Nymphal Diet Research Articles

Nutritional quality of Drosophila melanogaster as factitious prey for rearing the predatory bug Orius majusculus.

The predatory bug, Orius majusculus (Reuter), is an important predator of thrips commercially produced for augmentative releases using the eggs of the Mediterranean flour moth Ephestia kuehniella (Zeller). In this study, we assessed the potential for using frozen adults of fruit flies, Drosophila melanogaster (Meigen), either as nymphal rearing diet or as diet throughout the entire life-cycle. We compared life-history traits and reproduction of predators when fed D. melanogaster with high lipid body content (lipid-rich) and with high protein body content (protein-rich), using a diet of 100% E. kuehniella eggs as control. We also analyzed the biochemical composition of both prey and predator in order to assess the nutritional quality of each diet, which partially explained the adequacy of the different diets for O. majusculus. There were significant differences between predators fed the two types of D. melanogaster, with the protein-rich flies as diet providing the best results in terms of mortality and fecundity. Furthermore, we show that while feeding O. majusculus throughout their development with D. melanogaster increases mortality and reduces reproduction, protein-rich D. melanogaster can be used as nymphal diet with minimal reduction in reproductivity and minimal increase in mortality.

Effects of Nymphal Diet and Adult Feeding on Allocation of Resources to Glassy-Winged Sharpshooter Egg Production.

The glassy-winged sharpshooter is an invasive insect capable of transmitting the bacterial pathogen Xylella fastidiosa. Pre-oviposition periods of laboratory-reared glassy-winged sharpshooters are variable. Here, two questions were addressed: does nymphal diet affect pre-oviposition period and how do allocation patterns of resources differ for females that produce eggs versus females that do not? Nymphs were reared on one of three host plant species: cowpea, sunflower, or sorghum. Half of the females were sacrificed at emergence. The remaining adult females were held on cowpea, a host plant species known to support egg maturation via adult feeding. Females were sacrificed on the day of first oviposition or after 9 wk if no eggs were deposited. Females reared as nymphs on sorghum had longer development times and were smaller (head capsule width and hind tibia length) than females reared as nymphs on cowpea and sunflower. However, nymphal diet did not affect percentage of dry weight that was lipid at emergence. Further, nymphal diet did not affect time to deposition of the first egg mass or total number of eggs matured at the time of first oviposition. Egg production reduced the allocation of resources to insect bodies, with body lipid content decreasing with increasing egg production. In general, females increased wet weight 1.4-fold during the first week after adult emergence, with wet weights plateauing over the remaining 9 wk that adults were monitored. Thus, it seems reasonable to hypothesize that resources required for egg production were acquired via adult feeding during the first week after adult emergence.

Life cycles and nymphal feeding of Isoperla morenica Tierno de Figueroa and Luzón-Ortega, 2011 and Brachyptera vera cordubensis Berthélemy and Baena, 1984 (Plecoptera: Perlodidae and Taeniopterygidae) in a Mediterranean stream (Spain)

ABSTRACTSome aspects of the biology of two endemic Iberian stonefly species, Isoperla morenica Tierno de Figueroa and Luzón-Ortega, 2011 and Brachyptera vera cordubensis Berthélemy and Baena, 1984, were studied in a temporary stream from Sierra Morena (Southern Spain). Isoperla morenica shows a univoltine fast seasonal life cycle, with nymphs growing from November to April. After oviposition, eggs remain in a dormant state in the riverbed until the following autumn when the river water flows again. Nymphal diet is mainly composed of detritus in small individuals (they behave as gatherer–collectors) but when larger, they become predators. Brachyptera vera cordubensis also shows a univoltine fast seasonal life cycle, from November to March. Nymphs behave mainly as gatherer–collector and no significant ontogenetic changes in diet were detected. Male and female nymphs do not show differences in feeding in this species. Data obtained were compared with the previously known information on both species in another stream from the same mountain range as well as for other related species, and some differences in both aspects, mainly on feeding habits, could be detected.

