Performance of Amblyseius herbicolus on broad mites and on castor bean and sunnhemp pollen

Amblyseius herbicolus (Banks) is found associated with broad mites Polyphagotarsonemus latus in crops such as chili pepper in Brazil. The species has a potential for controlling P. latus, but little is known about its development and reproduction on this pest as well as on other food sources. We studied biological, reproductive and life table parameters of A. herbicolus on three different diets: broad mites, castor bean pollen (Ricinus communis) and sunnhemp pollen (Crotalaria juncea). The predator was able to develop and reproduce on all diets. However, its intrinsic growth rate was higher on the diet of broad mites or on castor bean pollen than on sunnhemp pollen. Differences among pollen species may be due to their nutritional content. Feeding on alternative food such as pollen can facilitate the predator’s mass rearing and maintain its population on crops when prey is absent or scarce. Other strategies of using pollen to sustain predator population and reduce pest damage are discussed.     

Development and Leaf Consumption by Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) Reared on Leaves of Agroenergy Crops

Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) is a polyphagous pest that threatens more than 24 species of crop plants including those used for biodiesel production such as Ricinus communis (castor bean), Jatropha curcas (Barbados nut), and Aleurites fordii (tung oil tree). The development and leaf consumption by S. cosmioides reared on leaves of these three species were studied under controlled laboratory conditions. The egg-to-adult development time of S. cosmioides was shortest when reared on castor bean leaves and longest when reared on tung oil tree leaves. Larvae reared on castor bean and Barbados nut leaves had seven instars, whereas those reared on tung oil tree leaves had eight. Females originating from larvae reared on castor bean and Barbados nut leaves showed greater fecundity than did females originating from larvae reared on tung oil tree leaves. Insects fed on castor bean leaves had shorter life spans than those fed on tung oil tree and Barbados nut leaves although the oviposition period did not differ significantly. The intrinsic and finite rates of increase were highest for females reared on castor bean leaves. Total leaf consumption was highest for larvae reared on tung oil tree leaves and lowest for those reared on Barbados nut leaves. We conclude that castor bean is a more appropriate host plant for the development of S. cosmioides than are Barbados nut and tung oil tree.     

Does vegetational diversification reduce coffee leaf miner Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae) attack?

The effects of increasing plant diversity on the population of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) were investigated in two organic coffee production systems. One system consisted of coffee intercropped with banana trees (shaded system) and the other one of coffee intercropped with pigeon pea (unshaded system). The increase in plant diversity on both systems was achieved via introduction of green manures such a perennial pea nut, sunn hemp and Brazilian lucerne. The population of L. coffeella, predation and parasitism of L. coffeella mines were biweekly evaluated during eight months. The increase in plant diversity on both systems did not affect the attack of L. coffeella on coffee leaves and the mine parasitism rate. However, there was a positive and significant relationship between increasing plant diversity and coffee leaf mine predation by wasps on unshaded coffee system and a negative relationship on shaded coffee system.     

Biology of Amblyseius largoensis (Muma) (Acari: Phytoseiidae), a potential predator of Aceria guerreronis Keifer (Acari: Eriophyidae) on coconut trees

Aceria guerreronis Keifer is considered one of the main pests of coconuts around the world. Amongst the Phytoseiidae recorded on this crop, Amblyseius largoensis (Muma) has been reported in association with A. guerreronis. In order to verify whether A. largoensis feeds on A. guerreronis, the biology of this predator was evaluated on different food sources, including A. guerreronis. Three types of diet were tested [Tetranychus urticae Koch + castor bean (Ricinus communis L.) pollen + honey at 10%, A. guerreronis + pollen + honey, and only A. guerreronis], determining its development, survivorship, oviposition, sex ratio and longevity at 27 degrees C, 60 +/- 5% RH 12 h photophase. Fertility life tables were constructed. The duration of the immature phase was lower when feeding only on A. guerreronis, while fecundity was higher when feeding on a prey + pollen + honey. There was no difference in relation to survivorship of the immature stages between the three diets. Parameters of fertility life tables were higher when the diet included A. guerreronis or T. urticae + pollen + honey, although the predator was able to complete its life cycle and reproduce when feeding exclusively on A. guerreronis. The results suggest that A. largoensis preys upon A. guerreronis under natural condition and that it might play some role in the control of the latter.     

