Effect of diet and mating status on ovarian development and oviposition in the polyphagous predator Macrolophus caliginosus (Heteroptera: Miridae)

The mirid bug Macrolophus caliginosus is commercially reared on eggs of Ephestia kuehniella, constituting an effective but expensive factitious food. Artificial diets can decrease the rearing costs of this natural enemy, but developing and evaluating an artificial diet is a very time-consuming activity. In the current study, development and reproduction of M. caliginosus on two artificial diets based on egg yolk were investigated. The artificial diets resulted in longer development and lower adult weights, but survival was comparable with that of control insects fed E. kuehniella eggs. Reproductive potential of the predator reared on factitious and artificial foods was assessed using a dissection method. The influence of nymphal food on fecundity was less important than that of adult food. Adults fed E. kuehniella eggs had a preoviposition period of about 4 days, whereas adults offered only plant material started laying eggs about 7 days after emergence. Ovarian scores at day 7 were higher for females fed E. kuehniella eggs than for those given access only to a tobacco leaf. Ovarian scores were not significantly affected by mating status. In a final test, a parallel comparison of two methods for assessing reproductive response to diet was made. Here, adult couples were offered one of four diets: E. kuehniella eggs, one of two artificial diets or no food. Half of the females were dissected and the other half was held for determining lifetime oviposition. Females fed E. kuehniella eggs had superior ovarian scores and laid more eggs than those fed either artificial diet or those given no extra food. A good correlation (r = 0.97) was obtained between ovarian scores and oviposition data, indicating that dissecting females after 1 week provides a reliable estimate of fecundity as affected by diet quality. Rapid reproductive assessments as used in the current study will help to increase the rate of development of artificial diets and may contribute to more cost effective production methods for augmentative biological control agents.     

Effect of diet and mating status on ovarian development and oviposition in the polyphagous predator Macrolophus caliginosus (Heteroptera: Miridae)

The mirid bug Macrolophus caliginosus is commercially reared on eggs of Ephestia kuehniella, constituting an effective but expensive factitious food. Artificial diets can decrease the rearing costs of this natural enemy, but developing and evaluating an artificial diet is a very time-consuming activity. In the current study, development and reproduction of M. caliginosus on two artificial diets based on egg yolk were investigated. The artificial diets resulted in longer development and lower adult weights, but survival was comparable with that of control insects fed E. kuehniella eggs. Reproductive potential of the predator reared on factitious and artificial foods was assessed using a dissection method. The influence of nymphal food on fecundity was less important than that of adult food. Adults fed E. kuehniella eggs had a preoviposition period of about 4 days, whereas adults offered only plant material started laying eggs about 7 days after emergence. Ovarian scores at day 7 were higher for females fed E. kuehniella eggs than for those given access only to a tobacco leaf. Ovarian scores were not significantly affected by mating status. In a final test, a parallel comparison of two methods for assessing reproductive response to diet was made. Here, adult couples were offered one of four diets: E. kuehniella eggs, one of two artificial diets or no food. Half of the females were dissected and the other half was held for determining lifetime oviposition. Females fed E. kuehniella eggs had superior ovarian scores and laid more eggs than those fed either artificial diet or those given no extra food. A good correlation (r = 0.97) was obtained between ovarian scores and oviposition data, indicating that dissecting females after 1 week provides a reliable estimate of fecundity as affected by diet quality. Rapid reproductive assessments as used in the current study will help to increase the rate of development of artificial diets and may contribute to more cost effective production methods for augmentative biological control agents.     

