| The main species of fruit flies that hazard cherries and other fruits are Drosophila Suzuki and Drosophila melanogaster, ecology and chemistry prevention research were done to master the characteristics of their occurrence and harm law, including life tables, circadian rhythm cycle, supercooling point, diapause sensitivity test field populations, different types of pesticides virulence and field efficacy trials and so on.1 Artificial feedingPupa survival rate reared by A and grape were 76.7% and 73.3%, respectively. If eggs were reared by A, their p upation rate and pupa weight were larger than the control’s,larvae survival rate, eclosion rate and fecundity of each female were similar to the control’s, but the larvae developmental period were lower than the control’s.2 EcologyThe intrinsic rate of increase(r), the finite rate of increase(λ), the net reproduction rate(R0) and the mean generation time(T) were 0.12 day–1, 1.13 day–1, 27.57 offspring, and 28.04 days, respectively, for D. suzukii and 0.17 day–1, 1.19 day–1, 38.17 offspring, and 21.27 days, respectively, for D. melanogaster. The use of the age-stage, two-sex life table method to study D. suzukii and D. melanogaster yielded considerably more accurate and useful data than would have been obtained by using the female-only age-specific life table. These life tables can be used for population growth projections, designing mass-rearing programs, and for pest management.The circadian rhythm of D. suzukii oviposition to have a single pattern with a peak from 20:00-24:00, while the peak oviposition of D. melanogaster was from 16:00-4:00(the next day). Neither D. suzukii nor D. melanogaster showed a daily pattern of egg hatch; the single peak of egg hatch for D. suzukii occurred 24-32 h after oviposition, while that for D. melanogaster followed a bimodal pattern, with the first peak of egg hatch from 0-4 h after oviposition and the second from 32-36 h after oviposition. Pupation in D. suzukii showed a single peak from 8:00~16:00, while in D. melanogaster pupation followed a bimodal pattern, with peaks from 4:00-8:00 and 12:00-20:00. Eclosion of of D. suzukii adults followed a unimodal pattern, and generally took place from 0:00-8:00, while that of D. melanogaster also showed a single peak, generally from 0:00-12:00. Meanwhile copulation of D. suzukii, which showed a bimodal pattern, was concentrated from 0:00-12:00 and 20:00-24:00(the next day), while copulation of D. melanogaster showed a single peak, generally from 0:00-12:00. Both D. suzukii and D. melanogaster had a preference for feeding in light, and in a 24 h photoperiod the percentages of feeding insects were 80.8and 81.1, respectively.The supercooling point SCP and freezing point(FP) of D. suzukii and D. melanogaster varied significantly among individuals, D.Suzuki larva had the highest SCP and FP(-12.62±0.24,-11.95±0.21)℃, 1 day old pupae had the lowest SCP and FP(-17.62±0.44,-16.66±0.41)℃; 3-day-old pupae of D.melanogaster had the highest SCP and FP(-11.97 ± 0.24,-11.75 ± 0.23)℃, 20-day-old male adults’ SCP and FP were the lowest(-21.50±0.39,-20.25±0.40)℃.Early emergenced adult of Drosophila Suzuki were reared under six different conditions, adult of Drosophila Suzuki rared in the condition of 10℃, L8: D16 appeard dipause, and the diapause rate was 81%, under other 5 conditions their ovarian development were at different stages, but did not appear diapause. Early emergenced adult of Drosophila Suzuki were reared under diapause(10℃, L8: D16) and non-diapause(10℃, L16: D8) for 10 days and both the ovarian anatomy and cross section ultrastructure can be seen diapaused ovarian were in follicular stage while non-diapause ovarian oocytes have traces of yolk deposition.3 Chemical ControlsSix kinds of pesticides that are widely used in the fruit tree management as the test agents, measuring resistant susceptibility of laboratory population and six populations inside and outside the region of Shandong Province, using stomach-tag combination virulent measurement method. Integrated population virulence determination results in all regions, relative toxicity of imidacloprid and avermectin are below emamectin benzoate, spinosad, azadirachtin and cyhalothrin. In addition to regional populations Laiwu azadiracht in LC50 resistance ratio was 3.38, sensitivity was reduced, the six populations inside and outside the region of Shandong Province are at a sensitive stage to the six kinds of pesticides.Pesticides on fruit fly larvae virulent were stronger than adults, and Drosophila Suzuki were more sensitive to pesticides. Carbamate insecticide indoxacarb, neonicotinoid insecticide thiamethoxam lethal effect on fruit flies were lower, neonicotinoid insecticide acetamiprid lethal effects on Drosophila melanogaster were higher than Drosophila Suzuki. Pyrethroid insecticide lambda-cyhalothrin lethal virulence were higher than pyrethroid insecticide bifenthrin, biologics spinosad and emamectin lethal virulence were the strongest.The control effect to cherry fruit flies of three kinds of pesticides(2.5% spinosad, 5% emamectin benzoate, 5% C hlorfluazuron) were between 81.08%-89.19%; and the control effect of 10% imidacloprid were relatively lower than other various pharmaceutical, its control effect of 6,000 times and 8,000 times were 70.27% and 56.76%. |
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