Hind Femur Length Research Articles

Effects of Repeated Applications of Bacillus thuringiensis israelensis on the Mosquito Predator Erythemis simplicicollis (Odonata: Libellulidae) from Hatching to Final Instar

Nymphs of a common dragonfly, Erythemis simplicicollis (Say), were exposed to Bacillus thuringiensis israelensis de Barjac at 1.2 ppm once a week for an entire life cycle in a controlled laboratory environment. Eight weekIy applications were administered to 2 treatment groups: external contact only, and external + internal contact using prey (mostly anopheline larvae) that had fed on B. thuringiensis . Each B. thuringiensis -treated group and a control group consisted of 15 nymphs. Mortality was not affected by B. thuringiensis applications. Repeated B. thuringiensis applications did not affect development to the adult stage, morphology, or maiden flight capability. Nymph size of the external contact group, measured by hind femur length and head width, was substantially smaller compared with the control group in most instars from 4–12. However, adult size, based on head width and hind wing length comparisons, did not differ among the 3 groups. Prey consumption and instar duration, which were highly correlated, did not account for the differences in size. Sex ratio (lower proportion of large females in the external group) and initial size (slightly smaller in instar 2 in the external group) appeared to be the major factors contributing to the size differences in the external group. However, these variables were not responsible for the external + internal contact group being smaller in instar 10 compared with the controls, as sex ratios and initial size were equal. If repeated B. thuringiensis applications affect size in E. simplicicollis , the effect may be insignificant in terms of reproductive success, as published studies do not show a positive relationship between size and reproductive success in dragonflies.

Inheritance of body and testis size in the bushcricket Poecilimon veluchianus Ramme (Orthoptera; Tettigoniidae) examined by means of subspecies hybrids

The inheritance of three parameters of body size: body mass, hind femur length and pronotum length, and of three measurements of male fertility: testis mass, relative testis mass (as part of body mass) and sperm number per spermatophore, were examined in crosses between the bushcricket subspecies Poecilimon veluchianus veluchianus and P. v. minor. Body size parameters differed surprisingly in their apparent genetic control: the genes determining pronotum length were autosomal, hind femur length was probably partly X-chromosomal and body mass was largely determined by genes on the X-chromosome. I consider whether sexually selected traits may commonly be sex-linked. Testis mass in the hybrid males was clearly different in reciprocal hybrids and was similar to the father's subspecies in both cases. As a result of the X-chromosomal (maternal) inheritance of body mass and a testis mass similar to the paternal subspecies, the relative testis mass in the hybrid males was larger or smaller than in the pure subspecies. In the male hybrids with reduced testis mass, the mean number of sperm was strongly affected. About 50% of these males transferred only a few sperm per spermatophore.

Inheritance of body and testis size in the bushcricket Poecilimon veluchianus Ramme (Orthoptera; Tettigoniidae) examined by means of subspecies hybrids

The inheritance of three parameters of body size: body mass, hind femur length and pronotum length, and of three measurements of male fertility: testis mass, relative testis mass (as part of body mass) and sperm number per spermatophore, were examined in crosses between the bushcricket subspecies Poecilimon veluchianus veluchianus and P. v. minor. Body size parameters differed surprisingly in their apparent genetic control: the genes determining pronotum length were autosomal, hind femur length was probably partly X-chromosomal and body mass was largely determined by genes on the X-chromosome. I consider whether sexually selected traits may commonly be sex-linked. Testis mass in the hybrid males was clearly different in reciprocal hybrids and was similar to the father's subspecies in both cases. As a result of the X-chromosomal (maternal) inheritance of body mass and a testis mass similar to the paternal subspecies, the relative testis mass in the hybrid males was larger or smaller than in the pure subspecies. In the male hybrids with reduced testis mass, the mean number of sperm was strongly affected. About 50% of these males transferred only a few sperm per spermatophore.

