Progress 01/01/05 to 12/31/05

Outputs
Fire ant: The project focused on the study of the fire ant queen molecular physiology. We discovered two new cDNAs, a glucose transporter 8 and the short neuropeptide F receptor. This receptor appears to be involved in feeding regulation in fire ant queens, RT-PCR experiments showed that the receptor transcript decreases significantly with starvation in fire ant queen brain with respect to a filamin transcript. The glucose transporter 8 transcript is the first of this type cloned from any insect species and the transcript was detected in various fire ant queen tissues. We also continued studying the evolution of resistance to pyrethroids in the bollworm, Helicoverpa zea. We have found that resistance is in high frequency in Williamson County and Corpus Christi area. Resistance has diminished in Burleson County perhaps in response to our recommendations to farmers, the high adoption of Bt cotton in the area and the general reduction of sorghum in the overall surrounding area.

Impacts
Ours is the first characterization and cloning of the glucose transporter 8 (GLUT8) in an insect, the fire ant. We have annotated the sequence of the Anopheles gambiae mosquito glucose transporter 8 and we have sub-classified two previously known genes as glucose transporters from Drosophila as being glucose transporter 8-like proteins, likely orthologs of the fire ant GLUT8. Our study presents the first phylogenetic analysis of glucose transporters in insects. With respect to the resistance monitoring program for H. zea pyrethroid resistance, we have already made an impact by educating farmers about this problem, advising them not to reduce the rate of compound below of that in the label, to try to control as many heterozygote insects as possible when resistance is in high frequency (medium to high rates), to alternate applications of insecticides with a different mode of action such as indoxacarb, spinosad, or emamectin benzoate. Burleson County showed a reversal to susceptibility in September of 2005 after growers applied this practices. We are continuing to study structure-activity relationships of kinin peptides on the Aedes aegypti mosquito kinin receptor as well as the tick Boophilus microplus receptor. We have identified the amino-butyric acid containing analog as the most potent on the mosquito kinin receptor. These experiments will lead to potential insecticide lead compounds for the development of novel insecticidal peptidomimetics.

Publications

• Chen, Mei-Er and P.V. Pietrantonio. 2006. The short neuropeptide F-like receptor from the red imported fire ant, Solenopsis invicta Buren (In press, Archiv. Insect Biochem. Phys.; proofs available).
• Chen, Mei-Er, Steven P. Holmes and Pietrantonio, P. V. 2006. The glucose transporter 8 from the fire ant Solenopsis invicta Buren.(In press, Archiv. Insect Biochem. Phys.; proofs available).
• Patricia V. Pietrantonio, T. Junek et al. 2005. Monitoring for Bollworm (Helicoverpa zea) Pyrethroid Resistance in Texas 2004. Proceedings Beltwide Cotton Conferences. January 4-7, 2005, New Orleans, Louisiana.
• Pietrantonio, P.V., C. Jagge and S. Taneja-Bageshwar. 2005. Invited by the EMBO organizing committee to the Workshop: Molecular and population biology of mosquitoes. G protein-coupled receptors from mosquito Aedes aegypti (L.) excretory system: characterization, function and structure-activity relationships. Oral presentation P.V.P. and abstract. 2005, Kolymbari, Crete, Greece.
• Nachman, RJ., H. Williams, S. Taneja-Bageshwar, Y.J. Kim, P. Zubrzak, G. M. Coast, A. Strey, M. Adams, J. Zabrocki, R. E. Isaac, P. Pietrantonio. 2005. Interaction of analogs of insect neuropeptides with expressed receptors. IV- International conference on arthropods: chemical, physiological and environmental aspects. Organized by the Faculty of Chemistry, Wroclaw University. September 19-23, Zakopane (Bialka Tatrzanska), Poland.
• Pietrantonio, P. V. 2005. Driving forces for target-based insecticide design in the 21st century. Book title: Entomology at the Land Grand University: Perspectives from the Texas A&M University Department Centenary. Texas A&M University Press. Heinz, K., Frisbie, R. and Bogran, C. Eds.

