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Nutritional status of German cockroaches from the field (HUD apartments) was estimated using uric acid content to measure amount of protein consumed, and respiratory quotient (RQ) to measure fat and carbohydrate metabolized. Initial trials demonstrated the stability of these two indicators as nymphal cockroaches grow and with timing of meals. Nutrient consumption (and presumed availability) was estimated by comparing uric acid content and RQ of nymphal cockroaches collected from kitchens of HUD apartments with those reared in the laboratory and provided a series of meridic diets. Uric acid content was linearly related to percentage of dietary protein (y=6.2x−32.07, r2=0.96) and RQ was linearly related to log10(% fat:% carbohydrate) (y=−0.148Log(x)+0.790, r2=0.68). Field-collected German cockroaches contained 10.9±7.7 to 22.9±5.1 μg/mg uric acid and RQ of 0.770±0.024 to 0.803±0.260. Comparatively, cockroaches provided rodent chow had greater uric acid content (125.1±9.6 μg/mg) and RQ (0.878±0.022). Employing linear calibration and these regressions, diet consumed by German cockroaches in the field was estimated at 7±3% to 9±3% protein and equivalent amounts of carbohydrates and fat as an energy source. German cockroaches in the field consume less protein and carbohydrates, and more fat compared to those provided a standard laboratory diet such as rodent chow. Diet available in the field is considered suboptimal, resulting in physiological stress; the biological implications of this stress are discussed.
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... Simpson et al. (2006) found that mass migrations and cannibalism in a cricket was induced by shortage of protein and salt. German cockroaches had less protein and carbohydrates available in the "field" (human apartments) than is present in the assumed optimal laboratory diet (Kells et al. 1999). Regarding true predators, Salomon et al. (2008) supplemented colonies of a social spider with protein-or lipid-rich prey and found that the latter increased the proportion of reproductive females. ...
Habitats vary in food resources with carnivores often being prey limited, but it is unclear whether habitats facilitate a nutritionally balanced diet. Two paradigms in nutritional ecology, ecological stoichiometry and nutritional geometry, predict that carnivores are limited mainly by protein or lipid, respectively. Using the carabid beetle Anchomenus dorsalis and 10 other predatory beetles from agricultural fields, we developed and tested two simple procedures for quantifying macronutrient‐specific habitat conditions without requiring information about the natural prey. Both procedures assume that predators forage for nutrients rather than specific prey. Our results show that 10 of 11 species were food limited. Five species were lipid limited and one species was protein limited in the field. Co‐existing predator species showed considerable segregation of fundamental macronutritional niches. A linear relationship between specific nutrient limitation and the target lipid:protein (L:P) intake ratio indicates that species with high L:P target are more protein limited while species with low L:P target are more lipid limited. The study illustrates how species within a natural assemblage vary in nutritional niche and in specific nutrient limitation. This article is protected by copyright. All rights reserved.
... As observed in the previous experiments, the higher consumption of protein from two complementary food sources at longer distance may be due to higher fidelity to a protein-rich food when the distance between food sources is longer. From an ecological perspective, this makes sense because of the typical scarcity of protein relative to carbohydrate available to omnivores and herbivores within most environments (Mattson, 1980;White, 1993), most likely including that of the German cockroach (Bell et al., 2007;Kells et al., 1999). If protein-rich food sources are required, for example for growth, but are typically rare in the environments where cockroaches have evolved, they are therefore likely to be perceived as more valuable than carbohydrate-rich sources once located, and larger amounts should be ingested before searching for complementary food. ...
The German cockroach (Blattella germanica L.) is an excellent model omnivore for studying the effect of foraging effort on nutrient balancing behavior and physiology, and its consequences for performance. We investigated the effect of foraging distance on individual German cockroaches by providing two foods differing in protein-to-carbohydrate ratio at opposite ends of long containers or adjacent to each other in short containers. Each food was nutritionally imbalanced, but the two foods were nutritionally complementary, allowing optimal foraging by selective feeding from both foods. We measured nutrient-specific consumption in fifth instar nymphs and newly eclosed females foraging at the two distances, hypothesizing that individuals foraging over longer distance would select more carbohydrate-biased diets to compensate for the energetic cost of locomotion. We then determined dry mass growth and lipid accumulation in the nymphs as well as mass gain and the length of basal oocytes in the adult females as an estimate of sexual maturation. Nymphs foraging over longer distance accumulated less lipid relative to total dry mass growth, but contrary to our predictions their protein intake was higher and they accumulated more structural mass. In concordance, adult females foraging over longer distance gained more body mass and matured their oocytes faster. Our results show a positive effect of foraging distance on fitness-related parameters at two life stages, in both cases involving increased consumption of specific nutrients corresponding to requirements at the respective life stage.
... 45 Moreover, in many insects, responses to olfactory 47 and gustatory 48 cues are heightened when either starved or deprived of key nutrients. Field B. germanica appear unable to meet their macronutrient intake target, 33 suggesting that nutritionally balanced baits with effective attractants and phagostimulants should be highly effective in these nutritionally austere environments. Lastly, consumption of diets may also be influenced by neophilia, as nutritionally deficient American cockroaches, 49 domestic rats 50 and grasshoppers 51,52 are known to become more neophilic compared with their nourished counterparts. ...
Bait formulations are widely used to control German cockroach (Blattella germanica) populations. To perform optimally, these formulations must compete favorably with non-toxic alternative foods present within the insect's habitat. We hypothesized that the nutritional history of cockroaches and their acceptance or avoidance of glucose would affect their food preference and thus bait efficacy. To test this hypothesis, we conducted a controlled laboratory experiment, first providing glucose-accepting and glucose-averse cockroaches nutritionally defined diets and then offering them identical diets containing the insecticide hydramethylnon as a bait proxy to evaluate the effect of diets of differing macronutrient composition on bait performance.
The interaction between diet composition and bait composition affected the survival of adult males as well as first instar nymphs exposed to excretions produced by these males. Survival analyses indicated different responses of glucose-averse and glucose-accepting insects, but generally, any combination of diet and bait that resulted in high diet intake and low bait intake decreased secondary kill.
This study represents a comprehensive examination of the effect of alternative foods on bait efficacy. We suggest that disparities between the nutritional quality of baits and the foods that are naturally available could profoundly impact the management of German cockroach infestations.
... Specifically, the 3/4-power law is currently being challenged by other models such as the cell-size model which predicts a wider range of mass scaling coefficients ( Chown et al., 2007;Glazier, 2005;Kozlowski et al., 2003;West et al., 1997West et al., , 2002). Metabolic rates also provide insight into what nutrients are being metabolized ( Kells et al., 1999;Vogt and Appel, 1999). Even though metabolic rates have been described in a number of taxa, bed bugs have received limited attention. ...
Metabolic rates provide important information about the biology of organisms. For ectothermic species such as insects, factors such as temperature and mass heavily influence metabolism, but these effects differ considerably between species. In this study we examined the standard metabolic rate of the common bed bug, Cimex lectularius L. We used closed system respirometry and measured both O2 consumption and CO2 production across a range of temperatures (10, 20, 25, 30, 35°C) and life stages, while also accounting for activity. Temperature had a stronger effect on the mass specific VO2 (ml g(-1) h(-1)) of mated males (Q10 = 3.29), mated females (Q10 = 3.19), unmated males (Q10 = 3.09), and nymphs that hatched (first instars, Q10 = 3.05) than on unmated females (Q10 = 2.77) and nymphs that molted (second through fifth instars, Q10 = 2.78). First instars had significantly lower respiratory quotients (RQ) than all other life stages. RQ of all stages was not affected by temperature VO2 (ml h(-1)) scaled more with mass than values previously reported for other arthropods or that would be predicted by the 3/4-power law. The results are used to understand the biology and ecology of the common bed bug.
... Cockroaches are opportunistic scavengers with limited foraging ranges (Schal et al. 1984; Mullins & Cochran 1986), and their diet is thus highly dependent upon the vagaries of their environment. Urban environments can be particularly challenging in this respect , in terms of the quality, consistency and temporal patterns of availability of foods (Cornwell 1968; Kells et al. 1999). Since B. germanica is a consummate survivor in these conditions, we predicted that they would be robust to enforced periods of nutritional imbalance, and also show a well-developed ability to redress nutritional imbalances using complementary food selection. ...
As extreme generalists, cockroaches mix their diet from foods that vary greatly in their nutrient composition. It might thus be predicted that these insects have evolved robustness to enforced periods of nutritional imbalance and a well-developed ability to redress imbalances by compensatory food selection. We investigated these predictions for German cockroaches, Blatella germanica, using synthetic foods ranging in their balance of the macronutrients protein and carbohydrate. We first confined cockroaches for the duration of the final larval stadium either to a near-balanced food (% protein:% carbohydrate = 15:45), or one of four imbalanced foods (47:13 or 24:36 = excess protein; 13:47 or 4:56 = excess carbohydrate). All insects survived, but nutritional imbalance resulted in slowed development and skewed body composition. We then investigated the compensatory responses of nymphs confined during the first 48 h (approximately the first quarter) of the stadium to one of three nutritionally imbalanced foods, and thereafter allowed to select an intake from all three. Macronutrient intake was measured after 4, 10, 24, 48 and 120 h. Within 48 h all groups had entirely redressed the respective imbalances accrued during the 2-day pretreatment period, and thereafter consumed an indistinguishable balance of macronutrients. Our results show in B. germanica remarkable robustness to nutritional imbalance, and provide the first evidence of such effective compensation through complementary food selection for nutritional imbalance accrued over a timescale of days.
... Food shortage is probably common in the wild (e.g. Kells et al., 1999) and is probably compounded by competition at higher population densities, when parasite transmission is more likely (Steinhaus, 1958). If parasites reduce a host's ability to assimilate food, then infection may further increase susceptibility to parasites. ...
Abstract Measurement of insect immune effector system function aimed at identifying costs has largely been stimulated by the ideas of Hamilton & Zuk (1982), who proposed that choosy females may derive some genetic benefit from selecting parasite-resistant males. Field studies of such systems assume that most variation in measured immune traits is affected strongly by genes and pay little attention subsequently to the role of nutritional status in determining the magnitude of assayed immune effector systems. In this paper the effects of nutrient deprivation on immune function are measured in the mealworm beetle (Tenebrio molitor L.) reared in otherwise ideal conditions. The results suggest that immune effector system function is down-regulated during short-term nutritional deprivation, but is rapidly up-regulated to pre-deprivation levels after animals are allowed access to food. This rapid modulation of immune function in the context of nutritional status has important implications for measuring immune function in the field, as well as the interpretation of those measures.
Fitness-related costs of evolving insecticide resistance have been reported in a number of insect species, but the interplay between evolutionary adaptation to insecticide pressure and variable environmental conditions has received little attention. We provisioned nymphs from three German cockroach (Blattella germanica L.) populations, which differed in insecticide resistance, with either nutritionally rich or poor (diluted) diet throughout their development. One population was an insecticide-susceptible laboratory strain; the other two populations originated from a field-collected indoxacarb-resistant population, which upon collection was maintained either with or without further selection with indoxacarb. We then measured development time, survival to the adult stage, adult body size, and results of a challenge with indoxacarb. Our results show that indoxacarb resistance and poor nutritional condition increased development time and lowered adult body size, with reinforcing interactions. We also found lower survival to the adult stage in the indoxacarb-selected population, which was exacerbated by poor nutrition. In addition, nutrition imparted a highly significant effect on indoxacarb susceptibility. This study exemplifies how poor nutritional condition can aggravate the life-history costs of resistance and elevate the detrimental effects of insecticide exposure, demonstrating how environmental conditions and resistance may interactively impact individual fitness and insecticide efficacy.
The gut microbiota of insects contributes positively to the physiology of its host mainly by
30 participating in food digestion, protecting against pathogens, or provisioning vitamins or amino
31 acids, but the dynamics of this complex ecosystem is not well understood so far. In this study, we
32 have characterized the gut microbiota of the omnivorous cockroach Blattella germanica by
33 pyrosequencing the hyper-variable regions V1-V3 of the 16S rRNA gene of the whole bacterial
34 community. Three diets differing in the protein content (0%; 24% and 50%) were tested at two time
35 points in lab-reared individuals. In addition, the gut microbiota of wild adult cockroaches was also
36 analyzed. In contrast to the high microbial richness described on the studied samples, only few
37 species are shared by wild and lab-reared cockroaches, constituting the bacterial core in the gut of
38 B. germanica. Overall, we found that the gut microbiota of B. germanica is highly dynamic as the
39 bacterial composition was reassembled in a diet-specific manner over a short time span, with no40
protein diet promoting high diversity, although the highest diversity was found in the wild
41 cockroaches analyzed. We discuss how the flexibility of the gut microbiota is probably due to its
42 omnivorous life-style and varied diets.
German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae), catch by five types of traps and modifications of each, were tested under controlled laboratory conditions. Cockroach catch differed significantly among traps. Lo-line trap caught the greatest number of cockroaches in the test arena for each size class (23% small nymphs, 39% of gravid females, and 60% of other size classes in the experimental arena). Jar traps caught the least number of cockroaches in the test arena for each size class (range, 7-23% of each size class trapped). Modifications of traps also altered catch of cockroaches. Food bait tablets increased catch significantly; however, increases were small (<10%). Size of traps did not affect catch; whole traps or half traps caught the same number of cockroaches. Jar traps were much less effective than sticky traps, catching only half the number of cockroaches as sticky traps. A thin layer of petrolatum was a more effective barrier in jar traps to cockroach escape than powdered Olancha clay. Traps with petrolatum caught about twice as many cockroaches as traps with clay. Trapping of any of six life stages was not significantly affected by catch of any of the other stages. Rather, trap catch of each life stage was dependent on the number of that life stage available in the experimental arenas. In conclusion, of the traps tested, the Lo-line trap was the most sensitive for measuring cockroach catch, whereas the Detector trap (one third of trap) was the most economical trap (greatest sensitivity for lowest cost).
The investment of nitrogenous materials by female and male German cockroaches Blattella germanica (L.) into their progeny was examined. Adult females maintained on dog food invested 34% of their dry mass and 26% of their nitrogen into an oothecae during their first gonadotrophic cycle. Females maintained on a low- (5%) protein diet and injected simultaneously with [3H]leucine and [14C]hypoxanthine incorporated less [3H]leucine-derived radiolabel in their oothecae than those on a dog food diet (25% crude protein). Females on the low-protein diet incorporated more [14C]hypoxanthine-derived material (primarily as [14C]urates) into their oothecae than they retained in their bodies. Stored [14C]urates were metabolized more readily by females on the low-protein diet. Oothecae obtained from females provided with an [15N]urate-amended diet contained at least four 15N-enriched amino acids, which supports the hypothesis that urates are utilized as a nitrogen resource in these insects. Dietary effects on paternal investment were also found to be significant. Females fed a low-protein diet and their oothecae contained 63% of the radiolabel made available to them at mating when paired with males injected simultaneously with [3H]leucine and [14C]hypoxanthine, whereas dog-food-fed females and their oothecae contained only 17% of the total radiolabel made available to them at mating.
The daily intake of a semisynthetic diet containing various proportions of a non-nutritive substance (aluminium oxide) was studied in adult males of the German cockroach, Blattella germanica (L.), after 3 days of starvation. When fed again, an increase in the quantity of food eaten was observed on the first day, whatever the dilution. With the less highly diluted foods, the intake decreased and returned to its usual value within 3 days. With the more highly diluted foods, the intake remained high throughout the duration of the experiment, and the insects were unable to recover from their metabolic deficiency. Taken as a whole, the data suggest that dry-matter consumption depends on several factors: phagostimulant properties of the food, degree of filling of the digestive tract, the speed at which food passes through it, metabolic utilization of the nutrients, and metabolic deficiency induced by starvation.
1.1. Young adult American cockroaches (Periplaneta americana L.) were allowed to accumulate nitrogen stores by maintenance on a highly positive nitrogen balance diet. Upon removal to one of three negative nitrogen balance diets, dietary nitrogen intake, body nitrogen uptake, body uric acid content and nitrogen elimination were monitored.2.2. Changes in body nitrogen, uric acid nitrogen and body weight were observed when cockroaches were placed on negative nitrogen balance regimes. The rate of uric acid mobilization was related to the amount of carbohydrate and nitrogen present in the diet. Insects maintained on dextrin for 17 weeks mobilized urate stores most rapidly.3.3. Females mobilized urate stores more rapidly than males. Oöthecal production accounted for a considerable portion of the nitrogen lost. Comparisons of the nitrogen balance values suggest that a portion of the uric acid nitrogen is utilized during egg production and may be incorporated into the oötheca.4.4. The mobilization of urate stores may involve the mycetocyte symbionts as well as the metabolic processes of the insect. Mobilization and utilization of nitrogen contained in stored urates is briefly discussed.
1.1. Newly molted adult American cockroaches (Periplaneta americana L.) were maintained on diets containing various concentrations of protein. Dietary nitrogen intake, body nitrogen, nitrogen uptake, uric acid storage and nitrogen elimination were monitored to examine nitrogen balance in response to maintenance on these diets.2.2. Adults on dog food (24% crude protein) and 24% casein protein diets increased in body nitrogen, but showed an initial decrease in uric acid nitrogen. This is suggestive of uric acid nitrogen utilization during the early post-molt period. Insects on a 5% protein diet decreased in total body and urate nitrogen.3.3. Cockroaches on diets containing 50, 79 and 91% casein protein showed large increases in body nitrogen which could be correlated with increased uric acid nitrogen storage. Evidence is presented that uric acid may be stored preferentially in situations where all excess dietary nitrogen is not excreted. The general metabolism of non-nitrogenous metabolic reserves may be utilized to store excess nitrogen as uric acid.4.4. Storage of nitrogen may involve the formation of a urate complex with protein, peptides and/or salts of urate.
1.1. German cockroaches were injected with either [14C]glycine, [14C]formate, or [14C]xanthine and maintained on different dietary nitrogen levels. They were analyzed for whole body radiolabel retention and incorporation of radiolabel into the urate fraction after feeding on various diets for one to two weeks. Groups of cockroaches were injected with labelled urate precursors and the 14CO2 released was collected. Release of 14CO2 was examined in relation to dietary nitrogen levels.2.2. Radiolabelled glycine was metabolized rapidly, some of it being released as 14CO2. There was a direct relationship between 14C incorporation into body urates and maintenance on different dietary nitrogen levels.3.3. Radiolabelled formate was rapidly partitioned into body urates by cockroaches maintained on specific diets. Comparatively low levels of 14CO2 were released.4.4. Incorporation of 14C-xanthine into urates was found to increase with elevated dietary nitrogen levels. Dietary effects on its metabolism were mirrored by 14CO2 released and other metabolites excreted in the feces.
Reports the accurate measurement of the VO2 of Camponotus fulvopilosus as a function of temperature (10-40°C), feeding state (0-14 days post-feeding), body mass (0.011-0.127 g) and group size. Colony VO2 could be accurately estimated from individual VO2, population size, mean body mass and temperature; no "group effect' was found. Minimum sensitivity of VO2 to temperature variation occurred at normal foraging temperatures, thus minimizing performance variability while foraging. VO2 of C. fulvopilosus declined with first order rate kinetics during starvation-induced dormancy. Implications of such dormancy with regard to energy storage strategies and ant speciation in marginal habitats are discussed. -from Author
Early experiments by Zabinsky (1928a,b, 1929) indicated that the German cockroach could be grown to maturity on artificial diets in which the sole source of “protein was glycine or gelatin. These early observations, based upon the use of relatively impure dietary ingredients and a very slow growth rate nevertheless indicated that the cockroach must differ in protein requirements from higher animals. Later studies by McCay (1938) who used more highly purified diets, indicated that “complete proteins such as caesein were more effective than zein or gelatin for the growth of German roaches. Recently Noland et al. (1949b,c) described a purified synthetic diet for roaches which resulted in a growth rate at least equal to that obtained with the best crude diets tested. This diet was used in the present experiments, in which the levels and kind of protein were varied, supplements of certain amino acids were fed, and the biosynthesis of tryptophan and methionine demonstrated.
Seven nonresistant (“normal“) strains of the German cockroach, BLATTELLA GERMANICA, were evaluated to determine their relative susceptibilities to chlordane, malathion, chlorpyrifos, diazinon, and propoxur. LT50 values reported were similar for all tested strains, with no strain showing resistance to any tested chemical. The reported values should be used to cross-tabulate resistances reported from laboratories where different “normal”strains of German cockroach are used.
The effects of four diets (commercial rat food, 5, 25, and 65% protein) on reproduction and daily food consumption of male and female German cockroaches were investigated. Females compensate for low dietary protein levels by elevating consumption rates and reproduce normally. Conversely, a high-protein diet significantly delayed mating in females and resulted in smaller oöthecae. Percentage hatch of oöthecae and male sexual maturation were unaffected by dietary protein content. Males that were allowed to copulate twice a week, ate more, and died sooner than males allowed to mate only once. The role of diet composition in regulating feeding behavior is discussed.
Uric acid was measured in fat body of several age groups of the German cockroach, Blattella germanica (L.). Fat body was dissected from insects and dried to constant weight; uric acid was measured on a percentage dry weight basis using an enzyme-specific assay with uricase. Aposymbiotic last stage nymphs contained about twice as much uric acid as normal nymphs (means of 48 and 23%, respectively). Uric acid increased with high significance in normal nymphs during the last stage. There was a marginally significant increase (mean of 54%) with age in aposymbiotic adult females, while normal adult females showed a highly significant increase and much greater variation (between 18 and 87%) than the other groups tested. Both adult normal and adult aposymbiotic males showed increases in uric acid with age in asymptotic fashion, approaching mean maximum values of about 72 and 81%, respectively.
There was an effect of harborage-to-resource distance but no main effect of density on the frequency of feeding and drinking activity of adult Blattella germanica, videotaped continuously for 96 h. Feeding and drinking diel periodicity was more pronounced when the resource was placed further from the harborage with activity peaking ca. 2 h into scotophase and declining at the onset of photophase. Nongravid females and males fed and drank more often than gravid females, with a high percentage of females carrying oothecae never feeding or drinking during the recording period.
Diet has a great influence on the well being and longevity of animals. By restricting caloric intake McCay and co-workers (1935) brought about retardation of growth in young rats that resulted in increase in the total life span of these experimental animals. In a later paper, reporting the results of their study of the nutritional requirements during the later half of life, McCay and co-workers (1941), stated: “The optimal conditions for a long life (of rats) proved to be thin bodies, exercise and a low protein diet with the protein supplied by liver. Slonaker's (1935) experiments also indicated that the life span of both virgin and bachelor rats was shortest in the group which were fed higher (26%) protein diet. Unfortunately, he used a rather small number of animals in his assay experiments.
La consommation journalière d'un aliment semi-synthétique contenant des proportions variées d'une substance non-nutritive (alumine) a éTÉ étudiée chez les mâles adultes de la blatte germanique, Blattella germanica L., après trois joûrs de jeûne. Lors de la réalimentation, on observe une augmentation de la quantiTÉ de nourriture consommée au cours du premier jour, quelle que soit la dilution. La consommation décroît et atteint sa valeur habituelle au bout de trois jours avec des nourritures peu diluées. Avec des nourritures plus diluées, la consommation reste importante pendant toute la durée de l'expérience et les insectes ne peuvent pas récupérer leur déficit métabolique. L'ensemble des résultats permet de penser que la consommation de matière sèche est réglé ***pur plusieurs facteurs: propriétfés phago-stimulantes de la nourriture, réplétion du tube digestif, vitesse du transit, utilisation métabolique de la nourriture et déficience métabolique provoquée par le jeûne.
The exploitation of food resources by the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae) was investigated experimentally in relation to distance from shelters and depletion of neighbouring food patches. In addition, the dynamics of exploitation of a patch were analysed. Observations were made after dark in a public swimming baths building and each one lasted 3 h. Food patches were placed in rows, at different distances from the shelters. The number of cockroaches in food dishes, in a 20 cm diameter circle round each food dish and in a 60 cm diameter circle round this first circle were recorded.
Food items nearest the shelters were exploited first. Exploitation of row 2 and of row 3 food items started later, after row 1 food patches had been depleted. Under these conditions, the moment a food patch was exploited was related to its distance from shelter. Exploitation of food patches occurred in a step-by-step manner, one patch attracting animals when a nearby patch had been depleted, and not following a model of ideal free distribution.
Although our experimental food patches were exploited in relation to their distance from shelter, we were able to demonstrate that distance did not influence the dynamics of exploitation of a food item. The mean number of cockroaches on a food patch, whatever its spatial position, increased regularly, reached a maximum at t = −10 min, and then decreased rapidly after all the food had been completely consumed, at t = 0 min. The mean number of animals in the 20 cm diameter circle round a food source peaked at t = 0 min, then decreased rapidly. This area appeared to be a transit area. The mean number of animals in a 60 cm diameter circle round the food source peaked later, and then decreased slowly. Animals remained in this area longer than in the area closer to the food dish, but their presence there was concomitant with the depletion of the food box.
The effects of food and water deprivation on survival and reproduction of adult female German cockroaches were examined. Females, maintained under constant conditions, were deprived of food or water following adult maturation, mating, during the oothecal incubation period, and after first oothecal hatch. It was found that both food and water deprivations caused increased mortality, delays in the reproductive cycle and decreased oothecal hatch. The relative importance of food vs. water deprivation on reproduction is discussed along with possible reproductive strategies for this species.
Action du jeûne et de la suppression d'eau sur la reproduction de femelles de Blattella germanica L.
Les femelles, maintenues en conditions constantes, ont été privées d'aliments et d'eau après la maturité imaginale, l'accouplement, pendant la période d'incubation et après l'éclosion de la première oothèque. On a observé une mortalité accrue, un retard dans le cycle de reproduction et une diminution des éclosions de l'oothèque. L'importance relative de l'alimentation par rapport au jeûne hydrique sur la reproduction est discutée en relation avec les stratégies reproductives possibles de cette espèce.
Nymphal development and adult female reproduction were examined in the German cockroach, Blattella germanica, using a defined artificial diet in which the type of protein was varied. Milk proteins, including casein, supported development poorly compared to meat and plant proteins. Soybean protein supported development better than all other highly purified proteins including vitamin-free casein which is commonly used in artificial diets. Last instar females fed the soybean-based diet eclosed earlier at higher eclosion weights, developed their oocytes at a faster rate and experienced higher fecundity than females fed a vitamin-free casein-based diet. Last instar females exhibited different dose-response patterns on diets containing soybean isolate or vitamin-free casein. However, at all concentrations soybean protein was superior to casein in supporting development. The results of a food utilization study during the last instar revealed that consumption rates varied between females fed the soybean and casein based diets. However, approximate digestibility, efficiency of conversion of digested food and the efficiency of conversion of ingested food did not vary significantly between the two dietary treatments. Differential development of females fed the two diets was attributed to differences in stage-specific consumption rates and the poorer quality of casein as a source of protein for development in this species.
Patterns of urate storage have been examined in young nymphs of the American cockroach in relation to dietary levels of nitrogen. On a standard dog food diet, stored urates gradually increase with age in a manner which roughly parallels weight gain. Excessive urate storage occurs when dietary nitrogen levels are high, while urate stores are depleted in insects on a nitrogen deficient diet. Excretion of urates was not detected under any conditions examined.
HARNSÄURESPEICHERUNG BEI JUNGLARVEN DER AMERIKANISCHEN SCHABE
An Junglarven der Amerikanischen Schabe wurde die Art der Uratspeicherung in Abhängigkeit vom Stickstoffgehalt der Nahrung untersucht. Auf einer Standard-Hundefutterdiät nimmt das eingelagerte Urat allmählich mit dem Alter zu und zwar ungefähr parallel mit dem Gewicht. Übermässig viel Urat wird eingelagert bei hohem Stickstoffgehalt der Nahrung. Dagegen werden die Uratvorräte abgebaut bei stickstoffarmer Nahrung. Eine Ausscheidung von Urat wurde unter keiner der berücksichtigten Versuchsbedingungen festgestellt.
Female brown-banded cockroaches, Supella longipalpa (F.) (Dictyoptera: Blattellidae), failed to elevate consumption rates when fed a 5% protein diet compared with females fed either 25% protein or commercial rat food. Adult performance was directly influenced by dietary protein level: Females fed 65% protein died rapidly, while in females fed 5% protein feeding and reproductive rates were reduced after production of three oothecae. In females fed a low protein diet as both late instar nymphs and as adults, mating was delayed and they required more time to form oothecae than females switched to 25% protein as adults. The role of nymphal reserves in adult reproduction is discussed.
Food is an important extrinsic factor in the control of moulting as well as in the control of reproduction in colonies of Blattella germanica. Starvation following a moult or a parturition delays the initiation of another moulting cycle or female reproductive cycle. The initiation of a moulting cycle after a period of starvation requires only a short period of food availability (12 hr). To be able to postpone development until adequate food is available is advantageous to intermittent feeders and scavengers, such as cockroaches, which must forage for food. Synchronization of the development of colonies of cockroaches by controlling the availability of the food is a valuable research tool.
Larvae of the brown-banded cockroach, Supella longipalpa, grown from the beginning of the third instar to the adult moult, self-selected a 15.5:85.5 casein:glucose ratio when given a choice between two diet cubes that were nutritionally complete except that one lacked protein (casein) and the other lacked carbohydrate (glucose). The self-selectors were superior in all utilization parameters to control larvae placed in similar arenas and fed on two nutritionally complete diet cubes, each containing equal amounts of casein and glucose. However, when forced to feed throughout their entire larval life on a diet containing a 20:80 casein:glucose ratio (approximating the self-selected ratio) incorporated into a single cube, larvae grew very poorly compared to others offered a 50:50 cube or an opportunity to self-select. Measurements of casein and glucose consumption throughout the entire first- and last-larval stadia showed that in each case carbohydrate intake was high at first, but decreased through the stadium, finally equalling the level of protein intake, which remained low and constant throughout the stadium. Thus, a 20:80 diet may be nutritionally unsuitable because it does not match closely enough the varying needs of the insect throughout the stadium.
