SECTION IV Cultural Practices © 2000 by CRC Press LLC 1 CHAPTER 5 Using Cultural Practices to Enhance Insect Pest Control by Natural Enemies N.A. Schellhorn, J.P. Harmon, and D.A. Andow CONTENTS 5.1 Introduction 148 5.2 Natural Enemy Colonization 149 5.2.1 Hypothesis 1 — Natural Enemy Abundance is Increased Because the Spatial Proximity of Source Populations Results in Higher Colonization 150 5.2.2 Hypothesis 2 — Natural Enemy Abundance is Increased Because the Previously Occupied Habitat is no Longer Suitable, which Results in Higher Colonization 153 5.2.3 Hypothesis 3 — Natural Enemy Abundance is Increased Because a Habitat is Attractive in Some Way, which Results in Higher Colonization 154 5.3 Natural Enemy Reproduction and Longevity 156 5.3.1 Hypothesis 1 — Natural Enemy Abundance is Increased Because Food is More Abundant, which Results in Higher Reproduction, Longevity, and/or Survival 156 5.3.2 Hypothesis 2 — Natural Enemy Abundance is Increased Because Food is Available During a Longer Period of Time, which Results in Higher Reproduction, Longevity, and/or Survival 158 5.3.3 Hypothesis 3 — Natural Enemy Abundance is Increased Because the Microclimate Allows Higher Reproduction and Longevity 160 5.4 Natural Enemy Diversity 160 © 2000 by CRC Press LLC 2 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION 5.5 Conclusions 162 References 163 5.1 INTRODUCTION Cultural control of insect pests includes any modification in the way a crop or livestock is produced that results in lower pest populations or damage. This includes both changes in production practices of the crop or livestock and changes in surrounding areas of production. Some pest management specialists define cultural controls as purposeful manipulation of production practices to reduce pest populations or damage, but the concept is used more broadly here to include any change in production practice that results in lower pest populations or damage, whether intentional or not. Cultural controls are defined to exclude production practices that act directly on insect pests, such as insecticide application, biological control, genetic control, and behavioral modifiers. In some treatments of the topic, plant and animal resistance is included as a cultural control. Because both the genetics and the environment of the crop or livestock influence plant and animal resistance to pest attack, resistance is in part determined by cultural practices. Traditionally, resistance is treated as a separate pest control tactic, and it is excluded from the present discussion of cultural control. Cultural controls include a diverse set of practices, including: sanitation; destruc- tion of alternate habitats and hosts used by the pest; tillage; water management; plant or animal density; crop rotation and fallow; crop planting date; trap cropping; vegetational diversity; fertilizer use; and harvest time. Sanitation is the removal and destruction of crop or animal material to reduce pest density, including the destruc- tion of crop residues and the disposal of animal wastes (Stern, 1991). Destruction of alternate habitats and hosts is usually aimed at overwintering habitats and hosts, and has met with limited success. Tillage is used to prepare soil for planting and to reduce weeds. The various forms of tillage have diverse effects on insect pests (Stinner and House, 1990). Water management, such as irrigation, can affect pest populations, but because of its importance for growth and development of crops and livestock, it has been little used as a pest control tactic (Pedigo, 1996). Plant and animal density has significant effects on pests (Teetes, 1991). Many pests become more abundant at higher plant or animal density, but some become rarer. Often, however, non-pest control considerations determine production densities, and the general effects of density are only partially understood. Crop rotation entails chang- ing the crop in subsequent plantings, and crop fallow involves suppressing all plant growth on a field for a production season. Both practices can disrupt the normal life cycle of a pest, reducing its populations and damage (Brust and Stinner, 1991). Planting date has dramatic effects on pests, and prior to the advent of inexpensive, synthetic organic insecticides, was widely used to avoid pest attack (Teetes, 1991). The timing of other cultural practices, such as cattle dehorning and crop harvest, can also affect pests (Stern, 1991; Pedigo, 1996). Trap cropping involves planting a crop to attract pests, to divert them from the nearby main crop or to concentrate them for easy destruction (Hokkanen, 1991). Vegetational diversity involves using © 2000 by CRC Press LLC USING CULTURAL PRACTICES TO ENHANCE INSECT PEST CONTROL 3 other plants in the crop field to reduce pest attack (Andow, 1991). This includes intercropping, strip cropping, and weedy culture. Nitrogen applications such as fertilizers can have large effects on insect populations and