Source: NORTH DAKOTA STATE UNIV submitted to
MECHANISMS OF HOST-PLANT SELECTION IN THE WHEAT MIDGE
 
PROJECT DIRECTOR: Harris, M. O.
 
PERFORMING ORGANIZATION
SCHOOL OF NATURAL RESOURCE SCIENCES
NORTH DAKOTA STATE UNIV
FARGO,ND 58105
 
NON TECHNICAL SUMMARY: The wheat midge attacks developing wheat kernels and is a serious pest in North America, Europe and Asia. For related midges, such as the Hessian fly and rice gall midge, host plant resistance has, for many decades, been an effective means of pest management. For the wheat midge, success in finding host-plant resistance eluded scientists until recently when Canadian researchers reported the discovery of a highly effective resistance that causes the death of wheat midge larvae before they establish a feeding site. This newly discovered resistance is conferred by a single gene. Within the next 3-5 years, it is anticipated that common and durum wheat cultivars, all carrying this single resistance gene, will be deployed across the Northern Plains of North America. There are concerns that the wheat midge will overcome this resistance gene through evolutionary modification. Combining, within a single wheat cultivar, traits that kill larvae with traits that reduce the number of eggs placed on the plant by the adult female might provide more sustainable control of the wheat midge. We will explore the potential for reducing egg numbers by studying fundamental aspects of the oviposition behavior of the wheat midge. Specific research objectives are to determine whether wheat midge females 1) locate wheat heads using odor cues and 2) respond to chemical and tactile traits of wheat heads during on-plant examining behaviors.
 
OBJECTIVES: Determine if female wheat midge exhibit upwind flight when stimulated by volatile chemicals from wheat heads. Quantify behavioral responses of mated females to high- and low-ranked grasses. Develop models of wheat heads that can be used for future testing of plant stimuli
 
APPROACH: To determine if wheat midge females orient to volatile chemicals from wheat heads, females will be tested in a wind tunnel containing wheat plants with and without wheat heads. Females will be scored for upwind flight, approach and landing. To quantify responses to high- and low-ranked grasses, foraging behavior of mated females will be quantified in arenas that contain both types of grasses. Using focal animal sampling, we will score time of arrival on the head, examining behaviors, and flight. To develop models of wheat heads that can be used for future testing of plant chemical stimuli, we will make extracts of wheat heads, apply extracts to simple models of wheat heads, and observe females foraging in arenas containing these models.
 
CRIS NUMBER: 0193542 SUBFILE: CRIS
PROJECT NUMBER: ND05900 SPONSOR AGENCY: NIFA
PROJECT TYPE: NRI COMPETITIVE GRANT PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: Sep 1, 2002 TERMINATION DATE: Aug 31, 2005

GRANT PROGRAM: ENTOMOLOGY/NEMATOLOGY
GRANT PROGRAM AREA: Plant Systems

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
211311011304.2100%

CLASSIFICATION HEADINGS
KA211 - Insects, Mites, and Other Arthropods Affecting Plants
S3110 - Insects
F1130 - Entomology and acarology
G4.2 - Reduce Number and Severity of Pest and Disease Outbreaks


RESEARCH EFFORT CATEGORIES
BASIC 50%
APPLIED 50%
DEVELOPMENTAL (N/A)%

KEYWORDS: wheat; grasses; cecidomyiidae; behavior; host selection; plant insect relations; chironomidae; insect behavior; insect ecology; plant insect resistance; insect genetics; genes; females; insect flight; volatile substances; crop pest models; insect larvae; mortality; insect physiology; defense mechanisms

PROGRESS: Oct 1, 2003 TO Sep 30, 2004
Behavioral observations of ovipositing wheat midge females were conducted under natural light conditions during the summer months when adults are active in the field. Using scan sampling and focal animal sampling, we compared behavior of females on three pairs of treatments 1)groups of females on pre- versus post-anthesis heads of a stimulatory hard red spring wheat, 2) groups of females on pre-anthesis heads of a stimulatory versus less stimulatory hard red spring wheat, and 3) groups of females on pre-anthesis heads of hard red spring wheat versus barley. Results showed that decisions about egglaying are made after the female lands on the wheat head and examines the modified leaves that comprise the florets of the wheat head. It also appears that landing and examining behavior is stimulated by the presence of other wheat midge females. Females held singly in a cage with a wheat head exhibit extremely low levels of activity.

IMPACT: 2003-10-01 TO 2004-09-30 Our research is aimed at improving the use of host plant resistance for the control of wheat midge. Little is known about the egg-laying behavior of the wheat midge. Yet this behavior is key to the pest status of the wheat midge. We will study fundamental aspects of this behavior such as host preference and movement between plants after single bouts of egglaying. A better understanding of the behavior of the adult female may create new opportunities for breeding wheat plants that are less attractive for egglaying females.

PUBLICATION INFORMATION: 2003-10-01 TO 2004-09-30
No publications reported this period

PROJECT CONTACT INFORMATION
NAME: Harris, M. O.
PHONE: 701-231-6445
FAX: 701-231-8557