Trap Crop Research Articles

Orange jasmine as a trap crop to control Diaphorina citri

Novel, suitable and sustainable alternative control tactics that have the potential to reduce migration of Diaphorina citri into commercial citrus orchards are essential to improve management of huanglongbing (HLB). In this study, the effect of orange jasmine (Murraya paniculata) as a border trap crop on psyllid settlement and dispersal was assessed in citrus orchards. Furthermore, volatile emission profiles and relative attractiveness of both orange jasmine and sweet orange (Citrus × aurantium L., syn. Citrus sinensis (L.) Osbeck) nursery flushes to D. citri were investigated. In newly established citrus orchards, the trap crop reduced the capture of psyllids in yellow sticky traps and the number of psyllids that settled on citrus trees compared to fallow mowed grass fields by 40% and 83%, respectively. Psyllids were attracted and killed by thiamethoxam-treated orange jasmine suggesting that the trap crop could act as a ‘sink’ for D. citri. Additionally, the presence of the trap crop reduced HLB incidence by 43%. Olfactometer experiments showed that orange jasmine plays an attractive role on psyllid behavior and that this attractiveness may be associated with differences in the volatile profiles emitted by orange jasmine in comparison with sweet orange. Results indicated that insecticide-treated M. paniculata may act as a trap crop to attract and kill D. citri before they settled on the edges of citrus orchards, which significantly contributes to the reduction of HLB primary spread.

Trap Cropping in South Asia: Concepts, Limitations, and Future Strategy

AbstractCultural methods are some of the most widely adopted approaches in integrated pest management. Trap cropping is based on the principle of using a relatively more preferred crop species to keep the pest away from the main crop and reduce pest damage. This technique has tremendous potential to keep the pest below the economic damage threshold and can be used for pest management in organic farming. Furthermore, trap crops can be linked to habitat management and conservation biological control to improve multiple ecosystem services in an agroecosystem. While trap cropping is one of the most common cultural pest management control methods in subsistence farming in South Asia, it has not yet become common in conventional agriculture, nor has this practice been well documented in this region. This work broadly reviews the most relevant literature related to trap cropping used in pest management in this region. Regional cooperation for knowledge-sharing and research collaborations, motivating farmers to promote organic farming, along with increased research and policy interventions to favor sustainable agriculture have been done to promote this pest management practice in South Asia.

Production of santalenes and bergamotene in Nicotiana tabacum plants.

Terpenes play an important role in plant–insect relationships, and these relationships can potentially be modified by altering the profile of terpenes emitted from plants using metabolic engineering methods. Transgenic plants generated by employing such methods offer the prospect of low-cost sustainable pest management; in this regard, we used chloroplast targeting and cytosolic mevalonic acid pathway enhancement in this study to investigate the interaction of santalenes and bergamotene with insects. The santalene- and bergamotene-emitting transgenic tobacco plants thus generated were utilized to study host preference in the green peach aphid (Myzus persicae (Sulzer)). The results showed that co-expression of either 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) or truncated HMGR with santalene synthase led to the production of higher amounts of santalenes and bergamotene in transgenic tobacco plants, and that these santalene- and bergamotene-emitting plants were attractive to green peach aphids. We accordingly propose that such transgenic plants may have potential application in pest management as a trap crop to prevent green peach aphid infestation of wild-type tobacco plants.

Effect of the trap crop, Solanum sisymbriifolium, on Globodera pallida, Globodera tabacum, and Globodera ellingtonae.

The effect of the nematode trap crop Solanum sisymbriifolium was assessed against three Globodera spp., the potato cyst nematode Globodera pallida (in Idaho), the recently described Globodera ellingtonae (in Oregon), and the tobacco cyst nematode Globodera tabacum (in Connecticut) in field trials. At all locations the ability of S. sisymbriifolium to reduce Globodera encysted second-stage juveniles (J2) in egg densities compared to fallow was considered. For G. ellingtonae, the impact of planting and termination dates of S. sisymbriifolium on final egg densities was also evaluated; and for G. pallida, the ability of the nematode to reproduce on potato (Solanum tuberosum) after exposure to S. sisymbriifolium was determined. Encysted J2 in egg densities of all three Globodera spp. declined from 25 to 68% after trap cropping with S. sisymbriifolium. For G. pallida, S. sisymbriifolium reduced final encysted J2 in egg density by 23 to 50% compared to the fallow treatment, and significantly decreased G. pallida reproduction on potato after exposure to S. sisymbriifolium by 99 to 100% compared to the fallow treatment (P < 0.0001). For G. ellingtonae, the planting date of S. sisymbriifolium in May or June did not impact final egg densities (P = 0.32). Rather, percentage reduction in G. ellingtonae encysted J2 in egg density was most influenced by the length of time to which nematodes were exposed to S. sisymbriifolium, with 30 and 81% reduction after 6 vs 12 wk of exposure, respectively (P < 0.0001). Similar levels of nematode reduction after S. sisymbriifolium were observed for G. tabacum after 12 to 14 wk of exposure to the trap crop; G. tabacum density changes consisted of a 114% increase after susceptible tobacco, a 65% decrease after resistant tobacco, and an 88% decrease after S. sisymbriifolium compared to bare soil. In conclusion, this research demonstrates the widespread applicability of S. sisymbriifolium in reducing a diversity of Globodera spp. present in the USA.

