Pepper Weevil Research Articles

Volatiles emitted by pepper weevil-infested plants and fruit strongly attract the pteromalid parasitoid Jaliscoa hunteri

Among the many ways arthropod pests may signal their whereabouts to natural enemies, the release of specific volatiles by either pests themselves or their infested host plants may represent some of the most valuable cues that dictate biocontrol agent host-attraction, trophic impact and host-specificity. In this study, we sought to elucidate how plant and insect host-specific volatiles mediate attraction of pteromalid wasp, Jaliscoa hunteri to immature pepper weevil, Anthonomus eugenii, an economically important and challenging-to-control pest of cultivated Capsicum sp. pepper crops across North America. To begin, we used an air-entrainment system to collect volatiles released by whole pepper plants infested or not by either egg, L1 or L3 stages of pepper weevil and in the presence or absence of parental adults. The chemical analysis of sample volatiles from pepper plants infested or not with A. eugenii larvae were then compared, and among these, five compounds were identified that had their emission increased from 1.5 to 8.1 times relative to the blend of volatiles emitted by undamaged pepper plants including: linalool, 1-hexanol, 4,8-dimethylnona-1,3,7-triene (DMNT), methyl salicylate, and 4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT). We next conducted Y olfactometer bioassays to compare the attractive potential of volatiles emitted by pepper fruit, infested or not by L1 or L3 immature pepper weevil, as well as by the alternative J. hunteri-rearing host, L3 or L4 immature Callosobruchus maculatus as they developed within infested chickpeas. Olfactometer bioassays showed that J. hunteri females preferred and consistently oriented towards the volatiles derived from pepper fruit infested by both larval stages of pepper weevil compared to the odour of undamaged pepper fruit. The females of J. hunteri also preferred for the odour emitted by chickpeas infested with C. maculatus compared to air. Ultimately this work highlights the considerable value of studying the composition of volatile headspace captures for pest-infested fruit and complimentary Y-tube assays for measuring or even improving the attraction potential of natural enemies to economically or ecologically important host species.

Characterization of the Spatial Distribution of the Pepper Weevil, Anthonomus eugenii Cano (Col.: Curculionidae), in Pepper Fields in South Florida.

The pepper weevil, Anthonomus eugenii Cano, is an economically important pest of cultivated peppers (Capsicum annuum) in tropical and subtropical regions of the world. This study aimed to ascertain the spatial distribution of pepper weevil infestation across various fields in Miami Dade County, South Florida. The spatio-temporal dynamics of pepper weevil were evaluated using 144 sample points within each of seven pepper fields. The data were analyzed using three different geospatial techniques, spatial analysis by distance indices (SADIE), Moran's I, and Geary's C, to determine the spatial distribution of pepper weevil. The SADIE analysis revealed a significant aggregation distribution in 18 out of 30 sampling dates across all fields. The results from Geary's C and Moran's I indices indicated a positive spatial autocorrelation (spatial clustering/aggregation) of pepper weevil regardless of field or pepper types. Overall, the findings from this study depict an aggregated spatial distribution pattern of pepper weevil populations, characterized by a tendency for aggregation that transitions to a more uniform distribution as the season progresses.

Influence of Parental Age on Reproductive Potential and Embryogenesis in the Pepper Weevil, Anthonomus eugenii (Cano) (Col.: Curculionidae).

