| Sugarcane(Saccharum officinarum Linn.) is an important economic crop,and it also is amomentous raw material for light industry, chemical industry and energy. Therefore, thedevelopment of sugarcane production has a very important position and role in improving thequality of human’s life, promoting the development of agriculture and related industries, andeven the development of the whole national economy. However, sugarcane thrips is an importantpest of sugarcane, it majorly damaged leaves and filed the blade suction sap, which caused thevictim showing yellow-white chlorotic leaves scars, severely leaves get brown and tips kinkeddry, worsely, the top few leaves rolled together which can not stretch. From April2011to July2012, the writer conducts the investigation and study in the experimental fields where is Instituteof Sugarcane Research, Fujian Agriculture and Forestry University, studying the biology ofsugarcane thrips (F. serratus) during the seedling stage of sugarcane, occurred habits, fieldactivities, damaging characteristics, sticky card trapping situation and controling effect, etc. Thearticle also analyzes the dominant species and field population dynamics and rules of sugarcanethrips (F. serratus). The results are summarized as following:(1) The species of thrips: there are2main species in sugarcane field, belonging to2familiesand2genera. There were both phytophagous, including Fulmekiola serratus Kobus is classifiedto Thripidae family, Fulmekiola genus and Haplothrips chinensis is classified to Phlaeothripidaefamily, Haplothrips genus. F. Serratus was the dominant species, covering99.64%of allcollected specimens.(2) The main biological characteristics of F. serratus: F. serratus is classified tohyperpaurometamorphosis insects, which has the developmental stages of egg, nymph and adult.There are4instars during nymph stage:1st instar nymph and2nd instar nymph can be activityand feed sugarcane leaves as food,3rd instar nymph and4th instar nymph basically were notfeeding. F. serratus crawled slowly when be disturbed, they usually oviposited in verdant andlarge leaves. The body of F. serratus is very small. Adults and nymphs can use itsrasping-sucking mouthparts to file blade juice, and they like to hide in unexpanded central leaves.The generation duration of F. serratus is very short, the thrips occured a total of5generations during the sugarcane seedling stage (April to July). In the late of April, the adults begin toreproduce and harm the seedlings. Nymphs begin to emergence in the early to mid-May. Thetime from oviposition to hatching for female adults is generally3-9d. The total growth time ofnymphs were about6-8d. The duration of each instar was about1-2d, the time of “prepupa” was1-3d. The whole period of generation in summer was generally17d. Females covered for97.1%of the total speciesmens, the proportion between female and male is33:1. Therefore it can beidentified that parthenogenesis is the main reproduction way.(3) The population dynamic of F. serratus in field: the population dynamic of sugarcanethrips (F. serratus) was changing with time. F. serratus sporadically occured in April, a smallamount to appear in the early of May. The number rapidly increased after mid-May, and thereare all insect states on sugarcane in the fields. The number reached its peak which sticky cardcapturing the thrip reached thousands in the late June and it was showed the explosion in state,the number began to slowly decrease after the end of July.(4) The comparison on population dynamic of F. Serratus among different sugarcanevarieties: in the survey of12varieties, the insect-leaf rates of F. Serratus was distributed within13.84%-29.07%, the variety yunzhe05-51suffered the lightest, the second was yuegan34.However, the most seriously damaged was the variety ROC16whatever damaged from thedegree of adults, nymphs or totals.(5) The capture effectiveness for kinds of insects on colored sticky card in sugarcane field:the kinds of main pest for sticky card capturing concluded sugarcane thrips, aphids, leaf bettles,leafhoppers, moths and so on. The kinds of neutral insects were mosquitoes,flies. The kinds ofnatural enemy insects were ladybirds, parasitic bees. The number proportion of pests, neutralinsects and natural enemies for sticky card capturing was109:16:1, The proportion of pests,neutral insects and natural enemies for yellow ones was172:23:1, the proportion of pests, neutralinsects and natural enemies for blue ones was68:13:1, the proportion of pests, neutral insectsand natural enemies for green ones was103:10:1, the proportion of pests, neutral insects andnatural enemies for white ones was21:5:1.(6) The capture effectiveness for F. serratus on colored sticky card in sugarcane field: there was a significant difference for capturing F. serratus among colored sticky card. The resultsshowed that significantly more thrips on blue captured sticky cards than on the other coloredones. And more thrips on yellow ones than green ones in field, but their numbers was notdiffered significantly. The capture effectiveness for F. serratus on white ones was the worst. Nosignificant difference was found in capture effectiveness among the3heights (the sticky cardedge away from plant tip was0cm,10cm,20cm), but the effect of10cm height wasoptimal.There was significant difference in capture effectiveness between2positions (east-west,south-north) and the effect of east-west position was optimal.(7) Controling effect of different pesticide on F. serratus in field: the durable effect of2.5%bifethrin was an increasing trend after spraying insecticide. The durable effect of5%acetamipridEC was an increasing trend despite the trend was increasing and falling during7-10d afterspraying insecticide. The durable effect of10%cypermethrin was an increasing trend after1-7dspraying insecticide, but the control efficiency was a sharply declining after the10th dayspraying insecticide. The durable effect of emamectin formate was up and down after1-7dspraying insecticide, and the pharmacodynamic was declining in the10th day, in addition, thecontrol efficiency was low side. The durable effect of1.8%avermectin and lorsban was betterafter the1st day pesticide application, but the trend has been downward after4-10d sprayinginsecticide. |
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