摘要:

Summary.All stages of the Coccid Bug,O. urticœ, were collected and bred in the laboratory to investigate the number of instars and the morphology.The first and second instar larvæ are sexually indistinguishable. The male has two larval, two nymphal, and a winged adult stage. The female has three larval and a wingless adult stage.Breeding and growth take place rapidly between May and the end of August. The males attain the adult stage in March, and are found in very small numbers until the middle of June. The females begin to form their brood‐sacs in May or June, and reproduce throughout the summer months. From the beginning of September to the end of January the insects hibernate.The occurrence ofO. urticøEin its different instars is summed up in the table see (p. 303), from the events noted during the time I have had the Coccids under observation.In the external morphology it is noticeable that there is a breaking‐up in the wax plates to coincide with the segmentation of the insect, and extra intermediate blocks are cut off from the originally‐placed main blocks. The glandular setæ become more numerous from the first to fourth instar of the female, and the outline of the insect becomes almost circular, the abdomen shortening considerably in the adult stage. The male nymph of the third and fourth instars possesses external wing‐stumps on the mesothorax, and an indication of metathoracic halteres is seen on the fourth instar nymph. The adult male has a pair of mesothoracic wings, but flies very little and only lives for

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07152.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07153.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07154.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

摘要:

Summary.1. Skins of the 16 known species of Pteroclidæ have been examined in the British Museum, and 14 species of Mallophaga referable to two genera, both peculiar to Sand‐Grouse, have been collected from 14 host species.2. The methods of collecting and preparation are described.3. A list of hosts and parasites is given.4. Judged by their prasites, Sand‐Grouse are related to the grouse and pheasants.5. Descriptions of a new genus and twelve new species are given, and a key appe

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07155.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07156.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07157.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07158.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07159.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

摘要:

Summary.A review is given of the literature on the parasitism of Braconids of the generaDinocampusandPerilitus. The records at present available show that these insects are parasites of beetals, usually of the adult insect, but occasionally of the Iarva also.Dinocampus(Perilitus)rutilusis a prasite of adult weevils ofSitona lineata, and has also been obtained fromS. hispidula.This Braconid is common throughout the British Isles and is widely distributed in Europe.Both sexes are equally numerous, but parthenogenesis may occur. Only males have been reared from unmated females.The adult Braconids lived in Captivity usually about a fortnight, but a few survived for three or four weeks.The female effect oviposition in the apex of the abdomen of the host. pursuing the beetle assiduously until her. task is accomplished.The egg, when laid, is very small, but, after oviposition, the chorion expands and the egg enlarges to a remarkable degree, attaining to over a thousand times its original size.During the development of the embryo a cellular membrane may be distinguished immediately beneath the chorion, and the cells of this membrane increase in size as the larva develops.When fully formed, the larva ruptures the chorion and becomes free in the abdomen of the host.At the same time the cells of the embryonic membrane commence to dissociate and to become dispersed thronghout the bodycavity of the beetle.They assume a globular form and become of an opaque white colour, due to the presence of fatty matter, whicli they absorb from the body‐fluid of the host.As the larva grows, the cells increase in size and their nuclei become of irregulnr shape.In their later stages the cells of the embryonic membrane consist almost entirely of globules of a fatty nature. The membiaries of the cells become much stretched and rupture with the least pressure, so that the fatty contents are discharged into the body‐fluid of the beetle.When the Braconid larva is young, as many as 600 or 700 dissocaiated cells of the embryonic membrane have been counted within the body of the host, but as the larva grows the cells diminish in number.The dissociated cells of the embryonic membrane with their ingested fatty contents constitute the principal food of the larva in its later stages. Their remains may be found in numbers within the mid‐gut of the full‐grown larva.If the parasite larva happens to die when still young, the cells of the embryonic membrane dissociate and continue to develop, sometimes attaining to an abnormally large size.Clomparatively few observations have been made in regard to the dissociation of the embryonic membrane in other parasitic Hymenoptera, and, while opaque white globnles have been recorded as occurring in certain parasitized insects, they have usually been mistaken for “disorganised fat‐body

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07160.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1928.tb07161.x

出版商:Blackwell Publishing Ltd    

年代:1928

数据来源: WILEY