Progress 01/01/04 to 12/31/04

Outputs
We have focused on major pests that are a threat to agriculture, urban environments and public and animal health in Texas. These are the mosquitoes Aedes aegypti and Culex quinquefasciatus; the red imported fire ant Solenopsis invicta; the heliothines bollworm and budworm (Helicoverpa zea and Helitothis virescens) key pests of cotton, and the tick Boophilus microplus. We have determined that the levels of insecticide resistance in Culex quinquefasciatus in Houston are due to increased esterase activity and may cause the failure of current control practices. We discovered and functionally characterized several receptors in the dengue vector Aedes aegypti such as those for serotonin, Aedes kinins and an orphan receptor. The serotonin receptor is the first hormone receptor characterized from mosquitoes. We discovered that aquaporin protein is present in tracheolar cells of mosquitoes. These G protein-coupled receptors could represent novel targets for the development of new mosquitocidal compounds. With respect to the fire ant we have cloned the first vitellogenin receptor from a social insect; this molecular knowledge of fire ant reproduction will lead to novel ways of fire ant control, perhaps affecting the expression and regulation of this receptor that is responsible for egg maturation. We discovered the myokinin receptor from the tick B. microplus, and we suspect that this receptor is involved in water balance. The receptor has been cloned and expressed in a stable mammalian cell line useful for pharmacological studies that aim at discovering a novel acaricide. Our research on pyrethroid resistance in Helicoverpa zea has helped the cotton industry in choosing effective insecticides to control this pest, particularly in the Corpus Christi area.

Impacts
Our research on G protein couple receptors of mosquitoes and ticks is pioneer work in this area. We have developed stably transformed cell lines expressing mosquito and tick G protein coupled receptors that are serving as critical tools for the screening of peptides or synthetic compounds that could be agonists or antagonists of these receptors. The G protein coupled receptors of arthropods are recognized by the pesticide industry as the next generation of successful pesticide targets based on the success of the pharmaceutical industry in developing therapeutic drugs for these type of receptors. Our research on the molecular mechanisms of reproduction in fire ant queens could lead to novel ways to control fire ants by interfereing with egg production. The cotton industry has benefited from the research on insecticide resistance.

Publications

• Pietrantonio, P. V., C. Jagge, S. Taneja-Bageshwar, R. Nachman, and R. Barhoumi. 2005. The mosquito Aedes aegypti (L.) leucokinin receptor is a multiligand receptor for the three Aedes kinins. Insect Mol. Biol. 14: 55-67.
• Pietrantonio, P.V., T. Junek, R. Baker, G. Cronholm, D. Fromme, G. Moore, D. Mott., R. R. Minzenmayer, E. Nino, J. Norman, R. Parker, R.P. Porter, K. Siders, N. Troxclair and C. G. Sansone. 2004. Monitoring for pyrethroid resistance in bollworm (Helicoverpa zea) in Texas-2003. 2004 Cotton Beltwide Conferences, San Antonio, TX, January 5-9. Proc. Beltwide Cotton Conference.
• Pietrantonio, P. V. 2004. Symposia on Insect Signal Transduction (Section 13) International Congress of Entomology in Brisbane, Australia. Leucokinin signal transduction in blood feeding vectors of disease, the mosquito Aedes aegypti (L.) and the Southern cattle tick, Boophilus microplus (Canestrini).
• Pietrantonio, P. V. 2004. Symposia on Biogenic Amines (Section 12) International Congress of Entomology in Brisbane, Australia. Understanding serotonin signal transduction in arthropods vectors of disease: Aedes aegypti (L.) and Boophilus microplus (Canestrini).