Biology and Management of the New Zealand Endemic Wheat Bug, Nysius huttoni (Hemiptera: Lygaeidae)

Abstract The wheat bug, Nysius huttoni White, mainly reported as a pest of wheat and forage brassicas, is native to New Zealand. This pest has been accidentally introduced into The Netherland and Belgium during apple exports from New Zealand. The bug population is abundant in open sparse vegetations and hot-dry habitats, and feeds on dropping seeds. It damages wheat grains during milk-ripe stage by piercing through the glumes into the developing grains that can reduce gluten protein and reduce baking quality. Bugs also suck phloem fluid from seedlings, which can reduce plant establishment in forage brassicas. Early scouting and field monitoring are suggested before making pest management decisions. Seed treatment with neonicotinoids, permethrin, and chlorpyrifos spray in the standing crops are chemical methods of management in New Zealand. These conventional synthetic pesticides have nontarget effects on human health, the environment, and biodiversity. However, preventive measures such as the use of less-susceptible cultivars, and using potential trap crops is other important pest management options. Alyssum (Lobularia maritima L. Desv. Brassicales: Brassicaceae) and wheat (Triticum aestivum L. Poales: Poaceae) are two potential trap crops of wheat bug. Kale (Brassica oleracea L.) cultivars, such as Corka and Regal, and wheat (Triticum aestivum) cultivars, such as Batten, Domino, and Oroua, are less-susceptible cultivars. Understanding the biology and ecology of the pest, and utilizing preventative pest management measures such as the use of trap crops and less-susceptible cultivars, and integrating these with ‘soft’ chemicals make a suitable integrated pest management strategy for this pest.

Influence of Pheromone-Baited Traps on Stink Bugs in Cotton.

Stink bugs (Hemiptera: Pentatomidae) are economic pests in fruit, vegetable, grain, and row crops worldwide. Pyramid traps baited with lures of stink bug aggregation pheromones capture these pests in the field, but stink bugs can congregate on plants near traps. Our specific objective was to examine the area of arrestment of stink bugs based on their density on cotton at different distances from pheromone-baited traps. We used lures of the aggregation pheromone of Euschistus spp., methyl (2E,4Z)-2,4-decadienoate (MDD), and Plautia stali Scott, methyl [2E,4E,6Z]-2,4,6-decatrienoate (MDT). Overall, Euschistus servus (Say), Euschistus tristigmus (Say), Chinavia hilaris (Say), and Nezara viridula (L.) were the main stink bug species on cotton. Over the 3-yr study, adult stink bug density was significantly higher on the row of cotton immediately adjacent to a pheromone-baited trap than on the second and third row from the trap. Stink bug density was significantly lower on the seventh cotton row beyond the trap in 2015, on the fourth, eighth, and 16th rows in 2017, and on the fourth and eighth rows in 2018 compared to the two or three rows nearest the trap. These results indicate that adult stink bugs congregated mainly on the three cotton rows (2.73 m in width) nearest a trap. Management strategies utilizing pheromone-baited traps for stink bug control, such as trap cropping in combination with traps, should take into consideration this area of arrestment.

Examining Host Selection by Mexican Bean Beetle (Coleoptera: Coccinellidae) Using Mark-Release-Recapture.