The interrelationship of two extrinsic factors-nutrition and pesticide exposure-was studied in German cockroaches, Blattella germanica (L.). Amount of dietary protein had no effect on susceptibility of male German cockroaches to propoxur and chlorpyrifos; however, the source of protein produced significant changes in insecticide susceptibility. Increased total body lipids, carbohydrates, and uric acid may have resulted in increased tolerance to these insecticides. Three days of food or water deprivation (or both) caused significant differences in susceptibility to chlorpyrifos and propoxur.
Computerized moving-image analysis measured the influence of starvation and lighting conditions on the locomotor activity of the German cockroach, Blattella germanica (L.). Starvation increased the distance traveled, velocity, and the proportion of time in motion of adult males and last instars but did not increase adult female movement. For females, males, and nymphs, starvation increased cockroach residence time around the source of water and harborage and decreased the distance traveled by females and nymphs around the observation arena's edge. Fluorescent light reduced the proportion of time in motion for males, but the velocity of males was greater in fluorescent light relative to infrared light. Adult males and females stopped more frequently in infrared light. Overall, males and nymphs were more mobile than females and they explored larger areas. The moving-image analysis technique is an efficient and accurate tool for observing movement of individual cockroaches and has applications in repellency, attractancy, and basic movement behavior studies.
Computerized moving-image analysis was used to determine movement behavior of adult German cockroaches among food, water, and harborage resource sites. Adults at different stages in the female reproductive cycle (nonmated females, mated nongravid females, and gravid females) and males were examined continually for 5 d under a photoperiod of 12:12 (L:D) h. Corresponding food and water consumption rates for these adult classes were also determined. Differences were evident among the female reproductive classes and males. Mated nongravid females were the most active overall, and consumed the most resources. Nonmated females were second to the mated nongravid females in consumption and were less active. Gravid females were the most inactive, spending the greatest time in the harborage and consuming the fewest resources. Males were second to females in the mated nongravid class regarding activity, but consumed significantly fewer resources than females in both the mated nongravid and nongravid females. Implications of these findings relating to the biology of these adult classes are discussed.
Computerized moving-image analysis was used to determine movement behavior of individual German cockroach, Blattella germanica (L.), nymphs (second and fifth instars) between food, water, and harborage resource sites. Both second and fifth instars (n = 10) were examined for the entire nymphal stadium, during which a 12:12 (L:D) photoperiod was maintained. In addition, corresponding resource consumption rates for these nymphal stages also were determined. Both nymphal stages exhibited a pattern of high activity for the first half of the nymphal stadium, especially during each scotophase. For the last third of the stadium, the nymphs remained continuously in the harborage, moved very little, and consumed little or no resources. We discuss implications of these findings regarding control, future research, and possible hormonal behavior regulation.
Inter-and intra-instar consumption in the German cockroach, Blattella germanica. Ento-mologia Experimentalis et Applicata 79
S M Valles
C A Strong
P G Koehler
Valles, S.M., Strong, C.A., Koehler, P.G., 1996. Inter-and intra-instar consumption in the German cockroach, Blattella germanica. Ento-mologia Experimentalis et Applicata 79, 171–178.
Characteristics of field-collected populations of the German cockroach Blattella germanica (Dictyoptera: Blattellidae)
P ENTOMOL SOC WASH
M H Ross
C G Wright
Ross, M.H., Wright, C.G., 1977. Characteristics of field-collected
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Reid, B.L., 1989. The dymanics of laboratory populations of the German cockroach, Blattella germanica (L.) and the influence of
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The nutritional requirements of Blattella germanica
C M Mccay
McCay, C.M., 1938. The nutritional requirements of Blattella germanica. Physiological Zoology 11, 89-103.
Density, fecundity, homogeneity, and embryonic development of German cockroach, Blattella germanica (L.) populations in kitchens of varying degrees of sanitation (Dictyoptera: Blattellidae). Proceedings of the
D A Sherron
C G Wright
M H Ross
M H Farrier
Sherron, D.A., Wright, C.G., Ross, M.H., Farrier, M.H., 1982. Density,
fecundity, homogeneity, and embryonic development of German
cockroach, Blattella germanica (L.) populations in kitchens of
varying degrees of sanitation (Dictyoptera: Blattellidae). Proceedings of the Entomological Society of Washington 84, 376-390.
Understanding and Controlling the German Cockroach
M H Ross
D E Mullins
Ross, M.H., Mullins, D.E., 1995. Biology. In: Rust, M.K., Owens,
J.M., Reierson, D.A. (Eds.), Understanding and Controlling the
German Cockroach. Oxford University Press, New York, pp. 21-48.