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Analysis of pooled genomic short read sequence data revealed the presence of nudivirus-derived sequences from U.S. populations of both southern corn rootworm (SCR, Diabrotica undecimpunctata howardi Barber) and western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte). A near complete nudivirus genome sequence was assembled from sequence data for an SCR population with relatively high viral titers. A total of 147,179 bp was assembled from five contigs that collectively encode 109 putative open reading frames (ORFs) including 20 nudivirus core genes. In contrast, genome sequence recovery was incomplete for a second nudivirus from WCR, although sequences derived from this virus were present in three geographically dispersed populations. Only 48,989 bp were assembled with 48 putative ORFs including 13 core genes, representing about 20% of a typical nudivirus genome. Phylogenetic analysis indicated that both corn rootworm nudiviruses grouped with the third known nudivirus of beetles, Oryctes rhinoceros nudivirus in the genus Alphanudivirus. On the basis of phylogenetic and additional analyses, we propose further taxonomic separation of nudiviruses within Alphanudivirus and Betanudivirus into two subfamilies and five genera. Identification of nudivirus-derived sequences from two species of corn rootworm highlights the diversity of viruses associated with these agricultural insect pests.

The EFSA Panel on Plant Health performed a pest categorisation of Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae) for the EU. This subspecies occurs in North and Central America. Adults oviposit on annual plants in the families Asteraceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Poaceae, Polygonaceae and Solanaceae. Adults feed on tender plant parts in hosts in 40 additional botanical families. Preimaginal development takes place on the roots of the host plant, where larvae feed and pupate. D. undecimpunctata howardi is a multivoltine species. Overwintering adults, which may enter a facultative diapause, abandon crops in autumn and reinvade them in spring. D. undecimpunctata howardi is not known to occur in the EU and is regulated in Annex IIA of Commission Implementing Regulation 2019/2072. This species is a competent vector of Erwinia tracheiphila (Smith) Bergey et al., which can cause bacterial wilt, a serious disease of cucurbits. The bacterium, which is restricted to temperate midwestern and eastern North America, is not regulated in the EU. Within Commission Implementing Regulation 2019/2072, potential entry pathways for D. undecimpunctata howardi, such as Asteraceae, Poaceae and Solanaceae plants for planting with foliage and soil/growing medium, and soil/growing media by themselves can be considered as closed. However, plants for planting of the families Chenopodiaceae, Cucurbitaceae, Fabaceae and Polygonaceae are not specifically regulated. Should D. undecimpunctata howardi arrive in the EU, climatic conditions and availability of susceptible hosts provide conditions suitable for establishment and further spread. Economic impact is anticipated in maize and outdoor cucurbit production. D. undecimpunctata howardi satisfies the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential Union quarantine pest. This species does not meet the criteria of being present in the EU, nor plants for planting being the main pathway for spread, for it to be regarded as a potential regulated non‐quarantine pest.

The EFSA Panel on Plant Health performed a pest categorisation of the beetle Diabrotica undecimpunctata undecimpunctata (Coleoptera: Chrysomelidae) for the EU. This species occurs in western USA and Mexico. Adults oviposit on annual plants in the families Chenopodiaceae, Cucurbitaceae, Fabaceae, Poaceae, Polygonaceae and Solanaceae. Adults feed on tender plant parts in hosts in 30 additional botanical families. Preimaginal development takes place on the roots of the host plant, where larvae feed and pupate. The insect completes one to three generations per year depending on temperature. Overwintering adults (no diapause) may abandon crops to seek shelter in wild vegetation and reinvade crops in spring. D. undecimpunctata undecimpunctata is not known to occur in the EU and is regulated in Annex IIA of Commission Implementing Regulation 2019/2072. This species is a competent vector of squash mosaic virus, a pathogen already present and not regulated in the EU. Within Commission Implementing Regulation 2019/2072, potential entry pathways for D. undecimpunctata undecimpunctata, such as Poaceae and Solanaceae plants for planting with foliage and soil/growing medium, and soil/growing media by themselves can be considered as closed. However, plants for planting of the families Chenopodiaceae, Cucurbitaceae, Fabaceae and Polygonaceae are not specifically regulated. Should D. undecimpunctata undecimpunctata arrive in the EU, climatic conditions and availability of susceptible hosts provide conditions suitable for establishment and further spread. Economic impact is anticipated. D. undecimpunctata undecimpunctata satisfies the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential Union quarantine pest. This species does not meet the criteria of being present in the EU nor plants for planting being the main pathway for spread for it to be regarded as a potential regulated non‐quarantine pest.

The genome sequence of a novel small RNA virus, tentatively named Diabrotica undecimpunctata virus 1 (DuV1), was discovered from the transcriptome of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber. DuV1 has a positive-sense, single-stranded RNA genome that encodes a single polyprotein of 3,401 amino acids with limited similarity to other viruses.

The genome of Diabrotica undecimpunctata virus 2 (DuV2), a putative positive-sense, single-stranded RNA virus identified from the southern corn rootworm transcriptome, comprises 5,313 nucleotides, including a short poly(A) tail. The two open reading frames encode a nonstructural polyprotein (p156) and a putative capsid protein (p25).

This publication discusses cucumber beetles, the plants they attack, the description of the damage, life cycle, distribution, disease transmission, and control practices 2808-1009 NP Revised

Spotted (Diabrotica undecimpunctata howardii) and striped (Acalymma vittatum) cucumber beetles (Coleoptera: Chrysomelidae) are serious pests of field-grown cucurbits in most areas of the United States where these crops are grown. This study aimed at quantifying, using a comparative approach, the behavioral response of A. vittatum and D. u. howardii to visual and olfactory cues associated with different trap types. In a first field study, Pherocon corn rootworm (CRW) traps baited with a 5-component floral-based lure (= AgBio lure) captured significantly more A. vittatum than traps baited with any other commercial lure. When used in combination with yellow sticky cards, the AgBio lure outperformed the other lures except for the Trécé lure TRE8274. Subsequent tests revealed that the response of both cucumber beetle species to the AgBio lure was positively associated with increases in the amount of lure used. In the last series of tests that involved color discrimination by the beetles, traps constructed using 3.8-liter jugs painted yellow outperformed the CRW trap. Results from on-farm research, conducted at a commercial vegetable farm, confirmed the beetles' visual preference for yellow, and also revealed an excellent performance of the mass trapping system, which kept cucumber beetle densities in the cash crop below economic thresholds. Combined findings indicate that the mass trapping system developed can be implemented as part of a broader IPM program aimed at managing cucumber beetles.

