Lampyrids recovered from emergence traps in the Great Smoky Mountains National Park

Citation: Buschman, L. & Faust, L. (2014). Lampyrids Recovered from Emergence Traps in the Great Smoky Mountains National Park. JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY, 87(2), 245-248. https://doi.org/10.2317/JKES130409.1Photinus carolinus Green is a popular firefly that attracts thousands of visitors each year to the Great Smoky Mountains National Park (GSMNP) (Faust, 2009). This firefly is famous for its synchronous flash display in late May and June. The adult flash behavior of this firefly was described by Lloyd (1966) and the synchronous flash behavior was further detailed by Copeland and Moiseff (1995) and Faust (2009, 2010). The biology and natural history of this insect was reported by Faust (2010). This firefly is dependent on larval feeding for its nutrition (adults are nonfeeding), but we know little about the seldom seen larval stage. Rearing has repeatedly proved difficult. For instance, though Buschman (1977) was able to record field and some laboratory observations on field collected larvae, only 2 of the original 59 Photinus consimilis Green complex larvae (closely related to P. carolinus) were successfully reared to adulthood (unpubl. obs.). These larvae were found in marshy habitat feeding on small annelids (Buschman, 1977). Some 40 yr later the biology and natural history of larval Photinus spp. remains poorly understood. This study was done to determine if the fireflies were emerging from the soil/leaf litter in the firefly habitat. This information on larval habitat will be important for understanding the conservation, survival and/or maintenance of fireflies like P. carolinus. It could also support the hypothesis that they are feeding on earthworms and/or other organisms in the soil and leaf litter

Dispersal of Adult \u3ci\u3eDiatraea grandiosella\u3c/i\u3e (Lepidoptera: Crambidae) and Its Implications for Corn Borer Resistance Management in \u3ci\u3eBacillus thuringiensis\u3c/i\u3e Maize

Dispersal of the southwestern corn borer, Diatraea grandiosella Dyar, was examined by release and recapture of dye-marked adults and by capture of feral adults in and around 50-ha center pivot irrigated fields of Bacillus thuringiensis (Bt) maize. Pheromone and blacklight traps were used to capture the adults. In 1999, 2000, and 2001, a total of 177, 602, and 1,292 marked males, and 87, 231, and 1,045 marked females were released in four irrigated Bt maize fields, respectively. Recapture beyond release point was 2.13, 6.17, 3.16, and 17.91% for males and 0, 0, 2.23, and 4.18% for females in the four fields, respectively. One male was recaptured over native vegetation outside the field perimeter, and one was caught in a neighboring maize field, 457 m from the release point. An exponential decay function explained recapture of marked adults across the dispersal distance. More than 90% of adults were recaptured within 300 m of the release point. Large numbers of feral adults were captured throughout the study fields and over native vegetation between fields. The feral adult dispersal could be described with a linear model. Virgin females (38% marked and 14% feral) were captured throughout the study fields. The recapture of marked insects suggests that the dispersal was limited. However, capture of feral adults throughout Bt maize fields indicates that the actual dispersal may be more extensive than indicated by recapture of marked adults. Potential refuge sources for the feral adults were 587-1,387 m from the edge of the fields. There seems to be some dispersal of D. grandiosella from the nontransgenic “refuge” fields into the transgenic fields, which may allow for some genetic mixing of the Bt-resistant and -susceptible insects to help suppress potential evolution of pest resistance to transgenic maize. However, it is not clear whether the dispersal recorded in this study is sufficient to support the current resistance management strategy for corn borers

Comparisons of Transcriptional Profiles of Gut Genes between Cry1Ab-Resistant and Susceptible Strains of Ostrinia nubilalis Revealed Genes Possibly Related to the Adaptation of Resistant Larvae to Transgenic Cry1Ab Corn

