Non-prey Food Research Articles

Dietary Ecology of Predatory Insects Examining the Role of Prey and Non Prey Foods of Ladybird Beetle

Ladybird beetles consume a wide variety of non-prey items in their natural habitats, including aphids, fruits, plants, fungi, honeydew, and nectar. These non-prey foods play several critical roles, such as boosting fertility, decreasing mortality during dormancy, supporting migration, and enhancing survival during times when prey is scarce. Larval ladybird beetles have more specialized nutritional needs compared to adults, with simple carbohydrates being crucial nutrients that can improve adult beetle function and reproductive success. Non-prey foods often provide similar or greater nutritional and caloric content compared to prey. Each non-prey item has distinct defense mechanisms and nutritional benefits, influencing its suitability for ladybird beetles. Research comparing diets consisting solely of prey with mixed diets that include non-prey foods revealed that while pollen improved larval and adult performance, a diet high in sugar alone was less effective for reproduction compared to an aphid-based diet. Wheat, which lacks essential nutrients such as proteins, could not adequately support egg production and larval development. Although pollen did enhance overall performance, it could not completely offset the nutritional shortcomings of a diet high in sugar. Adding sugar to a diet did not markedly enhance the performance of ladybird beetles compared to a diet composed entirely of prey. This review underscores the need to understand the varied diet of ladybird beetles within their ecological context, as it has significant implications for the success of conservation-oriented biological control effort.

Multigenerational Rearing on Non-Prey Foods Does Not Affect Prey (Aphid) Recognition Behavior of Coleomegilla maculata (Coleoptera: Coccinellidae)

The pink spotted lady beetle Coleomegilla maculata has been identified as a promising predator to mass rear and release into greenhouses and high tunnels to control aphids on small fruits and vegetables. This study tested the hypothesis that laboratory-reared C. maculata, without any exposure to aphids for multiple generations, could recognize, attack, and consume live aphids. The aphid adults of two species were collected from non-crop host plants (weeds) over two consecutive seasons. The time (seconds) that C. maculata adults required to recognize and partially or completely consume live, healthy adult aphids was recorded in Petri dish arenas in the laboratory. Regardless of the non-prey food source (brine shrimp egg diet, mealworm-protein-based artificial diet), C. maculata adults readily recognized aphids. Adult females were occasionally more voracious than males. One aphid species (Uroleucon erigeronense) was consumed more readily than the other aphid species (Aphis nerii). In conclusion, multigenerational rearing on non-prey foods did not affect the prey recognition behavior of C. maculata adults in the laboratory. Validating the ability of lady beetles reared on artificial diets to recognize and consume live aphids is an important protocol before augmentative releases for aphid control in greenhouses and high tunnels.

Control of feeding by a bottom-up midbrain-subthalamic pathway

Investigative exploration and foraging leading to food consumption have vital importance, but are not well-understood. Since GABAergic inputs to the lateral and ventrolateral periaqueductal gray (l/vlPAG) control such behaviors, we dissected the role of vgat-expressing GABAergic l/vlPAG cells in exploration, foraging and hunting. Here, we show that in mice vgat l/vlPAG cells encode approach to food and consumption of both live prey and non-prey foods. The activity of these cells is necessary and sufficient for inducing food-seeking leading to subsequent consumption. Activation of vgat l/vlPAG cells produces exploratory foraging and compulsive eating without altering defensive behaviors. Moreover, l/vlPAG vgat cells are bidirectionally interconnected to several feeding, exploration and investigation nodes, including the zona incerta. Remarkably, the vgat l/vlPAG projection to the zona incerta bidirectionally controls approach towards food leading to consumption. These data indicate the PAG is not only a final downstream target of top-down exploration and foraging-related inputs, but that it also influences these behaviors through a bottom-up pathway.

Potential of a new phytoseiid species Neoseiulus setarius (Acari: Phytoseiidae) as a biocontrol agent: Biological and demographic parameters on prey and non-prey foods