attack, because nitrogen is limiting to most insects that eat plants (Mattson, 1980). All of these direct cultural effects on insect pests have been evaluated for many decades and excellent reviews of most of these controls have been published recently. Here we focus on a less- evaluated factor: how cultural practices affect natural enemies of insect pests, con- centrating on predators and parasitoids. The effects of cultural practices on natural enemies and the potential consequent effects on insect pests are an indirect mechanism for cultural control. In some cases, these indirect effects could be discussed as a type of biological control, emphasizing the role of the natural enemies. In this chapter, however, the role of the cultural practices that can affect natural enemies will be emphasized to draw a more explicit link between the practices that humans can manipulate and the effects on the natural enemies. In the long run, it will be useful to identify these links so that reliable, sustainable insect pest control tactics can be developed. Cultural practices can affect natural enemy population densities and species diver- sity. Either of these can influence the ability of the natural enemies to suppress pest populations. Increased density of a particular species or a greater number of natural enemy species can result in greater mortality of the target pest. There are numerous examples in the literature demonstrating that cultural practices can enhance natural enemy abundance, and possibly their efficiency; however, the majority are descriptive and usually only compare abundance in one production system to another. Understand- ing the population processes involved in the population changes is necessary to develop a general realization of how cultural practices can result in higher densities of parasitoids and predators. Colonization, reproduction, and longevity are three fundamental popu- lation processes that influence natural enemy density. By concentrating on these pop- ulation processes it is possible to develop specific predictions for mechanisms by which cultural practices can affect natural enemy density. The effects of cultural practices on natural enemy diversity are less commonly studied. Greater species diversity of natural enemies may result in reduced pest populations, because each species kills a part of the pest population that otherwise would have survived (Riechert et al., 1999; Schellhorn and Andow, 1999; but see Rosenheim, 1998). The interactions among natural enemies require further study to understand the role of natural enemy diversity on pests. 5.2 NATURAL ENEMY COLONIZATION Natural enemy colonization may be higher in one location than another because: (1) there were more natural enemies near the location; (2) surrounding areas became less suitable and the natural enemies left these areas ending up in the location; or (3) the location became attractive to natural enemies and they accumulated there. The first hypothesis does not require that the natural enemies have a difference in preference among locations. If natural enemies are colonizing species (Southwood, 1962), or exhibit an oogenesis-flight syndrome (Johnson, 1960; Dingle, 1972), then they will © 2000 by CRC Press LLC 4 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION disperse from habitats irrespective of the relative quality of the surrounding habitats. Under these circumstances, locations that are near large numbers of natural enemies will be colonized more readily than those farther away. The second two hypotheses require that there is a difference in preference. In the second, natural enemies are induced to leave a deteriorating area, and in the third, they are attracted to a particularly good area. The importance of preference in habitat selection is predicted by foraging theory (Kamil et al., 1987). Using population dynamics theory, the conditions under which natural enemies will become more abundant in the target habitat are developed in Andow (1996). In practice, these three hypotheses are often difficult to distinguish. 5.2.1 Hypothesis 1 — Natural Enemy Abundance is Increased Because the Spatial Proximity of Source Populations Results in Higher Colonization Most agricultural crops do not by themselves have sufficient resources to keep and maintain high levels of natural enemies throughout the entire year. Parasites and predators use non-crops and non-crop habitats for overwintering sites, refuges, and more favorable microclimates, as well as additional prey, hosts, or food. Many natural enemies will move throughout the landscape to locate necessary habitats and resources. Cultural control tactics can be used to take advantage of this movement and increase the colonization of fields and crops that harbor pest species. If sufficient spatial and temporal synchrony is attained, natural enemy populations can increase in an area because of the proximity of nearby source populations, and the spatial structure of