Citation: Yao, J. X., Zhu, Y. C., Lu, N. Y., Buschman, L. L., & Zhu, K. Y. (2017). Comparisons of Transcriptional Profiles of Gut Genes between Cry1Ab-Resistant and Susceptible Strains of Ostrinia nubilalis Revealed Genes Possibly Related to the Adaptation of Resistant Larvae to Transgenic Cry1Ab Corn. International Journal of Molecular Sciences, 18(2), 17. doi:10.3390/ijms18020301A microarray developed on the basis of 2895 unique transcripts from larval gut was used to compare gut gene expression profiles between a laboratory-selected Cry1Ab-resistant (R) strain and its isoline susceptible (S) strain of the European corn borer (Ostrinia nubilalis) after the larvae were fed the leaves of transgenic corn (MON810) expressing Cry1Ab or its non-transgenic isoline for 6 h. We revealed 398 gut genes differentially expressed (i.e., either up- or down-regulated genes with expression ratio 2.0) in S-strain, but only 264 gut genes differentially expressed in R-strain after being fed transgenic corn leaves. Although the percentages of down-regulated genes among the total number of differentially expressed genes (50% in S-strain and 45% in R-strain) were similar between the R- and S-strains, the expression ratios of down-regulated genes were much higher in S-strain than in R-strain. We revealed that 17 and 9 significantly up- or down-regulated gut genes from S and R-strain, respectively, including serine proteases and aminopeptidases. These genes may be associated with Cry1Ab toxicity by degradation, binding, and cellular defense. Overall, our study suggests enhanced adaptation of Cry1Ab-resistant larvae on transgenic Cry1Ab corn as revealed by lower number and lower ratios of differentially expressed genes in R-strain than in S-strain of O. nubilalis

The Value of Bt Corn in Southwest Kansas: A Monte Carlo Simulation Approach

While most Corn Belt farmers consider planting Bt corn to control European corn borer, southwestern Kansas farmers must also take into account an array of other insect pests, including corn rootworm, spider mites, and southwestern corn borer. This research uses a decision analysis framework to estimate the expected economic value of Bt corn in southwest Kansas. Mean per acre Bt values ranged from $12.49 to$34.60, well above the technology fee assumed to be $14 per unit, or$5.25 per acre at a seeding rate of 30,000 seeds per acre. The minimum value over all scenarios was $8.69 per acre. Using Monte Carlo simulation, it was shown that European and southwestern corn borer infestation probabilities, expected corn price, and expected pest-free yields are important determinants of the value of Bt corn.Bt corn, decision analysis, European corn borer, integrated pest management, Monte Carlo simulation, southwestern corn borer, Crop Production/Industries,

Rubidium Chloride and Cesium Chloride Sprayed on Maize Plants and Evaluated for Marking \u3ci\u3eDiatraea grandiosella\u3c/i\u3e (Lepidoptera: Crambidae) in Mark–Recapture Dispersal Studies

Experiments were undertaken to determine the potential for using rubidium chloride (RbCl) or cesium chloride (CsCl) to mark southwestern corn borer, Diatraea grandiosella Dyar, for use in applied ecological studies. Maize, Zea mays L., plants were sprayed with aqueous solutions of RbCl or CsCl at rates of 100, 1000, or 10,000 µg/g and inoculated with D. grandiosella neonates. Rubidium and cesium were successfully absorbed and translocated in maize plants. There were only a few minor effects of the treatment on maize or on southwestern corn borers.Rb and Cs were detected in plants, but not in insects, by using Flame atomic absorption spectrophotometry. Graphite furnace-atomic absorption spectrophotometry (GF-AAS) and neutron activation analysis (NAA) allowed identification of Rb and Cs in adults. Rb and Cs were detected by GF-AAS in feral unmarked adults, and they contained higher levels of Rb than Cs. Males and females contained similar amounts of Rb, but Cs levels were higher in males than in females. Adults recovered from field maize treated with 1000 µg/g Cs had higher levels of Cs than did those from untreated plants. Using NAA, neither Rb nor Cs was detected in adults recovered from greenhouse-grown untreated maize. Males and females recovered from maize treated with 1000 µg/g RbCl and CsCl contained similar amounts of Rb, but females contained more Rb than Cs. We conclude that application of 1000 µg/g RbCl or CsCl on plants is effective in marking adults of D. grandiosella with Rb or Cs and would be useful for mark-recapture dispersal studies