Progress 08/12/98 to 08/11/04

Outputs
We have focused on major pests that are a threat to agriculture, urban environments and public and animal health in Texas. These are the mosquitoes Aedes aegypti and Culex quinquefasciatus; the red imported fire ant Solenopsis invicta; the heliothines bollworm and budworm (Helicoverpa zea and Helitothis virescens) key pests of cotton, and the tick Boophilus microplus. We have determined that the levels of insecticide resistance in the west nile virus and St. Louis encephalitis vector, Culex quinquefasciatus, in Houston are due to increased esterase activity and may cause the failure of the then current control practices. Our data helped changed the control regime of these mosquitoes, by not applying malathion for several years. Presently in 2007, as resistance levels to malathion decreased, control has been reinitiated with malathion and pyrethroid, alternatively, helping preserve both insecticides since there is no vaccine for any of these diseases. We discovered and functionally characterized several G protein-coupled receptors in the dengue vector, the mosquito Aedes aegypti, such as those for serotonin, Aedes kinins and the diuretic hormone receptor, as well as a neuropeptide orphan receptor. The serotonin receptor is the first hormone receptor characterized from any mosquito species. The kinin receptor responds to the 3 Aedes kinins, it is a multiligand receptor. We discovered that aquaporin protein is present in tracheolar cells of mosquitoes which may explain how water moves inside the respiratory system of insects. Fire ant: we have cloned the first vitellogenin receptor from a social insect; this molecular knowledge of fire ant reproduction will lead to novel ways of fire ant control, perhaps affecting the expression and regulation of this receptor that is responsible for egg maturation. We have also cloned and characterized the first glucose transporter 8 from insects and also classified the glucose transporters from Drosophila that surprisingly had not been previously clasified. We also characterized a short neuropeptide F and currently are attempting to prove its functionality in mammalian cells. We discovered the myokinin receptor from the tick B. microplus, and we suspect that this receptor is involved in water balance. We also identified the first neuropeptide from ticks, periviscerokinin, in collaboration with German scientists at Jenna. Receptors from tick and mosquitoes have been cloned and expressed in a stable mammalian cell lines useful for pharmacological studies and to test analogs and antagonists acting on these receptors that may be precursors of pesticides against these pests.

Impacts
Monitoring for resistance to pyrethroids in bollworm has provided a scientific basis on which to advise producers in nine Texas counties on the utility or not of proceeding with pyrethroid applications against bollworm in cotton. This has saved ineffective applications, with the simultaneous benefit to the producers and the environment. This program serves to educate producers about problems associated with the use of low pyrethroid rates, which allows the survivorship of heterozygote resistant insects, and has served as a model adopted by the North east network. This project is of national importance as migration of resistant insects affects other states. We produce results to have an accurate definition of the resistance levels present in the population, both in terms of resistance ratio (level of resistance) and the frequency of resistant individuals. This impacts management practices. Basic knowledge on reproduction of fire ant queens and virgin queens will aid in managing the fire ant. As a social insect the status as pest is mainly due to the high reproductive capacity and invasive and aggressive characteristics. We expect that new information about queen reproduction will aid in management practices. We pioneered the molecular characterization of fire ant cDNAs other than the peptides injected by the sting. Work on mosquitoes G protein coupled receptors involved in diuresis includes both basic and potentially applied aspects.The study the molecular basis of endocrine function, aids to validate these receptors as targets for new insecticide development.

Publications

• Pietrantonio, P.V., T.A. Junek, R. Parker, E. Bynum, G. Cronholm, G. Moore, D. Mott, C. Sansone, K. Siders, N. Troxclair. 2006. Monitoring for pyrethroid resistance in the bollworm (Helicoverpa zea) in Texas, 2005. Suggestions for resistance monitoring and collaborative research. Plant Health Progress, Accepted with editorial revisions July 10/06 (Online Journal of Plant Management Network)
• Blandon, M.A. 2006. Master of Science Thesis. (supervised student) Target validation of a myokinin receptor from the Southern cattle tick Boophilus microplus (Canestrini. Department of Entomology. Texas A&M University.
• Pietrantonio, P.V. and Chen, M.-E. 2006. The short neuropeptide F-like receptor from the imported fire ant (Solenopsis invicta, Buren). XV International Congress of the International Union for the Study of Social Insects. Washington DC, USA. July 30- August 4, 2006. Abstract published in Proceedings. Pp. 199. Poster #470.
• Chen, Mei-Er and P.V. Pietrantonio. 2006. The short neuropeptide F-like receptor from the red imported fire ant, Solenopsis invicta Buren. J. Insect Science Vol.6:10. Abstract.
• Parker, R., M. Treacy and P.V. Pietrantonio. 2005. (FALL) Bollworm Management in Cotton Grown in the Coastal Bend Region of Texas During 2003-2005. In: 2005, Results of Insect Control Evaluations on Corn, Sorghum, Cotton and Bermudagrass in Texas Coastal Bend Counties & Gulf Coast Crop Hybrid/Variety Comparisons. 88-91. http://agfacts.tamu.edu/~rparker/Book2005.pdf

Progress 01/01/03 to 12/31/03

Outputs
We have successfully characterized the vitellogenin receptor from the fire ant queen and a paper has been accepted to be published in 2004. The Toxicology Laboratory in collaboration with several extension personnel and IPM agents conducted a survey for resistance of bollworm (Helicoverpa zea) to pyrethroids during the 2003 season; thirteen counties participated in this survey and a publication has been submitted for the Proceedings of the Cotton Beltwide Conference, 2004. We completed the characterization of a serotonin receptor from the mosquito Aedes aegypti. We continued to express and characterize two neuropeptide receptors from the mosquito Aedes aegypti and a publication is in preparation. Two Ph.D. students graduated in December of 2003, one worked on the vitellogenin receptor from the imported fire ant and the second on the characterization of a myokinin receptor from the tick Boophilus microplus.