Cucurbit bacterial wilt, caused by Erwinia tracheiphila, is a devastating disease of cucurbit crops in the Midwest and Northeast U.S. Current management of bacterial wilt relies primarily on insecticide applications to control striped and spotted cucumber beetles (Acalymma vittatum and Diabrotica undecimpunctata howardi, respectively), which vector E. tracheiphila. Development of alternative management strategies is constrained by a lack of understanding of bacterial wilt etiology. The impact of host age on rate on symptom development and extent of bacterial movement in the xylem of muskmelon (Cucumis melo cv. Athena) was evaluated following wound inoculation of 2- to 8-week-old plants in growth chamber experiments. Wilting occurred more rapidly in plants after inoculating E. tracheiphila into 2- or 4-week-old plants than 6- or 8-week-old plants. Recovery of viable cells from stem segments revealed that vascular spread of E. tracheiphila was more extensive below than above the inoculation point. These findings provide experimental evidence that host age impacts the rate of symptom development in cucurbit bacterial wilt and that movement of the xylem-inhabiting pathogen E. tracheiphila within muskmelon plants occurs primarily in the downward direction.

Received: 2016-09-05 | Accepted: 2016-12-21 | Available online: 2017-12-31 http://dx.doi.org/10.15414/afz.2017.20.04.78-83 The study on the relative abundance of insect pests is a critical factor for a successful implementation of insect pest management program. Therefore, this experiment was conducted to compare the intensity of insect infestations among the selected three cucurbit crops (Cucumber, Egusi melon and Watermelon). The experiment was set up at Teaching and Research Farm Ladoke Akintola University of Technology, Ogbomoso in a Randomized Complete Block Design replicated three times. Significant difference was observed in the tested crops in respect to insect population density on leaf, flower and fruit. Among the tested crops, watermelon was observed to be the most susceptible to the observed insects meanwhile the cucumber had the least insect infestation rate 0.00 at P < 0.05. Also the insect infestation was low as the maturity of the leaves increased. The population density of flea beetle ( Phyllotreta cruciferea ) and spotted beetle ( Diabrotica undecimpunctata ) were observed to be relatively higher at vegetative stage and decreased at flowering stages while Dacus cucubitae caused significant economic damage during the fruiting stage to watermelon, melon and cucumber fruits (33.3, 20.0 and 1.0) respectively. This research work demonstrated that control of insect pests should be initiated at each growing stage of the selected crops. Keywords: Cucumber, Dacus cucubitae , Pyllotreta cruciferae , watermelon, melon References AFZAL, M. and BASHIR, M.H. (2007) Influence of certain leaf characters of some summervegetables with incidence of predatory mites of the family cunaxidae. Pak. J. Bot. , vol. 39, pp. 205–209. ALLWOOD, A. J. et al. (1999) Host plant records for fruit flies (Diptera: Tephritidae) in Southeast Asia. Raffles Bulletin of Zoology , vol. 47, pp. 1–92; 26. ALAO, F. O. and ADEBAYO, T. A. 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Control of cucurbit pests, such as striped cucumber beetle (Acalymma vittatum), spotted cucumber beetle (Diabrotica undecimpunctata howardi) and squash bug (Anasa tristis), in organic systems is difficult due to a lack of effective insecticide options. This has led to the development of many integrated pest management techniques, such as use of row covers, crop rotation and cover crops. This study explored the novel use of strip tillage and row covers to reduce pest pressure in summer squash (Cucurbita pepe) and muskmelon (Cucumis melo) production systems. Results showed that although strip tillage reduced striped cucumber beetle and squash bug numbers, there was a yield reduction in both crops compared with the plasticulture system. Row cover increased marketable yield in both systems, with the highest yield being in the plasticulture system. Unmarketable fruit directly attributed to insect damage was higher in the plasticulture systems, but was not significantly different when compared with the strip tillage system. Although there are many documented positive attributes of strip tillage, results from this study indicate that a combination of plasticulture and row cover may be a superior system for organic cucurbit production.

RNA interference is a powerful tool against corn rootworm. Adults and neonates of southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae), were exposed to the LC50 of vATPase-A and Snf7 double-stranded RNAs (dsRNAs), and the effects on female fecundity, egg viability, male fitness as measured by sperm viability and mating capacity, larval recovery along with dry weight, and instar determination 10 d after exposure to dsRNA, were determined. Significant reductions were observed for a number of parameters in dsRNA-exposed rootworms relative to control treatments. Female fecundity and larval recovery were significantly reduced after exposure to both dsRNAs. In addition, larval dry weight and recovery of 2nd and 3rd instars along with dry weight for 3rd instars were significantly reduced after neonate exposure to vATPase-A dsRNA. Neither dsRNA affected male capacity to mate or sperm viability after exposure to the respective LC50s. After 10 d of feeding on untreated corn roots, neonates that survived exposure for 2 d to the vATPase-A dsRNA LC50 exhibited lower dry weight than the control. There was significant gene knockdown in adult males and females after exposure for 5 d to LC50 of vATPase-A and Snf7 dsRNAs. The parameters are discussed in terms of fitness and possible outcomes after deployment of corn hybrids expressing dsRNAs.

Summary The coleopteran insect western corn rootworm (WCR, Diabrotica virgifera virgifera) is an economically important pest in North America and Europe. Transgenic corn plants producing Bacillus thuringiensis (Bt) insecticidal proteins have been useful against this devastating pest, but evolution of resistance has reduced their efficacy. Here, we report the discovery of a novel insecticidal protein, PIP‐47Aa, from an isolate of Pseudomonas mosselii. PIP‐47Aa sequence shows no shared motifs, domains or signatures with other known proteins. Recombinant PIP‐47Aa kills WCR, two other corn rootworm pests (Diabrotica barberi and Diabrotica undecimpunctata howardi) and two other beetle species (Diabrotica speciosa and Phyllotreta cruciferae), but it was not toxic to the spotted lady beetle (Coleomegilla maculata) or seven species of Lepidoptera and Hemiptera. Transgenic corn plants expressing PIP‐47Aa show significant protection from root damage by WCR. PIP‐47Aa kills a WCR strain resistant to mCry3A and does not share rootworm midgut binding sites with mCry3A or AfIP‐1A/1B from Alcaligenes that acts like Cry34Ab1/Cry35Ab1. Our results indicate that PIP‐47Aa is a novel insecticidal protein for controlling the corn rootworm pests.