the habitats on the landscape. Overwintering is a crucial part of the life cycle for most insects in temperate areas. Culture control tactics take advantage of this to directly reduce pests, for example, by sanitation and tillage. These same practices may also work to decrease natural enemy abundance. Overwintering might also be a key to abundant natural enemy populations. Adding overwintering sites such as hedge rows, grassy edges, non-crop habitats or other landscape modifications has been touted as a cultural control technique with great potential to increase enemy populations, strengthen the insect-enemy interaction, and increase the diversity of natural enemy species (Wrat- ten and Thomas, 1990). By increasing natural enemy overwintering survival, colo- nization from these overwintering sites may be an important mechanism to increase densities of natural enemies associated with target crops, fields, and livestock. Some artificial overwintering sites such as human-made boxes have found suc- cess in increasing the abundance of predators such as the green lacewing Chrysoperla carnea Stephens (Sengonca and Frings, 1989) and Polistes wasps (Gillaspy, 1971). Natural overwintering sites can be improved by management techniques. For exam- ple, adding leaves, grass, or other organic litter to the base of trees may lead to higher quality overwintering sites for the predaceous mite Metaseiulus occidentalis (Deng et al., 1988) and the coccinellid Stethorus punctum punctum (Fell and Hull, 1996). Where overwintering is associated with suppression of reproduction and the natural enemies continue to feed, planting specific vegetation and ensuring adequate food sources may be the key for reducing overwintering mortality (James, 1989). © 2000 by CRC Press LLC USING CULTURAL PRACTICES TO ENHANCE INSECT PEST CONTROL 5 Extensive research has been performed to determine how natural boundaries and edges surrounding agricultural fields influence aphid predators in cereal and grain crop systems in Europe. Studies have demonstrated how hedges and other boundary areas are crucial to the overwintering survival of species of carabid and staphylinid predators (Sotherton, 1984). By applying insecticides to these habitats, Sotherton (1984) was able to show a considerable reduction in the predator populations in adjoining crops the next spring. Other evidence for increased movement of natural enemies from overwintering sites include mark and recapture studies that have shown predators from edge habitats immigrate into nearby crop fields, and correlations between the number of predators in overwintering sites and the number of those predators in fields early in the growing season (Coombes and Sotherton, 1986). For some natural enemies such as species of ground beetles, progeny of overwintered adults have been shown to immigrate into adjacent fields and then have an affinity for returning to the same boundary areas as the previous generation (Coombes and Sotherton, 1986). In many systems, it may be important to look for changes in natural enemies’ populations both within and between generations. Maintaining field boundaries in an appropriate habitat can be an important way to increase colonization of a variety of natural enemy species into target fields, but it is important to consider numerous factors including the type of crop, field bound- ary, key predators, and disturbance schedule (e.g., pesticide applications, tillage, harvest). Each of these variables can have a significant effect on the timing and extent of predator colonization (Coombes and Sotherton, 1986; Thomas et al., 1991; Wallin, 1985). For example, Carillo (1985) showed that earwigs (Dermaptera) seem to have more limited movement through barley than they do through non-crop grasses. Wallin (1985) showed that different species of carabids used adjacent field boundaries at different times of the year for different purposes. In some cases, overwintering sites that are separated from crop fields are nec- essary for the survival of the natural enemy. Minute solitary egg parasitoids, Anagrus spp., have been found to be an important mortality factor for the western grape leafhopper, Erythroneura elegantula, an economically significant pest of grapes in the western U.S. (Corbett and Rosenheim, 1996). Anagrus spp. require an egg host to overwinter; however, all of the major species of leafhoppers found in grapes overwinter in the adult stage. Therefore, other leafhoppers must be used as over- wintering hosts of the parasitoids. Anagrus spp. can overwinter in the eggs of a native non-pest leafhopper found in wild blackberries and then move into vineyards the next year (Doutt and Nakata, 1973). Vineyards within 5.6 km of blackberries have been reported to benefit from parasitoids emigrating from the blackberry refuges (Doutt and Nakata, 1973). Kido et al. (1984) showed that Anagrus adults were also capable of parasitizing another leafhopper species, Edwardsiana pruni- cola, that