Biotic interference of biological control of purple loosestrife

Iowa State University has reared and released two European leaf-feeding beetle species to control purple loosestrife in Iowa wetlands. Expected reductions in loosestrife have not occurred, and biotic mortality factors may explain the failure of the beetles to curb the loosestrife

Diapause induction in eastern North American populations of \u3ci\u3ePropylea quatuordecimpunctata and Hippodamia variegata\u3c/i\u3e (Coleoptera: Coccinellidae)

Experiments examined the effect of photoperiod on the expression of adult diapause in North American populations of two Palearctic ladybird beetle species, Propylea quatuordecimpunctata and Hippodamia variegata. Comparative data for the reproductive responses to different photoperiod conditions for H. variegata were taken from Obrycki (2018). Additionally, comparisons of responses to the four photoperiods between P. quatuordecimpunctata from Jefferson County, NY, USA to P. quatuordecimpunctata from Montreal, Quebec, Canada were also conducted. Data for the Montreal, Quebec, Canada population are from Obrycki et al., (1993). Two Data sets are included: (1) Pre-oviposition period (days) as a measure of induction and duration of adult diapause in P. quatuordecimpunctata and H. variegata. (Data for Supplemental Table S8 in Jones et al 2024) (2) Pre-oviposition period (days) as a measure of induction and duration of adult diapause in P. quatuordecimpunctata from Jefferson County, New York, USA and P. quatuordecimpunctata from Montreal, Quebec, Canada. (Data for Supplemental Table S9 in Jones et al 2024. Hippodamia variegata were collected in August 2015. Propylea quatuordecimpuntata were collected in August 2019. The Canadian population of Propylea quatuordecimpuntata was collected in summer 1989. Adult Hippodamia variegata and Propylea quatuordecimpunctata collected from Jefferson County, New York, USA (43.98°N, 75.91°W). Adult Propylea quatuordecimpuntata were collected from Montreal, Quebec, Canada (45.50°N, 73.57°W

Diapause in eastern North American populations of \u3ci\u3eCoccinella septempunctata\u3c/i\u3e (Coleoptera: Coccinellidae)

Experiments examined the effect of photoperiod on the expression of adult diapause in the Palearctic ladybird beetle Coccinella septempunctata, within 10 years of its discovery in North America. The study used beetles from two populations in eastern United States and focused on two aspects of diapause. First, the effects of daylength on the induction and depth (or duration) of diapause were examined by rearing and maintaining adult beetles from Tompkins County, New York,(approx. 42.4°N, 76.5°W) under six constant photoperiods until oviposition, death, or the passage of 125 days. Second, the seasonal progression of diapause maintenance and termination under natural conditions was examined by periodically (between October and April) testing the photoperiodic responses of overwintering adults that had been held out-of-doors; this test used beetles from Bergen County, New Jersey. Two Data sets are included: (1) Photoperiodic effects on the pattern of reproduction (oviposition versus reproductive diapause) in female Coccinella septempunctata from Tompkins County, New York, USA. and (2) Seasonal effects on the progression of dormancy (diapause and postdiapause development) in Coccinella septempunctata held under natural conditions out-of-doors in Bergen County, New Jersey, USA

The effects of thrips on strawberry production in Iowa

The presence of thrips (tiny insects) in strawberry fields has been associated with undesirable bronzing of the fruit. This study examines the links between thrips and damage to Iowa strawberries

Trophic Interactions Between Two Herbivorous Insects, Galerucella calmariensis and Myzus lythri, Feeding on Purple Loosestrife, Lythrum salicaria, and Two Insect Predators, Harmonia axyridis and Chrysoperla carnea

