ハムシ亜科

In this paper the author summarized the knowledge of biology of earlier stages of Japanese Chrysomelinae, based on the author's observations conducted both in the field and laboratory comparing with many fragmentary contributions reported by many entomologists in the past. At present, thirty-one species belonging to thirteen genera of the subfamily are known from Japan. However, biological studies on the Japanese species of the subfamily have not been investigated satisfactorily. Only fragmental observations of eleven species were published previously, and of the other twenty species biological observations have been completely absent ; observations of three species, Chrysomela lapponica, C. tremulae and Dlochrysa fastuosa, were conducted in Europa and of one species, Paropsides duodecimpustulata, in Corea, but nothing has been done on those species in Japan. The author investigated the biology of eleven species. Of which five species, Chrysomela vigintipunctata subsp. costella, Gastrophysa atrocyanea, Phytodecta (Brachyphytodccta) rubripennis, Plagiodera versicolora subsp. distinct a and Potaninia cyrtonoides, were observed from oviposition to emergence, two species, Chrysolina (Lithoptheroides) exanthematica and Chrysomela populi, were from the first larval instar to emergence and four species, Gastrolina japonica, G. thoracica, Linaeidea aenea, Phytodecta (Phytodecta) rufipes, were on the last larval instar to emergence. Chrysolina (Lithoptheroides) exanthematica (Wiedemann, 1821) : In Fukuoka city, larvae are found in the middle of April, and new adults emerge from late in May. The second larval stage takes five to ten days, the third larval stage five to eleven days, the last (the fourth larval stage) fifteen to twenty-five days and pupal stage nine to thirteen days. Pupation takes place under the ground. Chrysomela PoPuli Linne (.1758) : At Mt. Hiko (Fukuoka Pref.), larvae are found in the middle of May. The second larval stage takes about four days, the last (the third) larval stage eight days, prepupal stage two days and pupal stage six days. Larvae molt twice and attain the last larval instar. Pupation takes place no under surface of leaves. Female oviposits in cluster on under surface of leaves. Chrysomela vigintipunctata subsp. costella (Marseul, 1888) : In Fukuoka city, eggs and larvae are found about in the middle of April and adults emerge from late in April from those larvae. Egg stage takes about five days, the first larst larval stage four to six days, the second larval stage three to six days, the last (the third) larval stage four to seven days, prepupal stage two to four days and pupal stage seven days. Pupation takes place on under surface of leaves. Female oviposits in cluster on under surface of leaves. Gastrolina japonica (Harold, 1877) : At Mt. Daisen (Tottori Pref.), larvae and pupa are observed late in May and the larvae pupate on under surface of leaves and new adults emerge after five days. Gastrolina thoracica Baly (1864) : Larvae are found at Akan (Hokkaido) in the middle of July and at Mt. Daisetsu (Hokkaido) early in August. The larvae collected at Mt. Daisetsu pupated on under surface of leaves and after five days new adults emerged. Gastrophysa atrocyanea Motschulsky (1860) : In Fukuoka city, eggs are found in the middle of March and the eggs hatched late in March. From those larvae new adults emerged late in April. Egg stage takes eleven days, the first larval stage five to ten days, the second larval stage three to six days, the last (the third) larval stage five to six days, prepupal stage three to four days and pupal stage nine to ten days. Pupation takes place under the ground. Female oviposits under surface of leaves in cluster. Linaeidea aenea auct. (nec Linne, 1758) : Larvae are observed at Mt. Daisetsu (Hokkaido) late in July and oviposition.at Mt. Daisen (Tottori Pref.) late in May. The larvae collected at Daisetsu pupated on under surface of leaves and new adults emerged after six days. Female oviposits on under surface of leaves in cluster. Phytodecta (Brachyphytodecta) rubripennis (Baly, 1862) : In Fukuoka city, eggs and young larvae are found in the middle of April and adults emerge from those larvae from the beginning of May. Egg stage takes about three to six days, the first larval stage three to five days, the second larval stage two to four days, the third larval stage two to four days, the last (the fourth) larval stage three to four days, prepupal stage one to two days and pupal stage six to eight days. Pupation takes place under the ground. Female oviposits in cluster on under surface of leaves. Phytodecta (Phytodecta) rufipes auct. (nec De Geer, 1775) : At Mt Daisen (Tottori Pref.), larvae are found early in June, and the larvae pupate under the ground from the middle of June and new adults emerge after six days. Plagiodera versicolora subsp. distincta Baly (1874) : In Fukuoka city, hibernated adults are activated from the beginning of April and the beetles oviposit from the middle of April. From the eggs new adults emerge from the middle of May. Egg stage takes five to nine days, the first larval stage three to six days, the second larval stage three to five days, the last (the third) larval stage three to five days, prepupal stage one to two days and pupal stage three to four days. Pupation takes place on under surface of leaves. Female oviposits in cluster on under surface of leaves. Potaninia cyrtonoides (Jacoby, 1885) : In laboratory, female collected at Mt. Hiko (Fukuoka Pref.) began to oviposit on 18 th May on surface of petri dish in cluster and the eggs were hatched 27 th May. The larvae pupated from 16 th June and new adults emerged from 22nd June. Egg stage takes about nine days, the first larval stage six days, the second larval stage four days, the third larval stage two days, the last (the fourth) larval stage eight days, prepupal stage two days and pupal stage six days. Pupation took place under the ground. Of the larval stage, the most conspicuous differences appear in number of moltings. Species belonging to Chrysomela, Plagiodera, Linaeidea, Gastrophysa, Phaedon, Phyllodecta, Prasocuris and Hydrothassa molt twice, those of Leptinotarsa, Chrysolina, Phytodecta and Potaninia, molt three times and Paropsides duodecimpustulata molts four times, in order to attain the last larval instar. In the pupal stage, the most conspicuous differences are seen in the place of pupation. Species belonging to Genera Chrysomcla, Plagiodara, Linaeidea, Gastrolina, Prasocuris and Hydrothassa pupate on the host plants. The pupae are always found gregariously on the under surface of leaves of the host plants. On the other hand, species of Leptinotarsa, Dlochrysa, Chrysolina, Gastrophysa, Phaedon, Phyllodecta, Phytodecta and Potaninia pupate under the ground. Thus, the species of genera Chrysomela, Plagiodera, Linacidea, Prasocuris, and Hydrothassa (perhaps Gastrolina also) molt twice and pupate on the host plant, while those Gastrophysa, Phacdon and Phyllodecta molt twice and pupate under the ground. Both the groups of genera, therefore, may be regarded as to represent separate biological groups. It may be pointed out that the genus Phyllodecta belongs to tribe Phyllodectini based on the classification of adults but it is different in biology from Phytodecta of the same tribe, and is more closely allied biologically to the genera Gastrophysa and Phacdon which belong to the different tribe Phaedonini.