BACKGROUND High tunnels are a season extension tool creating a hybrid of field and greenhouse growing conditions. High tunnels have recently increased in the USA and thus research on their management is lacking. One purported advantage of these structures is protection from common field pests, but evidence to support this claim is lacking. We compared insect pest populations in high tunnels with field production over two years for three crops: tomato, broccoli and cucumber. RESULTS Greenhouse pests (e.g. aphids, whiteflies) were more prevalent in high tunnels, compared to field plots. Hornworms (tobacco (Manduca sexta L.) and tomato (M. quinquemaculata Haworth)), a common field pest on tomato, were also more abundant in high tunnels, requiring chemical control while field populations were low. The crucifer caterpillar complex (imported cabbageworm (Pieris rapae L.), diamondback moth (Plutella xylostella L.) and cabbage looper (Trichoplusia ni Hubner)) was also more abundant in high tunnels in 2010. Cucumber beetle (striped (Acalymma vittatum F.) and spotted (Diabrotica undecimpunctata Mannerheim)) densities were higher in high tunnels in 2010 and field plots in 2011. CONCLUSION The common assumption that high tunnels offer protection from field pests was not supported. Instead, high tunnel growing conditions may facilitate higher pest populations. © 2017 Society of Chemical Industry

The purpose of this work is the synthesis and pesticidal activity testing of 9-aryl-N-aryl, alkyl-substituted 1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione derivatives which could become the basis of plant protection products. The substances investigated were obtained by three-component heterocyclization of primary amines with aromatic aldehydes and dimedone. The synthesized compounds were tested for certain types of insecticide (against toxoptera graminum, musca domestica, meloidogyne incognita, heliothis virescens, diabrotica undecimpunctata howardi, caenorhabditis elegans), fungicidal (against drechslera, erysiphe, puccinia, peronospora) and herbicidal (against amaranthus retroflexus, brassica rapa, abutilon theophrasti, alopecurus myosuroides , avena fatua, echinochloa crus galli) activities. All synthesized compounds have shown promising insecticidal activities against toxoptera graminum. 9-(4-methoxyphenyl)-, N-2-phenylethyl-substituted, 9-(3,4-methoxyphenyl)-, N-2-carboxyethyl-substituted and 9-(2-hydroxyphenyl)-N-octyl-substituted derivatives have shown significant herbicidal activities against amaranthus retroflexus. 9-phenyl-N-methyl-substituted derivative was active against amaranthus retroflexus, brassica rapa, and abutilon theophrasti. Only this compound showed antifungal activity against drechslera.

Quantitative reverse transcription PCR (RT-qPCR) is one of the most efficient, reliable and widely used techniques to quantify gene expression. In this study, we evaluated the performance of six southern corn rootworm, Diabrotica undecimpunctata howardi (Barber), housekeeping genes (HKG), β-actin (Actin), β-tubulin (Tubulin), elongation factor 1 alpha (EF1α), glyceraldehyde-3 phosphate dehydrogenase (GAPDH), 40 S ribosomal protein S9 (RpS9) and ubiquitin-conjugating protein (Ubi), under different experimental conditions such as developmental stage, exposure of neonate and adults to dsRNA, exposure of adults to different temperatures, different 3rd instar larva tissues, and neonate starvation. The HKGs were analyzed with four algorithms, including geNorm, NormFinder, BestKeeper, and delta-CT. Although the six HKGs showed a relatively stable expression pattern among different treatments, some variability was observed. Among the six genes, EF1α exhibited the lowest Ct values for all treatments while Ubi exhibited the highest. Among life stages and across treatments, Ubi exhibited the least stable expression pattern. GAPDH, Actin, and EF1α were among the most stable HKGs in the majority of the treatments. This research provides HKG for accurate normalization of RT-qPCR data in the southern corn rootworm. Furthermore, this information can contribute to future genomic and functional genomic research in Diabrotica species.

Erwinia tracheiphila, the causal agent of bacterial wilt of cucurbits, is transmitted by striped (Acalymma vittatum) and spotted (Diabrotica undecimpunctata howardi) cucumber beetles. Transmission occurs when infested frass with E. tracheiphila is deposited on plant surfaces with fresh feeding wounds. However, it is unclear whether the pathogen can survive as an epiphyte on leaves. Experiments were conducted in controlled environments to monitor E. tracheiphila survival on muskmelon (Cucumis melo) leaves under various temperature and moisture conditions. In the first experiment, muskmelon seedlings that had been spray inoculated with a rifampicin-resistant strain of E. tracheiphila were incubated at 10, 15, 20, 25, 30, or 35°C (±2°C) at ≥95% relative humidity, and E. tracheiphila populations were monitored for 72 h. In the second experiment, E. tracheiphila was monitored during alternating 12-h wet and dry periods, or continuous wet or dry conditions for 48 h at 20°C. Survival of E. tracheiphila on wet muskmelon leaves depended on temperature (P < 0.01), with the greatest survival at 10 and 15°C and least at 30 and 35°C. Leaf wetness also impacted survival; an initial 12-h dry period resulted in a 1,000- to 10,000-fold reduction in population size, followed by stabilization of the surviving population. These results demonstrate that E. tracheiphila can survive on muskmelon leaves under a wide range of environmental conditions, suggesting that epiphytic populations might serve as a reservoir of inoculum for infections.

Bacterial wilt, caused by Erwinia tracheiphila, is a major disease of cucurbit crops in the United States. Management of the disease relies on controlling two vector species, striped (Acalymma vittatum) and spotted (Diabrotica undecimpunctata) cucumber beetles. Six field trials were conducted at Iowa State University research farms during 2007, 2008, and 2009 to assess the efficacy of delayed removal of spunbond polypropylene row covers to control bacterial wilt on muskmelon (Cucumis melo). Treatments were (i) row cover removed at anthesis (conventional timing of removal), (ii) covers removed 10 days after row cover ends were opened at anthesis, (iii) covers removed 10 days after bumble bee hives were inserted under row covers at anthesis, and (iv) a noncovered control. In two field trials during 2007 and 2008, the delayed-removal row-cover treatments significantly suppressed bacterial wilt throughout the growing season and enhanced yield compared with the noncovered and removal-at-anthesis controls. In Gilbert in 2008, however, bacterial wilt suppression was equivalent among all three row-cover treatments. No bacterial wilt was observed during three trials in 2009, and there was minimal difference in marketable yield among treatments. Net returns were compared using partial budget and sensitivity analyses. Melon prices and occurrence of bacterial wilt had a strong impact on net returns. Using row covers increased production costs by 45%. In site years in which bacterial wilt occurred, delaying removal of row covers resulted in the highest returns. When bacterial wilt was absent, however, the delayed-removal row-cover treatments had the lowest returns. Results of the sensitivity analysis indicated that delaying removal of row covers for 10 days could be a cost-effective component of an integrated bacterial wilt suppression strategy for muskmelon where bacterial wilt occurs ≥50% of production seasons.

