入侵紅火蟻(Solenopsis invicta)自2003年起入侵台灣，目前在新竹縣有零星族群分布。本研究即針對新竹縣新豐鄉、新埔鎮、關西鎮等3鄉鎮進行500 m x 500 m大面積蟻相普查，利用3S技術(GIS、RSS、GPS)規劃出983個採樣點並進行GPS導航調查，共計誘得山蟻亞科Formicinae、家蟻亞科Myrmicinae及針蟻亞科Ponerinae等三亞科共15屬螞蟻，且螞蟻族群在春~秋季(3~10月)覓食活動相當頻繁，其中家蟻亞科採集管數最多，佔87.7%之比例，又以大頭家蟻屬Pheidole佔採集管數45.57%為最優勢族群，並在關西鎮s789採樣點成功偵測到1061隻入侵紅火蟻。針對3鄉鎮7個已發生入侵紅火蟻通報點劃分出之56個緩衝區內，仍以大頭家蟻屬螞蟻出現頻率最高，在和興村入侵紅火蟻通報點進行蟻相變化監測，結果顯示入侵紅火蟻消失後出現了單家蟻屬Monomorium及大頭家蟻屬螞蟻族群。本研究亦針對入侵紅火蟻常溫存活率進行測定，結果顯示僅餵食5μl水之入侵紅火蟻平均存活天數為35.25 ± 6.39天，對照組為23 ± 4.76天；致死溫度測定結果顯示入侵紅火蟻致死率隨溫度增加而提高，在52oC沒餵水環境1分鐘即達100%致死率，46oC以下10分鐘之死亡率皆低於50%。經由半致死時間測定結果顯示，入侵紅火蟻隨溫度增加半致死時間則隨之降低，在43oC之半致死時間LT50為72.9分鐘、44 oC為38.1分鐘、45oC為11.6分鐘。 The red imported fire ant (Solenopsis invicta) has invaded Taiwan in 2003, and distributed at some areas in Hsinchu county. Utilizing 500m x 500m large area in this research to investigate ant population in Sinfong, Sinpu, and Guansi townships of Hsinchu county. The 3S techniques (GIS, RSS, GPS) were applied to select 983 sampling sites and investigated by GPS navigation. Fifteen ant genera were sampled, inclusive of three subfamilies, Formicinae, Myrmicinae, and Ponerinae. Ant forage activity is very active during March and October. Myrmicinae is the most dominate population among three subfamilies and occupied 87.7% of attracted tubes. Moreover, Pheidole is the most population among fifteen genera and occupied 45.57% of attracted tubes. There were 1061 numbers of S. invicta detected in s789 sampling site in Guansi township. There were 56 buffer areas divided in seven fire ant reported sites among three townships, and Pheidole was also the most dominate population in buffer areas. We also monitored ant population variation in Hesing village fire ant reported site, Monomorium and Pheidole ants emerged while S. invicta was extinct. Survivival days of S. invicta in room temperature was tested. S. invicta could survive about 35.25 ± 6.39 days added with 5μl water, while control was about 23 ± 4.76 days. Lethal temperature assay of S. invicta demonstrated that mortality increased as temperature rose. The mortality reached to 100% under 52 oC without water for 1 minute, while the mortality was beneath 50% under 46 oC for 10 minutes. Lethal time assay of S. invicta demonstrated that LT50 decreased as temperature rose. LT50 of 43 oC was 72.9 minutes, 44 oC was 38.1 minutes and 45oC was 11.6 minutes.