overwinters as an egg in French prune tree orchards. They showed a correlation between grape leafhopper parasitism in vineyards and Anagrus dispersal during early spring from nearby French prune tree orchards that harbored E. pruni- cola. Laboratory studies revealed that parasitoids reared on one leafhopper species can readily parasitize the other species (Kido et al., 1984; Williams, 1984), so either alternative host can act as an overwintering refuge to increase the colonization of parasitoids to vineyards early in the growing season. © 2000 by CRC Press LLC 6 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION Significant correlation between the presence of French prune tree refuges and higher parasitoid abundance in grape vineyards has been found repeatedly (Kido et al., 1984; Murphy et al., 1996). To prove that these refuges were the source of parasitoids in grape vineyards, however, it was necessary to show that the overwin- tering parasitoids were indeed immigrating into adjacent vineyards. Corbett and Rosenheim (1996) used rare element labeling to mark overwintering parasitoids in the refuge and then track their movement by recapturing individuals in the vineyards the next year. This mark-recapture experiment demonstrated that parasitoids from the nearby refuges do colonize adjacent vineyards, yet the contribution colonists made to the total early season parasitoid population was relatively low and variable (1% and 34% of parasitoids in two experimental vineyards). By immigrating early in the season, even the smaller numbers of parasitoids from these refuges may be able to play a critical role in increasing parasitism and controlling populations of the western grape leafhopper (Murphy et al., 1998). It is also possible that the prune tree refuge may increase parasitoid immigration in more subtle ways. Flying insects accumulate in sheltered regions downwind of natural or artificial windbreaks (Lewis and Stephenson, 1966). Because dispersing A. epos accumulate at a much greater rate downwind of prune tree refuges, it has been speculated that the French prune trees act both as a collection of overwintering hosts and as a natural windbreak which influences the colonization of dispersing parasitoids (Corbett and Rosenheim, 1996). Further research may be needed to deter- mine optimal refuge size and placement in order to provide sufficient pest control. Aphid parasitoids in grass and cereal crops provide another example of an asso- ciation between higher colonization of natural enemies and the proximity of overwin- tering sites (Vorley and Wratten, 1987). Barley and early sown wheat (drilled before mid-October) provide a significant source of parasitoids that immigrate into later planted wheat fields. This was demonstrated both by trapping parasitoids in spatially oriented baffle traps, and by calculating the expected number of Aphidius spp. para- sitoids and comparing it to the actual field surveys. The early sown fields may benefit the parasitoids in two ways. First, it creates an overwintering refuge with high densities of aphid hosts in the fall. The early sown fields also allow for the development of an aphid host early in the season, which in turn allows for parasitoid populations to build up when other hosts may be relatively scarce. Vorley and Wratten (1987) suggested that one early planted wheat field generated sufficient parasitoids in the spring to account for immigration into about 25 late planted fields. Early movement of parasi- toids in the spring may coincide with the initial build up of aphids in the other fields, when parasitoids are capable of the greatest impact on aphid populations. Natural enemy populations may benefit from managing landscapes to increase the temporal availability of habitats and food so that resources are available for natural enemies throughout the growing season. This has been studied for aphids and their parasitoids on a variety of weeds and other non-crop hosts (Perrin, 1975; Stary and Lyon, 1980; Müller and Godfrey, 1997). Generalist predators such as coccinellids have also been shown to use resources from weeds and other non-crop habitats, especially early in the growing season (Banks, 1955; Perrin, 1975; Benton and Crump, 1981; Honek, 1982; Hodek and Honek, 1996). For example, in Central Bohemia, populations of the predator Coccinella septempunctata L. were found to © 2000 by CRC Press LLC USING CULTURAL PRACTICES TO ENHANCE INSECT PEST CONTROL 7 colonize habitats sequentially, starting with overwintering sites, then alfalfa and clover in early spring, followed by spring cereals later in the year (Honek, 1982). Other species use field boundaries and edges at different times throughout the season for reproduction and possible recolonization of adjacent fields (Boller et al., 1988; Wallin, 1985). Trap crops such as alfalfa interplanted with cotton may also provide a source of predators that can colonize adjacent fields and attack pest species (Corbett et al., 1991). Trap crops allow for the build up of pest and enemy populations in areas adjacent to crops being targeted for pest control. Few studies, though, have shown more than changes in the relative abundance of insects in the trap crops and other added habitats. Future studies are needed to understand the mechanisms of increased abundance and how to use this information for more effective cultural control. 