Neoseiulus setarius Ma, Meng & Fan is a newly described phytoseiid species found in Inner Mongolia of China. To evaluate the potential of N. setarius as a biocontrol agent, we studied life table parameters of N. setarius reared on four food resources, including western flower thrips Frankliniella occidentalis Pergande, eriophyoid mite Aceria pallida Keifer, cattail pollen Typha latifolia L. and poplar pollen Populus alba L. Neoseiulus setarius fed on two prey species developed faster and produced more eggs than those fed with two kinds of pollen. Neoseiulus setarius had the shortest juvenile development time on A. pallida (5.38 days), and the highest daily fecundity on F. occidentalis (2.43 eggs/female/day). The juvenile development time of N. setarius was similar on cattail pollen and poplar pollen, but the fecundity of N. setarius was significantly higher on cattail pollen. There were significant differences in the demographic parameters of N. setarius reared on the four different diets. The highest intrinsic rate of increase (rm) was on F. occidentalis (0.178 day−1), followed by A. pallida (0.159 day−1), cattail pollen (0.127 day−1) and poplar pollen (0.092 day−1). Neoseiulus setarius showed higher fitness in development and reproduction on prey (F. occidentalis and A. pallida) and cattail pollen. These results suggest that N. setarius could be a promising biocontrol agent for the management of thrips and gall mites.

The pre-oviposition period is associated with ovary maturation in Cryptolaemus montrouzieri Mulsant, 1850 (Coleoptera: Coccinellidae)

ABSTRACT The pre-oviposition period is critical in the development of reproductive organs in ladybirds, but there is little information about the main causes of this period. The pre-oviposition period in the ladybird Cryptolaemus montrouzieri was influenced by prey consumption, suggesting that there is a nutritional aspect from food intake that must affect ovary maturation after adult emergence. We also investigated whether feeding on non-prey food affects the maturation of ovaries. We have found that newly emerged females of C. montrouzieri have no developed ovary, and when feeding on adults of the mealybug Planococcus citri and in the absence of males, 5 days are required for full ovary development and egg maturation. Females feeding only on honey did not develop ovarioles even in 7 days. The ovarioles developed in each female on each side of the ovary is around 10 on a daily basis, with no significant difference between the left and the right side each day. On the fifth day, a great number of mature eggs were found, remaining constant on the following sixth day. Our results suggest that food quality, rather than just feeding, is a fundamental step to start the physiological chain that is responsible for the ovary development.

Carbohydrates complement high-protein diets to maximize the growth of an actively hunting predator.

In nature, food is often variable in composition and availability. As a consequence, predators may need to seek non‐prey food sources. Some predators are known to feed on nectar when food is limited. Nectar and other carbohydrate resources could also be beneficial when prey are more abundant if it helps predators balance protein‐biased diets. We tested if an actively hunting predator, the jumping spider, Phidippus audax, benefited from liquid carbohydrates when prey were not limited. We also tested if the benefit of carbohydrates varied with the nutrient content of prey (i.e., from protein to lipid biased). Spiders were reared on one of six live prey, Drosophila melanogaster, treatments that ranged from high protein to high lipid. Half of the spiders were given access to a 20% sucrose solution. After 2 months, we measured spider mass, cephalothorax width, instar duration, percent body fat, survival, and estimated number of prey eaten. Spiders reared on high‐protein diets with carbohydrates were larger and heavier than spiders on other treatments. Access to carbohydrates also increased percent body fat and survival across prey treatments. Our results suggest that carbohydrates may be a valuable component of spider diets, especially when prey have high protein and low lipid content as is commonly observed in prey in the field. Our results highlight the importance of diet balancing for predators, and that liquid carbohydrates can be an important nutrient to supplement a diet of prey rather than just being an energy supplement during periods of starvation.

Temporal Resource (Dis)continuity for Conservation Biological Control: From Field to Landscape Scales

Conservation biological control (CBC) seeks to promote the occurrence of natural enemies of agricultural pests by managing habitat to provide key resources in and around farm fields. In particular, vegetation diversity may help ensure temporal resource continuity such that natural enemies are less likely to experience detrimental gaps or bottlenecks as they move through and use different habitats. While the conceptual value of resource continuity has long been recognized by CBC researchers and practitioners, empirical studies have tended to focus on snapshots in space and time. Here we review how continuity of trophic (food) and structural (shelter) resources affect natural enemy conservation and pest control outcomes within farm fields and across agricultural landscapes. Key trophic resources include alternative prey and non-prey food (such as floral nectar and pollen), which can bolster natural enemy nutrition when pests are scarce. Vegetative and non-vegetative structural resources can protect enemies when crop fields are disturbed and provide important overwintering habitat in temperate regions. Within fields, non-crop plantings such as wildflower strips or beetle banks are the most popular habitat management strategies, but temporal intercropping, asynchronous planting/harvesting, and the construction of artificial shelters have high potential to contribute to resource continuity. Analogously, semi-natural habitat at the landscape scale may contribute to resource continuity in some cases, but crop diversity, asynchrony, and urban habitat can also be important. Simultaneous consideration of resource diversity and continuity could generate better predictions and more targeted management interventions for particular pest and enemy assemblages. Future research should strive to expand our understanding of natural enemy resource requirements in space and time.

