Vegetation indices calculated from the quantity of electromagnetic radiation reflected from plants measured using multi-spectral imaging systems have been used to quantify stress levels in plants. Greenbugs, Schizaphis graminum (Rondani), cause stress to wheat, Triticum aestivum L., plants and therefore multispectral remote sensing may be useful for detecting greenbug-infested wheat fields. The objectives of this study were to assess whether variation in light reflectance from plants infested with varying densities of greenbugs could be detected and quantified using airborne imagery obtained with a multi-spectral digital camera mounted in a fixed-wing aircraft. In a replicated experiment where greenbug density was manipulated in 1-m² plots of two winter wheat varieties (‘Jagger’ and ‘OK 101’) planted in a 1 ha field, we found that wheat infested with greenbugs exhibited a similar reflectance response for the two varieties. Both varieties showed a reduction in the normalized differenced vegetation index (NDVI) as greenbug density increased, as indicated by a negative slope for the regression of NDVI on greenbug density. Neither slopes nor intercepts differed significantly between the two varieties. A second vegetation index, Green NDVI, was not consistently correlated with greenbug density in the experiment. In a second experiment in large plots in four production winter wheat fields we found significant negative correlations between greenbug density and the vegetation indices for three of the four fields. The results indicated that airborne multi-spectral imaging can be used to detect stress caused by greenbug infestation of wheat fields.

Burning sugarcane, Saccharum sp. L., before harvest is a common practice in Mexico. Survival of the crambid stalkborer Diatraea considerata Heinrich and its braconid parasitoid Macrocentrus prolificus Wharton were compared in burned and nonburned sugarcane plots at Los Mochis, Sinaloa, México, during 2008. Survival of stalkborers collected from stalk tops was 58.6% in burned sugarcane, but adult emergence was nil after surviving larvae were reared in the laboratory. In contrast, 89.5% of stalkborers survived when collected from burned underground stalks, and 39.5% reached adulthood. Parasitism by M. prolificus was 0.5% in burned stalk tops and 18.4% in burned underground stalks. This study suggests that individuals surviving in burned underground stalks contribute to increase in abundance of the stalkborer and its parasitoid in ratoon crops.

Six rates of nitrogen were evaluated on onion thrips, Thrips tabaci Lindemann, on onions, Allium cepa L., in Quetta, Balochistan, Pakistan, in 2002 and 2003. Soil in the region is sandy loam, alkaline, moderate in calcium, and very low in nitrogen, phosphorous, and potassium. Low (50 kg N/ha) and optimum (150 kg N/ha) amounts of nitrogen applied to soil had no effect on abundance of thrips, although abundance of thrips (7.6 per plant) decreased at 150 kg of nitrogen per hectare. The maximum abundance of thrips (13 per plant) was observed with high rates of nitrogen (200 and 250 kg/ha), which increased abundance of thrips as much as 73.9%. Onion yields increased with nitrogen to 200 kg/ha. A rapid decrease in yield occurred when 200–250 kg/ha of nitrogen was used. Maximum yield (15,250 kg/ha) had the best cost-benefit ratio (1.43).

Tebufenozide and chlorpyrifos were evaluated in the laboratory and field to find an insecticide more compatible with integrated pest management for pecan, Carya illinoinensis (Wangenh.) K. Koch. Different developmental stages (eggs, larvae, and/or adults) of six predators of pecan aphids were exposed to the insecticides. Control of hickory shuckworm, Cydia caryana (Fitch), by the insecticides and selectivity to native predators of pecan aphids were also tested in commercial orchards. Tebufenozide had no significant adverse effect on coccinellids, but killed eggs of the lacewings Chrysoperla rufilabris (Burmeister) and adults of Chrysoperla carnea Stephens. Chlorpyrifos was very toxic to all stages of crysopids, exhibiting ovicidal activity on multicolored Asian lady beetle, Harmonia axyridis (Pallas). Both insecticides were effective in controlling hickory shuckworm in the field. Tebufenozide applied in orchards was innocuous, while chlorpyrifos killed beneficial insects. Chlorpyrifos significantly reduced the number of blackmargined aphids, Monellia caryella (Fitch). Tebufenozide because of its effectiveness in controlling hickory shuckworm and less detrimental impact on beneficial fauna is recommended rather than chlorpyrifos for integrated pest management. Also, tebufenozide is less toxic to human health and the environment.