Benzyl acetone (4-phenylbutan-2-one; BA), the dominant floral fragrance of the wild tobacco Nicotiana attenuata, is known to attract night-time pollinators, such as Manduca sexta hawkmoths. For this pollinator, BA is not only essential for the pollen transport between conspecific plants, but also for the moth’s short-distance handling of flowers at night. The emission of BA from the corolla limb, however, starts up to 4 hr before dusk, peaks at dusk and continues throughout the first half of the night. While the function of the nocturnal part of the emission is well studied, the function of the early part of the peak emission remained unknown. By using plants silenced in the expression of the biosynthetic gene of BA (Nachal1), we investigated the function of this early peak emission of BA in the plants´ native habitat in Southwestern Utah. By emitting BA before dusk, N. attenuata is able to prevent the establishment and resulting floral damage by a florivore, the cucumber beetle (Diabrotica undecimpunctata). Plants lacking BA emissions (CHAL) were not only more often colonized by florivores, but also suffered significantly more damage, than control empty vector plants (EV). Choice assays revealed that D. undecimpunctata feeding required the absence of BA. While feeding damage to CHAL flowers was higher than to EV flowers in the early night hours, the effect disappeared during the second half of the night, when flowers stop emitting BA. The close proximity of BA-emitting flowers to non-emitting CHAL flowers prevented D. undecimpunctata feeding. In the field, the emission of BA at dusk was sufficient to protect plants for the entire night, as beetles search for new hosts during the early evening hours and remain for the duration of the night, once a host is chosen. Floral BA emission before dusk may have evolved as a consequence of antagonistic interactions with florivores. A single floral volatile can thus simultaneously function as an important floral attractant for pollinators and as effective feeding deterrent against florivores in the same plant species. A plain language summary is available for this article.

Spotted (Diabrotica undecimpunctata howardi) and striped (Acalymma vittata) cucumber beetles are significant pests of cucurbits, and organic management options are limited. Beetle feeding results in aesthetic damage and reduction in marketable yields as well as transmission of bacterial wilt resulting in plant mortality. Biopesticides are formulated from naturally occurring organisms such as fungi and bacteria that are pathogenic or toxic to insect pests and may be used in organic production systems. These products are thought to have lower risk to non-target organisms including mammals and beneficial insects. This research examined the potential of novel microbial products and fungal organisms to reduce cucumber beetle damage on melons. Laboratory bioassays were performed to evaluate the efficacy of a bacterial extract of Chromobacterium subtsugae and two common strains of entomopathogenic fungi, Beauveria bassiana and Isaria fumosorosea, on cucumber beetles in a controlled environment. Trials were performed against adult beetles in organic field experiments on muskmelon (Cucumis melo L. cv. reticulatus Ser.). Prior to testing in the field, anti-feedant effects were observed when beetles were exposed to leaves with Chromobacterium subtsugae and Beauveria bassiana in the laboratory. However, in field applications, we did not observe a reduction in beetle populations below the economic threshold levels, and subsequently, there was no yield increase compared to the control. Additional research is needed to improve biopesticide efficacy through formulation and timing of delivery, determine efficacy on multiple life stages of the pest, and understand interactions of microbial biopesticides in the environment and potential for non-target impacts in organic systems.

The southern corn rootworm, Diabrotica undecimpunctata howardi Barber, can be a serious pest of peanut (Arachis hypogaea L.) pods. A laboratory bioassay was developed to test feeding cysteine proteinase inhibitors soyacystatin N (scN) and E-64 against southern corn rootworm reared on artificial diet to determine the effects on larval development and mortality. Soyacystatin N increased mortality of larvae and decreased larval development as measured by live weights at 4 and 7 d. Seven d weight gain for larvae in the control increased by 66%, while the 0.5, 1.0 and 2.0 mg/ml doses decreased by 50, 42, and 79%, respectively. The proteinase inhibitor proved to be a good candidate as a means of host-plant resistance for reducing larval development and increasing the chance to interrupt metabolism and increased mortality. E-64 also demonstrated significant larval mortality and decreased weight gain when fed through artificial diet. At 7 d, after feeding on the 0.50, 1.0, and 2.0 mg/ml doses, larval we...

Twelve field trials were completed in North Carolina from 2005 to 2007 to determine the impact of planting pattern on peanut yield, market grade characteristics, and pest reaction for the Virginia market type cultivars Perry and VA 98R. The first set of experiments was designed to evaluate incidence of Cylindrocladium black rot (caused by Cylindrocladium parasiticum) using a factorial treatment arrangement of two cultivars, two levels of fumigation (none or metam sodium at 112 L/ha), and two levels of planting pattern (single rows spaced 91-cm apart or twin rows spaced 18 cm apart on 91-cm centers). Visible symptoms associated with Cylindrocladium black rot were not affected by planting pattern. However, in 1 of 3 trials pod scarring as a result of feeding by southern corn rootworm (Diabrotica undecimpunctata Howardi) was greater in twin rows compared with single rows. Damage from tobacco thrips (Frankliniella fusca) was also higher in the cultivar VA 98R planted in twin rows than in single rows or for the cultivar Perry. In the second set of experiments designed to evaluate incidence of Sclerotinia blight (caused by Sclerotinia minor), a factorial treatment arrangement consisting of two cultivars, two levels of boscalid (none or boscalid at 0.44 kg ai/ha), and two levels of planting pattern was implemented. Boscalid decreased Sclerotinia blight incidence at one of 4 locations, and increased pod yield. Yield of Perry was lower when grown in twin rows versus single rows, but yield of VA 98R was higher in twin rows. Peanut planted in twin rows yielded more than peanut planted in single rows regardless of cultivar, fumigation, or disease history in most trials. Results from these experiments suggest that planting pattern can have a minor impact on response to pests and that yield and market grades are often improved when peanut is planted in twin-row planting patterns compared with single rows.

Cucurbit crops are attacked by a pest complex that threatens production via direct feeding and disease transmission. The goals of this study were to quantify the amount of biocontrol service supplied to pumpkin fields and determine if this was affected by local habitat management or the surrounding landscape. Using sentinel eggs, we measured predation of squash bug, Anasa tristis , and spotted cucumber beetle, Diabrotica undecimpunctata howardi , by generalist predators. We found that predators significantly removed D. undecimpunctata howardi but not A. tristis eggs. The guild of predators found to attack D. undecimpunctata howardi included Araneae, Carabidae, Cricetidae, Entomobryidae, Formicidae, Gryllidae and Opiliones. A smaller, but overlapping guild of predators was found to attack A. tristis , which included Araneae, Cricetidae, Formicidae and Gryllidae. Formicidae was consistently the dominate predator of both pest species. We examined how the addition of either a non-native annual plant insectary of sweet alyssum, Lobularia maritima , or a diverse insectary planted with native perennial forbs and grasses influenced predator abundance, composition, or biocontrol services relative to a grass control. We found no difference in either the predator community feeding on pest eggs or the proportion of eggs that they removed from adjacent pumpkin fields. Larger-scale landscape composition did influence the amount of egg predation occurring in pumpkin agroecosystems, however, these relationships varied among pests and across years of the study. Biological control is commonly predicted to increase with landscape diversity and the amount of non-crop habitat present surrounding focal fields, yet we found that when landscape did influence egg predation it was agricultural landscapes supporting the highest egg removal. This study illustrates that patterns relating landscape and localized habitat management to crop pest predation are not constants, they can vary among years within a crop as well as among agricultural cropping systems.