Biological and biochemical characteristics for quality control of Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae) reared on a liver-based diet

Biological and biochemical parameters of a flightless strain of Harmonia axyridis, fed on a pork liver-based artificial diet and on Ephestia kuehniella eggs as controls, were compared. The diet-grown larvae showed a significantly longer developmental time and a lower adult emergence rate compared to control larvae. The weights of the newly emerged adults were significantly higher for adults fed E. kuehniella eggs during their larval stages than fed the artificial diet. In contrast, larval food source had no effect on the duration of the pre-oviposition period or adult longevity. For adults fed on E. kuehniella eggs as larvae, a significantly longer pre-oviposition period, lower daily weight gain and fecundity were found for the diet-fed females compared to those fed on E. kuehniella eggs throughout the life span. The adult food source had no significant effect on longevity and fertility. Lower amino acid and fatty acid contents (in particular C16:1 and C18:3n-3) were found for the prepupae and newly emerged females obtained from diet-reared larvae compared to controls. Deficiencies in fatty acids C16:1 and C18:3n-3 were also observed in females obtained from E. kuehniella egg-reared larvae and fed on diet from adult emergence. The analyses of the foods showed deficiencies in artificial diet, especially for some amino and fatty acids. The results suggest a non-optimal composition of the artificial diet and some possibilities for its improvement. However, this polyphagous predator could be reared from first instar larvae to fully reproductive adults on a pork liver-based artificial diet.     

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.     

Influence of predator density,diet and living substrate on developmental fitness of Orius laevigatus

Mass rearing of Orius laevigatus on non‐insect foods could substantially increase the cost‐effectiveness of the production of this biological control agent which is largely based on the use of expensive eggs of the Mediterranean flour moth Ephestia kuehniella. In this study, the effect of substrate quality and predator density on nymphal development of O. laevigatus fed on E. kuehniella eggs, honeybee pollen or an egg yolk based artificial diet was assessed using several types of substrates as shelter materials in the rearing containers (wax paper, bean pod or no extra substrate). In general, E. kuehniella eggs proved to be a nutritionally superior food compared to pollen and artificial diet. Pollen supported nymphal development of O. laevigatus better than the artificial diet. Overall, increasing nymphal density resulted in higher mortality, which may be due in part to cannibalism. The addition of a bean pod compensated for the nutritionally suboptimal artificial, but had a negative effect when O. laevigatus was fed on pollen. The non‐insect foods tested could not adequately replace lepidopteran eggs as a food source for O. laevigatus but they may be useful as an alternative food or in a part of the rearing process.     

Fitness and predation potential of Macrolophus pygmaeus reared under artificial conditions

Abstract The biological parameters of Macrolophus pygmaeus Rambur after prolonged rearing in the absence of plant materials were compared with those of conventionally plant‐reared predators. When eggs of Ephestia kuehniella Zeller were provided as food, developmental and reproductive fitness of M. pygmaeus reared for over 30 consecutive generations using artificial living and oviposition substrates was similar to that of predators kept on tobacco leaves. Plantless‐reared fifth instars of the predator also had similar predation rates on second instars of the tobacco aphid, Myzus persicae nicotianae Blackman, as their peers maintained on plant materials. In a further experiment, predation on aphid prey by fifth instar M. pygmaeus fed one of two egg yolk‐based artificial diets was compared with that of nymphs fed E. kuehniella eggs. Despite their lower body weights, predators produced on either artificial diet killed similar numbers of prey as their counterparts reared on lepidopteran eggs. Our study indicates that artificial rearing systems may be useful to further rationalize the production of this economically important biological control agent.     

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.     

Liver-based artificial diets for the production of Orius laevigatus

Different meat- and liver-based artificialdiets were designed for the generalist predatorOrius laevigatus (Fieber) (Anthocoridae)and their suitability was compared to that ofits factitious food, Ephestia kuehniellaZeller (Pyralidae) eggs. The quality of thefood was measured by its ability to promotegrowth and oviposition of the insect. Nymphaldevelopment was slower on artificial diets thanon the control food, taking 15.0–15.9 days vs.14.3 days, respectively. Survival of nymphs fedartificial diets varied from 68.0–92.5%,compared with 96% for those fed E. kuehniella eggs. Adult weights were, however,not affected by diet. Fecundity of femalesprovided with liver diets was similar to orsomewhat lower than that of females fed Ephestia eggs. Oviposition rate and egg hatchwere similar on all diets tested. The resultssuggest that beef liver was the most importantcomponent of the diets tested, offering theessential nutrients to sustain growth andreproduction of O. laevigatus.Supplementing ingredients, like ground beef,egg yolk, sucrose and vitamin C can improve thenutritional value of the diet for O.laevigatus, but effects are rather small.Artificial diets containing liver and egg yolkas the main components may prove useful to makemass production of O. laevigatus andother heteropteran predators more cost effective.     