The pepper weevil (Anthonomus eugenii Cano) is a devastating pest that inflicts severe damage to pepper crops, leading to substantial economic losses. This study investigated the impact of aging on the reproductive success of the pepper weevil. Pepper weevil-infested fruit were harvested from pepper fields and subsequently transferred into an insect cage to facilitate the emergence of adults. The emerged adults were housed in separate cages and allowed to mature until they reached specified ages: 10 days old (young), 20 days old (middle-aged), and 30 days old (old) individuals. Eggs laid by each age group were carefully collected and incubated under controlled laboratory conditions (28 ± 1.5 °C). Several reproductive variables including the number of eggs laid, the percentage of hatched eggs, and the egg incubation period were recorded for each age group. Embryonic development was also monitored daily using a VHX digital microscope at a magnification of 200×. Differences in developmental stages such as the blastoderm, germ band, gastrulation, segmentation, and appendage formation were observed, and the time span of every stage was recorded. The results show that the 10-day-old weevils laid the most eggs and had the highest hatching rate and the shortest developmental time. The 30-day-old weevils laid the fewest eggs and had the lowest hatching rate and longest developmental time. Thus, the pepper weevil age significantly influenced the fecundity, length of time for each embryonic development stage, hatching rate, and incubation period, and should be considered when studying the reproductive biology of this pest insect. This first report of the effect of aging on the reproductive potential of the pepper weevil should enable pepper growers to adopt cultural practices aimed at reducing the pepper weevil populations, thereby helping to protect their crop from this important pest.

How plant and insect host characteristics affect pepper weevil Anthonomus eugenii parasitism efficacy by the pteromalid Jaliscoa hunteri

The pepper weevil Anthonomus eugenii (Cano) (Coleoptera: Curculionidae) is an economically important pest of both field and greenhouse pepper crops, Capsicum annuum Linnaeus (Solanaceae) in North America. Among its natural enemies is the parasitoid wasp Jaliscoa (= Catolaccus) hunteri (Crawford) (Hymenoptera: Pteromalidae), whose potential control of A. eugenii appears promising but is currently unclear. We conducted controlled environment trials to quantify A. eugenii offspring emergence following exposure to J. hunteri, examining how parasitoid exposure period, weevil host life stage, pepper cultivar, fruit size and abscission status affect weevil-natural enemy dynamics. In pepper cultivar comparison trials, we identified a significant reduction in weevil offspring emergence from three different cultivars of ornamental peppers infested by A. eugenii, but no difference among them. In trials comparing wasp exposure period and weevil larval instar, pepper plants of one cultivar (Blaze) were exposed to A. eugenii adults, and subsequently to J. hunteri wasps for either three or seven days, when offspring weevils were either at the L1 or L3 instar. Offspring emergence was significantly reduced up to 62% when L3 but not L1 weevils were exposed to wasps for 7 days. Following this longer exposure period, significantly greater weevil suppression occurred in small (71.7%) versus large fruit (62.5%), with an additional 15.1% weevil suppression resulting from attached relative to abscised fruit. These results highlight the potential for J. hunteri as a biological control agent of A. eugenii on pepper crops, with particular value in commercial greenhouse production where wasp retention rates can be high.

Exploring market-available pheromone lures and traps for monitoring Anthonomus testaceosquamosus (Coleoptera: Curculionidae).

The hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), is a significant threat to tropical hibiscus (Hibiscus rosa-sinensis) in Florida, USA, since its invasion in 2017. As a regulated pest in the state, early detection is crucial. Based on the success of pheromone-based monitoring programs for other weevil pests, such as the boll weevil, cranberry weevil, and pepper weevil, this study explores the potential use of these pheromone lures for early detection of HBW. To account for differences in efficacy based on trap color, height, and design, different pheromone lure sizes (4 mm, 10 mm, full-size), trap types (Yellow sticky trap, Japanese beetle trap, Boll weevil trap), and heights (0 m, 1.1 m) were also tested in this study. In laboratory assays, males and females exhibited higher attraction to full-size cranberry weevil lure discs than other lure size-type combinations. In semi-field trials, yellow sticky traps baited with cranberry weevil lures captured more weevils than Japanese beetle or boll weevil traps baited with cranberry weevil lures, while trap height did not influence HBW capture. In semi-field, 4-choice bioassays, yellow sticky traps baited with cranberry weevil lures captured more HBW compared to yellow sticky traps baited with pepper weevil, boll weevil, or unbaited traps. Further research is required to thoroughly evaluate the cranberry weevil lure's efficacy in capturing HBW. Our study suggests the potential for utilizing yellow sticky traps baited with lures for early HBW detection and highlights the importance of selecting the appropriate lure, trap type, and height for optimal efficacy.