Herbivory improves the fitness of predatory beetles.

While many predatory arthropods consume non-prey foods from lower trophic levels, little is known about what drives the shift from predator to omnivore. Predatory lady beetles often consume non-prey foods like plant foliage and pollen. One species, Coccinella septempunctata, eats foliage to redress sterol deficits caused by eating sterol-deficient prey. Here we explore how omnivory benefits lady beetle fitness. We reared seven species of lady beetles-from five genera distributed across the tribe Coccinellini-on pea aphids in the presence or absence of fava bean foliage; pea aphids have very low sterol content. Foliage supplements lengthened the development times of four species and decreased survival to adulthood of two species; it had no effect on adult mass. We mated beetles in a 2×2 factorial design (males with or without foliage paired with females with or without foliage). For each species, we observed a profound paternal effect of foliage supplements on fitness. Females mated to foliage-supplemented males laid more eggs and more viable eggs compared to females mated to non-supplemented males. Foliage-supplemented males produced 2.9-4.6 times more sperm compared to non-supplemented males for the three species we examined. We analysed the sterol profile of four beetle species reared on pea aphids-with or without foliage-and compared their sterol profile to field-collected adults. For two laboratory-reared species, sterols were not detected in adult male beetles, and overall levels were generally low (total ng of sterol/beetle range: 3-33ng); the exception being Propylea quatuordecimpunctata females (total ng of sterol/beetle range: 50-157ng). Laboratory-reared lady beetle sterol content was not significantly affected by the presence of foliage. Field-collected beetles had higher levels of sterols compared to laboratory-reared beetles (2,452-145,348ng per beetle); cholesterol and sitosterol were the dominant sterols in both field-collected and laboratory-reared beetles. Our findings indicate that herbivory benefits lady beetle fitness across the Coccinellini, and that this was entirely a paternal effect. Our data provide a rare example of a nutritional constraint impacting fitness in a sex-specific manner. It also shows, more broadly, how a nutritional constraint can drive predators towards omnivory.

Challenges facing arthropod biological control: identifying traits for genetic improvement of predators in protected crops.

Biological control is an efficient pest control method but there are still limitations that are hindering its wider adoption. Genetic improvement of biological control agents (BCAs) can help to overcome these constraints, but the choice of key attributes for better performance that need to be selected is still an open question. Several characteristics have been suggested but the harsh reality is that selective breeding of BCAs has received a lot of attention but resulted in very little progress. Identifying the appropriate traits to be prioritized may be the first step to reverse this situation. In our opinion, the best way is to look at the factors limiting the performance of key BCAs, especially generalist predators (pesticide compatibility, prey-density dependence, non-suitable crops, and extreme environmental conditions), and according to these challenges, to choose the attributes that would allow BCAs to overcome those limitations. The benefits of selection for higher resistance to toxins, whether artificially applied (pesticides) or plant produced (plant defenses); increased fitness when feeding on non-prey food (supplemented or plant-derived); and better adaptation to extreme temperature and humidity are discussed. In conclusion, genetic improvement of BCAs can bring about new opportunities to biocontrol industry and users to enhance biocontrol resilience. © 2020 Society of Chemical Industry.

A Floral Diet Increases the Longevity of the Coccinellid Adalia bipunctata but Does Not Allow Molting or Reproduction