Effect of Food Deprivation Period on the Development and Reproduction of Riptortus pedestris (Hemiptera: Alydidae), and Its Egg Parasitism.

The bean bug, Riptortus pedestris (F.) (Hemiptera: Alydidae) is one of the most important pests of soybean (Glycine max L. Merrill) in Korea and Japan. R. pedestris is known to appear early in spring when leguminous seeds such as soybean are not available. Because soybean has been reported to be the most important food source for R. pedestris development, in this study, we assessed the effect of this period of soybean deprivation during the nymphal stage on the development and reproduction of R. pedestris and on egg parasitism by its two egg parasitoids. More than 50% of the R. pedestris population tested survived on barley, even when they did not start feeding on soybean until the fourth instar. Nevertheless, R. pedestris nymphs deprived of soybean developed more slowly and became smaller adults than those provided with soybean. However, no difference was observed in the preovipositional period or fecundity between these groups. In addition, neither the hatch nor the egg parasitism rate by two egg parasitoids was affected by the presence or absence of soybeans in the nymphal diet. This study indicates that R. pedestris nymphs can develop successfully even when lacking this important food source in early life, and that adult reproduction is not affected by the quality of diet ingested during the nymphal period.

Insecticidal Activity of Some Reducing Sugars Against the Sweet Potato Whitefly,Bemisia tabaci, Biotype B

The effects of 16 sugars (arabinose, cellobiose, fructose, galactose, gentiobiose, glucose, inositol, lactose, maltose, mannitol (a sugar alcohol), mannose, melibiose, ribose, sorbitol, trehalose, and xylose) on sweet potato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) survival were determined using in vitro bioassays. Of these sugars, arabinose, mannose, ribose, and xylose were strongly inhibitory to both nymphal and adult survival. When 10% mannose was added to the nymphal diet, 10.5%, 1.0%, and 0% developed to the 2nd, 3rd, and 4th instars, respectively. When 10% arabinose was added, 10.8% and 0% of the nymphs molted to the 2nd and 3rd instars, respectively. Addition of 10% xylose or ribose completely terminated B. tabaci development, preventing the molt to the 2nd instar. With decreasing sugar concentrations the inhibitory effect was significantly reduced. In tests using adults, arabinose, galactose, inositol, lactose, maltose, mannitol, mannose, melibiose, ribose, sorbitol, trehalose, and xylose significantly reduced mean day survival. Mortality rates were highest when arabinose, mannitol, mannose, ribose, or xylose was added to the diet. Mean day survival was less than 2 days when adults were fed on diet containing 10% of any one of these five sugars. When lower concentrations of sugars were used there was a decrease in mortality. Mode of action studies revealed that toxicity was not due to the inhibition of alpha glucosidase (converts sucrose to glucose and fructose) and/or trehalulose synthase (converts sucrose to trehalulose) activity. The result of agarose gel electrophoresis of RT-PCR products of bacterial endosymbionts amplified from RNA isolated from whiteflies fed with 10% arabinose, mannose, or xylose indicated that the concentration of endosymbionts in mycetomes was not affected by the toxic sugars. Experiments in which B. tabaci were fed on diets that contained radio-labeled sucrose, methionine or inulin and one or none (control) of the highly toxic sugars showed that radioactivity (expressed in DPM) in the body, in excreted honeydew and/or carbon dioxide, was significantly reduced as compared to controls. Thus, it appears that the ability of insecticidal sugars to act as antifeedants is responsible for their toxicity to B. tabaci.

Developmental specialization and geographic structure of host plant use in a polyphagous grasshopper, Schistocerca emarginata (=lineata) (Orthoptera: Acrididae).

Host plant use and availability were determined in early nymphal and adult-stage Schistocerca emarginata (=lineata) (Orthoptera: Acrididae) populations at six localities in Texas, USA. Early instar nymphal populations were feeding almost exclusively on either Ptelea trifoliata (Rutaceae) or Rubus trivialis (Rosaceae). This study represents the first demonstration of a geographic structure of host plant specificity in a polyphagous grasshopper. Recognizing this geographic structure required investigations of both developmental and geographical variation in host plant use. Nymphal diet breadths were significantly less than adult diet breadths at four of six localities and smaller overall when pooled nymphal and adult diet breadths were compared among sites. Neither restricted nymphal mobility nor host plant availability accounted for the observed differences in host plant use between developmental stages and among localities. Evidence suggests that the differences in host use among populations are due to host-plant-associated genetic differentiation.

Suitability of Legume Cover Crops for Grasshopper (Orthoptera: Acrididae) Development and Reproduction

The use of legume cover crops is a potentially valuable practice in mitigating problems associated with annual crop-fallow rotations in the Northern Plains. Because grasshoppers may become a pest in a cover crop system, we determined the suitability of 4 annual legumes for grasshopper development and reproduction. No-choice diets of grass pea (Lathyros sativus L.), lentil ( Lens culinaris Medikus), field pea ( Pisum sativum L.), and hairy vetch (Vicia villosa Roth) were fed to 5 species of grasshoppers: Melanoplus bivittatus (Say), Melanoplus differentialis (Thomas), Melanopltls femtlrrubrum (De Geer), Melanoplus packardii Scudder, and Melanoplus sangllinipes (F.). Field pea and lentil were the least suitable legumes when considering the combination of grasshopper survival, development, and reproduction. The effect was most pronounced for M.sanguinipes and M. femurrubrum. These grasshoppers displayed poor survival and delayed development when fed field pea or lentil compared with other legumes or a control. Adult fecundity and fertility of eggs also were adversely affected when no-choice diets of field pea or lentil were offered. For M.packardii, a nymphal diet of field pea resulted in the poorest development; grasshoppers fed an adult diet of field pea did not reproduce. M. bivittatus and M. differentialis experienced limited mortality when fed field pea or lentil. Nevertheless, development was substantially delayed and reproduction inhibited to varying degrees. Field pea and lentil appear to have good potential in providing the benefits of cover crops, while decreasing the economic impact of common grasshopper species.

Developmental Response of Nymphs of Podisus maculiventris (Heteroptera: Pentatomidae) Reared with Low Numbers of Prey

Effects of maternal diet, maternal age, and nymphal diet on developmental time and survivorship of nymphs of Podisus maculiventris (Say) were studied using Mexican bean beetle, Epilachna varivestis Mulsant as prey. Developmental time of nymphs was shorter if nymphs were well fed and came from well fed and young mothers than if nymphs were poorly fed and came from poorly fed and older mothers. Nymphal survival was related to nymphal diet. Well-fed nymphs showed higher survivorship than poorly fed nymphs. Nymphs supplied prey at the lowest rates failed to reach adulthood and died, usually in the act of molting. Body sizes of adults from well-fed nymphs were larger than those from poorly fed nymphs. Impact of maternal effects on population dynamics of P. maculiventris is discussed.

Suitability of greenbugs, cotton aphids, and Heliothis virescens eggs for development and reproduction of Orius insidiosus

AbstractDevelopment, fecundity, and longevity of the predator, Orius insidiosus (Say) (Heteroptera: Anthocoridae), when reared on greenbug [Schizaphis graminum (Rondani)], cotton aphid (Aphis gossypii Glover), or eggs of tobacco budworm [Heliothis virescens (F.)] with green beans or water were examined. Developmental time was shortest when predators were reared on H. virescens eggs and beans and longest when reared on cotton aphids and water. Predators were most fecund when fed H. virescens eggs. The inclusion of beans in the nymphal diet further enhanced fecundity when fed eggs. Longevity of both females and males was significantly shorter when reared on aphids than on eggs. Beans in the nymphal diet enhanced longevity of female predators only in combination with budworm eggs. Female O. insidiosus were largest when reared on H. virescens eggs. Addition of green beans in aphid treatments resulted in increased size of O. insidiosus when compared to aphids and free water.

Suitability of Prey Infected by Nuclear Polyhedrosis Virus for Development, Survival, and Reproduction of the Predator Nabis roseipennis (Heteroptera: Nabidae)

Consumption of nuclear polyhedrosis virus-infected prey—larvae of the soybean looper, Pseudoplusia includens (Walker)—by the predator Nabis roseipennis Reuter variously affected development, survival, and reproduction of the predators. Nymphs fed infected prey larvae developed significantly faster at 25°C than nymphs fed uninfected prey. Nymphal survival was not affected by prey infection. Preoviposition periods were significantly longer for predator females maintained on infected prey throughout their lives than for those receiving uninfected prey during preimaginal or adult (or both) stages. Daily rates of oviposition were highest for females that received uninfected larvae as their nymphal diet, regardless of adult diet. In contrast, total fecundity was greatest for females receiving uninfected prey as adults, regardless of the nymphal diet. The nymphal diet, however, affected total fecundity of females. Consumption of infected larvae by adult predators significantly reduced their longevity, irrespective of the nymphal regimen.

Plant Feeding by Podisus maculiventris (Heteroptera: Pentatomidae): Effect on Survival, Development, and Preoviposition Period

Plant feeding enhanced survival and shortened developmental times and preoviposition period of the predaceous pentatomid Podisus maculiventris (Say). When potato foliage was provided in addition to prey (Colorado potato beetle, Leptinotarsa decemlineata (Say), larvae) and water, preimaginal survival increased by 27.5%. Also, developmental time from second instar to adult eclosion was reduced by 2.4 days, and the preoviposition period was shortened by 1.4 days. Adults of both sexes were significantly larger and males were significantly heavier when potato foliage composed part of the nymphal diet. Plant feeding has both positive and negative biological features that should be considered in evaluating predaceous hemipterans as biological control agents.

The effect of food and water on development, longevity, and fecundity in the Rutherglen bug, Nysius vinitor (Hemiptera : Lygaeidae)

N. vinitor subsists primarily upon the seeds of various plants. A wide range of seeds was found to be suitable for nymphal development, but some seeds were more suitable than others. Seeds suited for nymphal growth were not necessarily adequate for egg production. Some seeds promoted higher fecundity than others when used as food for adults. Nutritional requirements for fecundity appeared to be more specific than for development. Egg production was dependent mainly on the food consumed by the adult and was little affected by nymphal diet which, however, influenced potential egg production if obviously inadequate for nymphal development. Survival of females with access to water was uninfluenced by availability of food, but food was essential for egg production. Starvation decreased potential reproduction of females. Lack of water, even for a short period, stopped egg production and increased mortality.

The effects of different plant foods on the fecundity, fertility and development of a cotton stainer,Dysdercus superstitiosus(F.)

Dysdercus superstitiosus(F.) is capable of utilising a much wider range of food-plants than was previously supposed, and is able to complete a full breeding cycle on the several diets other than cotton. This has been demonstrated by rearing and breeding adults and nymphs in the laboratory, in Uganda, on selected food material,e.g., Sorghum vulgare, Pennisetum typhoides, Zea maysandVigna unguiculata, immature seeds of each being used. Diets other than mature cotton seeds are less suitable for breeding, as judged by fecundity of females and development of nymphs, but the influence of nymphal diet on adult fecundity is not consistent. Females reared on sorghum are smaller than those reared on cotton seed and they may lay fewer eggs.There is an indication that varieties of sorghum may differ in their suitability for producing maximum fecundity and fertility. Those varieties to which the stainer exhibits a predisposition in the field may not be the most suitable.When adults are fed on cotton bolls of ages 1–10 weeks, the fecundity of females, and the rate of egg-production increase with increasing age of boll, and the preoviposition period decreases.Stored cotton seed may be less suitable for egg-production than freshly harvested seed cotton.Extraction of oil from cotton seed with petroleum ether does not wholly impair the fecundity rate of females fed on the seed, but may reduce the fertility and nymphal survival in the first instar.A diet of cotton seed, heat treated at 150–190°C. for one hour, reduces the fecundity in the females, possibly by destroying the accessary food factors. Nymphal survival is possible on such treated seed, but not when thus heated for two hours at or above 150°C.