Impacts
We have cloned the first vitellogenin receptor from a social insect, the imported fire ant; it is expected that this molecular knowledge of fire ant reproduction will lead to novel ways of fire ant control, perhaps affecting the expression and regulation of this receptor that is responsible for egg maturation. We have expressed and characterized pharmacologically a serotonin receptor from the mosquito Aedes aegypti, the first hormone receptor characterized from mosquitoes; the function of this receptor could be similar in other pest mosquitoes such as the malaria vector Anopheles gambiae.

Publications

• Chen, M.-E., Lewis, D.K., Keeley, L.L., and Pietrantonio, P.V. 2004. cDNA cloning and transcriptional expression analysis of the vitellogenin receptor from the imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae.). Insect Mol. Biol. (accepted).
• Dae-Weon Lee and P. V. Pietrantonio. 2003. In vitro expression and pharmacology of the 5-HT7-like receptor present in the mosquito Aedes aegypti tracheolar cells and hindgut-associated nerves. Insect Mol. Biol. 12: 561-569.
• Bokonon-Ganta, A. H., J. Bernal, P.V. Pietrantonio and M. Setamou. 2003. Survivorship and development of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on conventional and transgenic maize cultivars expressing Bacillus thuringiensis Cry9C and Cry1A(b) endotoxins. International J. Pest Management 49 (2): 169-175.
• Ph.D. Dissertation. Chen, M.-E. 2003. cDNA cloning and transcriptional regulation of the vitellogenin receptor from the imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Department of Entomology, Texas A&M University.

Progress 01/01/02 to 12/31/02

Outputs
Our previous results showed that mRNA encoding a putative aquaporin (AQP) (GenBank accession number AF218314) is present in the tracheolar cells associated with female Aedes aegypti Malpighian tubules. Now immunohistochemistry detected the protein, AeaAQP, also in tracheolar cells, suggesting its involvement in water movement in the respiratory system. When expressed in Xenopus oocytes, AeaAQP increased the osmotic water permeability from 15.10-6 m/s to 150.10-6 m/s, which was inhibited by mercury ions. No permeability to glycerol or other solute was observed. AeaAQP expressed in oocytes was solubilized as an homotetramer in non-denaturing detergent as deduced from velocity centrifugation on density gradients. Phylogenetic analysis of MIP (major intrinsic protein) family sequences shows that AeaAQP clusters with other native orthogonal array forming proteins. Specific orthogonal arrays were detected by freeze fracture analysis of AeaAQP oocyte membranes. We conclude that in tracheolar cells of the mosquito A. aegypti, AeaAQP is likely a highly water permeable homotetrameric MIP protein which natively can form two-dimensional crystals. During experiments aimed at cloning G protein-coupled receptors from worker red imported fire ants, several PCR products were obtained. One product of 685 bp encodes the full open reading frame of troponin C, a calcium-binding protein that is critical for muscle contraction. Other protein-encoding fragments were also identified, including PCR products corresponding to a putative glucose transporter protein (534 bp), elongation factor 2 (850 bp), filamin (600 bp), dynein-associated polypeptide (652 bp) and dihydrolipoamide dehydrogenase (434 bp). These PCR products may be suitable for various experiments, such control probes for Southern and northern blots, in situ hybridization, semi-quantitative PCR or to design specific primers to amplify longer genomic DNA fragments to aid in phylogenetic analysis, or for cytogenetics and mapping.

Impacts
We are collaborating with another laboratory in characterizing the molecules and molecular mechanisms that allow egg formation in the fire ant. We will attempt to develop novel means of fire ant control through the exploitation of this knowledge of reproductive function regulation. We have proposed a molecular mechanism on how the female of the mosquito Aedes aegypti ventilates its tracheoles by transporting water through the aquaporin water channel (AeaAQP). This is a new discovery that will help understand insect respiration in a broad sense, and specifically mosquito respiration. Boll weevil malathion resistance monitoring is a key service activity of this laboratory that helps the Boll Weevil Eradication Foundation make informed decisions about malathion treatments in cotton fields. Novel means of control for fire ants, mosquitoes and ticks may arise from the discovery of novel receptors that control various functions in these organisms, from reproduction to diuresis and feeding.