Adalia bipunctata L. (Coleoptera: Coccinellidae) is a generalist aphidophagous coccinellid and an important natural enemy in many agroecosystems including orchards. Coccinellid species have been observed to consume non-prey food like nectar and pollen, but the value of these foods for A. bipunctata is poorly known. The objective of this study was to determine the effect of different prey and non-prey diets on A. bipunctata larval development and adult longevity and fecundity. Larval development was studied on three prey diets: The aphids Dysaphis plantaginea and Myzus persicae and Lepidopteran eggs of Ephestia kuehniella; five flower diets: Matricaria chamomilla, Daucus carota, Fagopyrum esculentum, Anethum graveolens and Sinapis alba; four pollen diets from three plant species: Typha angustifolia, Malus pumila (two varieties) and A. graveolens; and 1 M solutions of three sugars: glucose, fructose and sucrose. Adult longevity and fecundity were tested on one prey diet (E. kuhniella eggs), three flower diets (F. esculentum, A. graveolens and S. alba); the same four pollen diets and three sugar diets with larvae; and finally a mixed diet of sucrose and A. graveolens pollen. A water-only (starvation) control was used for both larval development and adult longevity and fecundity. Adult lipid content was assessed as a measure of how non-prey food affects the ladybeetles’ nutritional status. Larvae did not develop beyond the first instar on any of the non-prey diets, but they lived more than twice as long as on F. esculentum and sugar diets than on water. Sugar and flower diets improved A. bipunctata adult longevity (71-92 d and 10-66d, respectively) over a pure pollen diet (6-7d). Fecundity was nil on all non-prey diets, and within a normal range on E. kuhniella eggs. The results suggest that pure floral diets do not support A. bipunctata molting or reproduction, but flowering plants can prolong A. bipunctata larval survival and adults longevity considerably when prey are absent. Adults on sugar diets had high lipid content, indicating that sugar feeding can improve overwintering survival. The findings could be used in agroecosystem design, such as the composition of flower strips for optimal functional diversity.

Spiders actively choose and feed on nutritious non-prey food resources

Spiders are generalist predators adapted to consume a wide range of prey although their ability to exploit non-prey foods such as pollen, nectar, and honeydew has been referred but less studied. In this work, we investigated the effect of different non-prey food items (Glucose at 0.5 M; aphid honeydew; black scale honeydew; a mixture of glucose 0.5 M, phenylalanine 0.1 mM, proline 0.1 mM, and tryptophan 0.1 mM; honey at 10%, and pollen at 10%) on the survival of immature spiders of two functional groups represented by Haplodrassus rufipes (ground hunters) and Synema globosum (ambushers), and their feeding choices, in laboratory experiments. The overall survival of both species fed on non-prey foods significantly increased compared to individuals fed on water. The black-scale honeydew was the best food for H. rufipes increasing longevity up to 117 days. The highest survival reached by S. globosum was observed when fed on a mixture of glucose 0.5 M and three amino acids. When different non-prey food items were offered together, the exploring rate was significantly higher for H. rufipes than for S. globosum. H. rufipes chose to feed on honey whereas S. globosum chose the mixture treatment. The most chosen food items corresponded with those that provided the highest longevities in both species. Our results suggest that spiders could search, recognize and actively select the most beneficial non-prey food. Habitat management practices such as maintaining weed strips in the crop may provide these valuable supplementary food resources within agroecosystems contributing for biological pest control.

The Quality of Nonprey Food Affects Cannibalism, Intraguild Predation, and Hyperpredation in Two Species of Phytoseiid Mites.

Generalist arthropod predators not only prey on herbivores but also may engage in competitive interactions by attacking and consuming conspecifics (cannibalism) or other predators (intraguild predation [IGP] and hyperpredation). These types of interactions are quite common among predators used in biological control. Although there is evidence that nonprey food relaxes cannibalism and IGP, there is little information regarding the impact of the quality of the nonprey food. Herein, we examined how pollen of different nutritional quality (pine, narrow-leaf cattail, or apple) impacted 1) the cannibalism by females of Euseius stipulatus (Athias-Henriot) (Acari: Phytoseiidae) on conspecific larvae, 2) the reciprocal predation between gravid females of E. stipulatus or Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) and heterospecific larvae, and 3) the predation of E. stipulatus on the eggs of the aphid predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). E. stipulatus cannibalism was significantly reduced in the cattail pollen treatment, whereas in the pine pollen it did not significantly differ from control (no food). Predation between I. degenerans and E. stipulatus was significantly reduced in the cattail pollen treatment as compared to the control treatment. Finally, predation of E. stipulatus on A. aphidimyza eggs was significantly reduced when cattail or apple pollen was provided compared to the pine pollen or control treatments. These results suggest that cattail or apple pollen is suitable for mitigating negative interactions among generalist predatory mites used in biological control.