Assessing the sterility and quality of gamma-irradiated pepper weevils, Anthonomus eugenii (Coleoptera: Curculionidae), toward the development of the sterile insect technique.

The pepper weevil (PW), Anthonomus eugenii, is an economically significant pest of cultivated Capsicum spp. pepper crops in North America where it remains a challenge to manage because of its cryptic immature life stages. The sterile insect technique (SIT) is a genetic pest management tactic that relies on the release of insects that have been sterilized with ionizing radiation to lower the population reproductive rate. Toward developing an effective PW-SIT program, this study has, for the first time, investigated the effects of gamma irradiation on the sterility and survival of this species. Among the array of doses tested, we found that pupal PW males and females irradiated at 110 Gy produced no adult offspring. Furthermore, females mated with a male irradiated at 110 Gy had high egg sterility (97.3%), and irradiated females nearly completely failed to lay eggs (97.5%). Individuals irradiated at this dose had a shortened lifespan (lethal time to 50% mortality values of 12 and 11 days for males and females, respectively) and quantitatively reduced spontaneous flight activity. The eclosion rate of PW pupae was not significantly reduced by any radiation treatment. This study suggests that PWs irradiated at a gamma radiation dose of 110 Gy as pupae could feasibly be used in a PW-SIT program, because both males and females were 100% sterile at this dose. These findings will inform the development of a SIT program that could considerably improve the sustainability and effectiveness of PW management in greenhouse and field pepper crops worldwide. © 2023 His Majesty the King in Right of Canada and The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri Food Canada.

Integrated approach using insecticides in combination with reflective plastic mulch for the management of pepper weevil, Anthonomus eugenii (Coleoptera: Curculionidae).

Pepper weevil, Anthonomus eugenii Cano, is a serious pest of peppers (Capsicum annuum) in the United States and worldwide. This study evaluated the combined effect of insecticides (thiamethoxam and oxamyl) and reflective mulches (reflective silver on white and reflective silver on black) on pepper weevil suppression and yield increase. This study was conducted under field conditions in Homestead, FL, during the fall 2020, spring 2021, and 2022 growing seasons. The study consists of 2 mulch treatments as the main plots (reflective "silver on white," "white on black") and a bare ground with "no mulch" treatment in fall 2020 and spring 2021, and in spring 2022 with an additional treatment of reflective "silver on black" mulch. We hypothesized that jalapeño pepper grown on either reflective "silver on black" or "silver on white" plastic mulches would have fewer pepper weevil adults, fewer pepper weevil infested fruits, and higher yield than those grown on "white on black" plastic mulch or bare soil. Overall, the number of pepper weevil adults on plants and infested fruits was lower in the fall season compared to the spring season. In the fall 2020 season, the number of adults was not significantly different regardless of insecticide treatment and mulch type. However, infested fruits were higher on the untreated control plots than the treated plots in Fall 2020. Marketable yield was not significantly different among insecticide treatment on the "white on black" and reflective "silver on white" mulches. However, thiamethoxam treated plots had significantly higher yield than on the rest of the treatment on the bare soil with "no mulch." The number of adults was higher in the untreated control plot than the treated plots in spring 2021. The number of infested fallen fruits was not significantly different. However, marketable yield was significantly different among treatments on the "white on black" and reflective "silver on white" mulches in 2021. The treated plots on the reflective "silver on white" mulch produced significantly higher yield than the untreated control plots in 2022. The result of this study suggests that growing jalapeño peppers on reflective plastic mulch ("silver on white") in integration with thiamethoxam or oxamyl has the potential in reducing pepper weevil adult population and increasing yield of jalapeño pepper.

Odorant-Binding and Chemosensory Proteins in Anthonomus eugenii (Coleoptera: Curculionidae) and Their Tissue Expression.

