Effects Of High Temperature On Survival And Reproduction Of Zeugodacus Cucurbitae (Coquillett) And Evaluation Of Trapping Effect Of Sticky Boards

Zeugodacus cucurbitae（Coquillett）is an important pest of fruits and vegetables crops.High temperature has an important effect on the survival and reproduction of melon fly.In the context of global warming,the occurrence of extreme short-term high temperature events is frequent.In order to evaluate the effects of short-term high temperature stress on the survival and reproduction of melon flies,and the trapping effect of different hanging modes of sticky boards in high temperature season.The effects of high temperature on the survival and reproduction of the flies and the trapping effect were evaluated by biological and ecological methods.It has important theoretical basis and practical significance for the monitoring,warning and management of the flies in the hot area.The main findings are as follows（1）The effect of high temperature on the survival of Z.cucurbitae（Coquillett）The short-term high temperature was not beneficial to the survival of melon flies.With the increase of temperature and the number of high temperature treatments（one high temperature treatments in one generation）,the survival rate and life span of melon flies decreased significantly.The survival rate and life span of F₁adults were the lowest when they were treated at 45℃for 1h.The survival rate and life span of females were 54.2%and 113 d（CK₁,100%and 180 d at 25℃）,and that of males were 45.8%and 106 d（CK₁,100%and 167 d at 25℃）.The survival rate and life span of F₂generation adults were the lowest after treated at 45℃for 1 h,36.1%and 51 d for females（CK₂,100%and 173 d at25℃）,33.3%and 49 d for males（CK₂,100%and 170 d at 25℃）;The pupae of F₃generation were all females,and the survival rate of adults was 0 after treated at 45℃for 1h,which was significantly different from that of the control（CK₃,the survival rate and life span of females at 25℃were 100%and 183 d,and that of males were 100%and 178 d）.（2）The effect of high temperature on the reproduction of Z.cucurbitae（Coquillett）Short-term high temperature was not beneficial to the reproduction of melon fllies.The results showed that the total oviposition,daily oviposition and single female oviposition of the F₁generation were significantly increased after being treated at 45℃for1 h,while the other treatments were decreased with the increase of temperature and high temperature frequency.The total,daily and single female ovipositions of F₁generation were 8411,91 and 701,respectively,which were higher than 7766,49 and 647 of the control after treatment at 45℃for 1h.After one and two times（one generation of short-term high temperature treatment）,the preoviposition period of the melon flies was shortened with the increase of temperature.After the F₁generation was treated at 45℃for1 h,the initial stage of oviposition was only 6 d and CK₁was 11.2 d.However,after the F₃generation experienced short-term high temperature treatment,the preoviposition period of the melon flies was prolonged with the increase of temperature,and it could not survive after 45℃treatment for 1 h.The egg hatching rate of F₁generation was the lowest at 45℃for 1 h,only 31.9%,and CK₁was 90.6%.After three consecutive short-time high temperature treatments（F₃generation）,all the adults died and could not lay eggs.Pupa weight,pupation rate and eclosion rate decreased with the increase of generation number.Pupa weight,pupation rate and eclosion rate of F₃treated at 45℃for 1h were the lowest,which were 0.0037 g（CK₃was 0.0256 g）,8.3%（CK₃was 94.2%）and 13.9%（CK₃was97.3%）,respectively.Females were more resistant to high temperature than males,and the sex ratio（female/male）increased with the increase of temperature.In the F₂generation,the maximum value was 6:1 at 45℃,which was higher than that of the control（1.12:1）.In the F₃generation,after being treated at 45℃for 1 h,the emerging adults were all females,and the sex ratio was 1:0.（3）Trapping effect of different hanging time on fruit fliesThe yellow and blue sticky boards were hung at 8:00-11:00,11:00-14:00 and14:00-17:00 respectively.The results showed that the two colors of sticky boards attracted the largest number of flies from 14:00-17:00,and the number of fruit flies trapped by the yellow sticky board was 30 flies,which was significantly higher than that by the blue sticky board.Secondly,the number of fruit flies trapped by yellow sticky board was 21flies and that by blue sticky board was 10 flies during 8:00-11:00.In the period of11:00-14:00,the trapping effect was the worst,only 5 flies were trapped by yellow sticky board,and only 2 flies were trapped by blue sticky board.The results showed that the fruit fly was active from 14:00 to 17:00,and the trapping effect was the best.（4）Trapping effect of different hanging board positions on fruit fliesThe trapping effect of the east,south,west and north hanging sticky boards was evaluated,and the results showed that the southern treatments had the best trapping effect,which was significantly higher than other hanging sticky boards in the same treatment.After 24 h,55 flies were attracted by yellow board,which was significantly higher than 26flies by blue board.And the number of flies attracted by yellow board increased gradually with the extension of plate hanging time.After 72 h,the number of flies increased to 159flies attracted by yellow board and 87 flies by blue sticky board.（5）Trapping effect of different hanging board heights on fruit fliesThe yellow and blue sticky boards were hung at the height of 0.6 m,1.2 m and 1.8 m respectively to evaluate the trapping effect of three hanging board heights on fruit flies.The results showed that the two colors of sticky boards had better trapping effect when they were hung at 1.2 m for the same hanging time,and 149 flies were trapped by the yellow board after 72 h,which was the highest among all treatments.