Provisioning of food supplements enhances the conservation of phytoseiid mites in citrus

Phytoseiid mites (Acari: Phytoseiidae) are amongst the most abundant and important predators in citrus. They range from specialist species feeding exclusively on spider mites to generalist species that can feed and reproduce on several prey as well as non-prey foods such as pollen, fungi and honeydew. Feeding on non-prey foods is crucial for the conservation of phytoseiids especially during periods when prey are scarce or absent. In a greenhouse experiment using citrus plantlets we tested the impact of provisioning cattail pollen (Typha angustifolia L.) and a sucrose solution, alone or in combination, on the population development of the pollen adapted Euseius stipulatus (Athias-Henriot) (Acari: Phytoseiidae). The highest E. stipulatus populations were registered in the treatment where the pollen was supplied in combination with the sucrose solution. The phytoseiid abundance in the sugar and pollen treatment was significantly higher than the sum of the abundances when either the pollen or the sugars were supplied separately. Thus, pollen and sugar acted synergistically on the populations of E. stipulatus. Subsequently, we tested the combination of pollen and sugar in a six month field study in two commercial citrus orchards in eastern Spain. Provisioning of pollen and sugar resulted in significantly higher abundance of the resident phytoseiid mites compared to the control trees that received no food supplements. In both orchards this increase was higher from the end of May until the end of June and from September until the end of October. We conclude that the provisioning of sugar and pollen enhances the conservation of the resident phytoseiid mites in citrus.

Linking Life Table and Consumption Rate ofAmblyseius swirskii(Acari: Phytoseiidae) in Presence and Absence of Different Pollens

Amblyseius swirskii Athias-Henriot is used as a biocontrol agent against various pests. Pollen grains not only provide important nutrients but also play an important role in providing the energy source of migration and aid in the reproduction process for different predators such as phytoseiid mites, especially if being consumed along with main prey. Because no research has addressed the nutritional value of a combination of non-prey food diets with Tetranychus urticae Koch for A. swirskii , this study aims to determine some biological characteristics of this predator fed on T. urticae in the presence and absence of three different pollens. Individuals of A. swirskii successfully completed their immature development on all diets tested. The shortest and longest female and male developmental times were observed on T. urticae + almond pollen and T. urticae + bee pollen, respectively. Not only in the presence but also in the absence of T. urticae feeding on almond pollen resulted in higher intrinsic ( r ) and finite rate of increase ( λ ) compared with feeding on date and bee pollens. The highest female predation rate was observed for the T. urticae diet compared with other diets. The predators consumed more prey in the presence of bee pollen than in the presence of almond and date pollen. Amblyseius swirskii required an average of 17.69, 32.33, 27.87, and 18.04 prey to produce a single predator egg on date + T. urticae , bee pollen + T. urticae , T. urticae , and almond + T. urticae , respectively. Overall, A. swirskii had greater control potential of T. urticae in the presence of almond pollen than other diets.

Use of prey and non-prey food by the ladybird beetle Eriopis connexa (Coleoptera: Coccinellidae) under laboratory-rearing conditions

ABSTRACTPrey for predators can fluctuate in abundance and in quality over time requiring predator strategies to cope with food shortage. Coccinellinae are often associated with sap-sucking pests that exhibit high population unpredictability such as aphids and psyllids. Eriopis connexa (Germar) (Coleoptera: Coccinellidae) is a predator with potential for biological control, especially a well-studied population which is resistant to pyrethroids used to control insect defoliators. Both larvae and adult E. connexa were provided ad libitum prey and non-prey foods (pollen and honey water solution) at increasing intervals from 1 to 10 days. Neonate larvae of E. connexa required eating prey daily to develop into adults. However, non-prey food such as honey water solution did prolong larval and adult survival but neither fulfilled larval development nor adult reproduction. Honey water solution promoted 100% adult survival up to 25 days in the adult stage without prey with oviposition returning after daily feeding on prey. Females subjected to increased feeding intervals over four days reduced oviposition and lived longer, but 10-day feeding intervals correlated with risk to adult survival. These results indicate the importance of non-food sources in E. connexa maintenance and the ability of larvae and adult females to compensate for prey scarcity.

A synthesis of feeding habits and reproduction rhythm in Italian seed-feeding ground beetles (Coleoptera: Carabidae)

Many species of carabid beetles are important pre- and post-dispersal seed feeders of herbaceous plants. Here we summarise data from dissections, field observations, rearing and cafeteria experiments on 55 granivorous and 188 omnivorous species that occur in Italy. We tested the hypothesis that seed feeding carabids are restricted to taxa with pronounced morphological adaptations for manipulating and crushing seeds in both the larval and adult stages. The feeding guilds of carabids were rearranged into the following groups: (i) strict predators with long mandibles and predaceous larvae, often depending also on non-prey food; (ii) omnivorous species with stout mandibles and larvae of a seed-eating morphotype; (iii) granivorous species, feeding only on seeds with larvae sometimes of the scarabeoid c-form type. The seed feeding carabids in the Italian fauna belong to the tribe Zabrini (Amara and Zabrus genera) and to all the Harpalinae (sub)tribes, from Anisodactylini to Ditomina. The time of reproduction seems to be associated with habitat preference; wetland or dry open land, rather than true granivorous versus omnivorous habits, but in stenophagous seed feeders, a phenological coincidence with particular plants is sometimes recorded.