Publications

• Pietrantonio, P.V. and S. P. Holmes. 2002. Molecular characterization of G protein-coupled receptors from the blood feeding vectors Aedes aegypti (Diptera, Culicidae) and Boophilus microplus (Acari, Ixodidae). 10th IUPAC International Congress on the Chemistry of Crop Protection. August 4-9, Basel, Switzerland. Poster by P. V. Pietrantonio. Abstract published Book of Abstracts Vol. 1: 319.
• Pietrantonio, P.V., C. Jagge and C. McDowell. 2002. Hormone G protein-coupled receptors (GPCRs) from mosquito Aedes aegypti respiratory and excretory systems. International Symposium on Molecular Insect Science, Tucson, Arizona. May 28-June 2. Abstract.
• Holmes, S.P., R. Barhoumi, R.J. Nachman, and P.V. Pietrantonio. 2002. Discovery of the first arthropod myokinin receptor in the cattle fever tick, Boophilus microplus, by functional analysis in a transfected mammalian cell line. International Symposium on Molecular Insect Science, Tucson Arizona. May 28-June 2.Abstract.
• Duchesne, L., Hubert, J.- F., Verbavatz, J. M., Thomas, D., and P.V. Pietrantonio. 2003. Mosquito Aedes aegypti (Diptera, Culicidae) aquaporin present in tracheolar cells transports water, not glycerol, and forms orthogonal arrays in Xenopus oocyte membranes. Eur. J. Biochem. 270: 422-429.
• Pietrantonio, P.V. and Terry Junek . 2002. Susceptibility Status of Boll Weevil to Malathion in Texas. Proceed. Cotton Beltwide Conferences. Vol. 2. Atlanta, Georgia. January 8-12. Paper.
• Duchesne, J.-F. Hubert, Verbavatz, D. Thomas, Pietrantonio, P.V. 2002. Functional characterization of a mosquito Aedes aegypti aquaporin present in tracheolar cells associated with the Malpighian tubules presented as a Poster in the 2002 ESA Annual Meeting, Fort Lauderdale, Florida. Abstract.

Progress 01/01/01 to 12/31/01

Outputs
We focused on the most important pests of Texas in public health and agriculture. Basic and applied aspects were investigated. In cotton, we focused on the boll weevil and we monitored the resistance status to malathion of weevil populations from Lubbock and Burleson Co. This information will soon be published in the Beltwide Cotton Conference Proceedings. We participated in a project with Cotton Inc. and Dow Elanco for monitoring of resistance to Spinosad and Pyrethroids for the bollworm, Helicoverpa zea. With funding from NIH, we characterized a serotonin receptor and are characterizing a leucokinin-like receptor, both from the dengue vector, the mosquito Aedes aegypti. We cloned troponin C from the fire ant, Solenopsis invicta with funding from the Fire ant Research and management plan. The sequence was submitted to GenBank.

Impacts
Information on boll weevil susceptibility status was given to the Boll Weevil Eradication Found. and Cotton Inc. to monitor effectiveness of boll weevil eradication treatments. We discovered that serotonin may regulate tracheolar cell function in mosquitoes.