5.2.2 Hypothesis 2 — Natural Enemy Abundance is Increased Because the Previously Occupied Habitat is no Longer Suitable, which Results in Higher Colonization Unlike natural systems that typically have one disturbance over multiple years, agricultural systems are subject to multiple disturbances within and between growing seasons. Preparing the ground, planting seed, applying nutrients and pesticides, cultivation, and harvest can all act as significant disturbances to the crop ecosystem. Ecologists have begun to recognize that such disturbances can play a key role in structuring ecological communities and population dynamics (Pickett and White, 1985). Harvesting, for example, can have a tremendous detrimental effect on natural enemy populations. Honek (1982) estimated that alfalfa harvesting destroyed 90% of the recently immigrated Coccinella septempunctata population. Carillo (1985) demonstrated that cutting ryegrass for forage caused the European earwig, For ficula auricularia to immigrate to field margins. Therefore, it is important to find ways to encourage frequent colonization and recolonization of natural enemies to maintain high population densities of natural enemies. Refuges can be created in and around crop fields to reduce the effects of distur- bance on natural enemies and increase the likelihood of their recolonization. This has been examined by comparing the effects of block versus strip harvesting of alfalfa on the population dynamics of a parasitoid Aphidius smithi and its aphid host Acyrthosiphon pisum (van den Bosch et al., 1966; van den Bosch et al., 1967). Forage crops like alfalfa are cut and harvested two to four times a year. Each time, the fields are left devoid of vegetation for several days, creating a harsh microclimate where both parasitoid and host are exposed to direct solar radiation. Furthermore, they suggested that the lack of vegetation causes a decline in aphid parasitoids because of a radical reduction in their obligatory host. Altering planting and cutting dates can ameliorate these disturbances. By leaving strips of unmowed alfalfa, aphids and parasitoids are given a temporal refuge from cutting disturbances. These refuges allow A. smithi to retain a population in the fields so they can respond to aphid outbreaks as they occur. Additionally, it appears that A. smithi females gradually move from the taller, older alfalfa into the younger strips between cuttings. This increased immigration into young alfalfa puts the parasitoids in contact with young © 2000 by CRC Press LLC 8 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION aphid colonies, where they can have the greatest suppressive effect on aphid popu- lations. Gradual movement of parasitoids away from older plants to younger ones also means there will be fewer parasitoids at risk of being killed when the older plants are harvested. These temporal refuges reduce the effect of cutting on the parasitoid population and increase the parasitoid’s overall ability to control aphid pests. Similarly, Mullens et al. (1996) found that alternating the removal of manure from poultry facilities created temporal refuges that helped increase densities of predatory mites, Macrocheles spp., that helped control fly pest populations. Using a metapopulation model, Ives and Settle (1997) suggested a theoretical basis for the phenomena observed by van den Bosch (van den Bosch et al., 1966; van den Bosch et al., 1967). If fields are asynchronously planted and harvested, mobile natural enemies will have time to disperse from mature fields into younger ones. Therefore, the enemies can have a larger overall effect in controlling herbivore populations (Ives and Settle, 1997). If there are few mobile enemies in asynchronous plantings, then insect pest populations increase at alarming rates. Further studies can help determine what systems have the greatest potential for using refuges to give a greater advantage to natural enemy populations. 