Influence of diet on life table parameters of <Emphasis Type="Italic">Iphiseius degenerans</Emphasis> (Acari: Phytoseiidae)

Studies on the reproduction, longevity and life table parameters of Iphiseius degenerans (Berlese) were carried out under laboratory conditions of 25 ± 1 °C, 75 ± 5% RH and 16L:8D h. As food sources for the predatory mite, Ricinus communis L. pollen, all stages of the spider mite Tetranychus urticae Koch, Frankliniella occidentalis (Pergande) larvae, and Ephestia kuehniella Zeller eggs were selected. All diets were accepted as food by the adult mites. Female longevity ranged from 29.5 to 42.4 days, the highest value was recorded on a diet of Ephestia eggs. The highest percentage of females escaping the experimental arena was observed on the diet consisting of thrips larvae. The highest oviposition rate (1.9 eggs/female.day) was recorded when the predator was fed on spider mites on an artificial substrate. For other diets, oviposition rates ranged from 1.0 to 1.3 eggs/female.day. The intrinsic rate of natural increase (r _m) of I. degenerans varied between 0.015 and 0.142 females/female.day. The diet consisting of castor bean pollen resulted in the highest population growth whereas the diet on spider mites brushed off onto a bean leaf arena resulted in the slowest population growth. This can be explained by the inability of the predator to cope with the webbing of T. urticae, and the high escape rate of the progeny when reared on spider mites. The percentage of females in the offspring ranged from 40 to 73%.This revised version was published online in May 2005 with a corrected cover date.     

Diet‐dependent intraguild predation between the predatory mites Neoseiulus californicus and Neoseiulus cucumeris

Based on the hypothesis that matching diets of intraguild (IG) predator and prey indicate strong food competition and thus intensify intraguild predation (IGP) as compared to non‐matching diets, we scrutinized diet‐dependent mutual IGP between the predatory mites Neoseiulus cucumeris and N. californicus. Both are natural enemies of herbivorous mites and insects and used in biological control of spider mites and thrips in various agricultural crops. Both are generalist predators that may also feed on plant‐derived substances such as pollen. Irrespective of diet (pollen or spider mites), N. cucumeris females had higher predation and oviposition rates and shorter attack latencies on IG prey than N. californicus. Predation rates on larvae were unaffected by diet but larvae from pollen‐fed mothers were a more profitable prey than those from spider‐mite fed mothers resulting in higher oviposition rates of IG predator females. Pollen‐fed protonymphs were earlier attacked by IG predator females than spider‐mite fed protonymphs. Spider mite‐fed N. californicus females attacked protonymphs earlier than did pollen‐fed N. californicus females. Overall, our study suggests that predator and prey diet may exert subtle influences on mutual IGP between bio‐control agents. Matching diets did not intensify IGP between N. californicus and N. cucumeris but predator and prey diets proximately influenced IGP through changes in behaviour and/or stoichiometry.     

The Contribution of Extrafloral Nectar to Survival and Reproduction of the Predatory Mite Iphiseius Degenerans on Ricinus Communis

The phytoseiid mite Iphiseius degenerans (Berlese) is an effective predator of western flower thrips, Frankliniella occidentalis (Pergande), in Dutch greenhouses. In the Mediterranean area, castor bean, Ricinus communis L., is known as a year-round host plant for this predatory mite. On flowering castor bean plants in greenhouses, I. degenerans can be found in densities of more than 100 per leaf. For this reason, the plant is being used as a banker plant to augment biological control. It has been shown that pollen produced by the large apical flowers sustains reproduction and development for these mites. The objective of this study was to measure the contribution of the extrafloral nectar of this plant to the reproductive success of this predatory mite. A study conducted at 25°C in presence of free water showed that (1) I. degenerans is unable to develop beyond the protonymphal stage when fed only nectar and leaf tissue, (2) its ovipositional rate is higher when pollen is supplemented with nectar, (3) its reproduction ceases within a few days when fed on nectar only, but the predator can survive for several weeks and resume oviposition when fed pollen again and (4) the feeding of young females for one or two weeks with nectar only extends their longevity by approximately the same period and only slightly diminishes their lifetime reproductive potential (R0), as compared to mites continuously fed pollen. It can be concluded that extrafloral nectar can provide an important contribution to population growth and maintenance of I. degenerans on R. communis, particularly in pre- and post-blooming periods. Assuming these predators are beneficial to the plant in clearing them of herbivorous mites and thrips, this relationship may be regarded as an example of plant–predator mutualism. The combination of pollen and extrafloral nectar makes castor bean an ideal rearing and banker plant for I. degenerans.     