Life-history parameters of Chrysoperla carnea s.l. fed on spontaneous plant species and insect honeydews: importance for conservation biological control

Chrysoperla carnea s.l. (Stephens) (Neuroptera: Chrysopidae) larvae are generalist predators feeding on many crop pests while adults feed on non-prey food. The knowledge about the nutritional suitability of non-prey food for adults in agroecosystems is crucial to establish conservation biological control strategies and is poorly known in olive groves, where C. carnea s.l. larvae prey on different pests. In this study, the effect of honeydew secreted by two hemipteran olive tree secondary pests and 11 plant species on the life-history parameters (survival, reproduction and development time) of C. carnea s.l. were analyzed. Insect pest honeydew from the olive agroecosystem and several plant species, blooming throughout the year, were found to improve C. carnea s.l. adult survival. Pollen consumption seems to be essential for reproduction. These findings are important for designing and implementing new conservation biological control approaches.

Optimizing Crops for Biocontrol of Pests and Disease.

Volatile compounds and extrafloral nectar are common defenses of wild plants; however, in crops they bear an as-yet underused potential for biological control of pests and diseases. Odor emission and nectar secretion are multigene traits in wild plants, and thus form difficult targets for breeding. Furthermore, domestication has changed the capacity of crops to express these traits. We propose that breeding crops for an enhanced capacity for tritrophic interactions and volatile-mediated direct resistance to herbivores and pathogens can contribute to environmentally-friendly and sustainable agriculture. Natural plant volatiles with antifungal or repellent properties can serve as direct resistance agents. In addition, volatiles mediating tritrophic interactions can be combined with nectar-based food rewards for carnivores to boost indirect plant defense.

Amblyseius swirskii: what made this predatory mite such a successful biocontrol agent?

The predatory mite Amblyseius swirskii quickly became one of the most successful biocontrol agents in protected cultivation after its introduction into the market in 2005 and is now released in more than 50 countries. There are several key factors contributing to this success: (1) it can control several major pests including the western flower thrips, Frankliniella occidentalis, the whiteflies Bemisia tabaci and Trialeurodes vaporariorum and the broad mite, Polyphagotarsonemus latus, simultaneously in vegetables and ornamental crops; (2) it can develop and reproduce feeding on non-prey food sources such as pollen, which allows populations of the predator to build up on plants before the pests are present and to persist in the crop during periods when prey is scarce or absent; and (3) it can be easily reared on factitious prey, which allows economic mass production. However, despite the fact that A. swirskii provides growers with a robust control method, external demands were initially a key factor in promoting the use of this predator, particularly in Spain. In 2006, when exports of fresh vegetables from Spain were stopped due to the presence of pesticide residues, growers were forced to look for alternatives to chemical control. This resulted in the massive adoption of biological control-based integrated pest management programmes based on the use of A. swirskii in sweet pepper. Biological control increased from 5 % in 2005, 1 year before A. swirskii was commercially released, to almost 100 % of a total 6,000 ha of protected sweet pepper in Spain within 3 years. Later, it was demonstrated that A. swirskii was equally effective in other crops and countries, resulting in extensive worldwide use of A. swirskii in greenhouses.

Sex-specific interactions of microbial symbioses on cricket dietary selection.

The nutrients found in prey and nonprey foods, and relative digestibility of these foods, has a major influence on diet selection by omnivorous insects. Many insects have developed symbiotic relationships with gut bacteria to help with extracting nutrition from nonprey diets. Gryllus pennsylvanicus (Burmeister) (Orthoptera: Gryllidae) was assigned to one of two treatment groups, antibiotic-treated and nonantibiotic-treated, and consumption of seeds (nonprey) and eggs (prey) were measured. Male crickets administered antibiotics consumed more seeds and greater seed weight, while antibiotic-fed female crickets consumed fewer seeds and less seed weight, relative to the untreated male and female crickets, respectively. Both male and female antibiotic-treated crickets consumed similar weight of eggs as nonantibiotic-treated male and female crickets, respectively. These results provide evidence that gut symbionts influence diet selection of male and female G. pennsylvanicus differently. This sex-specific dietary selection may be because of the fact that male and female crickets have different nutritional requirements.