Fitness consequences of artificial diets with different macronutrient composition for the predatory bug Orius majusculus

The commercial production of Orius spp. (Hemiptera: Anthocoridae), including Orius majusculus (Reuter), relies on the use of eggs of Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) as rearing diet. However, E. kuehniella eggs have become an expensive fodder thus increasing the price of these key biological control agents. The use of artificial diets potentially decreases the production costs. In this regard, establishing a link between dietary composition and fitness could advance the development of an optimum alternative artificial diet for these predatory insects. The aim of the current study was to test the effect of six artificial diets with different macronutrient composition on the development and reproductive fitness of O. majusculus when compared with the effect of E. kuehniella eggs. In general, nymphal survival was not affected by diet, whereas development was slightly delayed on artificial diets. However, female body mass and fecundity were significantly lower on all of the artificial diets compared with the E. kuehniella eggs diet, suggesting that artificial diets were of inferior quality. Within artificial diets, females fed the viable diet with highest content in lipid laid more eggs than those raised on the most protein-rich diets. We found there was some variation in carcass composition between the O. majusculus fed the various diets, but these variations did not match the differences found in the fitness parameters measured.     

Effects of food and temperature on development,fecundity and life‐table parameters of Adalia bipunctata (Coleoptera: Coccinellidae)

Development, reproduction and life tables of Adalia bipunctata (L.) were studied at three temperatures (19, 23 and 27°C) on a mixture of frozen pollen and Ephestia kuehniella Zeller eggs as a factitious food and on the aphids Myzus persicae (Sulzer) and Acyrthosiphon pisum (Harris) as natural foods. Development time of A. bipunctata on all tested diets decreased with increasing temperature. Mortality was lowest at 23°C, averaging 44.5%, 42.6% and 24.3% on factitious food, A. pisum and M. persicae respectively. The shortest developmental time from egg to adult at this temperature was observed on factitious food (18.55 days). However, the factitious food was inferior to the aphid diets in terms of reproduction, yielding the longest pre‐oviposition period, shortest oviposition period and lowest fecundity. The mean oviposition rate at 23°C varied from 19.94 to 25.03 eggs day^?1 on factitious food and M. persicae respectively. The intrinsic rate of increase (r_m) on different foods increased with increasing temperature and ranged from a minimum of 0.08 females/female/day on factitious food (19°C) to a maximum of 0.18 females/female/day on A. pisum (27°C). The results suggest that a mixture of E. kuehniella eggs and pollen fully support development of A. bipunctata larvae and can be used as an alternative to live aphids in the mass rearing of the pre‐imaginal stages of the predator. However, reproductive performance of a laboratory population may be better on aphids than on the factitious food.     

Life table parameters, reproductive rate, intrinsic rate of increase, and estimated cost of rearing Podisus maculiventris (Heteroptera: Pentatomidae) on an artificial diet.

