| return migration of helicoverpa armigera (lepidoptera: noctuidae) during autumn in northern china. | the autumn migration of helicoverpa armigera (hübner) was observed with radar and two types of light-trap at langfang, hebei province, china in 2001 and 2002. the sudden increase in the proportion of h. armigera moths in the searchlight trap indicated migration into the area and catches increased 10-fold during the second half of the night due to the landing of migrants before dawn. the moths' migratory flights took place at up to 2000 m above the ground, and moths flew differentially at times, ... | 2005 | 16048684 |
| northward migration of helicoverpa armigera (lepidoptera: noctuidae) and other moths in early summer observed with radar in northern china. | the northward migration of helicoverpa armigera (hübner) and other moths in early summer was observed with radar in 2001 and 2002 at langfang, hebei province, china. migratory flights typically occurred at heights up to 1.2 km above ground level (agl), and high density layer concentrations frequently formed at 200-300 m agl. adult moths of local populations took off at dusk and ceased flight approximately 0.5 h before sunrise with area density peaking approximately 35 min after dusk. a strong du ... | 2004 | 15666739 |