走査型電子顕微鏡を用いてモモノゴマダラノメイガとマツノゴマダラノメイガ成虫の触角上の感覚器について形態,数,分布を比較検討した。観察に先立ち同一試料で検体の全面を観察できる特殊な試料固定装置を考案作製した。両種の触角からはBähm's bristle, s. styloconicum, s. trichodeum, s. chaeticum, s. squamiformium, s. basiconicum, s. auricillicum, s. coeloconicumの合計8種類の感覚器が見いだされ,これらの感覚器の形態および分布様式には性差あるいは種間差はなかった。一方,いずれの種においても,s. trichodeumは雌よりも雄に多く,その数は8,000∼8,500本(雄),6,500∼6,800本(雌)であり,逆にs. basiconicumは雄(760本)よりも雌(1,400本)に多く見いだされた。しかし,残りの7種類の感覚器に関しては数の上での性差は両種にはみられなかった。以上の結果から,モモノゴマダラノメイガとマツノゴマダラノメイガは,すでにそれぞれの触角上の嗅覚感覚器の匂い物質に対する感受性は一部分化しているが,感覚器の大きな形態的分化はまだ起きてないと結論した。
Larvae of the common cutworm Spodoptera litura infected with Japanese isolates of a microsporidium Nosema mesnili showed acute paralysis as early as 3 days postinoculation, and larval death followed within several days. Invasion of the parasites into the outer layer of larval ganglia occurred, and histopathological changes of the infected ganglia were evident. Small numbers of spores were observed in the cell body of the infected ganglia.
Incidence of egg parasitoids of Riptortus clavatus before and during soybean cultivation was investigated by placing host eggs on soybean and other leguminous plants in Tsukuba between May and October, 1985, and between April and May, 1986. Gryon japonicum, G. sp., Ooencyrtus nezarae, O. sp., and Anastatus japonicus were identified as the egg parasitoids. G. japonicum was found on soybeans from middle July to early October, mainly when pods were growing. This parasitoid was also common on white clover, common vetch and alfalfa as early as May, before soybean cultivation.
Developmental durations for egg and nymphal stages of Orius sp. were measured at four constant temperatures of 20, 25, 30, and 35°C. The durations for egg and nymphal stages decreased significantly with rise of temperature at 20-30°C. However there was no difference between the durations at 30°C and at 35°C. The developmental zero (T0) and the thermal constant (K)were calculated from the data obtained at 20°C, 25°C, and 30°C. T0 and K were estimated to be 11.6°C and 57.8 day-degrees for the egg stage and 11.9°C and 158.7 day-degrees for the nymphal stage, respectively. Hatchability was relatively low at 20°C and 35°C. Most nymphs died before adult emergence at 35°C.
The developmental success of larvae was superior on Osmanthus×Fortunei compared with that on O. fragrans var. aurantiacus. The results suggested that adult beetles showed a better harmonization of their ovipositional periods with the seasonal growth of immature leaves of O.×Fortunei.
Development time of nymphs and adults, daily fecundity and survival rate of adults were determined for the apterous and alate viviparae of Toxoptera citricidus (KIRKIALDY) reared on Gitrus natsudaidai HAYATA, at 20 and 25°C under 16L-8D photo-period regime. The nymphal and pre-reproductive periods of apterae were significantly shorter than those of alatae. The age specific fecundity of apterae was consistently higher than that of alatae. The net reproductive rate (R0) and capacity for increase (rc) of apterae were higher than those of alatae. The capacity for increase of each morph was higher at 25°C than that at 20°C.