John D. Sedlacek

Survey of insect pests in shelled corn stored on-farm in Kentucky.

Shelled corn stored in metal bins was sampled for insects on farms in the three westernmost crop reporting districts of Kentucky during 1989 and 1990 to identify pest insects present, determine the relative abundance of insect pests, and determine their geographic distributions. Thirty-six species or species groups were found in this survey. The most abundant insects were maize weevil, Sitophilus zeamais Motschulsky; Angoumois grain moth, Sitotroga cerealella (Olivier); flat grain, rusty grain, and flour mill beetles, Cryptolestes spp.; sawtoothed grain beetle, Oryzaephilus surinamensis (L.); foreign grain beetle, Ahasverus advena (Waltl); red and confused flour beetles, Tribolium spp.; and hairy fungus beetle, Typhaea stercorea (L.). Greater densities and numbers of species were caught later during the storage season and greater numbers were captured from the center versus edges of bins. The unexpectedly high abundance and widespread distribution of maize weevil and Angoumois grain moth suggests that gre...

Cry 1Ab and Cry 9C Transgenic Corn Hybrid Effects on Laboratory Populations of Indianmeal Moth (Lepidoptera: Pyralidae) and Angoumois Grain Moth (Lepidoptera: Gelechiidae)

Several Bacillus thuringiensis Berliner (Bt) Cry proteins including Cry 1Ab, Cry 1Ac, and Cry 9C, have been observed at relatively high levels in Bt corn grain using the CaMV 35S promoter. Thus, a laboratory experiment was conducted to quantify the impact of DeKalb 679 BTY Cry 1 Ab (MON 810) and Garst 8600 BLT Cry 9C (CBH 351) transgenic grain on Indianmeal moth, Plodia interpunctella (Hubner), and Angoumois grain moth, Sitotroga cerealella (Olivier), survival, development and fecundity. Eggs of Indianmeal moth or Angoumois grain moth were added to cracked or whole kernel corn. Emergence and fecundity were recorded for 5 wks. Emergence and fecundity of both moth species was reduced on both Cry 1Ab and Cry 9C-transformed corn, but only Cry 1 Ab-transformed corn delayed development of Indianmeal moth. Results indicate that populations of these moths may be negatively impacted in grain bins by Bt corn hybrids and that lepidopteran populations should be monitored in field-scale assays to examine the effects o...

Potential of Ripe Pawpaw Fruit Extract as an Insecticide and Feeding Deterrent for Striped Cucumber Beetle (Coleoptera: Chrysomelidae) on Squash

Laboratory experiments were performed to study the effects of pawpaw, Asimina triloba (L.) Dunal, fruit extract on mortality and feeding deterrence of striped cucumber beetle, Acalymma vittatum (F.). Recently, fruit tissues of pawpaw were found to contain phenolic and antioxidant compounds, as well as annonaceous acetogenin compounds having insecticidal activity. Ripe pawpaw fruit pulp from a range of pawpaw varieties was extracted with 100% ethyl alcohol to obtain acetogenin compounds. Pulp extracts of 0, 10, 100, 1,000, 10,000 and 50,000 ppm were then used to assess feeding deterrence and mortality of beetles. Buttercup squash leaf disks 3.5 cm in diameter were treated individually with each concentration and placed on water moistened filter paper in plastic Petri dishes (9 cm diam). Five striped cucumber beetles were placed on each leaf disk. All Petri dishes were then placed in an environmental growth chamber at 27°C and a 16:8 h light:dark photoperiod. Feeding activity was recorded 1, 4 and 24 h after beetle introduction. After 24 h the beetles were removed. Beetles did not feed on treated squash leaves at either 1 or 4 h of exposure. However, significant feeding occurred between 4 and 24 h after beetle introduction. Feeding was lowest and feeding damage least on 50,000 ppm pawpaw-treated leaf disks compared with leaf disks treated with < 10,000 ppm dilutions. Pawpaw fruit extract reduced feeding by 89% and 97% in the 10,000 and 50,000 ppm treatments, respectively. The calculated LC50 value was 50,538 ppm whereas the LCF10 (concentration at which only 10% of the leaves were consumed) was 2,033 ppm. At 10,000 ppm 10% of the beetles were killed; however, only 3% of the leaf tissue was consumed. Thus, pawpaw fruit extract may be an effective insect feeding deterrent. The duration of treatment effectiveness and susceptibility of other pest and beneficial insect species to the extracts also needs to be examined.

Ear Pests and Damage to Organic, Conventional and Bt-Protected Sweet Corn Grown in Central Kentucky

Sweet corn (Zea mays L. var. rugosa) was grown in replicated plots in 2004 and 2006 using organic, conventional, and genetically-engineered (Bt) production practices. Organic plots were treated wit...

The Pawpaw Peduncle Borer, Talponia plummeriana Busck (Lepidoptera: Tortricidae): A Pest of Pawpaw Fruit

ABSTRACT The pawpaw peduncle borer, Talponia plummeriana Busck (Lepidoptera: Torticidae), is a pest of pawpaw flowers often boring into the peduncle and causing flower drop. Here we document the first occurrence of this insect infesting ripe pawpaw fruit. Infested fruit that had been collected at the Kentucky State University Research and Demonstration Farm in Franklin County, Kentucky were dissected and small tan colored larvae with brown head capsules were discovered in the fruit. Pawpaw peduncle borer adults were reared from fruit held at room temperature in the laboratory.

Efficacy of Malathion Against Coleopteran Populations in Newly-Harvested Versus Year-Old Stored Corn

The impact of malathion treatment and duration of storage prior to treatment on species composition and relative abundance of beetle pests was investigated in shelled corn in newly-constructed galv...