A QUANTITATIVE STUDY OF CONSUMPTION AND UTILIZATION OF VARIOUS DIETS IN THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

Abstract

Con. Ent. 108: 1303-1318 (1976) Bionomics of the stream caddisflies, Ceraclea transversa (Hagen) (= Athripsodes angustus Banks) and Ceraclea ancylus (Vorhies) (= Athripsodes ancylus (Vorhies)) were compared with generalized trichopteran life cycles. The univoltine detritus-feeding C . ancylus has five larval instars and a brief adult emergence period. C. transversa has five larval instars but two distinct cohorts, in which larvae of the first cohort feed entirely on freshwater sponge, overwinter as inactive prepupae, pupate, and emerge the following spring. The second larval cohort feeds on sponge until the onset of gemmulation in autumn, then the larvae must overwinter as active third-or fourth-instar detritus-feeders, pupating and emerging later in the summer than the first cohort. The detritus-feeding C. ancylus larvae have a diurnal feeding cycle. The sand case of C. ancylus and the silk-secreted case of C. transversa differ in shape and composition, although both species initiate case construction using egg mass matrix, silk, and detritus. Emergence, flight activity, sex ratios, and adult survival depart from reported generalizations of caddisfly biology. Neither the validity of generalizing typical life cycles in benthic studies, nor the rationale that congeneric species operate as a functional unit in stream dynamics, is substantiated.Leptoceridae, in studies that rely only on benthic sampling. The single generic designation is misleading as the two species represent distinct and diverse branches of the caddisfly genus Ceraclea that differ both morphologically and ecologically. MethodsThe life histories of C . ancylus and C . transversa were studied in Brashears Creek, a stream in the Salt River drainage, Spencer Co., Kentucky, during 1970-1973 Creek is characterized by high hardness and alkalinity, and exhibited the following ranges of selected water chemistry parameters (in ppm): -NO,: 0.04-4.9; -NOz: 0.01-0.04; -PO4: 0.32-0.46; -SO4: 20-56; Ca: 33-86; hardness: 130-280; alkalinity: 79-212; and conductivity: 200-460 ohms. Biological and chemical features of the stream are fully described by Krumholz (1971), Krumholz andNeff (1972), and Krumholz (1973).Immature and adult stages of both species were collected using quantitative and qualitative techniques. Eggs for laboratory rearings were obtained by the method reported by Resh (1972). Larvae and pupae were collected quantitatively using a Surber sampler at monthly intervals over several annual cycles. These collections were supplemented by qualitative collections often taken as frequently as weekly. Since part of the life cycle of C. transversa is linked to the fresh-water sponge, samples of Spongilla lacustris (L.) were collected biweekly from May through November (1970)(1971)(1972)(1973). An attempt was also made to quantify these collections on a relative basis by standardizing the length of collection time, and recording the volume of sponge collected. Adults were collected according to a light trap sampling regime described in .Instar determinatio...

Consumption and utilization of food in different instars of muga silkwormAntheraea assama Westwood

“…A number of workers supported this trend of rise and fall in ECD and ECI in different insects (Bailey 1976;Yadava et al 1979;Rana et al 1987). Mukherji and Guppy (1970) and Latheef and Harcourt (1972) also supported this trend of ECD in different insects.…”

Respiratory changes throughout ontogeny in the tobacco hornworm caterpillar,Manduca sexta

“…For example, zebra caterpillars (Melancha picta) feeding on sugarbeet leaves increased feeding rates (leaf area/day) with age more than 70-fold (Capinera, 1979). Growing armyworms (Mamestra configurata, Bailey, 1976), saltmarsh caterpillars (Estigmene acrea, Capinera, 1978), and cotton bollworms (Helicoverpa zea, Huffman and Smith, 1979) also increased leaf feeding area per day with age. In addition, the massspecific feeding rates of our caterpillars decreased 60-fold from hatching to fifth instar (Fig.·6), a finding similar to that observed in other lepidopteran larvae (Slansky Jr, 1993).…”

Faecal weight as an index of development rate and energy content of imago of lepidopterous insects

“…But, Beddington et al (1976) are of the view that under these conditions the slope and intercept of the line have no simple biological interpretation (Mukerji and Leroux 1969). Although Mukerji and Guppy (1973) and Bailey (1976) have reported significant correlations between food consumption rate during the larval period and the initial or final dry weight of the Pe for a few lepidopterous insects, it is not possible to make use of their data to find support for the prediction of Pe and Ie from F r , as details of faecal weight and energy content of the Pe and Ie have not been provided by these authors.…”

“…Beddington et al (1976) andHassell (1978) have substantiated the dependence of development rate (expressed as the reciprocal or larval duration) and fecundity of predatory insects on prey density. Statistically significant correlations have been reported for the relations between food consumed and development rate as well as pupal weight in the armyworm Pseudaletia unipuncta (Mukerji and Guppy 1973) and Mamestra configurata (Bailey 1976). The present communication aims to examine whether faecal weight can be used as a reliable index of development rate (Dr) and energy contents of pupa (Pe) and imago (Ie) of lepidopterous insects.…”