摘要:

The colour polymorphism of theDanaus chrysippuspopulation at Dar es Salaam, East Africa, is controlled at three major loci, each with two alleles. Two of the loci, one governing ground colour and the other forewing pattern, are closely linked. The third locus, determining hindwing pattern, assorts independently.Thirty‐eight broods raised from wild mated pairs, Fl and F2 generations gave 857 offspring of 23 genotypes (out of 27 possible). The forewing length, taken as an index of size, was investigated in relation to the genotype. Heterosis is evident at all three loci. The two linked loci show epistatic interaction of an unexpected kind: double heterozygotes are smaller than heterozygotes at only one locus but larger than double homozygotes. The heterotic effect at the third, unlinked locus is the most pronounced and is additive to that at the other two. Heterosis is more marked in males than females.The possibility that body size has importance in connexion with sexual selection, food resources and mimetic relationships is discussed.Analysis of gene and chromosome frequencies in the wild parents of 61 broods suggests that double heterozygotes for the two linked loci may have heterozygous advantage. Seventy‐eight per cent of chromosomes are repulsion phase: thus, there is pronounced linkage disequilibrium which must be maintained by selection as crossing over is almost 296. In particular, the chromosome carrying both dominant alleles in coupling is rare.Consideration of the centres of distribution and present ranges of the alleles at all three loci suggests that three geographical races,aegyptius, dorippusandalcippus, were isolated by forest barriers, during wet periods in the Pleistocene, in south‐west, north‐east and north‐west Africa respectively. They have probably expanded their ranges in the post‐glacial period to overlap and interbreed in central and east Africa. Either heterozygous advantage or seasonal (directional) selection or a combination of both is responsible for the persistence of the p

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01933.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

One family, the Phlaeothripidae, is recognized in the suborder Tubulifera, whereas extant species of Terebrantia are classified into seven families: Uzelothripidae, Merothripidae, Aeolothripidae, Adiheterothripidae, Fauriellidae (stat. n.), Heterothripidae and Thripidae. A phylogenetic analysis of the relationships between these families is given, based on consideration of 35 imaginal characters; however, the relationships of Uzelothripidae and Phlaeothripidae to the rest of the Thysanoptera remain equivocal. The Phlaeothripidae are either derived independently from Protothysanoptera, or else are the sister‐group of the Thripidae, the most specialized family of Terebrantia.Diagnostic characters, diversity, distribution and relationships of each family are discussed. Keys to family and, in Fauriellidae, to genus are provided.HolarthrothripsBagnall (=AdiheterothripsRamakrishna, syn. n.) andOligothripsMoulton are removed from Heterothripidae to Adiheterothripidae andFauriellaHood,OpisthothripsHood andRopotamothripsPelikan (=OsmanothripsPriesner, syn. n.) from Heteromripidae to Fauriellidae (stat. n.). These transfers leaveAulacothripsHood,HeterothripsHood andScutothripsStannard as the only genera in Heterothripida

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01934.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Three week old tadpoles ofHyla regillawere exposed to the insecticides temephos, fenthion, methyl parathion, chlorpyrifos, and malathion for 24 h at concentrations less than and at field applied rates as recommended for mosquito control in California. The thermal tolerance was significantly lowered by all chemicals and concentrations tested. Chlorpyrifos and methyl parathion were the most active compounds tested whereas malathion was the least toxic toH regillatadpoles. Activity was depressed, in comparison to control tadpoles, by the chemicals methyl parathion (100 ppb) and malathion (500 ppb).

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01935.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The cladistic relationships ofArchaeopteryx, the earliest known bird, are re‐examined and previous hypotheses of relationships evaluated. The morphology ofArchaeopteryxis redescribed. New interpretations of the fossils are presented, particularly in regard to the morphology of the pectoral girdle, manus, pelvic girdle, tarsus and pes. These new interpretations challenge some of the phylogenetic hypotheses recently presented and a new version of thecodontian relationships is suggeste

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01936.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY