Pollen as a source of food for egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae)

The value of corn pollen as a food source for Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) was assessed in the laboratory by testing the effect of different pollen diets on the longevity, capacity of parasitism and other life-table parameters. T. brassicae females that fed on corn pollen and water (wet filter paper dusted with pollen) lived significantly longer (4.97 days) than females that fed on water alone (2.67 days), but significantly shorter than those feeding on honey alone (8.37 days) or corn pollen and honey (8.23 days), respectively, in the absence of host eggs. The presence of European corn borer eggs (Ostrinia nubilalis Huebner, Lepidoptera: Pyralidae) significantly increased longevity. With host eggs available, female T. brassicae that fed on corn pollen and water lived significantly longer (4.9 days) than on water alone (2.60 days), but significantly shorter than on honey alone (12.33 days) or corn pollen and honey (12.17 days), respectively. The cumulative lifetime fecundity was 82.53 offspring pupae when fed on pollen and water, which was significantly higher than 61.70 for water alone but lower than feeding on honey alone (95.70) or corn pollen and honey (99.97), respectively. Compared to water alone, corn pollen and water increased the net reproduction rate (R₀), intrinsic rate of increase (r_m), and finite rate of increase (λ), and reduced the doubling time (T₂), but had no effects on the emergence rate, sex ratio, and mean generation time (T_c). In another set of experiments, 13 out of 30 females reduced the number of pollen grains offered to them. The average number of pollen grains utilized per female in this 48-h test 2.46±0.40 (mean±SE). Hence, T. brassicae used corn pollen as food that significantly increased longevity and fecundity of the tested females. Pollen and honey supplied a complete diet for T. brassicae, compared to pollen and water or water alone.     

Effects of diet restriction on life history in a sexually cannibalistic spider

Diet restriction increases longevity while reducing fecundity in a broad range of organisms. However, there are exceptions to this rule, and the causes of these exceptions remain unclear. One hypothesis is that short‐lived, semelparous organisms gain no benefit from increased longevity regardless of nutritional resources. Another hypothesis is that organisms may alter their behaviour to compensate for nutrient deficiencies. We examined these hypotheses in the colonial orb‐weaving spider Cyrtophora citricola. Sexual cannibalism is frequent in this species so that females are long lived and interoparous while males are semelparous. Because of these differing sexual strategies, we predicted that the common pattern of increased longevity under diet restriction would hold for females but not for males. We also investigated in a semi‐natural setting whether spiders could compensate for diet restriction by altering their feeding behaviour. Diet‐restricted females produced fewer offspring but lived longer than well‐fed females, while diet had no effect on male longevity. Despite being semelparous, virgin males were quite long‐lived, suggesting that potential lifespan is relatively unimportant in determining the effects of diet restriction. Contrary to our predictions, females were unable to compensate for their restricted diet by altering their foraging behaviour. Instead, semi‐natural conditions increased the differences between spiders on high and low diets, suggesting that the effects of diet restriction can be pervasive under natural conditions.     

Effects of contact kairomone and experience on initial giving-up time

Reproduction and longevity of the anthocorid predators Orius laevigatus (Fieber) and Orius albidipennis (Reuter) (Heteroptera: Anthocoridae) were studied under controlled conditions in the laboratory. Three different diets were tested: eggs of the Mediterranean flour moth. Ephestia kuehniella Zeller, E. kuehniella eggs plus pollen, and pollen only. Small rooted plants of Spanish pepper (Capsicum annuum L. cv. Creta, long red) served as oviposition substrate and moisture source. In all treatments, total fecundity, oviposition period and female longevity of O. laevigatus were greater than that of O. albidipennis. When a diet of E. kuehniella eggs was supplemented with pollen, total fecundity of O. albidipennis was increased by about 40%. Female O. albidipennis fed only pollen laid five times less eggs than those fed flour moth eggs and pollen; also, longevity of females was shorter when only pollen was offered as food. Fecundity and longevity of O. laevigatus were not influenced when supplementing a diet of E. kuehniella eggs with pollen. Females of O. laevigatus receiving only pollen reduced egg production by about 60% but had a similar longevity as those receiving a diet including flour moth eggs. In either species, preoviposition period and egg hatch were not affected by diet. The ability of both anthocorids to use pollen as an alternative or additional food is discussed in relation to their practical use in integrated control programmes.     

成虫取食对棉铃虫雌蛾繁殖的影响

试验对雌蛾设置５个食物处理,定量地研究了成虫取食对棉铃虫蛾繁殖和寿命的影响,成虫取食对雌蛾与寿命和主效量均显著影响,补充营养延长雌蛾寿命,提高产卵量,并且」补充营养对产卵量的影响比其对寿命的影响更大,分析表明被营养的作用在于提高雌蛾后期的存活率和产卵量,前期补充营养比后期补充营养具有更大的作用。雌雌全重及其蝮部干重受成廊和的自龄的双重影响,补充营养时雌蛾体重、腹部干重及其脂肪含量下降慢,补充营养可     

Development of probiotic diets for the olive fly: evaluation of their effects on fly longevity and fecundity

One possible control strategy against the olive fly, Bactrocera oleae, the most serious olive crop pest, is the Sterile Insect Technique (SIT) application. However, a number of problems associated with this method remain that decrease the effectiveness of SIT, including the quality of reared insects. Taking the importance of the relationship between the olive fly and bacteria into consideration, the effects of probiotic diets enriched with Pseudomonas putida on B. oleae longevity and fecundity were evaluated. First, we found that the probiotic bacterium, P. putida, is conveyed from diets to the oesophageal bulb as well as to the fly midgut after feeding on the probiotic diet. Subsequently, B. oleae adults fed on either: (a) a standard full protein and sugar diet; (b) a sugar only diet; (c) a probiotic standard full protein and sugar diet; or (d) a probiotic sugar diet. Flies fed on probiotic diets were supplied with an inoculated gel containing P. putida; non‐inoculated gel was provided to the flies fed on non‐probiotic diets. B. oleae males and females that fed on sugar diets did not survive as long as those that fed on protein diets. A comparison of the longevity of adults fed on full diet and sugar with their respective probiotic diets revealed no significant difference. Males fed on the sugar only diet survived longer than males fed on probiotic sugar diet, and females fed on the full protein and sugar diet survived much longer than females fed on the full probiotic diet. As regarding fecundity, both full diets resulted in a higher number of eggs laid per female. Females fed on the probiotic sugar diet laid a higher number of eggs than females that fed on sugar only. The inoculated gel of the probiotic sugar diet contained a significantly higher quantity of leucine, isoleucine and proline than the non‐inoculated gel of the sugar only diet. The possible role of dietary bacteria in relation to functional aspects of olive fly physiology is discussed.     

Adult feeding and lifetime reproductive success in the parasitoid Aphytis melinus

The diet of adult females of the parasitoid Aphytis melinus DeBach (Hymenoptera: Aphelinidae) includes host insects and sugar-rich foods such as nectar and honeydew. We compared the contributions of host feeding to longevity and fecundity in A. melinus females in the presence and in the absence of honey meals. First, we assessed the longevity of females that were not allowed to oviposit. While the longevity of females fed honey was significantly increased by host feeding (median ages were 30.5 days for host-fed females and 17 days for females not allowed to host feed), the lifespan of parasitoids not fed honey did not exceed 3 days for any individual and there was no effect of host feeding on longevity in this group. In the second set of experiments, we assessed the fecundity and longevity of females allowed to oviposit. We conducted two experiments, one in which honey was continuously available, and one in which honey was not available. In both experiments, daily observations were made of females that were either allowed to host feed or manually prevented from host feeding. In the presence of honey, host feeding significantly increased both fecundity and longevity, and in the absence of honey, parasitoids died within 2 days and host feeding had no significant effect on either fecundity or longevity. The lifetime fecundity of females fed honey but not hosts exceeded the initial egg complement by 60% on average. Approximately one host per day was used for host feeding whether honey was supplied or not, and each host-feeding meal contributed approximately 3.9 eggs to the lifetime fecundity of honey-fed females. In the last experiment, we compared the rate of egg resorption over a 36-h period in A. melinus females that were deprived of hosts and either fed honey or starved. While no egg resorption was detected in honey-fed females over this time period, starved females resorbed approximately 9 eggs. Thus, the availability of a sugar-rich food interacts strongly with host feeding in influencing longevity and fecundity and has a strong direct effect on egg resorption.     

On the effect of the food ofMyzus persicae Sulz. on the hymenopterous parasiteAphelinus asychis Walker

Summary The effect of different synthetic diets of the hostMyzus persicae on the parasiteAphelinus asychis was tested. Deficient diets were prepared by reducing sucrose or iron concentration: sucrose concentration was reduced from 15% in the complete diet (D.I.) to 7.5% in D. II and 3.75% in D. III; that of iron from 0.0023% in D. I to 0.0011% in D. IV and 0% in D.V.The development of the immature stages ofA. asychis in aphids fed on the deficient diets was delayed (especially on D. V). The size of the emerging adults was small, which corresponds with the reduced size of the host. The percentage of the male parasites was found to be higher on the deficient diets than on the full one. The lowest average longevity of the females was found among those reared on aphids on D. III and D.V.If honeydew fromM. persicae was offered to the females, a marked reduction in the longevity of these parasites was observed on D. II and D. III. On the other hand, on honeydew from aphids on D. IV and D.V,A. asychis lived as long as on honeydew from those fed on D.I.The fecundity of the females ofA. asychis was found to be dependent on the food composition of the hosts during larval development as well as during adult life.     

Lipid-enhanced pollen and lipid-reduced flour diets and their effect on the longevity of honey bees (Apis mellifera L.)

Abstract  As eucalypt pollens contain low concentrations of lipid, enhancing pollen diets with fatty acids was hypothesised to improve honey bee longevity. Different concentrations of linoleic and oleic acid added to eucalypt pollen were trialled in small cages containing approximately 1400 bees each. Bees fed diets of redgum ( Corymbia calophylla (Lindl.) Hill & Johnson, formerly Eucalyptus calophylla ) pollen had the lowest mortality of 22 diets tested for 6 weeks and had life spans (50%) greater than 42 days. Linoleic acid mixed with a redgum diet in concentrations >6% corresponded to life spans of 24–25 days. Bee longevity appeared to be more sensitive to oleic acid as life spans decreased to 15–21 days when diets had concentrations >2%. The life spans of bees fed soya bean flour were 26 days on low (0.6% lipid) fat, 19 days on defatted and 20 days on full-fat diets. Bees fed lupin flour had a life span of 23 days. Adding redgum pollen to lupin flour caused increased mortality, but addition of pollen to soya bean flour was beneficial. Thus, beekeepers who choose to utilise soya bean or lupin flours as protein substitutes to pollen will have bees with reduced longevity. Bees fed redgum pollen that had been dried, crushed, irradiated and hermetically stored in a cool room for several years had similar longevity to bees fed fresh-collected and frozen redgum pollen.     

The effects of temperature, diet, and other factors on development, survivorship, and oviposition of Aethina tumida (Coleoptera: Nitidulidae)

Developmental rate and survivorship of small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), life stages were measured across different temperatures (21, 25, 28, 32 and 35 degrees C) and diets, which included natural and artificial pollen, honey, and bee pupae. Temperature affected hatch success, time to hatching, and larval growth. Eggs hatched in 61 h at 21 degrees C but in < 22 h at 35 degrees C. Larvae achieved peak weight in < 8 d at 35 degrees C but needed 17 d at 21 degrees C. Diet had comparatively little effect on larval survivorship or maximum weight, although larvae fed only bee pupae had lower survivorship. Access to soil influenced pupation success. Duration of the life stage spent in the soil, during which pupation occurs, was also affected by temperature: adults emerged after 32.7 d at 21 degrees C but after only 14.8 d at 35 degrees C, albeit with high mortality. Minimum temperature for development was estimated at 13.5 degrees C for eggs, and 10.0 degrees C for larvae and pupae. Temperature influenced adult longevity and oviposition: on a honey and pollen diet average adult lifespan was 92.8 d at 24 degrees C but only 11.6 d at 35 degrees C. Beetles lived longer at 28 degrees C or lower but produced the most eggs per female, regardless of diet, at 32 degrees C. Beetle density influenced fecundity: beetles kept at three pairs per vial laid 6.7 times more eggs per female than those kept as single pairs. Overall, beetles fared best at 28-32 degrees C with mortality of all stages highest at 35 degrees C.     

Life table and biological studies of Harmonia axyridis Pallas (Col., Coccinellidae) reared on the grain moth eggs of Sitotroga cerealella Olivier (Lep., Gelechiidae)

The developmental period of immature stages, survival per cent, longevity, fecundity and life table parameters of Harmonia axyridis by feeding on fresh and frozen grain moth eggs (GME) of Sitotroga cerealella were studied under laboratory conditions. The effect of crowding adults on fecundity of females was also determined. The total developmental time from egg hatching to adult eclosion ranged from 18.89 ± 0.32 to 22.5 ± 0.21 days on fresh and frozen GME, respectively. Survival per cent from egg hatching to adult emergence differed significantly when the predator fed on the two diets of GME. Also, pupal and adult weights were affected by feeding on fresh and frozen GME. There were no significant differences in longevity of females, while there were significant variations in fecundity of females and longevity of males. The calculated values of T , DT , R_o , r_m , and e^rm were high by feeding on fresh GME. Morever, rates of survivorship ( Lx ), and maximum oviposition per female per day ( Mx ) were higher when the predator was reared on fresh than on frozen GME. Crowding conditions of predator adults affected the fecundity of females due to egg cannibalism by both males and females of the predator.     

Longevity and fecundity ofAcarus siro on four field and eight storage fungi

Egg production and longevity of isolated pairs ofAcarus siro L., when fed on mycelial pellets of selected fungi from shake cultures, were compared with those on a control diet of wheatgerm and brewer's yeast. The mites were always less productive on the fungal diet. They did best on the yeastHansenula anomola and worst on the field fungusAlternaria alternata. There was very little difference between egg production on wheatgerm alone and that on the control diet of wheatgerm and yeast. On the control diet, males lived longer than females. Fungal diets usually shortened male lives, while in two-thirds of the cases female lifespans were unaffected.     

Sex differences in movement between natural feeding and mating sites and tradeoffs between food consumption,mating success and predator evasion in Mediterranean fruit flies (Diptera: Tephritidae)

Summary Systematic quantitative observations of the location and diel pattern of adult Mediterranean fruit fly, Ceratitis capitata (Wiedemann), activities were carried out in an orange grove and surroundings on the island of Chios in Greece. Natural fly foods were assessed for their contribution to fly longevity, fecundity and fertility. There were diel shifts in male and female location. Females required a substantial and varied diet to realize peak fecundity. This diet was acquired away from the primary host, orange. Foraging for food throughout most of the day on fig and non-host foliage (including feeding on bird droppings) as well as on fig fruit and grapes, females dispersed and fed more than males. A diet of grapes alone did not support any fecundity, contributing only to longevity. A diet of figs alone, on the other hand, sustained both longevity and egg production. Bird feces alone supported neither egg production nor longevity. However, when added to a diet of figs, bird feces significantly increased fly fecundity. Throughout most of the day, males aggregated in leks within the inner canopy of the primary host, orange. The arrival here during the warmest hours of the day of receptive females, followed by pair formation, reinforced the lek mating system on host foliage. In the afternoon, females shifted to orange fruit where they suffered from high predation mortality while ovipositing. Soon after, males also shifted to orange fruit, where they attempted matings with non-receptive ovipositing females. Male feeding on fig fruit occurred late in the day, a time when they were least likely to find a mate. Male survival did not differ between the natural diets. Tradeoffs between food consumption, mating success and predator evasion are discussed for each sex and related to fruit fly mating systems.     

Longevity and reproductive success of Aethina tumida (Coleoptera: Nitidulidae) fed different natural diets

The longevity and reproductive success of newly emerged, unfed adult Aethina tumida Murray assigned different diets (control = unfed; honey-pollen; honey; pollen; empty brood comb; bee brood; fresh Kei apples; and rotten Kei apples) were determined. Longevity in honey-fed small hive beetle adults (average maximum: 167 d) was significantly higher than on other diets. Small hive beetles fed empty brood comb lived significantly longer (average maximum: 49.8 d) than unfed beetles (average maximum: 9.6 d). Small hive beetle offspring were produced on honey-pollen, pollen, bee brood, fresh Kei apples, and rotten Kei apples but not on honey alone, empty brood comb, or in control treatments. The highest reproductive success occurred in pollen fed adults (1773.8 +/- 294.4 larvae per three mating pairs of adults). The data also show that A. tumida can reproduce on fruits alone, indicating that they are facultative parasites. The pupation success and sex ratio of small hive beetle offspring were also analyzed. Larvae fed pollen, honey-pollen, or brood had significantly higher pupation success rates of 0.64, 0.73, and 0.65 respectively than on the other diets. Sex ratios of emerging adults fed diets of pollen or brood as larvae were significantly skewed toward females. Because small hive beetle longevity and overall reproductive success was highest on foodstuffs located in honey bee colonies, A. tumida are efficient at causing large-scale damage to colonies of honey bees resulting in economic injury for the beekeeper. Practical considerations for the control of A. tumida are briefly discussed.     

Effects of age at mating of both sexes on female longevity and fecundity performance in Ophraella communa LeSage (Coleoptera: Chrysomelidae)

Life-history strategies of animals are governed by fitness-related trait trade-offs. In particular, the age at which either one of the two sexes copulate has been shown to affect insect reproductive output and longevity. This suggests that trade-offs between longevity and reproduction might drive the choice of a mating partner based on their age and ultimately such choices might select for different life-histories. Although several studies indicate that female age at mating dictates subsequent insect longevity, fecundity, and egg hatch rate, it is unclear how male age at copulation affects these life-history traits. In this study, we simultaneously investigated the effects of female and male age on female fecundity, eggs hatch rate, and adult longevity in Ophraella communa LeSage (Coleoptera: Chrysomellidae), the primary biological control agent of the invasive common ragweed, Ambrosia artemisiifolia L. We found that young mature females lived significantly longer when they were mated with older males. Maximum female fecundity and subsequent egg hatch rate occurred when young females mated with 3-day-old males. On the other hand, females lived longer when mating with an older male. These findings are in accordance with the cost-of-reproduction concept.     

Effect of Mating Frequency on Female Fitness in Caloglyphus Berlesei (Astigmata: Acaridae)

We studied the effect of mating frequency on female longevity and fecundity in the mite Caloglyphus berlesei. We tested the hypothesis that high promiscuity is selected for in this species because females receive nutrients during copulation. Females were constantly exposed to either one or four males and fed either a standard or poor diet. The prediction that frequent mating benefits females was not confirmed. On the contrary, females kept with four males had significantly lower longevity on both diets and on the standard diet they also had decreased fecundity compared to females exposed to one male. On the poor diet the number of males had no significant effect on fecundity. Thus, increased mating frequency had a detrimental effect on female fitness.     

Dietary complementation across life stages in the polyphagous lady beetle Coleomegilla maculata

We investigated the life history consequences of changes in diet between larval and adult life stages in the polyphagous lady beetle Coleomegilla maculata DeGeer (Coleoptera: Coccinellidae). Beetles were reared on three larval diets: greenbug, Schizaphis graminum Rondani (Homoptera: Aphididae), eggs of the flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), and bee pollen. The reproductive performance of females was then evaluated on an adult diet of either greenbug or moth eggs. Moth eggs appeared to be the most suitable diet for larvae, yielding the largest adults, and pollen the least suitable, resulting in the smallest adults and greatly extended developmental time. Pollen‐reared beetles tended to have lower fecundity and fertility than those reared on animal protein, regardless of adult diet. Female fitness was generally increased by a change in diet upon emergence to the alternative source of animal protein, suggesting that dietary complementation occurred across life stages. Among females reared on greenbug, a change of diet to moth eggs reduced the period required for production of 12 clutches and increased egg fertility compared to continued feeding on greenbug. Among females reared on moth eggs, a change of diet to greenbug increased fecundity compared to continued feeding on moth eggs. Among females fed an adult diet of greenbug, those fed moth eggs as larvae had faster production of 12 clutches and higher fecundity. We discuss these novel results in the context of coccinellid life history and ecology and their potential implications for other insects that are predatory as both larvae and adults.     

Influence of adult diet on the fecundity and survival of the predator,Chrysopa scelestes [Neur.: Chrysopidae]

Studies were conducted in the laboratory to determine the most suitable diet for adults ofChrysopa scelestes Banks that would result in the maximum fecundity and longevity, without adversely affecting hatchability. Out of 6 adult diets tested, the died containing 40% honey and pollen grains of castor,Ricinus communis L. has influenced upon the female for production of more eggs. On an average, 796 eggs were laid in 36.83 reproductive days, this was followed by Protinex^? + fructose + pollen grains and honeydew of mealy bug,Planococcus citri (Risso) + pollen grains. The diet consisting of 40 % honey had little effect either on the per day reproduction or on the effective ovipositional period for total number of egg production. Pre-ovipositional period was observed to be extended in 40% honey followed by honeydew ofP. citri + pollen grains. Hatching of larvae was found to be not affected by various diets.

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Résumé Des études de laboratoire ont été menées dans le but de mettre au point un régime pourChrysopa scelestes Banks assurant une fécondité et une longévité maximales et n'affectant pas l'éclosion des jeunes larves. Parmi les 6 régimes essayés, celui qui contient 40 % de miel et du pollen de ricinRicinus communis L. a donné lieu à la ponte la plus abondante de la part des femelles. En moyenne, chaque femelle dépose alors 796 œufs en 36,8 j de ponte. Viennent ensuite les régimes constitués de Protinex^￡, fructose et pollen, puis du miellat de la cochenille farineusePlanococcus citri (Risso) et de pollen. La nourriture à base de 40% de miel aboutit à une fécondité totale très réduite, tant par une incidence sur la fécondité quotidienne que sur la durée de la ponte. La durée de la période de pré-oviposition subit l'allongement le plus considérable dans le cas de l'alimentation avec 40% de miel, suivi par celui que provoque le miellat deP. citri additionné de pollen. L'éclosion des jeunes larves n'a pas été influencée par les divers régimes imaginaux testés.

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Contribution No. 350/83 of I.I.H.R., Bangalore-89.     

Effects of temperature and diet on oviposition rate and development time of the New Zealand flower thrips, Thrips obscuratus

The life history of New Zealand flower thrips (Thrips obscuratus (Crawford), Thysanoptera: Thripidae) was studied using a simple laboratory rearing method. The effects of temperature and diet on oviposition rate and development time were examined. Oviposition rate increased with increasing temperature between 10°C and 25°C. Development time for individual instars and for total development decreased with increasing temperature between 10°C and 27°C. Total development time ranged from 50 days at 10°C (female) to 10 days at 27°C (male). The relationship between temperature and development rate was expressed as a straight line such that lower thresholds of development of between 4.2°C and 6.3°C were established for life stages. Adult lifespan increased with decreasing temperature between 10°C and 25°C and females lived longer than males. At 10°C and 25°C females lived for an average of 34 and 3 weeks respectively. Thrips supplied with pollen exhibited highest and sustained levels of egg production in comparison to other diets. Larval mortality was lowest and development time fastest on diets of pollen and sucrose or fruit juice in comparison to other plant tissues. Larval development time was similar on four species of pollen.     

Floral resources impact longevity and oviposition rate of a parasitoid in the field

1. The use of floral resource subsidies to improve herbivore suppression by parasitoids requires certain trophic interactions and physiological changes to occur. While the longevity and fecundity of parasitoids are positively affected by nectar subsidies in laboratory studies, the impacts of floral subsidies on the fecundity and longevity of freely foraging parasitoids have not been studied. 2. We studied the longevity and per capita fecundity of naturally occurring Diadegma insulare foraging in cabbage plots with and without borders of flowering buckwheat, Fagopyrum esculentum, as well as relationships between longevity, fecundity, sugar feeding and parasitism rates on larvae of the diamondback moth, Plutella xylostella. 3. Relative longevity was estimated by counting broken setae on the fringe of the forewing. Floral borders increased the longevity of males and females in adjacent cabbage plots. 4. The egg maturation rate of D. insulare was estimated by comparing egg loads of females collected early in the day with egg loads of females held without hosts in field cages throughout the day. Females in buckwheat cages matured 2.7 eggs per hour while females in control cages resorbed 0.27 eggs over the same time period. 5. The fecundity of females collected in the afternoon was estimated by comparing their actual egg load to the estimated egg load in the absence of oviposition for females in a given plot. Females foraging in buckwheat plots had marginally fewer eggs remaining in their ovaries, and laid marginally more eggs than females in control plots. Females from both treatments carried 30-60 eggs by the afternoon and therefore were time-limited rather than egg-limited. 6. Plots where a greater proportion of females had fed on sugar had longer-lived females. This suggests that feeding enhanced longevity of D. insulare. However, plots with longer-lived and more fecund females did not exhibit higher parasitism rates, although the power of these tests were low.     

Nutrients in fruit increase fertility in wild-caught females of large and long-lived Euphaedra species (Lepidoptera, Nymphalidae)

Fruit-feeding butterflies can experience a more nutrient rich adult diet than nectar-feeding species, and can be expected to use these nutrients for egg production. Here we compare life span, and reproduction parameters of wild-caught females of large and long-lived species on either a sucrose or a mashed banana diet. With small sample sizes per species, but rich longitudinal data for each individual, we examined the longitudinal reproduction pattern, egg size and hatchability of these butterflies in captivity. Diet significantly affected mortality in captivity in a time-dependent manner. On average, we found that butterflies fed mashed banana laid 1.855 times more eggs than those fed sugar. They laid significantly more eggs when they laid and conserved egg size with age while butterflies fed sucrose showed significantly declining egg sizes. Egg hatchability was not significantly affected by diet. Long pre-oviposition periods, significantly smaller first eggs, and absence of age at capture effects on intensity of reproduction indicate low reproduction rates in the field that are due to low food availability. With our small sample sizes, we did not detect significant differences between the species in their response to the diet treatments.