Mexican bean beetle, Epilachna varivestis Mulsant, is a pest of snap bean and lima bean in the eastern United States. This pest is susceptible to many insecticides available to conventional growers; however, organic management using parasitoid releases and organic insecticides have inconsistent results. In the interest of developing cultural management techniques such as trap crops or push–pull systems, five bean cultivars were evaluated for preferential host selection by E. varivestis using marked beetles in field cages and open plots. Beetles were marked with a water-based paint pen and their locations on plants monitored over time. In field cages, the purple wax bean, Dragon’s Tongue (DT), was preferred over yellow wax, green bean and lima bean; soybean was the least preferred overall. Recaptures of E. varivestis adults in open field plots progressively decreased following beetle release, suggesting the affinity of adults to disperse despite being on or near acceptable hosts. The two wax beans were equally preferred in open field experiments, partially more than the green and lima bean and consistently more than the soybean. These experiments suggest that DT may be a suitable crop for trap cropping or attract and kill strategies for E. varivestis.

Corn Nitrogen Management Following Daikon Radish and Forage Oat Cover Crops

Core Ideas Daikon radish and forage oat cover crops following winter wheat sequestered residual autumn soil NO3–N levels. Nitrogen availability to the ensuing corn crop may be reduced when preceded by radish or oat cover crops. When using radish or oat cover crops, increased 5×5 starter rates (&gt; 45 kg N ha‐1) may be required if full SD is delayed until V11. Radish and oat cover crops preceding corn did not provide a subsequent N fertilizer replacement value but may still be effectively utilized as soil conservation tools. Cover crops (CC) preceding corn (Zea mays L.) may influence subsequent nitrogen (N) availability, but it is not clear whether N strategies require adjustment. Field studies conducted in 2015 to 2016 evaluated the effects of a daikon radish [Raphanus sativus (L.)], forage oat [Avena sativa (L.)], and no CC following winter wheat [Triticum aestivum (L.)] on soil chemical properties, corn growth, grain yield, and profitability. Nitrogen management strategies were equalized to 179 kg N ha–1 and included pre‐plant incorporated (PPI) N, poultry litter (PL) PPI (61 kg N ha–1) plus sidedress (SD) N V11, starter N (45 kg N ha–1) subsurface banded (5 cm below and 5 cm beside the seed, 5×5) followed by V4, V11, or V4 plus V11 SD, and a zero N control. Cover crops reduced autumn soil NO3–N levels 78 to 84% relative to no CC but occasionally reduced N during critical corn uptake periods. Cover crops did not increase soil base cation availability to the ensuing corn crop. When 5×5 starter was followed by full SD at V11, CCs reduced yield 3.2 to 3.9% and profitability 11.8 to 13.2% compared with no CC indicating reduced efficacy and possibly greater 5×5 requirements to maintain yield potential until SD time. In the zero N control, CCs reduced grain yield 11.8 to 14.2% and increased yield response to N 63 to 79% suggesting reduced N availability. Radish and oat CCs provided a trap crop for autumn residual N, but N management strategies may need to account for reduced N availability.

Hatching dynamics of the beet cyst nematode, Heterodera schachtii, following exposure to root leachates from cultivars of sugar beet, white mustard and radish

Summary The hatching and emergence of juveniles from cysts of Heterodera schachtii in response to various stimuli are well understood. These responses relate to means of optimising the chances of successful reproduction and survival of populations. However, the effect of different cultivars of host species is not so well understood. To gain a further understanding of any differences between cultivars of host species, we conducted a number of experiments using root leachates obtained from a range of cultivars of sugar beet (Beta vulgaris), radish (Raphanus sativus) and white mustard (Sinapis alba). Heterodera schachtii cysts were exposed to root leachate solutions in in vitro laboratory assays during which emergence of second-stage juveniles (J2) from cysts was monitored weekly. Significant differences in the stimulation of hatch of J2 were found in response to different sugar beet cultivars and these differences may be driven by differing growth habits of such varieties. However, results obtained from experiments using brassica varieties showed contrasting responses. In one experiment, root leachates appeared to inhibit hatch of J2. However, two experiments did show a stimulation of hatch of J2 and also significant differences in hatch responses due to the age of the plant. These findings may help develop future screening procedures for brassica trap crops and help identify those that show the greatest potential for H. schachtii control.