Annual Cycle of Gonad Maturation, Characteristics of Copulating Pairs and Egg-laying Rates in Cavernicolous Crickets, Particularyly Hadenoecus subterraneus (Insecta: Orthoptera)

-Monthly collections, fresh and dry weight determinations, and analysis of reproductive components were made of cave crickets Hadenoecus subterraneus and camel crickets Ceuthophilus stygius from caves in or near Mammoth Cave National Park, Ky. from April 1986 to March 1987. Minimal spermatophore frequency (50%) in adult male H. subterraneus occurred in September with essentially all mature males having spermatophores from October through May. Minimal occurrence of mature ova in adult female H. subterraneus was found in July and occurrence peaked in January and February. Cave crickets probably reproduce in all months with peak reproduction in January and February. Both sexes of C. stygius contain mature gonads only from August through October when nonparasitized, gravid females contain 25.5 ? 4.2 mature ova (weight = 10.6 ? 2.5 mg/egg). When spermatophores are present, mature males of both species invariably have two. Mature ova in H. subterraneus are seasonally consistent at 6.1-7.4 ova/female (weight = 5.4 mg/ egg) except for one winter sample from Sophy's Avenue of Mammoth Cave where females averaged 18.1 ova/female. Crickets of both sexes and species are mature when their hind femur length ?20.0 mm. Cave crickets in copulo of both sexes have higher wet carcass weights and markedly lower crop contents, and females contain the same number of mature ova (6.1 ova/female) as other gravid adults. Caged adult female cave crickets laid more ova in the 1st 2 days of captivity than in later successive 2-day periods and created many false oviposition holes throughout the testing period. Peak egg-laying frequency occurred in December and February tests. Estimated annual egg production in cave crickets ranges from 96 to 371.

Notes on the size distribution of a New Zealand cockroach, Celatoblatta vulgaris

Abstract Populations of Celatoblatta vulgaris were sampled over a 3-year period from a variety of collection sites. Subadult cockroaches were assigned to five size classes (probably instars) on the basis of interocular distance and hind femur length. Membership of size classes increased with increasing size class so that adults were markedly more abundant than any class of nymph, and large nymphs were more abundant than small nymphs. Adult males were more abundant than adult females.

Bioenergetics of the camel cricket Ceuthophilus stygius

1. 1. In early summer, camel crickets in Mammoth Cave National Park exhibit a sex-specific relationship between crop-empty live weight and hind femur length. 2. 2. They also exhibit curvilinear long-term weight loss patterns averaging 2.67 and 3.13 mg/hr for females and males, respectively, and caloric assimilation efficiencies of 65.6 and 70.5% for females and males, respectively.

Wing Dimorphism in Field Crickets (Orthoptera: Gryllidae: Gryllus)

Adult Gryllus are either short-winged (hind wings [HW] shorter than fore wings [FW]: HW/FW 1). Short-winged individuals are flightless, whereas long-winged individuals generally can fly. Hind wings are not shed after flight. Of five species occurring in peninsular Florida, G. ovisopis Walker is always short-winged (mean value of HW/FW ratio = 0.5), G. fultoni (Alexander) is virtually so (for short-winged morph, mean HW/FW = 0.6), G. assimilis F. is always long-winged (mean = 1.5), and G. firmus Scudder and G. rubens Scudder are dimorphic (mean = 0.8 and 1.6 for short- and long-winged morphs, respectively). In the four Florida species that have short-winged morphs, short-winged males had HW/FW ratios 5–15% less than short-winged females. In long-winged G. firmus and G. rubens , HW/FW ratios differed according to female parentage. In short-winged G. rubens , HW/FW ratios increased with body size (as measured by length of pronotum and hind femur).

Bioenergetics of the cave cricket, Hadenoecus subterraneus

1. 1. In late spring, cave crickets in Mammoth Cave National Park were investigated in order that their bioenergetics might be elucidated. 2. 2. A predictive relation between crop-empty live weight and hind femur length independent of sex was found. 3. 3. Long-term weight loss patterns were 1.55 and 1.19mg/hr for females and males, respectively, suggesting feeding intervals of 11.5 and 9.9 days. 4. 4. Calorific assimilation efficiencies were found to be 80.4% for females and 82.5% for males. 5. 5. The estimated maximal metabolic rates were half that expected for insects of similar mass. 6. 6. The mixed waste calorific levels were found to be exceptionally low.

Seasonality in a field population of two New Zealand cockroaches (Blattodea)

Abstract A population comprising Celatoblatta peninsularis and Parellipsidion pachycercum was sampled from Banks Peninsula, New Zealand over 1 year. Sub-adult cockroaches were assigned to 6 size classes (probably instars) by interocular distance and hind femur length. P. pachycercum was most abundant in December and January and adults were abundant in most months. In contrast, C. peninsularis was most abundant from February to June and adults were rare except in November. Adult females were less abundant than adult males in both species. Although both species may be bivoltine, they use difference overwintering strategies.

Individual and geographical variation in the stridulatory file ofOmocestus viridulus(L.) (Orthoptera: Acrididae)

Summary Samples of male specimens of Omocestus viridulus from 14 European countries were used to study the individual and geographical variation in the characters associated with the stridulatory file. Significant overall variation between the samples was demonstrated for the length of file, average density of pegs, length of hind femur and ratio of file length to hind femur length. This variation was found to be significantly correlated with several environmental factors, particularly annual range of temperature and amount of precipitation. These factors were considered to be good indicators of continentality, specimens from more continental regions having longer hind femora and longer files with a lower density of pegs. File length was found to be inversely correlated with amount of precipitation even when considered as a proportion of the hind femur. Number of pegs was also found to be inversely correlated with precipitation. In showing that femur length and file length increase and density decreases w...

A Histological and Bionietrical Study of Wing Development in the Grasshopper Melanoplus lakinus1,2

Melanoplus lakinus Scudder (Orthoptera: Acrididae) is a brachypterous grasshopper of Arizona rangeland that occasionally shows macropterism. Wing development is similar histologically to that in holometabolans, although the epidermal cells are less attenuated in this species. The cells extend to the middle membrane and generally are not continuous with opposing cells. They become distorted after the procuticle is secreted. Nuclei elongate and migrate toward the middle membrane to varying degrees. The middle membrane may be as much as 3 µ thick. Granular molting fluid occurs in large quantity and is prevalent during the last half of each instar. Chromatolysis may occur in the last stage of growth in the hindwing. On the surface of the wing pads polygonal cuticular plaques change to “shingled” rows in the last 2 instars. Two characteristics of mitotic activity in wing pads are revealed: (1) mitoses occur in distinct bursts and at fluctuating low levels, and (2) the process begins while the epidermis is still attached to the endocuticle and continues after deposition of the procuticle. A mitotic burst could be followed from its initiation to its termination, over a 6-hr period, by successive sampling of the 4 wings of 1 specimen. Mitotic activity corresponds well with the increase in nuclei during each instar. There are no obvious structural differences between nymphs of brachypterous and macropterous adults. The regression coefficient of wing length on hind femur length increases significantly during most instars. The large increase in wing length of the macropterous form occurs in the last instar and deviates greatly from simple allometric growth. Thus far, mating of macropterous forms in cages has increased their frequency from less than 4% to 39% in the F1 generation.

The biology of Culex nigripalpus Theobald (Diptera: Culicidae). 2. Adult characteristics at emergence and adult survival without nourishment.

Adults of Culex Nigripalpus Theobald were analyzed for size, dry weights and energy reserves at emergence. The specimens were obtained from larvae reared under 4 different environmental conditions—quantity of food, density of larvae per pan, salinity of the medium and temperature. Maximum expression of these characteristics was observed in adults at emergence, when larvae were reared on 2× basic ration in tap water at 27°C, with either 75 or 200 larvae per pan. Wing length, wing breadth and hind femur length were affected more by temperature than by quantity of food, whereas thorax length, dry weights and amounts of energy reserves were mainly controlled by the quantity of food. The adult survival patterns observed with 3 different groups, in which the adults have almost the same size but different amounts of energy reserves, showed the innate survival pattern, which is probably characteristic of C. nigripalpus. The 50% survival points in both ♂♂ and ♀♀ were found to be dependent on the amount of percent lipid at emergence. The percent glycogen does not affect 50% survival points. The loss in dry weight at 50% survival points was found to be about 35% of the dry weight observed at emergence, whereas percent lipid and percent glycogen were reduced by 80–90% of the amounts at emergence. Trehalose concentrations increase significantly immediately after emergence, sometimes reaching up to 300% within 12 hours after emergence. This high level of trehalose is then maintained until just before the 50% survival point is reached. It is believed that the adults obtained from the field would fall well within limits investigated in the laboratory study here reported.