5.2.3 Hypothesis 3 — Natural Enemy Abundance is Increased Because a Habitat is Attractive in Some Way, which Results in Higher Colonization Some predators and parasitoids can perceive and respond to sensory information from plants. Flowers, which are important sources of nectar for parasitoids, have been found to attract the parasitoid Microplitis croceipes by olfactory stimuli (Takasu and Lewis, 1993), and the parasitoid Cotesia rubecula by both olfactory and visual stimuli (Wäckers, 1994). Flowers and flower nectar also attract parasitoids of the tarnished plant bug (Streams et al., 1968; Shahjahan, 1974). Since many parasitoids have been found to forage for nectar and other food sources, increasing the avail- ability and physical proximity of these sources may increase the immigration of parasitoids from other sources to target fields. This, however, remains to be defini- tively documented. Natural enemies can also be attracted to plants at growth stages that may be associated with prey or hosts. The parasitoid Campoletis sonorensis was attracted to flowers and other plant parts that are associated with the presence of its host cotton bollworm (Elzen et al., 1983). The polyphagous heteropteran predator, Orius insidiosus is attracted to volatile chemicals from maize silk, which may help it feed on prey (Reid and Lapman, 1989). Other plants and volatile plant chemicals are detected by and attractive to the parasitoids Peristenus pseudopallipes (Monteith, 1960), Diaeretiella rapae (Read et al., 1970), Heydenia unica (Camors and Payne, 1972), Eucelatoria spp. (Nettles, 1979), and the chrysopid predator Chrysoperla carnea (Flint et al., 1979). The reaction of insects to plant stimuli often depends on the physiological state of the insect. For example, it has been found that hungry female parasitoids responded to food-associated odors, while well-fed females responded to the host- associated odors (Takasu and Lewis, 1993; Wäckers, 1994). The ability of an insect © 2000 by CRC Press LLC USING CULTURAL PRACTICES TO ENHANCE INSECT PEST CONTROL 9 to respond to an odor may also depend on previous experience. Microplitis croceipes is able to learn different odors and associate them with either host or food resources (Lewis and Takasu, 1990). Parasitic flies have also been found to be attracted to or repelled by plant odors from different trees, depending on the flies’ age in relation to reproductive maturity (Monteith, 1960). Natural enemies are also capable of perceiving and responding to other plant cues. In studying the mechanistic response of the predator Orius tristicolor White to a corn-bean-squash polyculture, five possible cues were described that could influence insect immigration: plant density, plant architecture, visual cues, volatile chemicals, and microclimate such as relative humidity (Letourneau, 1990). The results suggest that plant architecture and density increased colonization of the predator, regardless of prey density or plant diversity. Others have noted differences in predator abundance associated with variation in plant architecture and density, perhaps caused by microclimatic differences (Honek, 1982). Many species have the ability to detect their prey or hosts from a distance. Frass from the larvae and scales from adult of the corn earworm Helicoverpa zea (Boddie) contain chemical stimuli that invoke higher activity rates and oriented host-seeking behavior in the larval parasitoid M. croceipes, and egg parasitoids Trichogramma spp. (Jones et al., 1971; Jones et al., 1973; Gross et al., 1975). However, it remains uncertain how these attractants influence the population dynamics of the parasitoids and on what spatial scales these attractants can cause increases in colonization. Some natural enemies have also found to be attracted to volatile plant chemicals that are induced by insect herbivory. These compounds might be important in host habitat location and have been shown to be involved in the host location process. Attraction has been observed for the parasitoids Cotesia marginiventris (Turlings et al., 1990; Alborn et al., 1997), Microplitis croceipes (McCall et al., 1993), Cor- tesia glomerata (Mattiacci et al., 1994), and Cardiochiles nigriceps (De Moraes et al., 1998); the predaceous mites Metaseiulus occidentalis, Phytoseiulus persimilis (Sabelis and van de Baan, 1983), and Amblyseius potentillae (Dicke et al., 1990); and anthocorid predators (Drukker et al., 1995). Natural enemies have been shown to respond to plants that are typical food sources for their hosts or prey. It has been recently shown that plants give off different amounts of volatile compounds in response to different species of herbivores, and distinct parasitoid species can dif- ferentiate these chemical signals and may respond only to those compounds asso- ciated with their preferred hosts (De Moraes et al., 1998). Herbivore-induced plant volatiles have been shown to cause increased numbers of natural enemies in field situations (Drukker et al., 1995), but it is unclear at what distance natural enemies are attracted from and at what spatial scale they can be attracted. These results, however, demonstrate an enormous potential for using trap crops, intercropping, variation in planting pattern, or artificial chemicals to increase the attractiveness and colonization of species-specific natural enemies to target fields. Another method of increasing colonization is to use artificial sprays applied to target fields. The abundance of the generalist predator, Coleomegilla maculata can be increased with sprays of sugar plus wheast, an artificial food source that is a mixture of a yeast, Saccharomyces fragilis, plus its whey substrate (Nichols and Neal, 1977). A similar result has been found for coccinellid populations using sugar © 2000 by CRC Press LLC [...]