Publications

• Pietrantonio, P. V. , S. P. Holmes, C. Jagge and S. K. Frazier. 2001. Cloning of troponin C and other gene fragments from the red imported fire ant Solenopsis invicta Buren (Hymenoptera, Formicidae). Southwestern Entomologist, Suppl. Red Imported Fire Ant. In press.
• Pietrantonio, P. V., C. Jagge and C. McDowell. 2001. Cloning and expression analysis of a 5HT7 like serotonin receptor cDNA from mosquito Aedes aegypti female excretory and respiratory systems. Insect Molecular Biology 10: 357-370.
• Pietrantonio, P. V. and J. Sronce. 2001. Insecticide resistance status of boll weevil to malathion and of bollworm to pyrethroids in Texas. Beltwide Cotton Conference, Anaheim, CA, January 9 - 13. Proc. Beltwide Cotton Conference Vol. 2: 939-942.
• Pietrantonio, P. V. 2001. Cloning of the V-ATPase subunit c and other gene fragments from the Red Imported Fire Ant, Solenopsis invicta Buren. Annual Imported Fire Ant Research Conference. San Antonio, Texas, February 28-March 2, 2001. Oral presentation and Abstract in Proceedings of the Annual Imported Fire Ant Research Conference. In press.
• Payne, G. T., J. S. Bacheler, J. W. Van Duyn, R. D. Bagwell, B. R. Leonard, M. L. Boyd, B. L. Freeman, N. Liu , J. R. Weeks, A. Herbert, G. A. Herzog, D. R. Johnson, M. B. Layton, G. Lentz, R. Seward, S. H. Martin, P. V. Pietrantonio, M. E. Roof, M. J. Sullivan, R.K. Sprenkel. 2001. U. S. Cotton belt survey: testing the susceptibility of the bollworm, Helicoverpa zea (Boddie) to pyrethroid insecticides. Proc. Beltwide Cotton Conference Vol. 2: 782-785.

Progress 01/01/00 to 12/31/00

Outputs
We focused on the most important pests of Texas in public health and Agriculture. Basic and applied aspects were investigated. In cotton, we focused on the boll weevil and we monitored the resistance status to malathion of weevil populations from Lubbock, Burleson Co., Corpus Christi (Nueces Co.) and Rio Grande Valley (Hidalgo Co.). This information will soon be published. We participated in a project with IRAC and Dow Elanco for monitoring of resistance to SPINOSAD and PYRETHROIDS for the bollworm, Helicoverpa zea. With funding from NIH, we have begun to characterize a leucokinin receptor from the dengue vector Aedes aegypti; we have published this information. We cloned and localized an aquaporin from the same mosquito. The aquaporin cloned from A. aegypti was the first one from any mosquito species. We presented a new model of water movement in insect respiratory system where this protein may play a major role. We cloned and characterized a myotropin receptor from the Cattle fever tick, Boophilus microplus. We cloned a proton channel from the fire ant, Solenopsis invicta with funding from the Fire ant Research and management plan.The cDNA cloned from the fire ant is the first one encoding a functional protein, with the exception of the peptides found in the venom previously reported.

Impacts
The availability of the Boophilus receptor will help understand for the first time the structure-activity relationships for myotropin neuropeptides in arthropods, including insects. Our survey of resistance in the St. Louis encephalitis vector, Cx. quinquefasciatus mosquito from Houston is important to help mosquito control districts choose control strategies. Information on boll weevil susceptibility status was given to the Boll Weevil Eradication Found. and Cotton Inc.

Publications

• Holmes, S. P., Frazier, S. K. and Pietrantonio,P.V. 2000. Cloning of the 16-kDa V-ATPase proteolipid subunit from the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae)Arch. Insect Biochem. Physiol.In Press.
• Holmes, S., He,H., Chen,A.,Ivie,W. and Pietrantonio, P.V. 2000. Cloning and developmental expression of a lymnokinin-like receptor from the cattle fever tick, Boophilus microplus (Acari: Ixodidae). Insect Molecular Biology 9:457-465.
• Pietrantonio, P. V., Jagge,C., Keeley, L. and Ross,L. S. 2000. Cloning of an aquaporin-like cDNA and in situ hybridization in adults of the mosquito Aedes aegypti. Insect Molec. Biol. 9:407-418.
• Pietrantonio, P. V. Gibson, G., Petzel, D., and T. K. Hayes. 2000. Characterization of a leucokinin receptor from Aedes aegypti mosquito Malpighian tubules by photoaffinity-labeling. Insect Biochem. Molec. Biol. 30:1147-1159.
• Pietrantonio, P. V., Gibson,G., Nawrocki,S., Carrier,F. and Knight,W.P. Jr. 2000. Insecticide Resistance Status, Esterase Activity and Electromorphs from Mosquito Populations of Culex quinquefasciatus Say (Diptera: Culicidae), in Houston (Harris County), Texas. J. Vector Ecology: 25: 74-89.
• Drees, B. M. and Pietrantonio,P.V. 2000. Risk/benefit considerations for selecting Imported Fire Ant control products. Fire Ant Plan Fact Sheet (FAPFS #36).
• Pietrantonio, P.V., Nemec, L. and Sronce, J. 2000. Monitoring for resistance to cypermethrin in budworm and bollworm and to malathion in boll weevil in the Brazos River Bottom, Texas. Proc. Beltwide Cotton Conf. Vol.2: 1236-1239, Memphis, TN.
• Martin, S. H., Bacheler, J. S., R. D, Bagwell, M. L. Boyd, B. L. Freeman, G. A. Herzog, D. R. Johnson, M. B. Layton, B. R. Leonard, N. Liu, G. T. Payne, P. V. Pietrantonio, et al. 2000. Status of Bollworm, H.zea, susceptibility to pyrethroids: IRAC-US 1999 Update. Proc. Beltwide Cotton Conf.San Antonio, TX. Vol. 2: 1359-1365.