The pepper weevil Anthonomus eugenii is one of the most damaging pests to the pepper crop. To offer alternative management strategies to insecticides, several studies have identified the semiochemicals that are involved in the pepper weevil's aggregation and mating behavior; however, there is no information on its perireceptor molecular mechanism, to date. In this study, bioinformatics tools were used to functionally annotate and characterize the A. eugenii head transcriptome and their probable coding proteins. We identified twenty-two transcripts belonging to families related to chemosensory processes, seventeen corresponding to odorant-binding proteins (OBP), and six to chemosensory proteins (CSP). All results matched with closely related Coleoptera: Curculionidae homologous proteins. Likewise, twelve OBP and three CSP transcripts were experimentally characterized by RT-PCR in different female and male tissues. The results by sex and tissue display the different expression patterns of the AeugOBPs and AeugCSPs; some are present in both sexes and all tissues, while others show expressions with higher specificity, which suggests diverse physiological functions in addition to chemo-detection. This study provides information to support the understanding of odor perception in the pepper weevil.

El Picudo en chiltoma

Abstract This factsheet for farmers in Nicaragua provides information on the pepper weevil ( Anthonomus eugenii ), a pest of tomatoes ( Solanum lycopersicum ) and peppers. It includes details about its biology, ecology, symptoms, control and a photo of the pest. ISNAYA, Etelí

Foliar insecticide treatments in bell pepper for pepper weevil control, 2020

Foliar insecticide treatments in bell pepper for pepper weevil control, 2020

Effect of Pepper Variety on the Susceptibility of Pepper Weevil Parasitoids

Anthonomus eugenii Cano (Coleoptera: Curculionidae) is a key pest of cultivated peppers (Capsicum species) in tropical and subtropical America. Here we evaluated the effect of five pepper varieties on the susceptibility of A. eugenii to the parasitoids Bracon sp. (Hymenoptera: Braconidae), Eupelmus cushmani (Crawford) (Hymenoptera: Eupelmidae), and Jaliscoa hunteri Crawford (Hymenoptera: Pteromalidae). Potential parasitism was estimated by comparative analysis of parasitoid ovipositor size and the depth to which host larvae develop inside the fruit. Highest potential parasitism rates were achieved by Bracon sp. and E. cushmani on árbol and habanero peppers (84-99%) while the lowest rates were achieved by J. hunteri on serrano, bell, and jalapeño (7-18%). To validate potential parasitism rates, the actual parasitism rate by Bracon sp. and J. hunteri on three varieties of peppers was assessed. Actual parasitism rates of A. eugenii larvae in árbol were similar for Bracon sp. and J. hunteri (33%), while on bell and jalapeño Bracon sp. achieved 24% and 13% parasitism and J. hunteri achieved 14% and 8%, respectively. In most cases, actual parasitism was lower than estimated potential parasitism, although the latter had a notable predictive power (predicted R2 = 0.84). Results showed that the host was more vulnerable on small-fruited varieties because larvae were closer to the pericarp and could be reached by parasitoid ovipositors; likewise, in varieties with little placenta and seed, some larvae fed in the pericarp, where they were more vulnerable.

Population Structure and Genetic Diversity of the Pepper Weevil (Coleoptera: Curculionidae) Using the COI Barcoding Region

The pepper weevil Anthonomus eugenii Cano (Coleoptera: Curculionidae) is a pest of economic importance for Capsicum species pepper in North America that attacks the reproductive structures of the plant. The insect is distributed across Mexico, the United States, and the Caribbean, and is occasionally found during the pepper growing season in southern Ontario, Canada. Continuous spread of the insect to new areas is partially the result of global pepper trade. Here, we describe the genetic diversity of the pepper weevil using the mitochondrial COI barcoding region across most of its geographic range. In this study, 44 (H1–H44) highly similar haplotypes were identified, the greatest number of haplotypes and haplotype diversity were observed among specimens from its native Mexico, followed by specimens from the United States. Unlike Mexico, a low haplotype diversity was found among specimens from Canada, the Dominican Republic, Italy, and the Netherlands. Out of these 44 haplotypes, 29 are reported for the first time. Haplotype diversity in the Canadian population suggests either multiple and continuous introductions of the pepper weevil into this area or a single introduction of genetically diverse individuals. We discuss the importance of such population genetic data in tailoring pepper weevil management programs, using Canada as an example.