... 276:9 45- 948 Andow, D.A 1991 Vegetational diversity and arthropod population response Annual Review of Entomology 36 :56 1 -58 6 © 2000 by CRC Press LLC 18 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION Andow, D.A 1996 Augmenting natural enemies in maize using vegetational diversity In Biological pest control in systems of integrated pest management FFTC Book Series No 47, pp 137- 153 Food... cover Environmental Entomology 25( 5):972976 Flint, H M., S S Salter, and W S Walters 1979 Caryophyllene: an attractant for the green lacewing Environmental Entomology 8:1123-11 25 © 2000 by CRC Press LLC 20 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION Gillaspy, J E 1971 Papernest wasps (Polistes): observations and study methods Annals Entomological Society of America 64(6):1 357 -1361... Agriculture Experiment Station, Riverside, paper no 153 1 © 2000 by CRC Press LLC 22 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION McMurtry, J.A and H.G Johnson 19 65 Some factors influencing the abundance of the predaceous mite Amblyseius hibisci in sourthern California (Acarina: Phytoseiidae) Annals of the Entomological Society of America 58 :49 -56 Monteith, L G 1960 Influence of plants other... al (1989) found that under drought conditions, plant nitrogen uptake was limited for plants in soil with bacteria only, but it was enhanced in soils with both a predaceous protozoa (one that preys on soil bacteria) and bacteria © 2000 by CRC Press LLC 16 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION 5. 5 CONCLUSIONS The spatial and temporal arrangement of the landscape can play a significant... host plant in its protection Journal of Chemical Ecology 16(2):381-396 Dingle, H 1972 Migration strategies of insects Science 1 75: 1327-13 35 Doutt, R L and J Nakata 1973 The Rubus leafhopper and its egg parasitoid: An endemic biotic system useful in grape -pest management Environmental Entomology 2(3):381-386 Drinkwater, L.E., D.K Letourneau, F Workneh, A.H.C van Bruggen, and C Shennan 19 95 Fundamental differences... effectiveness © 2000 by CRC Press LLC 14 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION Although it is not clear how effective nectar plants are as a cultural control, sugar sources increase the fecundity and longevity of many species of natural enemies, whereas the absence of sugar sources significantly reduces fecundity and longevity Therefore, the presence of floral and extrafloral... and biocontrol — a review Biocontrol News and Information 17:11-22 Johnson, C.G 1960 A basis for a general system of insect migration and dispersal by flight Nature 186:348- 350 Jones, R L., W J Lewis, M Beroza, B A Bierl, and A N Sparks 1973 Host-seeking stimulants (kairomones) for the egg parasite, Trichogramma evanescens Environmental Entomology 2(4) :59 3 -59 6 Jones, R L., W J Lewis, M C Bowman, M Beroza,... 33(2):249- 255 Brust, G.E and B.R Stinner 1991 Crop rotation for insect, plant pathogen and weed control In D Pimentel (ed.), Handbook of pest management in agriculture, 2nd edition CRC Press, Boca Raton, Florida Brust, G.E., B.R Stinner, and D.A McCartney 1986 Predation by soil inhabiting arthropods in intercropped and monoculture agroecosystems Agriculture, Ecosystems and Environment 18:1 45- 154 Bugg,... Press, Boca Raton, Florida Stinner, B.R and G.J House 1990 Arthropods and other invertebrates in conservation-tillage agriculture Annual Review of Entomology 35: 299-318 © 2000 by CRC Press LLC 24 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION Streams, F A., M Shahjahan, and H G LeMasurier 1968 Influence of plants on the parasitization of the tarnished plant bug by Leiophron pallipes Journal... Trichogramma pretiosum The Southwestern Entomologist 5( 4):261-264 Adkisson, P L 1 958 The influence of fertilizer application on populations of Heliothis zea (Boddie), and certain insect predators Journal of Economic Entomology 51 : 757 - 759 Agnew, C.W., W.L Sterling, and D.A Dean 1982 Influence of cotton nectar on red imported fire ants and other predators Environmental Entomology 11:629-634 Alborn, H T., T . 2000 by CRC Press LLC 2 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION 5. 5 Conclusions 162 References 163 5. 1 INTRODUCTION Cultural control of insect pests includes any modification. 276:9 45- 948. Andow, D.A. 1991. Vegetational diversity and arthropod population response. Annual Review of Entomology 36 :56 1 -58 6. © 2000 by CRC Press LLC 18 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL. 1977). A similar result has been found for coccinellid populations using sugar © 2000 by CRC Press LLC 10 INSECT PEST MANAGEMENT: TECHNIQUES FOR ENVIRONMENTAL PROTECTION solutions (Ewert and Chiang,