亚洲玉米螟成虫寿命与繁殖力的地理差异

为探明亚洲玉米螟Ostrinia furnacalis繁殖力的地理差异,比较了亚洲玉米螟5个不同地理种群海南乐东(LD)、江西南昌(NC)、山东泰安(TA)、河北廊坊(LF)和黑龙江哈尔滨(HEB)的成虫寿命、产卵历期、产卵量,并分析了这些参数与各种群地理纬度的关系.成虫寿命随纬度升高而延长,从南到北各种群雌虫寿命分别为10.20、13.68、13.90、13.95 d和16.40 d,雄虫寿命分别为8.35、12.50、13.62、13.71 d和14.30 d；产卵历期随纬度升高而延长,从南到北各种群分别为7.45、10.45、11.90、10.62d和13.15 d；产卵量随纬度升高而增大,乐东产卵量显著低于其他种群,从南到北各种群产卵量分别为351.55、500.09、522.90、546.76粒和577.95粒/雌.这些研究结果初步揭示了亚洲玉米螟繁殖略策的地理差异.

Geographic variation in longevity and fecundity of the Asian corn borer, Ostrinia furnacalis Guene (Lepidoptera: Crambidae)

The Asian corn borer Ostrinia furnacalis (Guene) is a major pest of corn Zea mays (L.). It is widely distributed in China, encountering great diversity in climatic conditions among localities along the country's north-south axis and exhibiting considerable diversity in life history among different geographic populations. Populations show clear differences in voltinism, critical day-lengths, postdiapause emergence times and cold tolerance. However, little is known about geographic variations in the species' fecundity. In this study, specimens of O. furnacalis were collected from five different latitudes: Ledong, Hainan (LD, 18.8N, 109.2E); Nanchang, Jiangxi (NC, 28.8N, 115.9E); Taian, Shandong (TA, 36.2N, 117.1E); Langfang, Hebei (LF, 39.5N, 116.7E) and Haerbin, Heilongjiang (HEB, 44.9N, 127.2E). They were reared on an artificial diet under L16:D8 at 28 C for three consecutive generations, and the relationships between longevity, pre-oviposition period, oviposition period, fecundity and collection latitude were analyzed. Significant differences among populations were found in longevity, pre-oviposition and oviposition period, and egg production. Longevity was positively correlated with latitude (10.20d, 13.68d, 13.90d, 13.95d and 16.40d for females; 8.35d, 12.50d, 13.62d, 13.71d and 14.30d for males). The pre-oviposition period of the TA population was significantly shorter (2.00d) than that of other populations (LD: 2.75d, NC: 3.23d, LF: 3.33d, HEB: 3.25d). Oviposition period length tended to increase with latitude (7.45d, 10.45d, 11.90d, 10.62d and 13.15d) and was significantly shorter in the LD population. Mean egg production per female was also positively correlated with latitude and was significantly lower in the LD population (351.55 eggs) than in the other populations (NC: 500.09 eggs, TA: 522.90 eggs, LF: 546.76 eggs, HEB: 577.95 eggs). The results show the presence of geographic variation in the reproductive tactics of O. furnacalis and reveal significantly higher fecundity in the northern than in the southern populations, suggesting a possible reason for the generally higher losses of corn to Asian corn borer damage in northern than in southern China.