Identification of a Novel Aminopeptidase P-Like Gene (OnAPP) Possibly Involved in Bt Toxicity and Resistance in a Major Corn Pest (Ostrinia nubilalis)

Studies to understand the Bacillus thuringiensis (Bt) resistance mechanism in European corn borer (ECB, Ostrinia nubilalis) suggest that resistance may be due to changes in the midgut-specific Bt toxin receptor. In this study, we identified 10 aminopeptidase-like genes, which have previously been identified as putative Bt toxin receptors in other insects and examined their expression in relation to Cry1Ab toxicity and resistance. Expression analysis for the 10 aminopeptidase-like genes revealed that most of these genes were expressed predominantly in the larval midgut, but there was no difference in the expression of these genes in Cry1Ab resistant and susceptible strains. This suggested that altered expression of these genes was unlikely to be responsible for resistance in these ECB strains. However, we found that there were changes in two amino acid residues of the aminopeptidase-P like gene (OnAPP) involving Glu305 to Lys305 and Arg307 to Leu307 in the two Cry1Ab-resistant strains as compared with three Cry1Ab-susceptible strains. The mature OnAPP contains 682 amino acid residues and has a putative signal peptide at the N-terminus, a predicted glycosylphosphatidyl-inositol (GPI)-anchor signal at the C-terminal, three predicted N-glycosylation sites at residues N178, N278 and N417, and an O-glycosylation site at residue T653. We used a feeding based-RNA interference assay to examine the role of the OnAPP gene in Cry1Ab toxicity and resistance. Bioassays of Cry1Ab in larvae fed diet containing OnAPP dsRNA resulted in a 38% reduction in the transcript level of OnAPP and a 25% reduction in the susceptibility to Cry1Ab as compared with larvae fed GFP dsRNA or water. These results strongly suggest that the OnAPP gene could be involved in binding the Cry1Ab toxin in the ECB larval midgut and that mutations in this gene may be associated with Bt resistance in these two ECB strains

Bioluminescent behavior of North American firefly larvae (Coleoptera: Lampyridae) with a discussion of function and evolution

March 10, 2019.Observations were made on the ecology, natural history, and glowing behavior of five North American species of firefly larvae, two Pyractomena LeConte, two Photuris LeConte, and one Photinus Laporte. These observations focused on response and periodic glowing. Response glows were long-lasting glows produced by resting/hiding larva in response to a threatening stimulus. Periodic glows were short spontaneous glows produced by actively crawling larva. Durations of three short periodic glowers averaged 0.8 to 3.5 seconds with a duty cycle of 30 to 46%. Durations of five long periodic glowers averaged 4.1 to 6.5 seconds with a duty cycle of 40-52%. Larvae started glowing ca. 1 hr. after sunset and glowed all night until about 20 minutes before sunrise. Some 72-87% of periodic glows were produced during locomotion. Glowing and locomotion were significantly affected by time in the laboratory and by feeding status. Larvae seemed to switch between response and periodic glowing as though these were two alternative physiological conditions. When firefly larvae were crawling and glowing periodically, the first defensive response to disturbance was to freeze and stop glowing periodically. When similar larvae were hiding the first response to disturbance was to glow responsively. Response glowing appears to be part of a package of defensive behaviors that includes: nocturnal activity, camouflage, freezing or fleeing, response glowing, and emitting defense chemicals. Periodic glowing appears to be part of a second package of defensive behaviors that includes: nocturnal activity, camouflage, stopping periodic glowing, and freezing or fleeing. Glowing of firefly larvae did not seem to be involved in prey capture or feeding. The interaction between larvae and ants was unexpectedly non-hostile, as though larvae had chemicals to pacify ants. Vertebrate predators were probably the driving force in the evolution of aposematic defenses. No evidence was found to support any of the non-defensive functions for bioluminescence in firefly larvae. The function of bioluminescence in firefly larvae can best be understood in the context of the evolution of bioluminescence. The forces that may have driven the evolution of bioluminescence may still be active in modern firefly larvae