Polyphagy and primary host plants: oviposition preference versus larval performance in the lepidopteran pest Helicoverpa armigera

Oviposition preference and several measures of offspring performance of Helicoverpa armigera (Hübner) were investigated on a subset of its host plants that were selected for their reputed importance in the field in Australia. They included cotton, pigeon pea, sweet corn, mungbean, bean and common sowthistle. Plants were at their flowering stage when presented to gravid female moths. Flowering pigeon pea evoked far more oviposition than did the other plant species and was the most preferred plant for neonate larval feeding. It also supported development of the most robust larvae and pupae, and these produced the most fecund moths. Common sowthistle and cotton were equally suitable to pigeon pea for larval development, but these two species received far fewer H. armigera eggs than did pigeon pea. Mungbean also received relatively few eggs, but it did support intermediate measures of larval growth and survival. Fewest eggs were laid on bean and it was also the least beneficial in terms of larval growth. Among the host plant species tested, only flowering pigeon pea supported a good relationship between oviposition preference of H. armigera and its subsequent offspring performance. Australian H. armigera moths are thus consistent with Indian H. armigera moths in their ovipositional behaviour and larval performance relative to pigeon pea. The results suggest that the host recognition and acceptance behaviour of this species is fixed across its geographical distribution and they support the theory that pigeon pea might be one of the primary host plants of this insect. These insights, together with published results on the sensory responses of the females to volatiles derived from the different host plant species tested here, help to explain why some plant species are primary targets for the ovipositing moths whereas others are only secondary targets of this polyphagous pest, which has a notoriously broad host range. Handling Editor: Joseph Dickens     

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.     

Effect of some food sources associated with cassava in Africa on the development, fecundity and longevity of Euseius fustis (Pritchard and Baker) (Acari: Phytoseiidae)

Various foods associated with cassava were tested for their effect on the development, fecundity and longevity of Euseius fustis, the most common phytoseiid species found on cassava in Africa. Euseius fustis developed successfully to adulthood on the spider mite prey species Mononychellus tanajoa (Bondar) and Oligonychus gossypii (Zacher) and on pollen from maize, castor bean and cassava. Euseius fustis also completed development on water-diluted phloem exudate from cassava, diluted honeydew from the cassava mealybug and on various pollen and prey combinations. When reared on Tetranychus urticae Koch prey or free water only, E. fustis did not develop past the deutonymphal stage. All larvae held on clean leaf discs on water-soaked cotton died without moulting, suggesting that E. fustis must feed in order to moult to the nymphal stages. Diets of maize plus castor bean pollen and maize pollen plus M. tanajoa resulted in the highest rate of development, the highest fecundity and the greatest longevity. Castor bean pollen alone and maize pollen alone produced a higher fecundity and greater longevity than M. tanajoa tested alone. A colony of E. fustis reared continuously for seven generations on castor bean pollen produced nine times more adult females than a colony of E. fustis reared continuously on M. tanajoa. No negative effects on the development and fecundity of E. fustis were observed after seven generations were reared on pollen.     

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.     

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.     

Effect of six sugars on the longevity,oviposition performance and nutrition accumulation in an endoparasitoid,Meteorus pulchricornis (Hymenoptera: Braconidae)

The effects of six sugar resources (fructose, glucose, sucrose, trehalose, raffinose and honey) on the longevity, oviposition performance and nutrition levels of Meteorus pulchricornis, a thelytokous larval endoparasitoid of the common cutworm Spodoptera litura were examined under laboratory conditions. Female adults of M. pulchricornis fed 1 M fructose, glucose, trehalose or sucrose solutions survived longer than those fed on other sugar solutions or water. When provided with honey or sucrose solutions, the female parasitoids laid more offspring than those fed other sugar diets or the control. The body size of offspring driven from honey-, fructose-, sucrose-, and glucose-fed females, along with water-fed group, were larger than the trehalose- and raffinose-fed females. However, the emergence rates of all offspring generated from different sugars- and water-fed females were similar. When separately given honey, sucrose or fructose, M. pulchricornis females accumulated fructose at a higher level than the other groups. Parasitoid wasps fed trehalose solution accumulated the highest level of total sugar. Glycogen levels and lipid content were highest at emergence and then decreased across all diets. In addition, females fed on trehalose had the highest level of glycogen compared to other sugar diets and water control regardless of emergency level. Females fed trehalsoe, fructose, and glucose solutions had a higher level of lipid than those fed other sugar solutions and water at life end. The outcome of this study can benefit both laboratory rearing and management interventions that improve sugar sources for the parasitoid in the field.     

