by ovipositing females. The number of eggs laid on different species over a season will be a function of plant size and phenology as well as female preference. We examined seasonal egg deposition and females' oviposition choices by comparing the number of eggs laid by free-flying wild monarchs on each of nine native milkweed species occurring in Iowa (Asclepias syriaca, Asclepias tuberosa, Asclepias incarnata, Asclepias verticillata, Asclepias exaltata, Asclepias hirtella, Asclepias speciosa, Asclepias sullivantii, and Cynanchum laeve). One plot, consisting of clusters of each of the nine species, was established at each of 14 sites across the state of Iowa. Eggs were counted weekly in June, July and August 2015–2017. The highest egg totals were recorded on A. incarnata and A. syriaca in all years. Fewer eggs were counted on A. exaltata, A. hirtella, A. tuberosa, A. verticillata, and C. laeve. Our results show that monarchs prefer some milkweed species over others, but that they can use all nine native milkweed species for oviposition