@article{brust_king_1994, title={EFFECTS OF CROP-ROTATION AND REDUCED CHEMICAL INPUTS ON PESTS AND PREDATORS IN MAIZE AGROECOSYSTEMS}, volume={48}, ISSN={["1873-2305"]}, DOI={10.1016/0167-8809(94)90077-9}, abstractNote={A 2-year study examined the effects of no-rotation, 2-year and 4-year rotations with either conventional management (CM) practices (involving use of herbicides, synthetic fertilizers and prophylactic soil insecticides) or reduced chemical inputs (RCI), on insect pests and their predators in maize agroecosystems. Artificial infestations of the soil pest, southern corn rootworm, Diabrotica undecimpunctata howardi, and a foliage feeder, European corn borer, Ostrinia nubilalis, were applied in order to measure the amount of predator activity. Pest populations were influenced both by rotation and by chemical-input. Multi-layer rotations significantly reduced pest numbers compared with no-rotations. Reduced chemical inputs decreased pest numbers by 38% compared with CM systems. The use of herbicides and a soil insecticide reduced early-season soil predators, but their populations increased rapidly after mid-May. Predator populations were more effected by rotation, multi-year rotation systems having significantly more predators than no-rotation systems. In 1989, multi-year rotation RCI systems had significantly less corn root feeding because of artificial rootworm infestations that no-rotation CM systems. Artificial European corn borer infestations significantly reduced grain fill in no-rotations and CM systems compared with 2- and 4-year rotations and RCI systems.}, number={1}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={BRUST, GE and KING, LR}, year={1994}, month={Feb}, pages={77–89} }
 @article{brust_barbercheck_1992, title={EFFECT OF DIETARY CUCURBITACIN-C ON SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE) EGG SURVIVAL}, volume={21}, ISSN={["1938-2936"]}, DOI={10.1093/ee/21.6.1466}, abstractNote={Laboratory, greenhouse, and field studies were conducted to determine whether the eggs of southern corn rootworm, Diabrotica undecimpunctata howardi Barber, from adults that had fed on a bitter (cucurbitacin C-containing) cucumber variety experience less predation than eggs from beetles that had fed on a nonbitter (noncucurbitacin C-containing) cucumber variety. Human taste tests and insect bioassays indicated the presence of cucurbitacin in the “bitter” eggs. Eggs from adults that had fed upon bitter and nonbitter cucumber cotyledons and early foliage were placed into soil at three different distances from one another and at four different density combinations of bitter:nonbitter eggs. There were no significant differences in predation of eggs by any of the four arthropod predators tested caused by cucumber variety or by egg distance and density. In a laboratory experiment, eggs from adults feeding on bitter and nonbitter cucumber varieties were compared for percentage egg hatch without moisture stress (held at 100% RH) or stressed for 6, 12, or 18 h at 94% RH before being held at 100% RH. Bitter eggs in both unstressed and stressed for 6 h treatments hatched significantly earlier than nonbitter eggs. There was no significant difference in hatched rate between bitter and nonbitter eggs stressed for 12 or 18 h. The presence of cucurbitacin C does not appear to protect southern com rootworm eggs from predation by the arthropod predators tested compared with nonbitter eggs. However, more rapid development and earlier eclosion of bitter eggs relative to nonbitter eggs may help bitter eggs survive in soils that fluctuate between dry and moist conditions.}, number={6}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={BRUST, GE and BARBERCHECK, ME}, year={1992}, month={Dec}, pages={1466–1471} }
 @article{brust_1991, title={AUGMENTATION OF AN ENDEMIC ENTOMOGENOUS NEMATODE BY AGROECOSYSTEM MANIPULATION FOR THE CONTROL OF A SOIL PEST}, volume={36}, ISSN={["1873-2305"]}, DOI={10.1016/0167-8809(91)90014-O}, abstractNote={Three cultural methods of agroecosystem manipulation (tillage, weeds and irrigation) were used in a corn system in an attempt to increase the endemic entomogenous nematode Heterorhabditis heliothidis (Khan, Brooks, Hirschmann) to levels high enough to control artificial infestations of the soil pest, southern corn rootworm (SCR) (Diabrotica undecimpunctata howardi (Barber)). Laboratory studies were conducted to investigate the relative density of entomogenous nematodes required for infecting each larval instar of the rootworm. Galleria mellonella (L.) larvae were used as bioassays to measure the relative density of H. heliothidis in the different systems. Field studies demonstrated that no-tillage (NT) and the presence of weeds significantly increased the infection of G. mellonella. The presence of irrigation did not increase infection percentages significantly. Laboratory experiments demonstrated that third instar southern corn rootworm larvae were highly infected at four levels (5, 10, 15 and 20 infective juveniles 1−1 of soil) of nematode density. However, a higher range of nematode densities was needed before a significant (P≤0.05) percentage of first and second instar SCR were infected. This experiment demonstrates the possibility of agroecosystem manipulation for the augmentation of endemic biocontrol agents.}, number={3-4}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={BRUST, GE}, year={1991}, month={Aug}, pages={175–184} }
