Effect of Female Flight Activity on Reproduction in the Navel Orangeworm (Amyelois transitella)

Thumbnail Image
Date
2016-01-01
Authors
Rovnyak, Angela
Major Professor
Advisor
Thomas W. Sappington
Aaron J. Gassmann
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Organizational Unit
Entomology

The Department of Entomology seeks to teach the study of insects, their life-cycles, and the practicalities in dealing with them, for use in the fields of business, industry, education, and public health. The study of entomology can be applied towards evolution and ecological sciences, and insects’ relationships with other organisms & humans, or towards an agricultural or horticultural focus, focusing more on pest-control and management.

History
The Department of Entomology was founded in 1975 as a result of the division of the Department of Zoology and Entomology.

Related Units

Journal Issue
Is Version Of
Versions
Series
Department
Entomology
Abstract

The navel orangeworm Amyelois transitella is an economically important pest of almonds and pistachios in California. Successful management at the correct spatial scale requires an understanding of insect dispersal, particularly relative to when mating occurs. A previous study found that unmated navel orangeworms were capable of flying longer distances than previously assumed, but it was not clear how mating affects dispersal in this species, nor how dispersal affects fecundity. To address these critical unknowns, females were allowed to fly on a flight mill on the night either before or after mating, and flight performance was assessed. Following the flight test, the females were set up for oviposition. The eggs produced were collected daily and monitored for fertility and compared to those produced by females that were minimally-handled and by tethered but unflown controls. Timing of flight relative to mating did not affect fecundity, nor did the distance or duration of flight. However, mated females flew significantly longer and farther than unmated moths. In addition, trials were conducted where females were forced to fly for predetermined periods of time up to 2 h. There was no effect of forced flight on fecundity. There was an increase in weight lost with time flown, but the effect was weak. The data from this study revealed no obvious trade-off between flight activity and reproductive output in female navel orangeworm. The results indicate that most females mate in or near their natal habitat, and some may disperse relatively long distances to oviposit elsewhere. It is also possible that the long flights by mated females observed on the flight mills represent appetitive ranging behavior, perhaps searching for oviposition host cues, rather than purposeful dispersal. In that case, net displacement in the field would be less because of meandering flight patterns. Although it is unclear if the navel orangeworm is a true migrant, mating is associated with different female behavior on the flight mills, including propensity to make longer-distance flights than unmated females. Long-flight capacity without loss of fecundity is an important feature contributing to the colonizing ability of this opportunistic pest.

Comments
Description
Keywords
Citation
Source
Subject Categories
Copyright
Fri Jan 01 00:00:00 UTC 2016