Pepper weevil, Anthonomus eugenii (Coleoptera: Curculionidae) suppression on jalapeño pepper using non-host insect repellent plants

Pepper weevil, Anthonomus eugenii Cano is the most harmful insect pest of pepper, Capsicum annum L., an important crop in Florida and several other states in the southern region of the United States. All commercially cultivated peppers, including jalapeño peppers, are susceptible to pepper weevil. The use of broad-spectrum insecticides is the primary management tool for controlling pepper weevil. Their continuous use has led to the development of resistance and elimination of natural enemies. Therefore, alternative approaches are needed for effective control. Studies were conducted to evaluate the effectiveness of intercropping non-host insect repellent plants (Ocimum basilicum L. (basil), Tagetes patula L. (marigold), Brassica oleracea L. (cabbage), and Coriandrum sativum L. (cilantro)) with jalapeño pepper on pepper weevil population suppression. Each of the four non-host plants consisted of individual treatments and were compared to a jalapeño pepper only (untreated control), or a jalapeño pepper with a standard insecticide regimen of thiamethoxam (positive control). Parameters evaluated include the number of pepper weevil adults on plants, number of infested fallen fruit, and marketable yield. Infested fruit collected from each treatment plot were dissected to evaluate pepper weevil (adult, pupae, and larvae) density. The non-host plant treatments reduced the number of pepper weevil adults found on jalapeño plants, infested fruit, and pepper weevils in infested fruit but not marketable yield when compared with the control treatment. This information is a step forward into finding a sustainable approach for the management of pepper weevil.

Biology of Anthonomus testaceosquamosus Linell, 1897 (Coleoptera: Curculionidae): A New Pest of Tropical Hibiscus.

Simple SummaryAlthough native to northeastern Mexico and southern Texas, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell 1897, was recently discovered infesting hibiscus in south Florida in 2017. During outbreak events, HBW feeding on hibiscus buds has been found to significantly affect the marketability of the crop. Therefore, it is vital that an integrated pest management (IPM) program be developed for this pest in order to mitigate the economic loss to the hibiscus industry of south Florida. However, a comprehensive understanding of the HBW’s biology is critical to the development of such a program. In this study, we sought to determine how temperature and diet affect the life history of the HBW. Four temperatures were tested 10, 15, 27 and 34 °C. Life cycle completion was found to only occur at 27 °C, but weevils developed equally as fast on hibiscus buds as on an artificial diet. Adult HBW could survive solely on pollen, but reproduction did not occur. Without water at 27 °C, HBW survived for ≈15 days; survival times reached nearly 30 days when water was accessible. Our results suggest that if left unmanaged, the HBW may cause significant economic damage to the hibiscus industry. We provide a foundation for future research endeavors that aim to better manage this weevil in south Florida. Originating in northeastern Mexico and southern Texas, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell 1897, was discovered infesting China rose hibiscus (Hibiscus rosa-sinensis L.) in south Florida in May 2017. Although the biologies of the congeneric boll weevil, A. grandis Boheman 1843, and pepper weevil, A. eugenii Cano 1894 are well documented, no data are available regarding the biology of HBW. Here, we present a comprehensive study on the biology of this pest when reared at 10, 15, 27 and 34 °C and on different food sources. This weevil has three larval instars and its life cycle was completed only at 27 ± 1 °C. Weevil development was similar on an artificial diet when compared with a diet of hibiscus buds. Adult HBW could survive solely on pollen, but reproduction did not occur. Without water, HBW survived for ≈15 days; survival times reached nearly 30 days when water was accessible. Our results suggest that if left unmanaged, HBW has the potential to cause significant economic damage to the hibiscus industry. Given that a comprehensive understanding of a pest’s biology is critical for development of effective integrated pest management, our results provide a foundation for future research endeavors to mitigate the impact of this weevil in south Florida.