The impact of an insect-free artificial diet provided at nymphal and/or adult stage upon the developmental rate, life table parameters, and fertility table parameters was examined for Podisus maculiventris (Say). This study showed that when fed an insect-free artificial diet during both the nymphal and adult stage, developmental time was prolonged, preoviposition period was extended, and reproductive rate (R0) and intrinsic rate of increase (r) were significantly lower than when fed larval insect prey at both nymphal and adult stages. Additionally, feeding larval prey to adults reared as nymphs on an artificial diet significantly increased the proportion of fertile females, the number of eggs laid by mated females, the reproductive rate and intrinsic rate of increase, but the mean generation time was not significantly different. Likewise, feeding artificial diet to adults reared on larval prey resulted in a significant reduction in reproductive rate and intrinsic rate of increase. The "realized" cost to rear P. maculiventris on the artificial diet was calculated (as the cost to double the population size) using raw material cost, fertility table parameters and doubling time values. Raw material cost for rearing P. maculiventris colony on Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) was only 1.4 times higher than the cost of artificial diet raw materials required to rear the same size colony. However, the realized cost of rearing was 3.5 times higher when rearing on artificial diet because of the prolonged developmental time and reduced reproductive output. The cost efficiency of rearing a beneficial insect on an artificial diet that decreases the intrinsic rate of increase of a colony is discussed, as well as the advantages and disadvantages of supplementing adult diets with natural prey at the reproductive stage.     

Nutritional value of brine shrimp cysts as a factitious food for Orius laevigatus (Heteroptera: Anthocoridae)

Decapsulated cysts of the brine shrimp Artemia franciscana were assessed as a factitious food for rearing the anthocorid predator Orius laevigatus. Developmental and reproductive traits of O. laevigatus reared for a single generation on A. franciscana from three geographical locations or on gamma-irradiated eggs of the Mediterranean flour moth Ephestia kuehniella were compared. There was no effect of diet on nymphal survival but nymphal period on E. kuehniella eggs (12.2 days) was 0.7-1.6 days shorter than on the Artemia diets. The predator developed 0.5-1 day faster on cysts from San Francisco Bay (USA) than on cysts from Great Salt Lake (USA) or Macau (Brazil). Fecundity on brine shrimp cysts from different locations was similar to that on flour moth eggs (142-187 eggs/female). The biochemical composition of decapsulated cysts from San Francisco Bay was compared with that of E. kuehniella eggs. Depending on the type of analysis, Artemia cysts contained higher or similar amounts of protein as compared with E. kuehniella eggs, but amino acid patterns were generally similar. Flour moth eggs were almost three times richer in fatty acids than brine shrimp cysts, with some marked differences in fatty acid profiles. Because nutrient imbalances in a diet may be expressed only after several generations of rearing, the predator was cultured for three consecutive generations on A. franciscana cysts from San Francisco Bay. In the third generation on brine shrimp cysts, nymphs took 18% longer to develop, and adults were shorted-lived and about 60% less fecund than those maintained on E. kuehniella eggs. Brine shrimp cysts may be used as a supplement in the mass production of O. laevigatus but may not be a suitable food for long-term culturing of the predator.     

Nutritional plasticity of the predatory ladybeetle Harmonia axyridis (Coleoptera: Coccinellidae): comparison between natural and substitution prey

The predatory coccinellid Harmonia axyridis is a polyphagous species, efficient at controlling certain aphid species and already commercialized in Europe for that purpose. The complete development of this predator can be accomplished using the aphid Acyrthosiphon pisum or Ephestia kuehniella eggs as substitution prey. Biochemical analyses were conducted on the proteins, lipids, and carbohydrates of these two different prey species. E. kuehniella eggs were 2 times richer in amino acids than A. pisum adults (12% of the fresh weight vs. 6%). E. kuehniella eggs were 3 times richer in lipids than the aphids but, on the contrary, the aphids were 1.5 times richer in glycogen. The impact of these two kinds of food on the body composition of the coccinellid was evaluated to appreciate the degree of nutritional plasticity of the coccinellid. The composition of the coccinellids feeding either on E. kuehniella eggs or on aphids was compared for amino acid, fatty acid and glycogen contents, revealing a good capability of H. axyridis to develop on foods that are very different in their biochemical composition. Nevertheless, when fed on aphids, the crude protein content of the predator was reduced and the lipid content decreased by a factor of two, with a change in amino and fatty acid patterns. Some biological parameters, such as larval mortality, adult weight, and fecundity, were modified according to the food eaten.     

