Biology of the hyperparasite Tetrastichus sp. (Hymenoptera : Eulopidae)

고차기생봉(高次寄生蜂) Tetrastichus sp.의 생태(生態)

This study was carried out to clarify the primary hosts of Tetrastichus sp. and its host relationship, development and reproductive capacity. Protopulvinaria mangiferae was parasitized by Aneristus ceroplastae, Microterys flavus, Coccophagus hawaiiensis. All of these primary parasitoid were attecked by the hyperparasite Tetrastichus sp.. Tetrastichus sp. was bound to be a solitary ectoparasite. Eggs were laid on the pupa of the primary host or attached to the inner surface of the integument of the scale insect. Threshold of the development and thermal constants for completion of immature stages were $9.8^{\circ}C$ and 272 day-degrees, respectively. At $25^{\circ}C$ the life span of both sexes without any food or with water were very short as compared with that with honey. After a pre-oviposition periods of about one day they laid on overage 220 eggs each, almost all during the first half of their life. The value of the net reproduction(Ro), the mean length of a generation(T) and the intrinsic rate of natural increase(r) were calculated as 99.6, 32days and 0.142 per female per day respectively.

고차기생자(高次寄生者) Tetrastichus sp.는 단기생성(單寄生性) 외부기생자(外部寄生者)로 일차기생자(一次寄生者) Aneristus ceroplastae, Microterys flavus, Coccophagus hawaiiensis의 종령유충(終齡幼蟲)이나 용에 산란(産卵)하였다. 란(卵)부터 성충(成蟲)까지의 발육한계온도(發育限界溫度)와 유효적산온도(有效積算溫度)는 각(各) $9.8^{\circ}C$와 272일도(日度)로 계산(計算)되었다. $25^{\circ}C$의 항온(恒溫), 16시간(時間) 조명조건(照明條件)에서 봉밀원액(蜂蜜源液)을 급여(給與)하며 사육(飼育)한 자(雌) 성충(成蟲)의 평균수명(平均壽命)은 40일(日) 이었다. 성충(成蟲)은 우화(羽化) 24시간후(時間後)부터 산란(産卵)을 시작하여 일생(一生)동안 평균(平均) 220란(卵)을 낳았으며, 50% 누적산란율(累積産卵率)은 산란개시(産卵開始) 14일(日) 후(後)에 달성(達成)되었다. 순번식율(純繁殖率)(Ro)과 세대기간(世代期間)(T), 내적자연증가율(內的自然增加率)(r)은 각(各) 99.6/세대(世代), 32일(日), 0.142/♀/일(日) 이었다.