Progress 01/01/99 to 12/31/99

Outputs
Receptors from mosquito Aedes aegypti excretory system: We obtained the full-length clone of a serotonin receptor from a Malpighian tubule library; the receptor has been fully sequenced. A manuscript is in preparation. We also cloned, sequenced and localized an aquaporin protein in mosquito Aedes aegypti Malpighian tubule. A manuscript has been submitted to Insect Molecular Biology. We developed antibodies against a mosquito neuropeptide receptor that recognizes a protein of the expected size in mosquito Malpighian tubules, as determined by western blot. A grant was submitted to NIH and funded for three years for this project (2000-2003). G protein-coupled receptors from the Cattle fever tick, Boophilus microplus: We obtained a full-length clone for a neuropeptide receptor from the cattle fever tick, sequenced it and determined the developmental expression of the receptor throughout the life stages of the tick. A manuscript is in preparation. G protein-coupled receptors from fire ant: we obtained DNA probes from fire ant cDNA for a serotonin receptor, a sugar transporter and myosin heavy chain. We cloned the proton channel (subunit c) from the fire ant Vacuolar ATPase, and determined the transcript sizes by northern blot. Insecticide resistance monitoring: We determined the resistance status of Heliothines (H. zea and H. virescens) to the pyrethroid cypermethrin in Burleson County. We also determined the susceptibility status of boll weevils to malathion in Burleson County. These results will be published in the Proceedings of the San Antonio (TX) Beltwide Cotton Conference held in January 2000. We determined the resistance status of the Saint Louis Encephalitis vector, the mosquito Culex quinquefasciatus, to the insecticide malathion in Harris County. This work was in collaboration with the Harris County Mosquito Control Division. A manuscript was submitted and accepted for publication.

Impacts
Gene discovery of receptors in insects and ticks may provide new gene targets for the rational development of new insecticides/acaricides for their control. This will improve the control of vectors of human and cattle diseases, such as dengue fever, lime disease and cattle fever. This is important because arthropod vectors of disease, worldwide, are highly resistant or tend to rapidly develop resistance to applied insecticides and acaricides.

Publications

• Pietrantonio, P. V., Gibson, G., Nawrocki,S., Carrier, F., and W. P. Knight.2000. Insecticide resistance status, esterase activity and electromorphs from mosquito populations of Culex quinquefasciatus Say, in Houston, Texas. J. Vector Ecology (Accepted 1999).
• Pietrantonio, P. V. and Benedict, J. H. 1999. Effect of new cotton insecticide chemistries, Tebufenozide, Spinosad and Chlorfenapyr, on Orius insidiousus and two Cotesia species. Southwestern Entomologist 24(1): 21-29.
• Pietrantonio, P. V., K. Heinz.1999. Distribution of Heliothine larvae in Bt and non-Bt cotton in Texas. Beltwide Cotton Conference. Orlando, Florida, Jan. 5-8 1999. Proc. Beltwide Cotton Conferences. Vol. 2. 945-948.
• Martin, S. H., R. D, Bagwell, M. L. Boyd, B. L. Freeman, G. A. Herzog, D. R. Johnson, M. B. Layton, B. R. Leonard, N. Liu, G. T. Payne, P. V. Pietrantonio, M. E. Roof, M. J. Sullivan, J. W. Van Duyn, and J.R. Weeks.1999. Status of bollworm, Helicoverpa zea, susceptibility to pyrethroids: IRAC-US 1998 Update. Proc. Beltwide Cotton Conferences. Orlando, Florida, Jan. 5-8 1999. Vol. 2. 867-871.