 @article{brust_1990, title={DIRECT AND INDIRECT EFFECTS OF 4 HERBICIDES ON THE ACTIVITY OF CARABID BEETLES (COLEOPTERA, CARABIDAE)}, volume={30}, ISSN={["0031-613X"]}, DOI={10.1002/ps.2780300308}, abstractNote={Four herbicides, atrazine, simazine, paraquat, and glyphosate were tested for their acute and chronic toxicity as well as repellent effects on five common carabid beetles (Amara sp., Agonum sp., Pterostichus sp., Anisodactylus sp., and Harpalus sp.) in laboratory and greenhouse experiments. These carabid species are potential biocontrol agents and interference with their biology through herbicide applications, either directly or indirectly, could lead to soil pest outbreaks. Short-term field studies also were conducted to verify laboratory and greenhouse results. The four herbicides did not have significant acute or chronic effects on male or female carabid longevity or food consumption during one year after exposure to initial field-rate applications. Only simazine and atrazine had a repellent effect on carabids, which lasted approximately three days in greenhouse studies. Behavioral studies indicate that once carabids, especially smaller ones ( 10 mm length) carabids. Glyphosate and paraquat had the greatest effect on carabids by the second week in field studies, with significantly fewer large carabids found in these two treatments than in the control. Large carabids did not return to paraquat- and glyphosate-treated field areas until approximately 28 days after application; consequently, lower rates of predation of early-season lepidopteran pests by these carabid species may occur in no-tillage corn fields that utilize herbicides for weed control.}, number={3}, journal={PESTICIDE SCIENCE}, author={BRUST, GE}, year={1990}, pages={309–320} }
 @article{brust_1990, title={EFFECTS OF BELOWGROUND PREDATOR WEED INTERACTIONS ON DAMAGE TO PEANUT BY SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE)}, volume={19}, ISSN={["0046-225X"]}, DOI={10.1093/ee/19.6.1837}, abstractNote={The below-ground effects of weeds ( Amaranthus retroflexus L., Chenopodium album L., Ambrosia artemisiifolia L., Digitaria sanguinalis L., Setaria viridis L., Panicum dichotomiflorum Michx.) and increased soil moisture on damage to peanut pods by southern corn rootworm, Diabrotica undecimpunctata howardi Barber, was investigated in a 2-yr field and greenhouse study. Field experiments demonstrated that weedy areas had less pod damage overall and higher predator numbers than nonweedy areas. However, increased soil moisture, which increased southern corn rootworm oviposition and egg and larval survival, confounded the results. Greenhouse studies showed that three broadleaf species and three grass species were not as good food sources as peanuts for southern corn rootworm larvae. Although the presence of weeds growing with peanuts did not lower larval survival, weeds did significantly ( P ≤ 0.05) slow larval developmental rate. In greenhouse studies, damage to peanut pods was approximately 66% in peanut-only (control) treatments, 55% in peanut + weed treatments, 32%in peanut predator treatments, and 9%in peanut + weed + predator treatments. The interaction of predators and weeds in lowering the amount of damage caused by southern corn rootworm was significant ( P ≤ 0.05). Field and greenhouse experiments demonstrated that at least two factors were operating to reduce pest damage in this belowground, multispecies plant association. Predators and the structural complexity of the weed-crop root association may be working synergistically to reduce southern corn rootworm damage to peanuts.}, number={6}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={BRUST, GE}, year={1990}, month={Dec}, pages={1837–1844} }
 @article{brust_house_1990, title={EFFECTS OF SOIL-MOISTURE, NO-TILLAGE AND PREDATORS ON SOUTHERN CORN-ROOTWORM (DIABROTICA-UNDECIMPUNCTATA-HOWARDI) SURVIVAL IN CORN AGROECOSYSTEMS}, volume={31}, ISSN={["1873-2305"]}, DOI={10.1016/0167-8809(90)90220-8}, abstractNote={Field experiments in 1987 and 1988 were conducted to discern the effects of no-tillage (NT), conventional-tillage (CT), and soil moisture (irrigated and non-irrigated) on a below-ground corn pest, the southern corn rootworm (SCR), Diabrotica undecimpunctata howwadi Barber (Coleoptera: Chrysomelidae), and its natural enemies. Soil moisture, number of SCR eggs, and soil predators found in each system were recorded, as were observations of below-ground SCR/predator interactions. To measure the impact of SCR feeding in each treatment, root ratings, percent stand loss and grain yields were taken. There were 80% more SCR eggs in NT than CT, and 62% more eggs in irrigated systems than non-irrigated systems. Soil moisture levels were not