Development and reproduction of Geocoris varius (Hemiptera: Geocoridae) on two types of artificial diet

Biological control using the polyphagous predator big-eyed bug Geocoris varius (Uhler) (Hemiptera: Geocoridae) is currently being investigated in Japan. However, the production costs of G. varius are relatively high because the eggs of Ephestia kuehniella Zeller (Lepidoptera; Pyralidae) are used as the major food source for mass rearing. Development time and reproductive fitness were therefore examined for G. varius fed two types of artificial diet based on liver and ground pork. The diets were administered either by wrapping in Parafilm^® or by presenting the food in lyophilized form. The results were compared with those obtained by rearing G. varius on E. kuehniella eggs. Although development time of Geocoris varius fed the artificial diets was significantly delayed compared with G. varius fed on E. kuehniella eggs, delays are slight and not serious for mass rearing projects. The findings suggested that both artificial diets could be used to reduce the costs associated with mass rearing of G. varius.     

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.     

Development, long-term survival, and the maintenance of fertility in Neoseiulus californicus (Acari: Phytoseiidae) reared on an artificial diet

The effectiveness of non-prey food items, such as pollen, honeydew, and microbes, in maintaining phytoseiid mite populations is widely accepted. However, the availability of such naturally occurring non-prey foods varies with the season and surrounding environment; thus, it is difficult to manipulate and maintain supplies of these food sources. A great deal of research has examined the development and reproduction of phytoseiid mites on artificial diets. Although phytoseiid mites frequently develop, several studies have detected low fecundities of adult females reared on artificial diets. Therefore, the use of artificial diets for commercial propagation is often difficult. However, the potential of artificial diets to maintain phytoseiid mite populations has not yet been evaluated. In this study, we investigated the developmental success and survival of Neoseiulus californicus (McGregor) on an artificial diet. This mite may be one of the most effective phytoseiid species used in agricultural systems for the control of spider mites. N. californicus successfully developed on the artificial diets: 93.5-100% of individuals reached adulthood 4-7 days after hatching. The survival rates of gravid adult females maintained on the AD-1 artificial diet composed of yeast components, saccharides, and egg yolk at 25 degrees C were 100, 80, and 48.9% over 36, 60, and 90 days, respectively. Moreover, >80% of the surviving females maintained on AD-1 for 36 or 60 days laid eggs after being switched to a diet of the spider mite Tetranychus urticae Koch, although they had laid few eggs during the maintenance periods on the artificial diet. Our results indicate that artificial diets can serve as a potentially useful food source for the long-term maintenance of N. californicus populations.     

Artemia cysts as an alternative food for the predatory bug Macrolophus pygmaeus

The suitability of cysts of the brine shrimp Artemia sp. as a factitious food for the predator Macrolophus pygmaeus Rambur was investigated. The influence of decapsulation time and hydration of the cysts on the performance of the predator were studied in the absence of plant material. A longer time of decapsulation had a positive influence on the development of the predator. Hydration of cysts had a significant impact on nymphal survival when cysts where non‐decapsulated or poorly decapsulated. An experiment in which nymphs were switched from a diet of hydrated cysts to non‐hydrated cysts showed that in the absence of plant material the relative importance of hydrating the cysts decreased with nymphal age. Especially, the first instar and to a lesser extent the second instar appear to be susceptible to water shortage. Effects of prolonged rearing on development and reproduction on brine shrimp cysts from different origins were tested in the presence of plant material. Rearing M. pygmaeus on Artemia sp. (Jingyu Lake) cysts yielded similar survival, development, adult weight and fecundity in the fourth as in the second generation. In contrast, for Artemia franciscana cysts, an increase in nymphal development was notable. Biochemical analyses showed that total amino acid content and the concentration of the different amino acids did not differ among diets and generations. There were, however, differences in total fatty acid content between the different diets and generations and in the concentration of certain fatty acids, indicating that insects fed brine shrimp cysts may show nutritional deficiencies compared to those reared on a diet of Ephestia kuehniella eggs. Our results indicate that decapsulated brine shrimp cysts are an economically viable alternative food source in at least part of the rearing process for M. pygmaeus.     