Dispersal of Adult \u3ci\u3eDiatraea grandiosella\u3c/i\u3e (Lepidoptera: Crambidae) and Its Implications for Corn Borer Resistance Management in \u3ci\u3eBacillus thuringiensis\u3c/i\u3e Maize

Dispersal of the southwestern corn borer, Diatraea grandiosella Dyar, was examined by release and recapture of dye-marked adults and by capture of feral adults in and around 50-ha center pivot irrigated fields of Bacillus thuringiensis (Bt) maize. Pheromone and blacklight traps were used to capture the adults. In 1999, 2000, and 2001, a total of 177, 602, and 1,292 marked males, and 87, 231, and 1,045 marked females were released in four irrigated Bt maize fields, respectively. Recapture beyond release point was 2.13, 6.17, 3.16, and 17.91% for males and 0, 0, 2.23, and 4.18% for females in the four fields, respectively. One male was recaptured over native vegetation outside the field perimeter, and one was caught in a neighboring maize field, 457 m from the release point. An exponential decay function explained recapture of marked adults across the dispersal distance. More than 90% of adults were recaptured within 300 m of the release point. Large numbers of feral adults were captured throughout the study fields and over native vegetation between fields. The feral adult dispersal could be described with a linear model. Virgin females (38% marked and 14% feral) were captured throughout the study fields. The recapture of marked insects suggests that the dispersal was limited. However, capture of feral adults throughout Bt maize fields indicates that the actual dispersal may be more extensive than indicated by recapture of marked adults. Potential refuge sources for the feral adults were 587-1,387 m from the edge of the fields. There seems to be some dispersal of D. grandiosella from the nontransgenic “refuge” fields into the transgenic fields, which may allow for some genetic mixing of the Bt-resistant and -susceptible insects to help suppress potential evolution of pest resistance to transgenic maize. However, it is not clear whether the dispersal recorded in this study is sufficient to support the current resistance management strategy for corn borers

Characterization of cDNAs encoding serine proteases and their transcriptional responses to Cry1Ab protoxin in the gut of Ostrinia nubilalis larvae

Serine proteases, such as trypsin and chymotrypsin, are the primary digestive enzymes in lepidopteran larvae, and are also involved in Bacillus thuringiensis (Bt) protoxin activation and protoxin/toxin degradation. We isolated and sequenced 34 cDNAs putatively encoding trypsins, chymotrypsins and their homologs from the European corn borer (Ostrinia nubilalis) larval gut. Our analyses of the cDNA-deduced amino acid sequences indicated that 12 were putative trypsins, 12 were putative chymotrypsins, and the remaining 10 were trypsin and chymotrypsin homologs that lack one or more conserved residues of typical trypsins and chymotrypsins. Reverse transcription PCR analysis indicated that all genes were highly expressed in gut tissues, but one group of phylogenetically-related trypsin genes, OnTry-G2, was highly expressed in larval foregut and midgut, whereas another group, OnTry-G3, was highly expressed in the midgut and hindgut. Real-time quantitative PCR analysis indicated that several trypsin genes (OnTry5 and OnTry6) were significantly up-regulated in the gut of third-instar larvae after feeding on Cry1Ab protoxin from 2 to 24 h, whereas one trypsin (OnTry2) was down-regulated at all time points. Four chymotrypsin and chymotrypsin homolog genes (OnCTP2, OnCTP5, OnCTP12 and OnCTP13) were upregulated at least 2-fold in the gut of the larvae after feeding on Cry1Ab protoxin for 24 h. Our data represent the first indepth study of gut transcripts encoding expanded families of protease genes in O. nubilalis larvae and demonstrate differential expression of protease genes that may be related to Cry1Ab intoxication and/or resistance