The effects of two herbivorous insects, Galerucella calmariensis Duftschmid and Myzus lythri L. (Coleoptera: Chrysomelidae), feeding on purple loosestrife, Lythrum salicaria L. (Myrtiflorae: Lythraceae), were measured in the presence of two insect predators, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). A greenhouse cage experiment examined the direct effects of these predators on these herbivores, and indirect effects of predation on aboveground biomass, defoliation, number of leaves, and internode length. Eight treatment combinations with G. calmariensis, M. lythri, H. axyridis and C. carnea were applied to caged L. salicaria. The experiment ended when G. calmariensis adults were observed, 11 to 13 days after release of first instar G. calmariensis. G. calmariensis larvae alone removed significant amounts of leaf tissue and reduced the number of L. salicaria leaves. Predators did not reduce levels of defoliation by G. calmariensis. C. carnea had no effect on G. calmariensis survival, but H. axyridis reduced G. calmariensis survival in the presence of M. lythri. Both predators reduced the survival of M. lythri. This short duration greenhouse study did not demonstrate that predator-prey interactions altered herbivore effects on L. salicaria

Trophic Interactions Between Two Herbivorous Insects, \u3cem\u3eGalerucella calmariensis\u3c/em\u3e and \u3cem\u3eMyzus lythri\u3c/em\u3e, Feeding on Purple Loosestrife, \u3cem\u3eLythrum salicaria\u3c/em\u3e, and Two Insect Predators, \u3cem\u3eHarmonia axyridis\u3c/em\u3e and \u3cem\u3eChrysoperla carnea\u3c/em\u3e

The effects of two herbivorous insects, Galerucella calmariensis Duftschmid and Myzus lythri L. (Coleoptera: Chrysomelidae), feeding on purple loosestrife, Lythrum salicaria L. (Myrtiflorae: Lythraceae), were measured in the presence of two insect predators, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). A greenhouse cage experiment examined the direct effects of these predators on these herbivores, and indirect effects of predation on aboveground biomass, defoliation, number of leaves, and internode length. Eight treatment combinations with G. calmariensis, M. lythri, H. axyridis and C. carnea were applied to caged L. salicaria. The experiment ended when G. calmariensis adults were observed, 11 to 13 days after release of first instar G. calmariensis. G. calmariensis larvae alone removed significant amounts of leaf tissue and reduced the number of L. salicaria leaves. Predators did not reduce levels of defoliation by G. calmariensis. C. carnea had no effect on G. calmariensis survival, but H. axyridis reduced G. calmariensis survival in the presence of M. lythri. Both predators reduced the survival of M. lythri. This short duration greenhouse study did not demonstrate that predator-prey interactions altered herbivore effects on L. salicaria

Biological control of the tarnished plant bug in Iowa

TPB, the tarnished plant bug (Lygus lineolarisj, attacks strawberries in Iowa and the Midwest. The egg parasitoid (Anaphes \o\e) has been observed to parasitize TPB in several crops in the western United States, but its activities have not been studied in strawberries in the Midwest. Under laboratory conditions, it was determined that A. iole will parasitize TPB eggs in strawberry stems. Releases of A. iole females in large field cages containing low densities of TPB eggs did not result in successful parasitization

Use of intra-field alfalfa trap cropping for management of the potato leafhopper

Potato leafhopper, a serious alfalfa pest, may be controlled by early harvest or by application of insecticide. Using natural enemies to battle the leafhopper is another option. Selective cutting in alfalfa fields may help curb leafhopper infestations by confining the pests in one strip, which also may harbor a fungus that helps to control the leafhopper

The cereal leaf beetle in Iowa oats: Research and education program for biological control and sustainable management practices

The cereal leaf beetle, (Oulema melanopusj, a serious insect pest of small grains, including oats, was detected in the eastern half of Iowa in the early 1990s. Iowa\u27s five leading counties for oat production are located in northeastern Iowa, and field surveys were conducted in this area to document Entomology the levels of cereal leaf beetle infestations, potential impact on production, and the presence of natural enemies. Findings showed that current cereal leaf beetle numbers are too low to cause economic damage and no compelling need exists to establish a management program aimed against this particular pes