The saltmarsh caterpillar, Estigmene acrea (Drury), is an occasional pest of cotton, Gossypium hirsutum L., in the U.S. Although saltmarsh caterpillar is most often encountered late in the season, the most damaging populations are usually dispersing late instars infesting seedling cotton. Three cotton varieties, a non-Bt, a Bollgard 2 (Cry 1Ac Cry2Ab), and a Widestrike (Cry1Ac Cry1F), were evaluated at the two true-leaf stage for resistance to feeding by neonate and late fourth-instar saltmarsh caterpillars. The Bollgard 2 and Widestrike varieties were very resistant to neonate saltmarsh caterpillars, killing 100% with no visible damage after 3 days of exposure. Mortality on the non-Bt variety was 0% and damage was evident. When exposed to fourth-instar larvae, the Widestrike and Bollgard 2 varieties killed 80 and 90%, respectively, after 7 days of exposure. Mortality by the non-Bt variety was 10%. Leaf consumption by fourth-instar saltmarsh caterpillars on the Bt varieties was negligible, while a mean of 19.7-cm² of the non-Bt variety was consumed per larva. Based on relative leaf area of cotton on the Texas High Plains and the estimate that cotyledon- to two true-leaf-stage cotton can withstand 75% damage without significantly impacting yield, treatment thresholds for late-instar saltmarsh caterpillars may approximate 0.5, 1.0, and 1.5 larva per plant on cotyledon, one true-leaf, and two true-leaf-stage cotton, respectively.

The chironomid midge Polypedilum (Polypedilum) newaygo Taber is described from the western Lower Peninsula of Michigan. Numerous adult males and several adult females were collected in clearings of quaking aspen, Populus tremuloides Michaux, and red maple, Acer rubrum L., forest while flying from both emergent and marginal herbaceous vegetation associated with ephemeral standing water in late April and May 2009. Preliminary findings indicate the larvae develop in aquatic moss.

Aging of bovine dung for 3–5 years under refrigeration resulted in smaller sizes of horn fly, Haematobia irritans (L.), pupae. Growth of horn fly larvae in mixtures of aged and fresh dung resulted in production of larvae and pupae stunted in proportion to the relative amount of aged dung. Reduction of size of pupae produced in aged dung was because of nutrient limitation, which was partially reversible by supplementation with a bacteriological medium or yeast extract that increased the numbers of bacteria for consumption by horn fly larvae. Similar stunting of growth and development of horn fly larvae was produced by crowding larvae in fresh bovine dung. Stunting was dependent on the amount of larval crowding, with greater larval densities resulting in smaller individuals but greater aggregate pupal weight, suggesting that stunting at great larval density resulted from phagoinhibition rather than depletion of nutrients in the fresh dung. Successful eclosion of adult horn flies was dependent (0.9578 correlation) on pupal size between 1.0 and 2.7 mg. The smaller size limit for pupae that were successful in eclosion of adult flies was about 1.0 mg, compared to an average weight for horn fly pupae of 4.2 mg. Implications for modeling and control of horn flies are discussed.

The blacklegged tick, Ixodes scapularis Say, is the principal vector of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner east of the Rocky Mountains. The population genetic structure was determined using DNA sequences of a 253-bp region of the mitochondrial DNA rRNA 16S gene from 46 blacklegged ticks collected from canines, Canis lupus familiaris L., and white-tailed deer, Odocoileus virginianus (Zimmermann), in four Arkansas ecoregions. Of the 253 nucleotide characters, 21 were variable. Eighteen haplotypes were identified of which 11 occurred only once. Most of the sequences were haplotype I×9 (30%) which was found in all three ecoregions and on both host species. Molecular phylogenetic relationship of the 18 blacklegged tick haplotypes was constructed using other Ixodes species as outgroup taxa, and two I. scapularis clades were found representing the American and Southern lineages. Our results indicated that blacklegged tick is genetically variable in Arkansas, and the presence of the American lineage increases the risk for Lyme disease in Arkansas.