Progress 01/01/98 to 12/31/98

Outputs
Objective A: Define new molecular targets for the rational design of novel insecticides. Task 1. Characterization of G protein coupled receptors from the red imported fire ant (Solenopsis invicta Buren, Hymenoptera, Formicidae). We have produced two PCR products corresponding to two different receptors: one corresponds to a serotonin receptor and the other to a peptide-hormone receptor, with simmilarity to neuropeptide Y, lymnokinin and other tachykinin-like hormone receptors. Task 2: Characterization of G protein-coupled receptors from the cattle fever tick (Boophilus microplus.): we obtained the full open reading frame for a receptor that exhibits high similarity to a lymnokinin receptor from the pond snail, Lymnaea stagnalis. We obtained this PCR product using 5' and 3' RACE methodology. We can now begin expression experiments in mammalian cells in order to test the hypothesis that it corresponds to a leucokinin-like receptor. Task 3. Molecular characterization of G protein-coupled receptors for kinin peptides that influence diuresis in the mosquito Malpighian tubule. A Malpighian tubule library was constructed. We are currently isolating a serotonin-like receptor, we expect to obtain the full length clone. We have ordered antibodies against the leucokinin-like receptor. Our research provides new knowledge on regulation of mosquito homeostasis. Objective B. Develop detection strategies for use in resistance monitoring and management for synthetic insecticides for key arthropod pests. Task 1: Insecticide resistance monitoring in the boll weevil (Anthonomus grandis grandis Boheman): we monitored for resistance in the boll weevil using vials coated with malathion. We tested trap collected weevils and weevils collected from squares. We tested a total of about 3,000 weevils. These data do not support the existence of malathion resistance in the boll weevil in populations collected around College Station, TX. This is significant considering the planned expansion of the Boll Weevil Eradication Program in Texas. Task 2: Monitoring resistance of bollworm (Helicoverpa zea (Boddie) and tobacco budworm (Heliothis virescens (F.) (Lepidoptera, Noctuidae) to pyrethroids and other insecticides. Data for 1998 continue to indicate high levels of resistance to pyrethroids in budworm and the probable presence of a pyrethroid resistance allele in bollworm, currently at very low frequencies in Texas. Pyrethroids do not control budworm effectively and pyrethroids should be used cautiously against bollworm. Monitoring for resistance should continue. Objective C. Develop a resistance management plan for target lepidopterans in transgenic (B. t.-CryIAc toxin) cotton Task 1. Determine larval distribution of heliothines in both B.t. and non-B.t. cotton. We completed two years of research. We concluded that heliothine larvae are present mainly towards the middle of the plant in B.t. cotton, and that the terminal is a key factor in heliothine mortality in B.t. cotton. Flowers in B.t. cotton do not appear to support higher numbers of larvae than in non-B.t. cotton. This is significant for the improvement of scouting guidelines for B.t. cotton.

Impacts
(N/A)

Publications

• Gill, S. S., P. B. Chu, P. Smethurst, P. V. Pietrantonio and L. Ross. 1998. Isolation of the V-ATPase A and c subunits cDNAs from mosquito midgut and Malpighian tubules. Arch. Insect Biochem. Physiol. 37: 80-90.
• Pietrantonio, P. V. and C. Jagge. 1998. Receptors and channels from female Aedes aegypti Malpighian tubule. Third International Symposium in Molecular Insect Science, Snowbird, Utah, June 5-10 1998. Published by The Center for Insect Science. The University of Arizona, Tucson, Arizona. Pp.101.(Abstract).
• Holmes, S. P, He, H., and P. V. Pietrantonio. 1998. Characterization of G protein-coupled receptors in the cattle tick, Boophilus microplus. Third International Symposium in Molecular Insect Science, Snowbird, Utah, June 5-10 1998. Published by The Center for Insect Science. The University of Arizona, Tucson, Arizona. Pp. 50. (Abstract).
• Pietrantonio, P. V. and T. Hayes. 1998. G protein-coupled receptors from mosquito Aedes aegypti Malpighian tubule. Keystone Symposium "Toward the genetic manipulation of insects". Taos, New Mexico. Jan. 9-15, 1998. Keystone Symposia on Molecular and Cellular Biology; Sponsored by the John D. and Catherine T. MacArthur Foundation (Abstract).
• Pietrantonio, P. V. and K. M. Heinz. 1998. Distribution of Heliothine larvae in B. t.- and non B. t. cotton in Texas. Proceedings of the Second World Cotton Conference, Athens, Greece, September 1998. (paper in press).