乐都紫皮大蒜根蛆主要为害特性及杀虫剂对其毒杀活性的初步研究

Preliminary study on the main harmful characteristics of Ledu purple Allium sativum L.and the toxicidal activity of insecticides against it

根蛆是乐都紫皮大蒜的主要害虫,具有繁殖快、危害重等特点,为明确其取食特性,本文在室内将根蛆幼虫接于大蒜、白菜的根部,记录根蛆幼虫在各作物上的死虫数,并采用浸蒜法进行室内生物活性测定,评定22.4%螺虫乙酯悬浮剂(Suspension concentrate,SC)和25%呋虫胺可湿性粉剂(Wettable powder,WP)2种杀虫剂对根蛆的毒杀活性。结果表明:大蒜根蛆完成1个世代需要46 d,各虫态历期卵3 d、幼虫17 d、蛹20 d、成虫6 d,在温湿度系数为1.44~3.14(平均温度16~21℃,相对湿度30.3%~52.4%)时,根蛆存活率达到95%~100%;根蛆主要取食大蒜和白菜的根部及大蒜的鳞茎,且均能在大蒜和白菜上完成整个世代;22.4%螺虫乙酯SC和25%呋虫胺WP浸渍大蒜后,3 h时根蛆幼虫的校正死亡率均达到100%。综上可知,根蛆在一定温湿度条件下,既会取食大蒜,也会取食白菜,22.4%螺虫乙酯SC和25%呋虫胺WP对大蒜根蛆均有较好的杀虫活性。

Delia antiqua is a major pest of Ledu purple Allium sativum L.with the characteristics of rapid reproduction and great harm.In order to clarify its feeding characteristics,larvae are attached to the roots of Allium sativum L.and Brassica pekinensis to record the number of dead larvae.The biological activity is carried out by impregnation-garlic method to evaluate the toxicity of 22.4% Spirulina ethyl estersuspension concentrate(SC)and 25% dinotefuran wettable powder(WP)to Delia antiqua.The results show that it takes 46 days for Delia antiqua to complete one generation.The duration of each insect state is 3 days for egg,17 days for larva,20 days for pupa and 6 days for the adult.The survival rate of Delia antiqua reaches 95%~100% when the temperature-humidity coefficient is 1.44~3.14(average temperature 16~19.4℃,humidity 30.25%~52.4%).Delia antiqua mainly feeds on the roots and bulbs of Allium sativum L.and Brassica pekinensis,and it can complete the whole generation on these two vegetables.The corrected mortality of Delia antiqua larvae reaches 100% at 3 hours after Allium sativum L.is soaked with 22.4% Spirulina ethyl ester SC and 25% dinotefuran WP.In summary,Delia antiqua will feed on both Allium sativum L.and Brassica pekinensis under certain temperature and humidity conditions.In addition,22.4% Spirulina ethyl ester SC and 25%dinotefuran WP have good insecticidal activity against Delia antiqua.