Virginia market type peanut (Arachis hypogaeaL.) cultivars are grown primarily in North Carolina, South Carolina, and Virginia in the US, although growers in these states often plant other market types if marketing opportunities are available. Information on yield potential and management strategies comparing these market types is limited in North Carolina. In separate experiments, research was conducted to determine response of runner, Spanish, and Virginia market types to calcium sulfate and inoculation withBradyrhizobiumat planting, planting and digging dates, planting patterns, and seeding rates. In other experiments, control of thrips (Frankliniellaspp.) using aldicarb, southern corn rootworm (Diabrotica undecimpunctataHowardi) using chlorpyrifos, eclipta (Eclipta prostrataL.) using threshold-based postemergence herbicides, and leaf spot disease (caused by the fungiCercospora arachidicolaandCercosporidium personatum) fungicide programs was compared in these market types. Results showed that management practice and market types interacted for peanut pod yield in only the planting date experiment. Yield of runner and Virginia market types was similar and exceeded yield of the Spanish market type in most experiments.

Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract and kill” strategy is one of the powerful ways to control pest population. To address our key objective of the practical utility of the synthetic pheromone, we have developed a simple synthetic strategy to produce gram scale southern corn rootworm pheromone in nine simple steps starting from S-Citronellol. The present strategy takes advantage of the existing chiral center of commercially available S-Citronellol. To get the basic carbon skeleton of the pheromone, the main step in the synthetic strategy is coupling of aliphatic units through Wittig reaction. The phosphonium salt from a non-functionalized aliphatic bromide followed by Wittig reaction improved the overall yield in the multistep synthesis of this pheromone. The large-scale production of pheromone enabled us to test it in the field.

As high tunnel vegetable production acreage increases in the United States, so does the need for management strategies tailored to their unique growing environment. Cucumbers are an ideal crop in these systems; they can be vertically trellised to maximize the production area and provide high yields to balance the increased costs associated with high tunnel construction. One of the most limiting factors in cucurbit production in general is the cucumber beetle complex and the bacterial pathogen they transmit. In this study, we investigated the optimal size of netting installed on high tunnels to prevent cucumber beetle colonization while maintaining ventilation to reduce heat stress. Of the three mesh sizes investigated across 4 yr, the intermediate mesh with a pore size of 0.72 × 0.97 mm was optimal to exclude cucumber beetles, maintain ventilation, and produce the highest yields for both cucumber and melon plants. The smallest (0.16 mm2) and intermediate mesh sizes resulted in secondary pest outbreaks (e.g., aphids), which did not occur in open tunnels and to a lesser extent in tunnels covered with the largest (1.00 × 4.00 mm) mesh. Despite these secondary pests, yield was higher in small- and intermediate-sized mesh treatments due to relief from cucumber beetle infestations, including striped (Acalymma vittatum Fabr. (Coleoptera: Chrysomelidae)) and spotted (Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae)) beetles. Overall, we conclude that insect exclusion netting is an effective method to exclude cucumber beetles from high tunnels, but mesh size should be carefully considered when weighing the collective effects on yield and primary/secondary pest abundance.

The southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae), was exposed over multiple generations to vacuolar (v)ATPase-A double-stranded (ds)RNA, first as adults and later, as neonate larvae. During adult selection, high mortality and lower fecundity were observed in the RNAi-selected cages after beetles were exposed to sublethal dsRNA concentrations that varied between LC40 and LC75. During larval selection, a delay in adult emergence and effects on population growth parameters were observed after neonates were exposed to sublethal dsRNA concentrations that varied between LC50 and LC70. Some of the parameters measured for adult emergence such as time to reach maximum linear adult emergence, time elapsed before attaining linear emergence, termination point of the linear emergence, and total days of linear emergence increase, were significantly different between RNAi-selected and control colonies for at least one generation. Significant differences were also observed in population growth parameters such as growth rate, net reproductive rate, doubling time, and generation time. After seven generations of selection, there was no indication that resistance evolved. The sublethal effects caused by exposures of southern corn rootworm to dsRNAs can affect important life history traits and fitness especially through delays in adult emergence and reduction in population growth. Although changes in susceptibility did not occur, the observation of sublethal effects suggests important responses to potential selection pressure. Assuming resistance involves a recessive trait, random mating between susceptible and resistant individuals is an important factor that allows sustainable use of transgenic plants, and delays in adult emergence observed in our studies could potentially compromise this assumption.

Con la finalidad de determinar los principales fitófagos que ocurren en el pajuro (Eryhrina edulis Triana Ex. Micheli 1892), a lo largo de todo el año, se evaluaron plantas aisladas y de cercos vivos del valle de Cajamarca, encontrándose como fitófagos a: Diabrotica undecimpunctata, Liriomyza sp. Aphis fabae y Empoasca sp; los mismos que presentan poblaciones muy bajas que no pueden catalogarse como plagas peligrosas pero si como plagas potenciales que en el futuro podrían ocasionar problemas si se incentiva el cultivo del pajuro en forma intensiva. Esto coincide con muchos autores que indican que el pajuro es una planta muy rústica. También se pudo observar que el pajuro es un cultivo marginal caracterizado por la presencia de plantas aisladas y en raras ocasiones integrando cercos vivos con varios individuos. La producción por planta oscila entre 20 a 30 kg y los granos solo son consumidos cocidos por las personas.No utilizan el follaje como forraje para animales domésticos.

