Macrolepidoptera

Abstract: The Ditrysia, which comprise the great majority of extant Lepidoptera, are divided into thirty superfamilies (instead of the fifteen to twenty usually recognized). Several of them are conceived in a new sense and one is newly proposed: the Choreutoidea. The Dudgeoneidae are reassigned to the Cossoidea, the Sematuridae and Uraniidae to the Geometroidea, while the Anthelidae and Lasiocampidae are placed in the Lasiocampoidea, a superfamily differing from the Bombycoidea mainly in retaining unfused prothoracic coxae in the larva. The Alucitoidea comprise the Tineodidae, Oxychirotidae and Alucitidae, and the Drepanoidea the Epicopeiidae and Drepanidae. Sister group relationships are recognized between the following superfamilies: Yponomeutoidea / Gelechioidea, Cossoidea / Sesioidea, Alucitoidea / Pterophoroidea, Hesperioidea / Papilionoidea and Drepanoidea / Geometroidea. Reliable monophyletic groups are the Mimallonoidea + Lasiocampoidea + Bombycoidea and the Hedyloidea + Rhopalocera. A few clades are suggested at a higher level, e.g. the Apoditrysia, the Obtectomera (based on two autapomorphies: pupa with fixed abdominal segments 1-4, and imago with modified pulvilli) and the Macrolepidoptera (mainly based on the shape of the first axillary sclerite in the forewing base). Several other changes are introduced: the ' Pseudocossinae' are restricted to the Madagascan genus Pseudocossus Kenrick (possibly belonging in the Brachodidae); the Macropiratinae (stat. n.) are regarded as the most primitive Pterophoridae; the Charideinae are transferred from the Zygaenidae to the Thyrididae; within the Thyrididae, the Argyrotypinae are regarded identical with the Siculodinae (syn. n.). Finally, two families are newly proposed within the Apoditrysia: the Simaethistidae (fam. n.) and Whalleyanidae (fam. n.). The superfamily relationships of these two families have not been determined.

Abstract: Data are presented on the richness of Macrolepidoptera faunas in the Indo-Australian tropics, and on the proportional representation of the various families. Both overall diversity and diversity of families decline with latitude and also with isolation from major land areas. Exceptions are noted. Measures of alpha-diversity from quantitative light-trap samples indicate that diversity within the tropics is often greatest at altitudes around 1000 m, declining above that level. Diversity is much lower in Pacific archipelagos. Loss of diversity through disturbance and conversion to agriculture is evident and marked. Problems in the measurement of diversity with light-traps are discussed, exemplified by results obtained using different trap types. Changes in family proportions with habitat type are examined. Family diversity generally decreased with altitude and with disturbance and conversion to agriculture, though there are exceptions to this decline.

Abstract: Our purpose in this paper is to determine how the degree of polyphagy of different herbivorous insect species affects their yearly population variability. We assembled data from three studies on herbivorous insects: on British aphids, British moths, and Canadian Macrolepidoptera. Within each data set, we compared estimates of population variability across species, and related these differences to estimates of the degree of polyph- agy. The degree of polyphagy was negatively correlated or uncorrelated with population variability, i.e., highly polyphagous species have a weak tendency to be less variable than host specialists. This result lends some support to MacArthur's (1955) argument that polyphagous species may be less susceptible to fluctuating resource levels. Population variability in monophagous or oligophagous herbivorous insects may, in part, reflect vari- ation in resource levels. However, we have not yet evaluated the possibility that the levels of predation and parasitism suffered may affect variability even more strongly.