EFFECT OF COMBINING METHYL EUGENOL AND CUELURE ON THE CAPTURE OF MALE TETHRITID FRUIT FLIES

Captures of males of species responding to methyl eugenol and cuelure were significantly reduced when both attractants were combined in a single trap as compared with the captures obtained in traps containing either of the attractants alone. When traps containing methyl eugenol and cuelure were placed side by side the number of flies responding to methyl eugenol was reduced, and the number of flies responding to cuelure was increased, as compared with captures in single isolated traps. Copyrigh

STERILIZATION OF DACUS CUCUMIS FRENCH (DIPTERA: TEPHRITIDAE) BY GAMMA RADIATION: III. EFFECT OF IRRADIATION IN NITROGEN ON STERILITY, COMPETITIVENESS AND MATING PROPENSITY

When newly emerged adult Dacus cucumis French were irradiated in nitrogen, following a 15 min exposure to an atmosphere of pure nitrogen, the degree of sterility induced by a given dose was less than that obtained with the same dose in air. To achieve sterility in males of approximately 98 per cent doses of 7 krad in air and 13 krad in nitrogen were required. With females, total sterility through infecundity was achieved by 6 krad in air and 13 krad in nitrogen. Based on the hatch of eggs from competitive mating tests, males receiving 14 krad in nitrogen were significantly more competitive than males given 9 krad in air. The optimal light intensity for mating of D. cucumis under artificial conditions was 16.2 1x. With this light intensity the mating propensity of males irradiated with 9 and 11 krad in air was significantly less than that of untreated males. The mating propensity of males given 14 krad in nitrogen approximated that of untreated males. Copyrigh

Effects of larval rearing temperature on the development of the mediterranean fruit fly, Ceratitis capitata

As the temperature at which larvae of C. capitata were reared decreased from 30° to 25° to 20° the yield of pupae from eggs increased from 15% to 25% to 30% and the mean weight of pupae decreased. Within each temperature regime the weight of pupae produced on successive days declined and the fat content of those pupae varied

STERILIZATION OF DACUS CUCUMIS FRENCH (DIPTERA: TEPHRITIDAE) BY GAMMA RADIATION: I. EFFECT OF DOSE ON FERTILITY, SURVIVAL AND COMPETITIVENESS

The effect of gamma radiation administered to newly emerged adults of Dacus cucumis French on sterility and competitiveness was evaluated. A dose of 11 krad caused almost complete sterility in males while females given 6 krad were totally sterile, through infecundity. Sterilized males showed reduced competitiveness. In competitive mating tests a dose of 7 krad gave the lowest egg hatch and this hatch was significantly lower than that given by 9 and 11 krad. In a paired comparison mating test, 7 and 9 krad treated males mated significantly less frequently than untreated males, but the ability of 6 krad treated males was unimpaired. Copyrigh

BIOLOGY AND CHEMICAL STERILIZATION OF THE FRUIT FLY DACUS CUCUMIS FRENCH (DIPTERA: TEPHRITIDAE)

Hitherto unavailable data on the biology and reproduction of Dacus cucumis French is presented. Sterilization of both sexes was achieved by topical application, tarsal contact, and oral administration of both metepa and hempa. Following topical application metepa was a better sterilant than hempa with male flies, but the reverse was true with females. When offered to adult flies in sugar, hempa was a better sterilant than metepa with both sexes and females required higher doses than males for complete sterility. At high levels of sterility the competitiveness of treated flies was reduced, but the data suggest, that following oral administration, hempa was less deleterious than metepa. Copyrigh

INSECTICIDE SUSCEPTIBILITY OF, AND METABOLISM OF DDT BY DACUS TRYONI (FROGGATT) AND DACUS CUCUMIS FRENCH (DIPTERA: TEPHRITIDAE)

The susceptibility of a strain of Dacus tryoni (Froggatt) from New South Wales and a strain of Dacus cucumis French from south‐east Queensland to the insecticides DDT, DDD, malathion, azinphos methyl and carbaryl was investigated. The available evidence suggests that these strains were susceptible to the above insecticides and therefore the data could be used as reference data should resistance in these species be suspected in the future. Both species were able to detoxify DDT to DDE with D. cucumis having a greater capability than D. tryoni. In both species penetration of C‐DDT over a post‐treatment period of 72 hr was biphasic. In the initial phase of rapid penetration, the rate of penetration followed first‐order kinetics. As the post‐treatment temperature was increased from 21 to 25 to 30°C both the rate of absorption and metabolism of DDT increased, but metabolism increased relatively more than absorption

DEVELOPMENTAL AND REPRODUCTIVE BIOLOGY OF SPODOPTERA LITURA (F.) (LEPIDOPTERA: NOCTUIDAE)

On artificial medium Spodoptera litura (F.) adults developed from first instar larvae in 23.4 days at 28°C. Mean female longevity was 8.3 days and mean fecundity was 2673 eggs. Mean male longevity was 10.4 days. No mating took place on the night of emergence and maximum mating response occurred during the second night after emergence. The mean number of matings per male was 10.3 and per female was 3.1. Males transferred a mean of 1,052,640 sperm per mating and eupyrene and apyrene sperm were present in approximately equal amounts. Both sperm types persisted in the utriculus of the spermatheca throughout the life of the female but no sperm were ever found in the lagena. The morphology of the male and female reproductive systems is described. Copyrigh

CHEMOSTERILIZATION OF PLUTELLA MACULZPENNZS (CURTIS) (LEPIDOPTERA: PLUTELLIDAE) BY EXPOSURE TO RESIDUES OF METEPA

Sterilization of adults of Plutella maculipennis (Curtis) by exposure to residues of metepa is reported. Males were sterilized by exposure for 3 hours to a residue of 1.57 mg/cm2 without any deleterious effect on longevity. With females high mortality occurred before a high degree of sterility was achieved. Copyrigh

Aliesterase activity and reproduction in Musca domestica: Effects of DDT and metepa

The chemosterilant metepa, administered orally and topically to adult M. domestica, was found to reduce aliesterase activity, to reduce the hatch of eggs, and when administered orally it also prolonged the pre-ovipositional period. Orally administered DDT had little effect on aliesterase but did reduce egg viability. Selection of a strain of M. domestica with diazinon, in an attempt to increase its resistance to diazinon, had the unexpected result of the flies becoming more susceptible but concomitantly their level of aliesterase was significantly increased. The aliesterase level of the immature stages of M. domestica is reported

MIXED‐FUNCTION OXIDASE ACTIVITY IN LARVAE OF HELIOTHIS PUNCTIGER WALLENGREN (LEPIDOPTERA: NOCTUIDAE)

The O‐demethylation of 4‐nitroanisole was used to evaluate mixed‐function oxidase (MFO) activity in last and penultimate instar larvae of H. punctiger. The specific activity of tissues of early fifth instar larvae in decreasing order were midgut, integument, fatbody, head capsule, and whole larva. Specific activity of the midgut rose rapidly from the beginning of the instar and then returned to a relatively low level when the insect stopped feeding. Fatbody specific activity increased until early in the last instar and remained at about this level until pupation. Specific activity of the integument was highest at the beginning and end of the instar and lowest in the middle. O‐demethylase activity per larva revealed that although midgut activity was low late in the fifth instar, the insect still possessed relatively high levels of MFO's in the integument and particularly the fatbody. Copyrigh