Despite the fact that synthetic insecticides are fast acting, they constitute environmental hazard thereby necessitating the use of ecologically based alternative such as plant based insecticide. This experiment was conducted during the late and early planting seasons of 2011 to determine the insecticidal efficacy of Tephrosia vogelii and Moringa oleifera extracts at three tested concentrations (5, 10 and 20% v/v) against insect pests of watermelon. The experiment was set up in a randomized complete block design with three replicates. The results showed that M. oleifera extracts had 62% reduction of Phyllotreta cruciferae compared with T. vogelii which had 45% control. However, T. vogelii extracts had 64% control of Diabrotica undecimpunctata and Bactrocera curcubitea but M. olefera extracts had 50% control. The plant extracts proved effective against studied insects when compared with untreated plots. However, the effectiveness of the two plants extracts were concentration dependent. Therefore, the two plant extracts can be used in the control of insect pests of the watermelon

Predators can limit prey abundance and/or levels of activity. The magnitudes of these effects are contingent on predator and prey traits that may change with environmental conditions. Aberrant thermal regimes could disrupt pest suppression through asymmetric effects, e.g. heat-sensitive predator vs. heat-tolerant prey. To explore potential effects of warming on suppressing pests and controlling herbivory in a vegetable crop, we performed laboratory experiments exposing an important pest species to two spider predator species at different temperatures. Heat tolerance was characterised by the critical thermal maxima parameter (CTM50) of the cucumber beetle (Diabrotica undecimpunctata), wolf spider (Tigrosa helluo), and nursery web spider (Pisaurina mira). Cucumber beetles and wolf spiders were equally heat tolerant (CTM50 > 40 °C), but nursery web spiders had limited heat tolerance (CTM50 = 34 °C). Inside mesocosms, beetle feeding increased with temperature, wolf spiders were always effective predators, nursery web spiders were less lethal at high temperature (38 °C). Neither spider species reduced herbivory at ambient temperature (22 °C), however, at warm temperature both species reduced herbivory with evidence of a dominant non-consumptive effect. Our experiments highlight the contingent nature of predator-prey interactions and suggest that non-consumptive effects should not be ignored when assessing the impact of temperature change.

Nitrogen fixation, nodulation, and organ dry weights of soybean infested with the larvae of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, were estimated under controlled conditions. Larval southern com rootworm reduced the nitrogen-fixing activity of mid-vegetative and early reproductive soybean, Glycine max Merrill. Soybean of both stages responded to the infestation and subsequent injury by increasing nodulation and organ dry weights of below-ground tissues relative to above-ground tissues. Infestation increased the dry weight of small nodules on vegetative plants and caused a 78.6% increase in the total number of nodules on R5 plants. Leaf area as well as leaf and stem dry weight was reduced in vegetative plants by infestation.

The Rag1 gene confers antibiotic resistance to soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and in 2010, varieties expressing Rag1 were released for commercial use in the United States. We do not know how Rag1 varieties will influence the broader community of defoliating insects that inhabit soybean fields. In 2010 and 2011, the preference and performance of pest insects that defoliate soybeans [Glycines max (L.) Merr] were tested using Rag1 and aphid-susceptible varieties. Three coleopterans and four lepidopterans were used: northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae); southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae); bean leaf beetle, Ceratoma trsifurcata Forster (Coleoptera: Chrysomelidae); fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae); corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae); soybean looper, Chrysodeix includens (Walker) (Lepidoptera: Noctuidae); and velvet-bean caterpillar, Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae). The preference of insects was evaluated in choice and no-choice tests using Rag1 and susceptible soybeans. Lepidopterans also were evaluated on Rag1 leaves using four nutritional indices: relative growth rate, approximate digestibility, and efficiency of conversion of ingested material. In the majority of preference tests, no effect of Rag1 was detected, and in cases where preferences were found, there was no consistent pattern of preference for Rag1 vs. susceptible leaf tissue. Helicoverpa zea demonstrated a preference for resistant leaf tissue, but this was dependent on the genetic background of the variety. Evaluations of nutritional indices indicated that three species of Lepidoptera, S. frugiperda, H. zea, and A. gemmatalis, displayed reduced conversion efficiency for Rag1 soybeans, suggesting effects of antibiosis.

Zucchini, Cucurbita pepo L., is often colonized by economically important insect pests such as the striped ( Acalymma vittatum Fab.) and spotted ( Diabrotica undecimpunctata howardi Barber) cucumber beetles. To evaluate the impact of an interplanted cover crop on arthropods associated with zucchini, field experiments were conducted in which sunn hemp ( Crotalaria juncea L.) was interplanted with zucchini as a living mulch and compared with zucchini monoculture (bare-ground) during 2009, 2010 and 2011 growing seasons. The experiment consisted also of two types of fertilizer usage including the application of synthetic or organic fertilizer in the form of chicken manure. Foliar counts of arthropods conducted on zucchini plants showed significantly lower numbers of the striped cucumber beetle in sunn hemp interplanted plots compared to bare-ground treatment plots. Also, fewer spotted cucumber beetles were found on zucchini plants in sunn hemp plots. Aphid abundances were variable during the study and significantly lower in sunn hemp treatment plots at one study site in 2009. Among predators, spiders were significantly more abundant in sunn hemp treatment plots during 2009. Fertilizer type did not have a significant effect on arthropod numbers on zucchini plants. Potential causes of arthropod population differences among the two treatments are discussed.

An insectary mixture of flowering annuals suitable for use in the high desert irrigated agriculture of New Mexico was developed over 3 years using pumpkins, Cucurbita moschata L., as a model cropping system. Plant establishment, survival, and flowering phenology were assessed in both clay and sandy soils by using weekly quadrat samples. Abundance of beneficial insects and spotted cucumber beetle, Diabrotica undecimpunctata howardi Barber, were monitored with yellow sticky cards (Trece Inc., Adair, OK). Abundance of squash bug, Anasa tristis (DeGeer), was monitored weekly by sampling eggs and nymphs. Establishment of the flowering mixture was significantly better in clay than sandy soils in each of the 3 years. Of the fifteen plant species tested, California bluebell (Phacelia campanularia A. Gray), buckwheat (Fagopyrum esculentum Moench), dill (Anethum graveolens L.), Plains coreopsis (Coreopsis tinctoria Nuttall), garden cosmos (Cosmos bipinnatus Cavanilles), and sweet alyssum (Lobularia maritim...

The ability of the biomass crop Miscanthus (Miscanthus × giganteus Greef and Deuter ex Hodkinson and Renvoize) to support larval development for both United States and European populations of the western corn rootworm, Diabrotica virgifera virgifera LeConte, suggests an avenue for interactions with corn (Zea mays L.). To provide context to survival of D. v. virgifera on Miscanthus, adult activity and oviposition of Diabrotica spp. were monitored in central Illinois in 2010–2011 in Miscanthus, corn and switchgrass (Panicum virgatum L.). For D. v. virgifera, vial traps within corn plots captured 3–10 times as many adults as in Miscanthus or switchgrass, while soil samples showed females laid approximately 10 times as many eggs in corn as in the perennial grasses. Adult southern corn rootworms, Diabrotica undecimpunctata howardi Barber, were the most abundant species in 2010 and clearly preferred switchgrass as an adult habitat, with vial traps in switchgrass capturing 5–10 times as many D. u. howardi as those in corn or Miscanthus. Based on the small production areas for Miscanthus and switchgrass (and low use of both by D. v. virgifera), it seems likely that there are no current impacts of these perennial grasses on pest status of Diabrotica spp. in corn or other crops. However, adaptations by Diabrotica spp. to pest management practices suggest they could be a source for interactions between biomass and food or feed crops. Early-season soil samples did not recover eggs of D. u. howardi, but their use of switchgrass as an adult habitat suggests additional research in areas where switchgrass may be grown near peanuts, alfalfa or other hosts may be needed. Also, investigation of other candidate bioenergy crops known to support Diabrotica spp. larval development is needed to better understand the possible effects of a changing agricultural landscape on corn rootworms.

Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above- and below ground. The transformation, which resulted in the constitutive emission of (E)-β-caryophyllene and α-humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an (E)-β-caryophyllene-synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted (E)-β-caryophyllene and α-humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies.

We tabulated plant species that served as floral hosts of adult beetles as reported by Charles Robertson in his 33-yr data set of flower-visiting insects of central Illinois. Robertson listed 153 species of beetles (28 families) that visited 141 species of plants (44 families), most of which were in the Asteraceae. The most common beetle species were the cantharid Chauliognathus pennsylvanicus (De Geer), the chrysomelid Diabrotica undecimpunctata Mannerheim, and the scarab Trichiotinus piger (F.). Most of the beetle species (81%) were observed on five or fewer plant species. In general, non-native plant species were associated with fewer beetle species than were native plant species. Nevertheless, plant species that had the greatest diversity of beetle visitors were the non-native umbellifer Pastinaca sativa L. and the native rose Aruncus dioicus (Walter) Fernald variety vulgaris (Maxim). These findings may find application in guiding research on insect ecology and behavior, for selecting plant species in ornamental landscapes that will foster populations of native beetle species, and for identifying plant species that may be used in agricultural settings to improve pollination or biological control services.

While many studies have characterized changes to the transcriptome of plants attacked by shoot-eating insect pests, few have examined transcriptome-level effects of root pests. Maize (Zea mays) seedlings were subjected to infestation for approximately 2 weeks by the root herbivore southern corn rootworm (SCR) Diabrotica undecimpunctata howardi, and changes in transcript abundance within both roots and shoots were analyzed using a 57K element microarray. A total of 541 genes showed statistically significant changes in transcript abundance in infested roots, including genes encoding many pathogenesis-related proteins such as chitinases, proteinase inhibitors, peroxidases and β-1,3-glucanases. Several WRKY transcription factors – often associated with biotic responses – exhibited increased transcript abundance upon SCR feeding. Differentially expressed (DE) genes were also detected in shoots of infested vs control plants. Quantitative Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) was used to confirm patterns of transcript abundance for several significant DE genes using an independent experiment with a 2–6 day period of SCR infestation. Because of the well-documented roles that jasmonic acid (JA) or salicylic acid (SA) play in herbivory responses, the effect of exogenous JA or SA application on transcript abundance corresponding to the same subset of SCR-responsive genes was assessed. The response of these genes at the level of transcript abundance to SA and JA differed between roots and shoots and also differed among the genes that were examined. These data suggested that SA- and JA-dependent and independent signals contributed to the transcriptome-level changes in maize roots and shoots in response to SCR infestation.

The bitter plant-derived compounds cucurbitacins are known to stimulate feeding of adult cucumber beetles (Coleoptera: Chrysomelidae). A cucurbitacin-based gustatory stimulant applied as a flowable bait combined with either spinosad or carbaryl was compared with foliar sprays of spinosad and carbaryl for controlling two cucumber beetle species (Diabrotica undecimpunctata undecimpunctata Mannerheim and Acalymma trivittatum Mannerheim) in honeydew melons (Cucumis melo L.). Field studies were conducted on the University of California-Davis plant pathology farm in 2008 and 2009. Beetle densities after applications and fruit damage from beetle feeding were compared among treatments. In addition, beetle survival was compared within field cages placed over the treated foliage infested with beetles. Using all three measures of efficacy, we determined that the addition of cucurbitacin bait had no effect on the level of cucumber beetle control with carbaryl in either 2008 or 2009. In both years, spinosad did not significantly reduce cucumber beetle densities in either field cages or field plots and did not reduce fruit damage relative to the untreated control. The addition of the bait to spinosad did not improve its efficacy. A laboratory bioassay of the spinosad formulation used in the field showed it had significant lethal effects on adults of both cucumber beetle species. Results indicated that the bait formulation used did not improve cucumber beetle control but may benefit from the addition of floral attractants or using a different type of cucurbitacin.

The western spotted cucumber beetle, Diabrotica undecimpunctata undecimpunctata Mannerheim, is an important pest of melons (Cucurmis melo L.) in northern California. Recent observations indicate that adults are using alfalfa (Medicago sativa L.) as a feeding host and larvae may be developing on the roots. Greenhouse studies were conducted during the winters of 2009 and 2010 in which larval development was compared on the roots of six field and vegetable crops commonly grown in the southern Sacramento Valley. The growth parameters used to evaluate the hosts were larval and pupal head capsule width, body width, and body length as well as total survival percentage and survival percentage to the third instar. According to larval growth and survivorship in 2009, maize (Zea mays L.) was the best host, followed by alfalfa and tomato (Solanum lycopersicum L.) that were roughly equivalent to one another. Melon was a slightly weaker host than alfalfa and tomato; sunflower (Helianthus annuus L.) was a completely incompatible host and thus dropped from the 2010 study. In 2010, melon was the weakest host for larval development. Maize was the superior host again followed closely by alfalfa that performed slightly better than tomato and lima bean (Phaseolus lunatus L.). Data suggest that larval western spotted cucumber beetles may primarily develop outside of melon fields and the adults emigrate to melons.

Cowpea chlorotic mottle virus (CCMV) is a bromovirus transmitted by species of chrysomelid beetles, including the spotted cucumber beetle, Diabrotica undecimpunctata howardii Barber. An experimental system was set up to identify the viral determinant(s) of the beetle transmission of CCMV. Nicotiana clevelandii was selected as an experimental plant host because it supports the replication and accumulation of both CCMV and a second member of the family Bromoviridae, cucumber mosaic virus (CMV). Using a reverse genetic system for CMV, a cDNA copy of the CCMV capsid protein (CP) gene was substituted for that of the CMV CP gene. The resulting 'CMV-hybrid' consisted of wild-type CMV RNA1, RNA2, and a chimeric CMV RNA3 expressing the CCMV structural protein. The CMV-hybrid replicated and formed virions in N. clevelandii; in electron micrographs the hybrid virus was indistinguishable from CCMV. In beetle feeding assays, both CCMV and the CMV-hybrid were transmitted by D. undecimpunctata, while beetle transmission of CMV was not observed. Conversely, only CMV was observed to be transmitted by the aphid Myzus persicae. Surprisingly, the CMV-hybrid was transmitted more efficiently than the parental CCMV, and a virus-induced alteration in beetle feeding behaviour is proposed to account for the difference. These results indicate that the CCMV CP is a viral determinant for beetle vector transmission.