Overwintering of Anthonomus eugenii (Coleoptera: Curculionidae) in Southern Georgia

Overwintering of <i>Anthonomus eugenii</i> (Coleoptera: Curculionidae) in Southern Georgia

Extraction of Pest Insect Characteristics Present in a Mirasol Pepper (Capsicum annuum L.) Crop by Digital Image Processing

One of the main problems in crops is the presence of pests. Traditionally, sticky yellow traps are used to detect pest insects, and they are then analyzed by a specialist to identify the pest insects present in the crop. To facilitate the identification, classification, and counting of these insects, it is possible to use digital image processing (DIP). This study aims to demonstrate that DIP is useful for extracting invariant characteristics of psyllids (Bactericera cockerelli), thrips (Thrips tabaci), whiteflies (Bemisia tabaci), potato flea beetles (Epitrix cucumeris), pepper weevils (Anthonomus eugenii), and aphids (Myzus persicae). The characteristics (e.g., area, eccentricity, and solidity) help classify insects. DIP includes a first stage that consists of improving the image by changing the levels of color intensity, applying morphological filters, and detecting objects of interest, and a second stage that consists of applying a transformation of invariant scales to extract characteristics of insects, independently of size or orientation. The results were compared with the data obtained from an entomologist, reaching up to 90% precision for the classification of these insects.

Host utilization by the pepper weevil (Anthonomus eugenii): suitability, preference and offspring performance.

Host plant selection is a key factor affecting the survival, population establishment, and spread of herbivorous insect pests. The pepper weevil is one of the most important pests of cultivated pepper in North America with a capacity to rapidly expand its geographic range, in part through its ability to switch between cultivated and wild Solanaceous host plants. Towards a better management of this pest, this study examined metrics of pepper weevil host use including oviposition preference, development time, and successful offspring emergence on wild Solanaceous species and cultivated pepper cultivars. Pepper weevil successfully developed within fruit of several Solanaceous species including eastern black (Solanum ptycanthum) and climbing nightshade (S. dulcamara), in which development time was on average 4 days faster relative to Capsicum annuum cv. jalapeno peppers. Oviposition events occurred in all fruit types assessed and no strong host preference was detected among these. However, the number of emerged offspring was significantly lower than the number of oviposition events in C. chinense cv. habanero pepper fruit. Although not all nightshade species are suitable hosts for pepper weevil development, those permissive to offspring production do allow for faster development than in C. annuum peppers. While host preference was not detected among fruit types tested, low offspring emergence from fruit with high capsaicin content suggests a reduced ability of pepper weevil to tolerate high concentrations of this metabolite. These findings help elucidate the factors influencing pepper weevil bionomics, and their implications on pepper weevil management are discussed. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Domestication of Chili Pepper Has Altered Fruit Traits Affecting the Oviposition and Feeding Behavior of the Pepper Weevil.

Simple SummaryThe pepper weevil is an economically important pest that causes major damage to fruits of chili pepper varieties selected for consumption. However, the impact of this pest on wild and ornamental peppers remains unknown. Therefore, we studied the effect of chili domestication on the feeding and oviposition behavior of pepper weevil when exposed to wild chili, ornamental varieties, and varieties used for consumption. More specifically, we examined how changes in fruit and flower size, fruit thickness, spiciness level, and fruit position as a result of the domestication of chili peppers affected their susceptibility to this specialist pepper pest. In addition, we recorded that fruits and flowers from wild and ornamental plants were less susceptible to pepper weevil attacks than those from chili varieties selected for consumption. Our results have important implications for chili pepper breeders and could guide the selection of new resistant varieties against this pest.The pepper weevil, Anthonomus eugenii, Cano (Coleoptera: Curculionidae), is one of the most destructive pests of chili pepper. It causes extensive damage on varieties selected for consumption. However, the occurrence of this pest on wild and ornamental peppers remains unknown. We investigated the consequences of chili domestication on the feeding and oviposition of A. eugenii on fruits and flowers. We used plants of one wild accession, Bird Eye Pepper, five ornamental varieties (Pops Yellow, Black Pearl, Sedona Sun, Chilli Chilli, and Salsa Deep), and two domesticated varieties selected for consumption (Scotch Bonnet and Jalapeño). First, we characterized the plants according to their fruit and flower sizes, pericarp thickness, capsaicin level, fruit position, and flower color. Then, we evaluated the susceptibility of fruits and flowers to A. eugenii. Overall, domestication increased fruit and flower sizes and pericarp thickness, altered capsaicin levels, and altered fruit position and flower color. Weevils laid more eggs and caused more feeding damage on varieties selected for consumption than on wild and ornamental plants. Our results add to the growing literature on the consequences of crop domestication on herbivores. This knowledge could be integrated into breeding programs to select varieties resistant against the pepper weevil.

