Phylogenetic relationships among the holometabolous insect orders were inferred from cladistic analysis of nucleotide sequences of 18S ribosomal DNA (rDNA) (85 exemplars) and 28S rDNA (52 exemplars) and morphological characters. Exemplar outgroup taxa were Collembola (1 sequence), Archaeognatha (1), Ephemerida (1), Odonata (2), Plecoptera (2), Blattodea (1), Mantodea (1), Dermaptera (1), Orthoptera (1), Phasmatodea (1), Embioptera (1), Psocoptera (1), Phthiraptera (1), Hemiptera (4), and Thysanoptera (1). Exemplar ingroup taxa were Coleoptera: Archostemata (1), Adephaga (2), and Polyphaga (7); Megaloptera (1); Raphidioptera (1); Neuroptera (sensu stricto = Planipennia): Mantispoidea (2), Hemerobioidea (2), and Myrmeleontoidea (2); Hymenoptera: Symphyta (4) and Apocrita (19); Trichoptera: Hydropsychoidea (1) and Limnephiloidea (2); Lepidoptera: Ditrysia (3); Siphonaptera: Pulicoidea (1) and Ceratophylloidea (2); Mecoptera: Meropeidae (1), Boreidae (1), Panorpidae (1), and Bittacidae (2); Diptera: Nematocera (1), Brachycera (2), and Cyclorrhapha (1); and Strepsiptera: Corioxenidae (1), Myrmecolacidae (1), Elenchidae (1), and Stylopidae (3). We analyzed approximately 1 kilobase of 18S rDNA, starting 398 nucleotides downstream of the 5' end, and approximately 400 bp of 28S rDNA in expansion segment D3. Multiple alignment of the 18S and 28S sequences resulted in 1,116 nucleotide positions with 24 insert regions and 398 positions with 14 insert regions, respectively. All Strepsiptera and Neuroptera have large insert regions in 18S and 28S. The secondary structure of 18S insert 23 is composed of long stems that are GC rich in the basal Strepsiptera and AT rich in the more derived Strepsiptera. A matrix of 176 morphological characters was analyzed for holometabolous orders. Incongruence length difference tests indicate that the 28S + morphological data sets are incongruent but that 28S + 18S, 18S + morphology, and 28S + 18S + morphology fail to reject the hypothesis of congruence. Phylogenetic trees were generated by parsimony analysis, and clade robustness was evaluated by branch length, Bremer support, percentage of extra steps required to force paraphyly, and sensitivity analysis using the following parameters: gap weights, morphological character weights, methods of data set combination, removal of key taxa, and alignment region. The following are monophyletic under most or all combinations of parameter values: Holometabola, Polyphaga, Megaloptera + Raphidioptera, Neuroptera, Hymenoptera, Trichoptera, Lepidoptera, Amphiesmenoptera (Trichoptera + Lepidoptera), Siphonaptera, Siphonaptera + Mecoptera, Strepsiptera, Diptera, and Strepsiptera + Diptera (Halteria). Antliophora (Mecoptera + Diptera + Siphonaptera + Strepsiptera), Mecopterida (Antliophora + Amphiesmenoptera), and Hymenoptera + Mecopterida are supported in the majority of total evidence analyses. Mecoptera may be paraphyletic because Boreus is often placed as sister group to the fleas; hence, Siphonaptera may be subordinate within Mecoptera. The 18S sequences for Priacma (Coleoptera: Archostemata), Colpocaccus (Coleoptera: Adephaga), Agulla (Raphidioptera), and Corydalus (Megaloptera) are nearly identical, and Neuropterida are monophyletic only when those two beetle sequences are removed from the analysis. Coleoptera are therefore paraphyletic under almost all combinations of parameter values. Halteria and Amphiesmenoptera have high Bremer support values and long branch lengths. The data do not support placement of Strepsiptera outside of Holometabola nor as sister group to Coleoptera. We reject the notion that the monophyly of Halteria is due to long branch attraction because Strepsiptera and Diptera do not have the longest branches and there is phylogenetic congruence between molecules, across the entire parameter space, and between morphological and molecular data.
[1]
Ryuichi Matsuda,et al.
MORPHOLOGY AND EVOLUTION OF THE INSECT THORAX
,
1970
.
[2]
The Origin of Wings and Venational Types in Insects
,
1943
.
[3]
S. Holm.
A Simple Sequentially Rejective Multiple Test Procedure
,
1979
.
[4]
H. E. Hinton.
The Phylogeny of the Panorpoid Orders
,
1958
.
[5]
John F. Lawrence,et al.
EVOLUTION OF THE HIND WING IN COLEOPTERA
,
1993,
Canadian Entomologist.
[6]
R. Willmann.
The phylogenetic system of the Mecoptera
,
1987
.
[7]
J. Kukalová-Peck.
Ephemeroid wing venation based upon new gigantic Carboniferous mayflies and basic morphology, phylogeny, and metamorphosis of pterygote insects (Insecta, Ephemerida)
,
1985
.
[8]
L. Smith,et al.
Molecular evidence that the myxozoan protists are metazoans.
,
1994,
Science.
[9]
E. Zimmer,et al.
Systematics of holometabolous insect orders based on 18S ribosomal RNA.
,
1993,
Molecular phylogenetics and evolution.
[10]
A. Sharov.
Basic arthropodan stock : with special reference to insects
,
1966
.
[11]
R. Snodgrass.
The genital ducts and the ovipositor
,
1934
.
[12]
R. Kinzelbach.
The Systematic Position of Strepsiptera (Insecta)
,
1990
.
[13]
C. Bult,et al.
TESTING SIGNIFICANCE OF INCONGRUENCE
,
1994
.
[14]
K. Bremer,et al.
BRANCH SUPPORT AND TREE STABILITY
,
1994
.
[15]
J. Kukalová-Peck.
Origin and evolution of insect wings and their relation to metamorphosis, as documented by the fossil record
,
1978,
Journal of morphology.
[16]
W. Wheeler,et al.
Insect homeotic transformation
,
1994,
Nature.
[17]
R. Matsuda.
Morphology and evolution of the insect head
,
1965
.
[18]
The Abdominal Morphology of Povilla adusta Navas (Polymitarcidae) and of Ephemeroptera in General
,
1971
.
[19]
John M. Hancock,et al.
Complete sequences of the rRNA genes of Drosophila melanogaster.
,
1988,
Molecular biology and evolution.
[20]
J. Felsenstein.
Cases in which Parsimony or Compatibility Methods will be Positively Misleading
,
1978
.
[21]
J. Kukalová-Peck.
Fossil history and the evolution of Hexapod structures
,
1991
.
[22]
Bernard J. Crespi,et al.
Do long branches attract flies?
,
1995,
Nature.
[23]
W. Rice.
ANALYZING TABLES OF STATISTICAL TESTS
,
1989,
Evolution; international journal of organic evolution.
[24]
J. Hedgpeth,et al.
Arthropod Phylogeny with Special Reference to Insects
,
1979
.
[25]
A. Kluge.
A Concern for Evidence and a Phylogenetic Hypothesis of Relationships among Epicrates (Boidae, Serpentes)
,
1989
.
[26]
N. P. Kristensen.
Phylogeny of Insect Orders
,
1981
.
[27]
Z. T. Poonawalla.
The Respiratory System of Adult Odonata. Part 1: The Spiracles
,
1966
.
[28]
R. A. Crowson.
The Phylogeny of Coleoptera
,
1960
.