Location: Chemistry Research Unit
2011 Annual Report
1a. Isolation and identification of elicitors or biotic agents of induced plant volatile emission and other inducible plant defenses.
1b. Elucidation of the signalling interactions that mediate insect and insect elicitor induced plant defenses and volatile emission.
2. Identification and evaluation of chemicals that regulate or influence behaviors, including foraging, mating and oviposition, of important pest insects.
2a. Isolate and identify plant volatiles and insect produced pheromones that in combination attract male and female pepper and cranberry weevils.
2b. identification of oviposition deterring pheromone from pepper weevil.
2c. Interaction between Insect and Host Volatiles on Reproductive Development of Anastrepha spp. (Dipera:Tephrididae).
2d. Identification of oviposition deterring pheromones for Tephritid Fruit Flies.
2e. Influence of Fruit Volatiles on attraction of Small Hive Beetle.
Studies were initiated to identify all of the additive and interactive components of the cranberry weevil pheromone blend to enable development of an improved monitoring trap. Similar studies to elucidate pepper weevil attraction demonstrated that virgin females and males preferred volatiles of plants fed on by males, which contained a combination of male aggregation pheromone and plant volatiles. The interactive role of role of herbivore-induced volatiles and male aggregation pheromone is currently being evaluated. A series of harmless mineral and organic deterrents were compared to commercial pesticides in both the laboratory and field plots to assess their effectiveness in reducing pepper weevil feeding and oviposition. In multiple field trials under heavy pepper weevil infestation, the mineral and organic deterrents resulted in marketable yields and performed equally to the standard pesticide treatments.
Studies were conducted to identify natural products that regulate oviposition deterrence and attraction for pepper weevils. Solvent extractions were performed on large scale collections of female oviposition plugs to find behavioral modifying chemicals. Normal-phase chromatography was used to isolate both attractive and deterrent fractions which were then analyzed by gas chromatographic-mass spectrometric (GC-MS). Collection of volatiles emitted directly from oviposition plugs were also assayed for biological activity. One volatile chemical from plugs elicited attraction and searching behavior by female weevils. These studies provide critical information useful in the development of semiochemical mediated control programs for pepper weevils based ‘push-pull’ strategies.
Cha, D.A., Linn Jr., C.E., Teal, P.E., Zhang, A., Roelofs, W.L., Loeb, G.M. 2011. Eavesdropping on plant volatiles by a specialist moth: significance of ratio and concentration. PLoS One. 6(2):1-8.
Cabrera Cordon, A.R., Donohue, K.V., Khalil, S.M., Scholl, E., Opperman, C., Sonenshine, D.E., Roe, R.M. 2011. New approach for the study of mite reproduction: the first transcriptome analysis of a mite, Phytoseiulus persimilis (Acari: Phytoseiidae). Journal of Insect Physiology. 57:52-61.
Torto, B., Fombong, A.T., Arbogast, R.T., Teal, P.E. 2010. Monitoring Aethina tumida (Coleoptera:Nitidulidae) with baited bottom board traps: occurrence and seasonal abundance in honey bee colonies in Kenya. Environmental Entomology. 39(6):1731-1736. Cabrera Cordon, A.R., Kreschmar, J.V., Bacheler, J.S., Burrack, H., Sorenson, C.E., Michael, R.R. 2011. Resistance monitoring of Heliothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay. Crop Protection Journal. 30:1196-1201.
Addesso, K.M., Mcauslane, H.J., Alborn, H.T. 2011. Attraction of pepper weevil to volatiles from damaged pepper plants. Entomologia Experimentalis et Applicata. 138(1):1-11.
Gomez-Simuta, Y., Teal, P.E. 2010. Hormonas juveniles y su aplicacion en la tecnica del insecto esteril. In: Montoya, P., Toledo, J., Hernandez, E., editors. Moscas de la Fruta: Fundamentos y Procedimientos para su Manejo. Mexico:S y G Publishers. p. 357-368.
Schmelz, E.A., Kaplan, F., Huffaker, A., Dafoe, N.J., Vaughan, M.M., Ni, X., Rocca, J.R., Alborn, H.T., Teal, P.E. 2011. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize. Proceedings of the National Academy of Sciences. 108(13):5455-5460.