Rearing <Emphasis Type="Italic">Chrysoperla externa</Emphasis> Larvae on Artificial Diets

We tested three artificial diets for rearing larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), aiming at reducing the production costs of this predator. Two of the diets come from studies with other species of lacewings, and the third is a modification described in this paper. All diets were based on animal protein and were supplied to 2nd and 3rd instar larvae, whereas 1st instar larvae received eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae). We evaluated the preimaginal duration and survival, adult size, longevity and fecundity, egg hatchability, and predatory capacity of larvae produced. The performance of the diets was followed for seven generations. The diet we describe showed to be the best among the artificial diets tested. Our results show that C. externa can be successfully reared on artificial diets during second and third instars, reducing in 90% the dependency on eggs of A. kuehniella.     

Evaluation of diets for the development and reproduction of Franklinothrips orizabensis (Thysanoptera: Aeolothripidae)

The suitability of ten diets for the development and reproduction of Franklinothrips orizabensis Johansen, the key natural enemy of Scirtothrips perseae Nakahara, a pest of California grown avocados, was determined in the laboratory. The experimental diets evaluated were: (i) irradiated Ephestia kuehniella Zeller eggs; (ii) irradiated E. kuehniella eggs and avocado pollen; (iii) Tetranychus pacificus McGregor eggs; (iv) T. pacificus eggs and avocado pollen; (v) irradiated E. kuehniella eggs and T. pacificus eggs; (vi) irradiated E. kuehniella eggs, T. pacificus eggs and avocado pollen; (vii) Scirtothrips perseae; (viii) Heliothrips haemorrhoidalis (Bouchè); (ix) avocado pollen; and (x) a young avocado leaf. Franklinothrips orizabensis larvae were unable to develop to adulthood on diets 9 and 10. The remaining eight diets supported complete development of F. orizabensis, but only diets 1, 2, 5, 6, 7 and 8 produced fecund females. On diet 5, F. orizabensis exhibited high larval to adult survivorship (90%), mated females exhibited highest daily and lifetime fecundity, and the progeny of mated females were female biased (53%). Analysis of jackknife estimates of net reproduction (Ro), intrinsic rate of increase (rm), and finite rate of increase (lambda) were all significantly greater for F. orizabensis reared on irradiated E. kuehniella eggs and T. pacificus eggs (i.e. diet 5) than corresponding values for other diets on which female F. orizabensis were able to complete development and reproduce. Incorporation of avocado pollen into diets had an adverse effect on demographic statistics for F. orizabensis, and low quality diets resulted in male biased sex ratios for this predator.     

Development and reproduction of the predatory mite Amblyseius swirskii on artificial diets

Development, survival and reproduction of the predatory mite Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) were assessed when fed on cattail pollen (Typha latifolia L.), dried fruit mite (Carpoglyphus lactis L.), or on two artificial diets. The basic artificial diet (AD1) was composed of honey, sucrose, tryptone, yeast extract, and egg yolk. This diet was enriched (AD2) by adding hemolymph from oak silkworm pupae (Antheraea pernyi (Guérin-Méneville)). Mites fed on C. lactis and AD2 had shorter immature and preoviposition periods than those fed on the other diets. The total number of deposited eggs was significantly higher for females fed on AD2 than for those maintained on the other diets. The intrinsic rate of increase (r_m) of A. swirskii was highest on AD2 and C. lactis, followed by T. latifolia pollen, and AD1. In conclusion, the artificial diet AD2 supported development and reproduction of A. swirskii to the same extent as a factitious prey which is routinely used in the mass rearing of the phytoseiid. Our findings indicate the potential of artificial diets for the mass production of this economically important predatory mite.