STERILIZATION BY GAMMA RADIATION FOR THE CONTROL OF THE NAVEL ORANGEWORM PARAMYELOIS TRANSITELLA (WALKER) (LEPIDOPTERA: PHYCITIDAE)

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4127196

Husseiny, M M

The possibility of using the sterile insect technique for the control of the navel orangeworm Parainyelois transitella (Walker) was investigated. Studies were made to deterinine if gamina rays could be used to sterilize the navel orangeworm without causing serious adverse effects on mating behavior. A cobalt- 60 unit was set to give approxiinately 197500 rads per hour. Mature pupae, 8 days old, were found to be the most desirable stage to irradiate without causing appreciable damage to the insect. This stage was also the most convenient to handle and could be easily sexed. At a dosage of 160000 rads no adults were able to merge. At 80,000 rads, over 50% of both males and feinales were still able to mate but reduction in egg laying was considerable in the case of irradiated females. Coinplete sterility was obtained in both sexes when mature pupae were exposed to 50000 rads. At this dose, longevity, egg laying, and mating habits did not seem to be affected. No effect on fertility was detected when the insects were exposed to 20000 rads or less but drastic reduction in fertility was obtained at 30000 and 40000 rads of gamma radiation. When exposing other stages of the navel orangeworm to gainina radiation, eggs were more susceptible to radiation dainage than mature larvae and the latter stage inore so than mature pupae. After obtaining complete sterility, laboratory tests were carried out to determine the efficiency of sterile males and females in reducing the number of fertile eggs deposited by normal moths. This was done by introducing sterile and fertile insects into oviposition cages in varying ratios. The results showed that sterile females could be used as successfully as sterile inales and that inuch better results might be obtained by using both sterile males and females for the control or eradication of the navel orangeworm. Mating behavior in the laboratory and field was also investigated. By dissecting the feinales and counting the spermatophores in the bursa copulatrix, it was possible to determine the number of times each female has mated. From these investigations it was clear that most females mate but once in the field and only 8% mated twice. Both males and females seemed to mate with about the same frequency when the sex ratio is about 1: 1 which is the ratio found in this insect. (TCO)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-003573
• OSTI ID: 4127196
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AGE
AGRICULTURE
BIOLOGY AND MEDICINE
COBALT 60
EGGS
FRUIT
GAMMA RADIATION
INSECTS
ORANGES
PARASITES
RADIATION DOSES
RADIATION EFFECTS
REPRODUCTION
STERILIZATION