Assessing the performance of pea and lentil at different seeding densities as trap crops for the management of wireworms in spring wheat

AbstractWireworms, the larvae of click beetles (Elateridae), are difficult to manage due to their habitats and behaviour. Wireworms pose a major threat to the wheat crop in the north‐western USA. Seed treatment with neonicotinoids, biological control management and some cultural controls are recommended to manage these pests. Trap cropping is an emerging way to manage wireworms. In strawberry and potato crops, trap cropping has been found effective at attracting wireworms away from the principal crop. An earlier study in the Golden Triangle area of Montana found that pea and lentil could be effective trap crops for managing wireworms in spring wheat. In the present study, experiments were conducted at two locations. The effectiveness of peas and lentils as trap crops with wheat at different seeding densities was assessed [pea at 0, 4, 8, 16 seeds/sq.ft. or 0, 43, 86, 172 seeds/sq.m.; lentil at 0, 6, 12, 18 OR 0, 65, 130, 194 seeds/sq.m.; both with wheat at 0, 11, 22, or 28 seeds/sq.ft. or 0, 120, 230, 300 seeds/sq.m.] in a randomized design where all three crops were intercropped. Both trap crops were found to be effective in protecting wheat at standard seeding rates of 8 seeds/sq.ft. for pea and 12 seeds/sq.ft. for lentils. At these seeding rates, higher numbers of wireworms were found to be attracted to the trap crop, resulting in higher yield (7%–10%) of the associated spring wheat plant stands at 22 seeds/sq.ft. To develop an effective trap crop strategy, the pea–wheat and lentil–wheat spatial patterns that are possible need to be assessed in further field trials. Proper design and evaluation of the cost–benefit ratio of pea and lentil as trap crops are likely to produce good results for wheat crops in Montana.

Trap Crops: How Far We Are From Using Them in Cereal Crops?

AbstractTrap crops are plants grown along with the main crop in order to manipulate insect behavior to manage the insect pests and are used as a cultural management strategy in several crops. Trap crops also provide habitat to natural enemies and can reduce the need for insecticides and hence reduce the development of insecticide resistance. The attractiveness of the trap crop, the timing of planting, and the space it occupies are major factors to consider before selecting and using a trap crop. The addition of semiochemicals and incorporation of ‘stimulo-deterrent diversion’ can increase the efficiency of trap crops. The important insect pests of cereal crops reported to managed by using trap crops include the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), on wheat and the stem borers Chilo partellus (Swinhoe) and Busseola fusca (Fuller) on maize and sorghum. Other insect pests such as soil-dwelling wireworms [Agriotes obscurus L., Limonius californicus (Mannerheim) (Coleoptera: Elateridae)] on potatoes and the aphids Schizaphis graminum (Rondani) (Hemiptera: Aphididae), and Rhopalosiphum padi L. on wheat and the brown planthopper Nilaparvata lugens (Stål) on rice are also possible to manage by using trap crops. Cereal crops such as maize and wheat are sometimes themselves used as trap crops, yet there have been only a handful of attempts made to use trap crops in cereal crops. The major limiting factors in using trap crops in cereal crops are environmental conditions, variation in landscape and cultivation practices. Nonetheless, trap crops remain an important tool of integrated pest management, and future studies should work to improve the efficacy, cost efficiency, and availability of alternative trap crops for use in cereal cultivation.

INTEGRATED MANAGEMENT OF LEAF MINERS LIRIOMYZA SPP. (DIPTERA: AGROMYZIDAE) ON SHALLOT CROPS BY TRAP CROPPING SYSTEM AND ARBUSCULAR MYCORRHIZAE

ABSTRACT Integrated pest management (IPM) has been recognized as the best solution to minimize the adverse effects of insecticides applied to farmland. This study aims to evaluate the effectiveness of the trapping crop system (TCS) and arbuscular mycorrhizae (AM) against leaf miner, an important horticultural pest throughout the world including on shallot crops in Indonesia. In a factorial research design, cucumbers use in TCS was planted in three different pattern: one rows in the center; TC1, two rows in the middle; TC2, and one-row surroundings the shallot; TC3, while AM consists of two levels that are with (M1) and without AM (M2) application. The variables measured were: population and infestation of leaf miners as well as parasitism at the main and trap crops. The results showed that the leaf miners population was significantly reduced by TCS application but had no relation with AM. The leaf miners population decreased by about 40.1% at the TCS compared with the controls. However, the combination of TCS and AM reduced the leaf miner infestation by about 47.5% where TC3M1 showed the best treatment against leaf miners. Increasing of the parasitoids population and parasitism at the shallot and cucumbers as trap crops as well as the shallot resistance against leaf miner may explain the compatibility of TCS and MA to manage the pest. The study denoted the importance of IPM against shallot leaf miners to support sustainable farming system.