significantly (P > 0.05) different between any of the treatments when SCR were ovipositing in April and May. However, in early June, CT without irrigation (CT/WOI) had very low soil moisture levels, while the other three treatments had adequate to good soil moisture. Predatory arthropods were found in nearly equal numbers in April and May, but numbers decreased in June and July, then increased in August. Predator numbers fluctuated, but remained relatively high in all NT treatments and slowly decreased in CT with irrigation (CT/WI) treatments. Although the numbers of arthropods were generally the same among treatments in the early season, predator activity was greatest in NT systems, while in CT systems (including irrigated) predator activity was much lower. Seven predator species were found responsible for removing large numbers of SCR stages. Mesostigmatid and Tyrophagus putrescentiae Shrank (Acaridae: Acarinae) mites, cantharid, carabid, and staphylinid larvae, centipedes, and formicids (ants) all fed extensively on SCR immatures. Root ratings and percent stand loss showed that SCR feeding was greatest in CT systems and least in NT systems, regardless of irrigation. NT systems had greater grain yields compared with CT systems. The importance of early season SCR damage and predators and mid-to-late season water-stressed corn is discussed.}, number={3}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={BRUST, GE and HOUSE, GJ}, year={1990}, month={Jul}, pages={199–216} }
 @article{brust_house_1990, title={EFFECTS OF SOIL-MOISTURE, TEXTURE, AND RATE OF SOIL DRYING ON EGG AND LARVAL SURVIVAL OF THE SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE)}, volume={19}, ISSN={["0046-225X"]}, DOI={10.1093/ee/19.3.697}, abstractNote={Greenhouse studies were conducted to determine the effects of four soil textures and four soil drying periods on southern corn rootworm, Diabrotica undecimpunctata howardi Barber, egg and larval survival and maturation. Soil drying intervals had the most detrimental effect on survival. After 4 d of soil drying (no water added to pots), only 20% of larvae survived to pupation. Low clay or organic matter and low levels of soil moisture were not conducive to survival of southern corn rootworm. The interaction of soil texture and soil drying indicates that at 4 d of soil drying, larval survival decreased (70%) in all soils, except dark-textured soils (35% decrease) compared with 2 d of soil drying. Low levels of soil moisture slowed developmental time of larvae. Eggs and first instars were the stages most negatively affected by moisture stress and different soil textures. However, in quartz-sand, the more mobile stages had low survival, probably because of cuticle abrasion from soil particles. The results of these experiments demonstrate the importance of considering the effects of rapidly drying soil on survival of southern corn rootworm and not simply the percentage of soil moisture at any one time.}, number={3}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={BRUST, GE and HOUSE, GJ}, year={1990}, month={Jun}, pages={697–703} }
 @article{brust_house_1990, title={INFLUENCE OF SOIL TEXTURE, SOIL-MOISTURE, ORGANIC COVER, AND WEEDS ON OVIPOSITION PREFERENCE OF SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE)}, volume={19}, ISSN={["0046-225X"]}, DOI={10.1093/ee/19.4.966}, abstractNote={Oviposition preferences of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, were investigated in greenhouse experiments where abiotic and biotic parameters were manipulated. Southern corn rootworm oviposition distance from corn seedlings was quantified. Four soil moistures, four soil textures, and the presence of weeds were examined in caged greenhouse experiments for their effect on southern corn rootworm oviposition preference. Additional experiments were conducted to elucidate southern corn rootworm oviposition preference for corn seedlings in the presence of broadleaf weeds, grass weeds, a wheat straw cover, or bare soil in large-cage experiments in the greenhouse. Southern corn rootworm adults oviposited >90% of their eggs within 3 cm of a corn stem with <1% oviposited 10–15 cm from the plant. Soil moisture and texture significantly affected oviposition preference. Moist or wet soil and dark soils (moderately high in organic matter and clay) were preferred for oviposition. Significant interactions occurred between these two variables. The presence of weeds significantly increased the number of eggs oviposited and influenced the oviposition preference for particular soil moistures and textures. Southern corn rootworm adults preferred to feed on and oviposit in areas that contained broadleaf weeds compared with grass weeds, wheatstraw, or bare soil. The presence of a wheatstraw cover was significantly ( P < 0.05) preferred to bare soil. We discuss how this study elucidates a number of seemingly contradictory field observations of southern corn rootworm infestations.}, number={4}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={BRUST, GE and HOUSE, GJ}, year={1990}, month={Aug}, pages={966–971} }