Insect-flower Relationship in the Temperate Deciduous Forest of Kibune, Kyoto : An Overview of the Flowering Phenology and the Seasonal Pattern of Insect Visits

Abstract

In 1984-1987, insect visitors to flowers were bimonthly or weekly surveyed on a total of 115 plant species or 49 families in the temperate deciduous forest of Kibune, Kyoto, Japan. Flowering was observed from early April to early November. The number of plant species that concurrently bloomed was nine to 17 from May to September. The monthly total number of flowering plant species peaked twice in May (34 spp.) and September (33 spp.). From April to August, floweringperiods were staggeredamong congeneric woody species, e.g., Lindera, Rubus, Hydrangea and Deutzia. A total of 4603 individuals of 889 species in 12 orders of Insecta and 2 orders of Arachnoidea were collected. The most abundant order was Hymenoptera (46 % of the total number of individuals), and it was followed by Diptera (30 %) and Coleoptera (14%). The number of species was highest in Diptera (37 %), followed by Hymenoptera (32 %) and Coleoptera (17 %). The numbers of both species and individuals of all the insect groups peaked in June and September. There were six families, 14 genera and 73 species in Apoidea. Abundant families were Halictidae (36 % of individuals), and followed by Bombinae (24 %), Xylocopinae (18 %), Andrenidae (8 %), Hylaeinae (5 %) and Nomadinae (5 %). Andrenidae and Nomadinae appeared only before August, whereas Halictidae, Xylocopinae, Bombinae and Apinae were active throughout the flowering season. Cluster analysis separated 49 plant families into five groups: 13 families were mainly visited by Hymenoptera, 17 by Diptera, five by Coleoptera and two by Hemiptera. The other 12 families were visited by various insect groups. Flowers visited by hymenopterans were further separated into plant families mainly visited by Bombinae, Xylocopinae, Halictidae, Apinae, Xylocopinae, Megachilidae, Vespoidea, Ichneumonoidea and others. Flower preference was compared among insect orders and among families. The most preferred plant family was Saxifragaceae in Lepidoptera, Coleoptera and Hymenoptera, Labiatae in Hemiptera and Umbelliferae in Diptera. Flower preference greatly varied among families in Apoidea. The most preferred plant family was Umbelliferae in Colletidae, Saxifragaceae in Halictidae and Andrenidae, Compositae in Megachilidae, Balsaminaceae in Bombinae, and Rosaceae in Apinae.