Trap Crops and Insectary Plants in the Order Brassicales

Abstract This paper reviews the most important cases of trap crops and insectary plants in the order Brassicales. Most trap crops in the order Brassicales target insects that are specialist in plants belonging to this order, such as the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), the pollen beetle, Meligethes aeneus Fabricius (Coleoptera: Nitidulidae), and flea beetles in the genera Phyllotreta and Psylliodes (Coleoptera: Chrysomelidae). In most cases, the mode of action of these trap crops is the preferential attraction of the insect pest for the trap crop located next to the main crop. With one exception, these trap crops in the order Brassicales have been used with brassicaceous crops. Insectary plants in the order Brassicales attract a wide variety of natural enemies, but most studies focus on their effect on aphidofagous hoverflies and parasitoids. The parasitoids benefiting from insectary plants in the order Brassicales target insects pests ranging from specialists, such as P. xylostella, to highly polyfagous, such as the stink bugs Euschistus conspersus Uhler and Thyanta pallidovirens Stål (Hemiptera: Pentatomidae). In the order Brassicales, the three most common trap crops are Indian mustard, Brassica juncea (L.) Czern, Chinese cabbage, Brassica rapa L., and yellow rocket, Barbarea vulgaris R. Br., while the three most common insectary plants are sweet alyssum, Lobularia maritima (L.) Desv., white mustard, Sinapis alba L, and B. vulgaris. Except for Tropaeolum majus L. (Tropaeolaceae) and Capparis decidua (Forssk.) Edgew. (Capparaceae), the tested trap crops and insectary plants in the order Brassicales belong to the family Brassicaceae.

Application of Trap Cropping as Companion Plants for the Management of Agricultural Pests: A Review

Companion planting is a well-known strategy to manage insect pests and support a natural enemy population through vegetative diversification. Trap cropping is one such type of special companion planting strategy that is traditionally used for insect pest management through vegetative diversification used to attract insect pests away from the main crops during a critical time period by providing them an alternative preferred choice. Trap crops not only attract the insects for feeding and oviposition, but also act as a sink for any pathogen that may be a vector. Considerable research has been conducted on different trap crops as companion plant species to develop improved pest management strategies. Despite this, little consensus exists regarding optimal trap cropping systems for diverse pest management situations. An advantage of trap cropping over an artificially released natural enemy-based biological control could be an attractive remedy for natural enemies in cropping systems. Besides, many trap crop species can conserve natural enemies. This secondary effect of attracting natural enemies may be an advantage compared to the conventional means of pest control. However, this additional consideration requires a more knowledge-intensive background to designing an effective trap cropping system. We have provided information based on different trap crops as companion plant, their functions and an updated list of trap cropping applications to attract insect pests and natural enemies that should be proven as helpful in future trap cropping endeavors.

Host preference by two Bemisia tabaci biotypes in Costa Rica and Florida

Despite being a polyphagous insect, Bemisia tabaci (Gennadius) shows a marked preference for certain hosts, which in turn may depend upon the particular whitefly biotype involved. The objective of this research was to compare preference towards a selected group of host crops, by two biotypes of Bemisia tabaci , New World in Costa Rica, and MEAM1 in Florida. Therefore, choice experiments were conducted in greenhouses both at Turrialba (Costa Rica) and Immokalee (Florida), in April and June-September, 1998, respectively. The same crops and varieties were exposed to the New World and MEAM1 biotypes, which predominate in each one of these locations, respectively. Host species included green beans ( Phaseolus vulgaris ), bell pepper ( Capsicum annuum ), eggplant ( Solanum melongena ), cucumber ( Cucumis sativus ), tobacco ( Nicotiana tabacum ) and tomato ( Solanum lycopersicum ). Seedlings were transplanted in large pots, which were distributed on the greenhouse floor. B. tabaci adults were released in the late afternoon, and the number of individuals on each plant was recorded the next morning. In Turrialba, tobacco was greatly preferred by New World biotype adults, followed by eggplant, whereas the MEAM1 biotype in Florida preferred green beans and eggplant. Thus, both biotypes showed a strong and significant preference for eggplant, which suggests its possible utility as a trap crop.