Aggregation behavior of adult western spotted cucumber beetles (Diabrotica undecimpunctata undecimpunctata Mannerheim) (Coleoptera: Chrysomelidae) was examined in six snap bean (Phaseolus vulgaris) fields adjacent to corn fields in western Oregon in 2004-2006. In the 2004 and 2005 studies, sweep net sampling was used to estimate beetle numbers along transect lines running perpendicular to the edges of the bean fields next to sweet corn fields. Beetles were collected from the fields and dissected to determine sex and egg development. Beetles were highly aggregated along the edge of the snap bean field next to the sweet corn, with the highest number of beetles occurring within the first meter next to the edge. Beetles in the aggregation areas were mostly females (average female to male ratio of 8.4 to 1), whereas beetles in the field section away from the edges were mostly male (female to male ratio of 0.6 to 1). Of the females collected in the aggregation areas, an average of 53% contained developing or fully developed eggs. In the 2006 study, beetle densities in the field edges were compared with densities within the fields in 40 bean fields with adjacent corn fields. Linear regression analysis showed that, across fields, nearly two times as many beetles were found in the field borders as in the rest of the field. These data suggest modifying traditional field scouting protocol to include field margins when a bean field is adjacent to or near a sweet corn field. A pest management strategy of only spraying the edges of bean fields containing beetle aggregations shows potential for significant pesticide reduction, as well as reducing risk of economic loss from crops harvested from the highly aggregated areas.

Organic methods for managing striped cucumber beetles (Acalymma vittatum) and spotted (Diabrotica undecimpunctata) cucumber beetles were examined in the production of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) using sticky traps to monitor beetle populations. In 2002, the numbers of trapped striped and total (striped + spotted) cucumber beetles were significantly (P ≤ 0.05) reduced by the combined use of three companion plants thought to repel cucumber beetles [radish (Raphanus sativus), tansy (Tanacetum vulgare), and nasturtium (Tropaeolum spp.)] or by the combined use of three companion plants known to attract beneficial insects [buckwheat (Fagopyrum esculentum), cowpeas (Vigna unguiculata), and sweetclover (Melilotus officinalis)]. In 2003 and 2004, the single companion plant treatment consisted of the combined use of radish and buckwheat. In 2003, use of aluminum-coated plastic mulch (Al-plastic) or companion plants significantly increased muskmelon yields and vine cover, while significantly reducing numbers of trapped striped, spotted, and total cucumber beetles. The use of pyrethrin insecticide did not significantly affect muskmelon yields or vine cover. In 2004, the beneficial effects of companion plant and Al-plastic treatments on muskmelon yields and vine cover were also significant and similar to those in 2003; however, these treatments only affected early season numbers of trapped beetles. The use of rowcovers significantly increased muskmelon yields and vine cover in 2003 and 2004 and did not affect beetle populations after rowcover removal. It was concluded that use of companion plants and Al-plastic increased muskmelon yields and vine cover while reducing populations of cucumber beetles, particularly striped cucumber beetles. The use of rowcovers also increased muskmelon yields and vine cover.

Production of sweetpotatoes, Ipomoea batatas (L.) Lam. (Convolvulaceae), is limited by several insect pests, including Diabrotica spp. (Coleoptera: Chrysomelidae), and new integrated pest management (IPM) techniques for this crop are needed. Host plant resistance is one attractive approach that fits well into IPM programs. A host plant resistance research program typically depends on reliable bioassay procedures to streamline evaluation of germplasm. Thus, a bioassay technique was developed for evaluating sweetpotato germplasm by using adults of the banded cucumber beetle, Diabrotica balteata LeConte, and spotted cucumber beetle, Diabrotica undecimpunctata howardi Barber. A single beetle was placed on a piece of sweetpotato peel (periderm and cortex with stele removed) that was embedded periderm-side up in plaster in a petri dish. Feeding and longevity of insects on 30 sweetpotato genotypes were evaluated in two experiments by using this procedure. Adult longevity ranged from 7 to 11 d for starved individuals to 211 d for beetles fed a dry artificial diet. Longevity of banded cucumber beetles that fed on sweetpotato peels ranged from 12 d for the most-resistant genotype to 123 d for SC1149-19, a susceptible control cultivar. Longevity of spotted cucumber beetles was slightly shorter than longevity of banded cucumber beetles. For the most resistant sweetpotato genotypes, both Diabrotica species exhibited a significant delay in initiation of feeding, and more beetles died on these genotypes before they had fed. Both antibiosis and nonpreference (antixenosis) are important mechanisms of resistance in sweetpotato genotypes. This bioassay was consistent with field results, indicating that this technique could be useful for evaluating resistance to Diabrotica spp. in sweetpotato genotypes.

An experiment was conducted to determine the paternity of F1 progeny using morphological and molecular methods in Diabrotica (Coleoptera: Chrysomelidae) subspecies: Diabrotica undecimpunctata howardi Barber, also known as spotted cucumber beetle, and D. undecimpunctata undecimpunctata Mannerheim, also known as western cucumber spotted beetle. Results from crosses that involved the females of D. u. howardi and the males of D. u. undecimpunctata had all F1 progeny with phenotypes as the male parent. Similarly, in all the crosses that involved the females of D. u. undecimpunctata and the males of the D. u. howardi, all the F1 progeny had phenotypes as the male parent. DNA from females and males were amplified using two primers to confirm the paternity of F1 progeny. The study on the inheritance of body color in these two subspecies appeared to be governed by one dominant gene (monogenic), and it is the male that determines the body color of progeny in both subspecies.

Sexual dimorphism in basitarsal pad morphology is described for prothoracic and mesothoracic legs of Diabrotica virgifera virgifera LeConte, Diabrotica barberi Smith & Lawrence, and Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae) and for prothoracic legs of Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae). On the indicated legs of these diabroticite beetles, the typical structure of the hairy tarsal pads of chrysomelid beetles is replaced proximally on tarsomere 1 of males by a hairless planar ovoid patch that may facilitate maintenance of the mating posture of males upon the elytra of females. This basitarsal patch proved as reliable as the standard supra-anal plate character for establishing sex of these important crop pests.