Responses of Amblyseius ovalis (Evans) (Acarina: Phytoseiidae) to natural food resouces and two artificial diets

Six phytophagous mites, maize pollen, and two artificial diets were fed to Amblyseius ovalis to evaluate their food suitability for the predator. The parafilm diet-chip of Hager and Tassan was adopted for artificial diet studies. The floating leaf method was the best among all tested methods, producing high survival, developmental, and reproductive rates of the predator. Offspring of A. ovalis fecding on artificial diets did not complete their life cycles. A. ovalis feeding on E. orientalis, O. mangiferus, ad O. taiwanicus developed into adult form faster than those feeding on other food resources. Predators feeding on the natural food, except those feeding on T. kanzawai, had much higher immatural survival rates, lower escape rates, and shorter developmental durations than those feeding on the artificial diets.All A. ovalis laid an average of two eggs per female per day after 2 days of preoviposition, except for those feeding on T. kanzawai which produced none. A. ovalis feeding on artificial diets showed a shorter oviposition period, lower daily and total reproductive rates, and shorter longevity. The complicated webbing life type of T. kanzawai inhibited the activities of A. ovalis, indicating that the predators may require nutrients other than T. kanzawai eggs to molt into adults and to reproduce. The functions varying the phytoseiid-tetranychid relationship during the predator's approach to the microhabitat of the prey were postulated from the predator's structures and the prey's life type. Most predator eggs were laid by 2–18 day-old females feeding on natural food resources. A. ovalis retained its high activity on the low webbing habitats of O. mangiferus and E. orientalis, and on maize pollen. The intrinsic rate of increase, mean generation time, and net reproductive rate of A. ovalis on each of nine tested food resources were evaluated from its life tables. The predator showed the highest intrinsic rates of increase when feeding on the prey of E. orientalis, O. mangiferus, and on maize pollen, and the lowest rates when feeding on the artificial diet even when the immatures had fed on the O. mangiferus and maize pollen. Consequently, the optimal food resources for A. ovalis appear to be O. mangiferus or O. oriintalis with supplements of maize pollen. When fed on these food resources, the predators demonstrated the highest rates of survival, longevity, fecundity, and intrinsic increase.     

Non-prey food for subsistence of Amblyseius idaeus (Acari: Phytoseiidae) on cassava in Africa

The nutritional effects of pollen from cassava, oil palm, castor bean, Leucaena leucocephala and a phloem exudate from cassava were tested in the laboratory for their effect on survivorship and oviposition of Amblyseius idaeus (Denmark & Muma). Survival and longevity of even-aged females were enhanced on the aforementioned non-prey diets when compared with the control of no food. Castor bean pollen provided sufficient nutrition to induce an irregular and low ovipositional rate of A. idaeus over a five week interval. Oviposition ceased after 48 h in the presence of the other non-prey foods or free-water only. These studies suggest that A. idaeus is capable of switching or supplementing its diet with non-prey foods during periods when spider mite populations are low.     

Development and reproduction of Adalia bipunctata on factitious and artificial foods

The native coccinellid Adalia bipunctata (L.) (Coleoptera: Coccinellidae) may be an alternative to exotic species like Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) for the biological control of aphid pests in Europe. The availability of adequate factitious or artificial foods may help optimize its mass production. This study examines the nutritional value of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae) eggs plus bee pollen, pea aphids Acyrthosiphum pisum (Harris) (Hemiptera: Aphididae) and mixtures of bee pollen and cysts of Artemia franciscana Kellogg (Branchiopoda: Artemiidae) and/or a lyophilized artificial diet based on bovine meat and liver. Reproducing adults of A. bipunctata were obtained on all diets tested, but immature survival, adult weights, development times and reproductive rates differed among diets. Over 84% of first instars fed on E. kuehniella eggs plus pollen or aphids survived to adulthood. Feeding predator larvae on pollen combined only with A. franciscana cysts or artificial diet yielded 40–55% immature survival, but survival increased to 74% when all of these components were mixed. Adult weights of A. bipunctata on the mixtures of pollen, A. franciscana cysts and/or artificial diet were 55–75% of those on aphids or on E. kuehniella eggs plus pollen. Lifetime fecundity was superior on E. kuehniella eggs plus pollen (1,864 eggs) to that on the other diets (264–889 eggs). The use of mixtures of plant and animal foods for A. bipunctata and other predators may contribute to increasing the cost-effectiveness of commercial mass production by reducing inputs of natural prey like aphids, or of nutritious but expensive factitious foods like lepidopteran eggs.     