Preferencia de hospedantes por dos biotipos de Bemisia tabaci en Costa Rica y Florida

Despite being a polyphagous insect, Bemisia tabaci (Gennadius) shows a marked preference for certain hosts, which in turn may depend upon the particular whitefly biotype involved. The objective of this research was to compare preference towards a selected group of host crops, by two biotypes of Bemisia tabaci, New World in Costa Rica, and MEAM1 in Florida. Therefore, choice experiments were conducted in greenhouses both at Turrialba (Costa Rica) and Immokalee (Florida), in April and June-September, 1998, respectively. The same crops and varieties were exposed to the New World and MEAM1 biotypes, which predominate in each one of these locations, respectively. Host species included green beans (Phaseolus vulgaris), bell pepper (Capsicum annuum), eggplant (Solanum melongena), cucumber (Cucumis sativus), tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). Seedlings were transplanted in large pots, which were distributed on the greenhouse floor. B. tabaci adults were released in the late afternoon, and the number of individuals on each plant was recorded the next morning. In Turrialba, tobacco was greatly preferred by New World biotype adults, followed by eggplant, whereas the MEAM1 biotype in Florida preferred green beans and eggplant. Thus, both biotypes showed a strong and significant preference for eggplant, which suggests its possible utility as a trap crop.

Influence of Trap Crops on Management of Insect Pests by Exploitation of Heteropteran Predatory Bugs in Cotton

Influence of Trap Crops on Management of Insect Pests by Exploitation of Heteropteran Predatory Bugs in Cotton

A Hierarchy of Cues Directs the Foraging of Pieris rapae (Lepidoptera: Pieridae) Larvae.

The foraging patterns of insects reflect a combination of biotic and abiotic constraints. Pieris rapae (L.) (Lepidoptera: Pieridae) larvae exhibit plasticity in their foraging behavior, and their movements in response to flowers, young foliage, light, and gravity were studied. As predicted for palatable cryptic larvae, young instars of P. rapae exhibited predator avoidance behaviors. First- and second-instar larvae fed underneath the leaves where their eggs were oviposited, while late second- and third-instar larvae migrated away from their feeding damage. Using taxis experiments and choice tests, the direction of larval movement was significantly influenced by a hierarchy of three cues. Third-instar larvae exhibited negative gravitaxis, which could be supplanted by positive trophotaxis to young leaves and flowers. The larvae exhibited a significantly greater attraction to the inflorescence than to young foliage. For both the inflorescence and young foliage, visual cues were sufficient to direct larval movement. Understanding the cues that guide larval foraging may lead to more efficient trap crops for pest management.

Bt rice plants may protect neighbouring non-Bt rice plants against the striped stem borer, Chilo suppressalis.

The area planted with insect-resistant genetically engineered crops expressing Bacillus thuringiensis (Bt) genes has greatly increased in many areas of the world. Given the nearby presence of non-Bt crops (including those planted as refuges) and non-crop habitats, pests targeted by the Bt trait have a choice between Bt and non-Bt crops or weeds, and their host preference may greatly affect insect management and management of pest resistance to Bt proteins. In this study, we examined the oviposition preference of the target pest of Bt rice, Chilo suppressalis, for Bt versus non-Bt rice plants as influenced by previous damage caused by C. suppressalis larvae. The results showed that C. suppressalis females had no oviposition preference for undamaged Bt or non-Bt plants but were repelled by conspecific-damaged plants whether Bt or non-Bt. Consequently, C. suppressalis egg masses were more numerous on Bt plants than on neighbouring non-Bt plants both in greenhouse and in field experiments due to the significantly greater caterpillar damage on non-Bt plants. We also found evidence of poorer performance of C. suppressalis larvae on conspecific-damaged rice plants when compared with undamaged plants. GC-MS analyses showed that larval damage induced the release of volatiles that repelled mated C. suppressalis females in wind tunnel experiments. These findings suggest that Bt rice could act as a dead-end trap crop for C. suppressalis and thereby protect adjacent non-Bt rice plants. The results also indicate that the oviposition behaviour of target pest females should be considered in the development of Bt resistance management strategies.

Progress Toward Integrated Pest Management of Pea Leaf Weevil: A Review

The pea leaf weevil, Sitona lineatus (L.; Coleoptera: Curculionidae), is a significant pest of field peas (Pisum sativum L.) and faba bean (Vicia faba L.) in most temperate regions. Considerable research progress has been made towards understanding its basic life cycle, including flight patterns, plant host interactions, and geographic distribution throughout its native and invasive ranges in Europe and North America, respectively. Management tactics investigated include chemical insecticides and tillage, but less work has been done on biological control, host plant resistance, intercropping and trap crops. Future research should focus on better integration of tactics that utilize an ecostacking approach to maximize diversity at various scales to mitigate risks from insect pests and subsequently reduce the need for chemical interventions.