Donald E. Mullins

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 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.

Cold tolerance of Halyomorpha halys (Hemiptera: Pentatomidae) across geographic and temporal scales

Abstract The brown marmorated stink bug, Halyomorpha halys (Stål), is native to eastern Asia and is presently invading North America. Little is known about the exposure to and effects of winter temperatures in newly invaded regions on H. halys. The overwintering habitats that this species utilizes vary greatly in their thermal buffering capacity. They naturally overwinter in aggregations beneath loose bark on trees and in cliff outcroppings, but will also commonly aggregate in buildings. Effects of cold temperatures such as mortality and freezing have yet to be quantified in the invading population. We report that H. halys is chill intolerant (i.e., dies before reaching its freezing point), and that the degree of cold tolerance of populations in North America differs by season, sex, and acclimation location. The mean winter supercooling point (± SEM) of individuals acclimated in Minnesota was –17.06°C ± 0.13 and in Virginia was –13.90°C ± 0.09. By using laboratory assays of lower lethal temperatures and ambient air temperature records, we accurately forecasted mortality for field experiments in Minnesota and Virginia. Temperature refugia provided by human-built structures are likely crucial for overwintering survival during atypically cold winters and possibly contribute to the northern geographic range expansion of this economically damaging insect in the temperate climates of North America.

Isolation and partial characterization of uric acid spherules obtained from cockroach tissues (Dictyoptera)

Abstract 1. 1. Urate spherules obtained from three cockroach species have been isolated, purified and examined by scanning electron microscopy, atomic absorption, i.r. and Kjeldahl analysis. 2. 2. Purified spherules exposed to ionic environments may change from a smooth to a textured form. 3. 3. Ion analysis confirmed that the spherules are high in K+ and low in Na+. 4. 4. All preparations from the cockroach tissues diaplayed similar i.r. spectra, but were dissimilar to those of uric acid and urate salt standards. 5. 5. It appears that there is a distinct pattern or mechanism by which the cockroach urates are deposited in the spherule matrix.

Physiology of Environmental Adaptations and Resource Acquisition in Cockroaches

Cockroaches are a group of insects that evolved early in geological time. Because of their antiquity, they for the most part display generalized behavior and physiology and accordingly have frequently been used as model insects to examine physiological and biochemical mechanisms involved with water balance, nutrition, reproduction, genetics, and insecticide resistance. As a result, a considerable amount of information on these topics is available. However, there is much more to be learned by employing new protocols, microchemical analytical techniques, and molecular biology tools to explore many unanswered questions.

From April to August—Wild Bees Pollinating Crops Through the Growing Season in Virginia, Usa

ABSTRACT Few baseline data exist regarding the role of wild, primarily native, non-Apis bees in pollinating crops through the growing season in the mid-Atlantic United States. Apis mellifera L., honey bees, generally are assumed to provide the majority of crop pollination, with the value of pollination provided by non-Apis bees estimated at between one-half and one-sixth the value of honey bees, though many non-Apis bees are known to be more effective in pollinating some crops. In this study, the first documenting wild bees visiting crop flowers through the growing season, non-Apis bees accounted for the majority of crop visitation for several economically important entomophilous crops in Virginia, such as apple, blueberry, caneberry, and cucurbit) and likely provided most of the pollination. Wild bees made up between 68% (in caneberries) and 83% (in cucurbits) of bees visiting crop flowers. Between 43 and 59 non-Apis bee species visited flowers of each crop (105 species overall). Species turnover was very high between sites, ranging from only 13% shared species in pairwise comparisons for blueberries to 30% shared species for caneberries. Native bee taxa most abundant on crops were Andrena F., mining bees, Bombus Latreille, bumble bees, and Osmia Panzer, mason bees, on apples and blueberries; Losioglossum Curtis, sweat bees, on caneberries; and Peponapis pruinosa Say, squash bees, and Bombus on cucurbits. Overall, this study highlights the substantial role of native bees in agricultural pollination in this region.

Behavior and daily activity patterns of specialist and generalist predators of the hemlock woolly adelgid, Adelges tsugae

Abstract The behavior and daily activity patterns of two specialist predators, Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae, Sasaji and McClure (Coleoptera: Coccinellidae), and a generalist predator, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), of hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), were examined using digital video recording in the laboratory. The two specialists are part of a biological control program for A. tsugae, and it is not known if competitive interactions with previously established generalist predators will negatively impact their effectiveness. The behavior and daily activity patterns of adult females of each species were documented in single- and paired-predator assays under simulated spring and summer conditions. Behavior varied qualitatively and quantitatively by species, and did not appear to be highly coordinated temporally or spatially. All species exhibited continuous activity patterns that were punctuated by longer periods of rest. Extensive and intensive searching behavior occurred in all species, with intensive searching being highly variable. Specialist predators appeared to be more selective of feeding and oviposition sites, and rested at more concealed locations than the generalist species. In spring conditions, L. nigrinus had greater activity and a more even behavior distribution than S. tsugae or H. axyridis, which were skewed towards resting. In summer, the latter two species showed increased activity at higher temperatures. Conspecifics significantly altered the time allocated to specific behaviors for L. nigrinus and H. axyridis, resulting in reduced predator effectiveness by reducing time and energy expenditure on activities that directly impact the adelgids. In contrast, S. tsugae conspecifics and all heterospecific combinations showed non-interference. The activity of each species varied with time of day; L. nigrinus was more active at night, while S. tsugae and H. axyridis were more active during the day. All predator groupings maintained a high degree of spatial separation relative to assay size. The use of multiple-predator species combinations that include the specialist predators, is recommended over single-species for biological control of A. tsugae, as temporal and spatial patterns were not highly coordinated. Low-density releases may reduce the potential negative effects of intraspecific competition.

Initial reproductive investment and parental body size in Cryptocercus punctulatus (Dictyoptera: Cryptocercidae)

Abstract. Females of the subsocial woodroach Cryptocercus punctulatus Scudder generally have a single oviposition period during which they produce one to four oöthecae. Monogamous pairs and their recently deposited oöthecae were collected in the field, and measured, weighed and analysed for nitrogen in the laboratory. Females put 9.8 ± 2.4% (mean ± SD) of their dry weight and 11.6 ±0.5% of their body nitrogen into oöthecae. The total nitrogen and dry weight of the brood were positively related to the post‐oviposition total nitrogen and dry weight of the mother. A females investment, on a per nymph basis, averaged 0.06% of her post‐oviposition dry weight. Females may be able to recover up to 58.7% of the nitrogen invested into a brood by consuming the egg cases after hatch. Overall, there was little variation in the width of head capsules of adults in this species, and this parameter was not significantly different between the sexes. Females were heavier than males (dry weight) (P =0.06). Within pairs, the weights and nitrogen contents of males and females were positively correlated, probably because they feed together in the same log for nearly a year prior to reproduction.