Isolation of native entomopathogenic fungi with potential for control of the pepper weevil, Anthonomus eugenii Cano, in Puerto Rico

Entomopathogenic fungi were isolated parasitizing coffee borer beetle (Hypothenemus hampei Ferrari) and banana weevils (Cosmopolites sordidus Germar) in different parts of the island of Puerto Rico to be identified and examined for their pathogenicity on pepper weevil (Anthonomus eugenii Cano). Fungi were isolated and purified in acidulated potato dextroseagar (PDA) in the laboratory of the Plant Disease Clinic at the Agricultural Experiment Station, Juana Díaz. Seven fungal isolates were obtained from the municipality of Comerío, and one from the municipality of Adjuntas. Morphology, DNA sequences of different genetic regions of interest, and microsatellites were used for identification of fungal isolates. Two of the eight isolates were identified as Beauveria bassiana, three as Beauveria caledonica, two as Paecilomyces fumosorosea and one as Paecilomyces lilacinum. Pathogenicity tests were conducted in vitro using conidia suspension (1 x 106 conidia/mL). Insects were inoculated by immersion (10 sec) in the conidia suspension. Daily mortality data was taken (TL50, TL90) and the mean of the treatments were determined. All the fungal species were pathogenic to A. eugenii. The most effective treatments were: P. fumosorosea (Pae1) and B. bassiana (Bb1 &amp; Bb3) with TL50 of 2.39, 2.53 and 2.56 days, respectively, while TL50 for the control was 6.56. A 100% mortality for treatments occurred between the fourth and sixth day compared to control, which reached it in 12 days. These isolates have the potential to be used on an integrated management program for the control of the pepper weevil.

A multicomponent marking pheromone produced by the pepper weevil, Anthonomus eugeni (Coleoptera: Curculionidae)

Insects in several orders deposit marking pheromones following oviposition. In addition to preventing the female from visiting the same site again, the pheromone also signals the presence of eggs to conspecific females. This form of chemical marking is particularly prevalent in species which oviposit on discrete hosts with limited resources available for developing larvae. The pepper weevil is a major pest of cultivated pepper throughout the southern United States, Mexico and the Caribbean. The weevil deposits eggs singly in a cavity chewed in flower buds and small fruits and caps these cavities with a plug derived from an anal secretion. The deterrent was found to be located in this oviposition plug and comprised of volatile and contact-acting components. Plug volatiles were collected by inducing oviposition into Teflon tape sachets containing pepper leaves and collecting volatiles from plugs laid on the tape surface. Of the two major components observed by GC/MS analyses, only acetophenone elicited a behavioral response by the female weevil in small arena and wind tunnel assays. Investigations of the oviposition plug matrix identified several free unsaturated and saturated fatty acids as major constituents of the plug which was in stark contrast to pepper tissue and seeds that contained only trace levels of free fatty acids and a distinctly different total fatty acid composition. The combined free fatty acids as well as acetophenone tested singly gave no significant reduction in oviposition while a plug-mimicking blend of unsaturated fatty acids tested in combination with acetophenone as artificial ‘plug spots,’ decreased oviposition on treated peppers by up to 75%. We propose that the combination of volatile and contact acting marking components improves oviposition site selection efficiency by pepper weevils on discrete hosts.