Microsatellite markers are used in genotypic studies of Diabrotica spp. Usually commercial kits are used for DNA extraction from preserved tissues. A simplified procedure, based on the CTAB, was used to obtain DNA from tissues preserved in 75% ethanol and from fresh samples of Diabrotica spp. from Durango and Jalisco, Mexico. Significantly more DNA was obtained from fresh than preserved tissues (926 and 827 ng/µL, respectively). However, the quality of DNA was similar (A260nm/A280nm mean value = 1.93) between the two kinds of tissue. The CTAB procedure was used to isolate similar quality and quantity of DNA as obtained by using commercial kits but was less time consuming and expensive. The DVV-D2 loci, a characteristic microsatellite of Diabrotica genus, was amplified.

Pink hibiscus mealybug, Maconellicoccus hirsutus (Green), causes serious economic damage to agriculturally important crops. To date, the genome of this pest has not been studied by molecular techniques. Enriched genomic libraries containing (GT)₁₀, (GA)₁₀, and (GC)₁₀ motifs were generated in a Mexican population of the mealybug. Sequencing analysis revealed eight microsatellite loci with different repeat unit lengths in the genome. The dinucleotide repeat sequence (GC)₄ from locus Seq1–56 was selected for primer design because of its length. A primer pair amplified (GC)₄ in samples from 21 populations from different geographical origins, including a different species. Sequencing of the locus Seq1–56 indicated two alleles. No polymorphism was found among populations of pink hibiscus mealybug, but polymorphism was found between the pink hibiscus mealybug and M. australiensis (Green & Lidgett). This is the first report of isolation of microsatellites in pink hibiscus mealybug and provides new information on the molecular biology of this insect pest.

During a 3-year period, pecan, Carya illinoinensis (Wangenh.) K. Koch, orchards were sampled to determine species and seasonal occurrence of phytophagus stinkbugs. Stinkbug adult and egg masses were collected from pecan and pistachio, Pistacia vera L., orchards, wild vegetation and neighboring annual crops in order to determine percentage of natural parasitism. Twelve species of Hemiptera associated to pecan trees were found: Brochymena sulcata and B. parva were found during all the vegetative stages; Chlorochroa ligata, Leptoglossus zonatus, L. clypealis, L. oppositus, L. phyllopus, Euschistus servus, and Nezara viridula were found throughout the nut-filling and shuck-opening periods. Thyanta custator was detected at midsummer. Largus cinctus appeared from late April to mid June, while Acanthocephala granulosa occurred sporadically. Thirteen species were collected from five Hymenoptera families parasitizing Hemiptera eggs and 10 species of Tachinid flies parasitizing Hemiptera adults of the previously mentioned bug species. The percentage of egg masses parasitized by Hymenoptera varied from 50 to 100% and affected 46 to 100% of the eggs of each egg mass. Tachinids parasitized between 1.0 and 30% of adult bugs.

We evaluated vertical and horizontal dispersal of Trichogramma platneri Nagarkatti, T. exiguum Pinto & Platner, and T. pretiosum Riley in pecan trees by placing Sitotroga cerealella (Olivier) eggs as hosts at different heights in the tree canopy. We also observed the effect of tebufenozide an insect growth regulator and the insecticides spinosad and chlorpyrifos in adult emergence for the three parasitoid species. The application was made by submerging S. cerealella eggs parasitized by Trichogramma spp. for 5 seconds in a liter of the solution for each treatment. T. platneri produced greater parasitism at different heights in the tree canopy 24 hours after exposure. None of the species was capable of moving to other trees. Insect growth regulator, tebufenozide had no detrimental effect on the three Trichogramma species evaluated, since all exhibited emergence of more than 85%. Spinosad showed a drastic effect on emergence of the three species evaluated and chlopyrifos had a 100% detrimental effect.