Donald G. Cochran

FOOD AND WATER CONSUMPTION DURING THE REPRODUCTIVE CYCLE OF FEMALE GERMAN COCKROACHES

Food and water consumption by adult female German cockroaches has been examined in relation to the reproductive cycle. Daily consumption was recorded for individual insects and was related to certain landmark events in each of four egg‐case production cycles. It was shown that peaks of feeding and drinking occur during the egg maturation period, but are abruptly terminated at the appearance of each egg case. During the period when females carry the egg case, they feed and drink sparingly. The possible role played by feeding and especially drinking in the regulation of reproduction in this important pest species is discussed.

Nitrogen metabolism in the american cockroach—II. An examination of negative nitrogen balance with respect to mobilization of uric acid stores

Abstract 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. Oothecal 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 ootheca. 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.

Nitrogen metabolism in the american cockroach—I. An examination of positive nitrogen balance with respect to uric acid stores

Abstract 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.

A GENETIC DETERMINATION OF INSEMINATION FREQUENCY AND SPERM PRECEDENCE IN THE GERMAN COCKROACH

By use of a recessive‐genetic marker, it has been shown that adult female German cockroaches, Blattella germanica (L.), can be successfully inseminated by more than one male. Reinsemination was demonstrated to occur rarely between the first mating and production of the first egg case, while about 20% of the females examined remated between egg cases. The total impact of second matings on the offspring produced was small because of remating infrequency and the prevalence of incomplete sperm precedence in those that were reinseminated.

A comparative study of nitrogen excretion in twenty-three cockroach species

Abstract o 1. Nitrogen and cation excretion/storage in 23 cockroach species representing 11 subfamilies have been examined. Measurements of externally excreted ammonia nitrogen, uric acid nitrogen, total nitrogen, potassium and sodium were made. Values of total body nitrogen, body urate nitrogen, and body potassium and sodium are also reported. 2. A significant correlation was found between body nitrogen and body uric acid nitrogen. Certain species contained very high levels of uric acid/urates representing as much as 72% of their total body nitrogen. Contrarily, other species were found to contain low levels of uric acid/urates, representing as little as 3% of their body nitrogen. 3. A less significant correlation was found between internal nitrogen storage and external nitrogen excretion. Certain species can be classified as uricotelic, since as much as 62% of their total fecal nitrogen may be excreted as uric acid-nitrogen. Other species can be designated as ammonotelic, since they may excrete as much as 70% of their total fecal nitrogen as ammonia nitrogen. 4. Increased body nitrogen retention may be correlated with increases in body potassium and/or sodium. The internal storage of nitrogen as uric acid appears to involve the formation of potassium and/or sodium urate salts.

Nitrogenous excretory materials from the American cockroach

Abstract Excreta obtained from both sexes of the American cockroach, Periplaneta americana , maintained on three different diets was examined for the presence of numerous possible nitrogenous materials in an effort to establish what substances are excreted by this insect. It was found that none of the classical terrestrial insect excretory products, including uric acid, could be detected by the methods employed. Rather, ammonia, amino groups, three tryptophan metabolites, unidentified water soluble materials, and water insoluble components constitute most of the total nitrogen excreted. Ammonia seems to be the largest single component, and it was quantitated in fresh and dried excreta. Upon lyophilization of the excreta more than half of the ammonia is lost.

Food and water deprivation effects on reproduction in female Blattella germanica

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.

Comparative analysis of excreta from twenty cockroach species

Abstract 1. 1. The excreta from twenty species of cockroaches have been examined for the presence of uric acid by several methods of analysis. 2. 2. Uric acid is voided by only three of these species (Shawella couloniana, Symploce hospes and Parcoblatta spp.) all belonging to the subfamily Blattellinae. 3. 3. Each of these species voids uric acid in formed pellets which are separate from the fecal wastes, and which contain a high percentage of uric acid. 4. 4. Blattella germanica, which belongs to the same subfamily, eliminates small amounts of uric acid, but the mechanism appears to be entirely different. 5. 5. The fat body of fourteen species was shown to contain uric acid stores. 6. 6. The significance of these results is discussed in terms of phytogeny, species biology, pellet formation and functioning of the malpighian tubules.

Xanthine dehydrogenase activity in the cockroach endosymbiont Blattabacterium cuenoti (Mercier 1906) hollande and favre 1931 and in the cockroach fat body

Abstract 1. 1. Crude extracts of concentrations of endosymbionts from newly formed cockroach oothecae have been assayed anaerobically and aerobically for enzyme activity related to the degradation of uric acid. 2. 2. The extracts exhibited uric acid-dependent oxidation of both methyl viologen and NADH 2 when strictly anaerobic conditions were maintained throughout the extraction and assay procedures. 3. 3. Under aerobic conditions, extracts from egg endosymbionts and cockroach fat body catalyzed the xanthine-dependent reduction of NAD + . 4. 4. The enzyme activity exhibited is strikingly similar to that of xanthine dehydrogenase. 5. 5. The significance of these results is discussed in relation to uric acid storage in the cockroach fat body.

Comparative analysis of excreta and fat body from various cockroach species

Abstract 1. 1. Five additional cockroach species were shown to void uric acid to the exterior bringing the total to nine out of 49 species examined. All nine belong to the subfamily Blattellinae. 2. 2. Uric acid content in whole excreta from six species of Parcoblatta varied from 5.7 to 11.2%, while that in the white, formed-pellets varied from 25.4 to 36.1%. 3. 3. Young Parcoblattait nymphs void little uric acid during the first month of life, but subsequently expel it at adult rates. 4. 4. Fat body from 35 species of cockroaches has a consistent general cytological pattern involving three cell types. 5. 5. Fat body from all species examined contains uric acid within urate cells. 6. 6. Several possible strategies for urate utilization by cockroaches are discussed.