Osmotic adjustment is a prime drought stress adaptive engine in support of plant production

Osmotic adjustment (OA) and cellular compatible solute accumulation are widely recognized to have a role in plant adaptation to dehydration mainly through turgor maintenance and the protection of specific cellular functions by defined solutes. At the same time, there has been an ongoing trickle of skepticism in the literature about the role of OA in supporting crop yield under drought stress. Contrarian reviews argued that OA did not sustain turgor or that it served mainly for plant survival rather than productivity. This critical review examined 26 published studies where OA was compared with yield under drought stress in variable genotypes of 12 crops, namely, barley, wheat, maize, sorghum, chickpea, pea, pigeon pea, soybean, canola, mustard, castor bean and sunflower. Over all crops a positive and significant association between OA and yield under drought stress were found in 24 out of 26 cases. Considering that it is generally difficult to find a singular plant trait responsible for yield advantage of numerous crops under different drought stress conditions, this evidence is no less than remarkable as proof that OA sustains crop yield under drought stress.     

Life tables of Neoseiulus cucumeris exclusively fed with seven different pollens

The juvenile development and survival, and demographic parameters of the predatory mite Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) fed on pollen of castor bean, tulip, apple, Christmas cactus, horse-chestnut, maize, and birch were assessed under laboratory conditions. Deprivation of food and pollen of castor bean plants resulted in 100 % juvenile mite mortality. Feeding mites with tulip and horse-chestnut pollen resulted in the shortest development and the highest total fecundity. Adult mites fed on birch, tulip, maize, and apple pollen lived significantly longer compared with those fed on pollen of horse-chestnut and Christmas cactus. The intrinsic rate of natural increase ranged between 0.1013 ♀♀/♀/day for maize and 0.1806 ♀♀/♀/day for horse-chestnut pollen as food. Net reproductive rate was the lowest when fed with maize pollen and highest when fed with horse-chestnut pollen. Population doubling time was highest on maize pollen and shortest on horse-chestnut pollen. Our study revealed that birch, tulip, horse-chestnut, apple, and maize pollen can be used by N. cucumeris from early spring to late summer as a suitable alternative food in periods when prey in the field are scarce or absent.     

Biology of Mastrus ridibundus (Gravenhorst), a potential biological control agent for area‐wide management of Cydia pomonella (Linneaus) (Lepidoptera: Tortricidae)

The codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is a serious pest of pome fruit crops. A natural enemy of codling moth, the larval ectoparasitoid Mastrus ridibundus (Gravenhorst) (Hymenoptera: Ichneumonidae) has been imported into South America from the USA but little is known about the biology and ecology of the wasp, knowledge that is needed to design an efficient strategy of release and establishment. Experiments were carried out to assess important traits of the biology of the parasitoid in relation to its possible use as a biocontrol agent for codling moth. When M. ridibundus females were offered larvae ranging in weight from 37 to 78 mg, they oviposited more eggs on heavier hosts. In another study, the adult wasps were offered honey, diluted honey (10%) or pollen in paired choice tests and both males and females preferred honey over the other two foods. Females preferred 10% honey over pollen, while the males showed the opposite preference. Honey‐fed females lived longer than starved females. Adults died rapidly at 35°C, while they lived 20 days at 25°C and 12–17 days at 15°C. Female wasps had on average 25 ± 14 and 18 ± 11 progeny at 15 and 25°C, respectively, but they did not had progeny at 35°C. The development time (egg to adult emergence) was on average 44 ± 7 and 24 ± 2 days at 15 and 25°C respectively. Immature insects did not reach the adult stage at 35°C.     

The effects of Eucalyptus pollen on longevity and fecundity of Eucalyptus longhorned borers (Coleoptera: Cerambycidae)

The longevity and fecundity of adult Phoracantha recurva and Phoracantha semipunctata were strongly affected by diet. Female P. recurva fed a diet of Eucalyptus pollen and sucrose solution lived 34-56% longer than females fed diets containing other types of pollen, ground dog chow, or sucrose solution alone. Diet had no significant effect on longevity of P. recurva males. Similarly, longevities of P. semipunctata females were increased 48-71% on the Eucalyptus pollen diet compared with the other diets. Male P. semipunctata also lived longer on the Eucalyptus pollen diet than most of the other diets. Fecundity was dramatically affected by diet, with P. recurva females fed the Eucalyptus pollen diet laying approximately 4-8 times more eggs than females on the other diets. Eucalyptus pollen also increased the fecundity of P. semipunctata females approximately 3-5-fold. Diet resulted in only minor effects on egg size and percent egg hatch for both beetle species.