[IN1341] Stem Borers (Lepidoptera: Crambidae) in Florida Rice

Three stem borers, the sugarcane borer, Diatraea saccharalis (F.), rice stalk borer, Chilo plejadellus Zincken, and Mexican rice borer, Eoreuma loftini (Dyar), infest rice in the southern United States. They occur in Florida, with the Mexican rice borer being an invasive species recently introduced into the state. This publication briefly describes stem borers and sampling methods and reports results of the first extensive survey conducted to measure their occurrence in Florida rice.

Diatraea saccharalis (sugarcane stalk borer).

D. saccharalis is generally considered to be a pest of substantial economic importance. The extent of economic losses may vary depending on factors such as environmental conditions and sugarcane varieties. Losses to the sugarcane borer often vary across geographic regions (e.g. crop losses to the borer in Louisiana), USA may range from 4-30% annually, possibly twice as high as in Florida (Ingram et al., 1951).

Phytosanitary state of sugar beet agrocenosis in 2019 and forecast of the number of phytophages in the current year

Purpose. To generalize and analyze the data provided by state phytosanitary inspections of the Department of Phytosanitary Safety of the State Veterinary Service of Ukraine on the dynamics of development of the main pests in sugar beet stands in Ukraine in 2019 and to forecast their appearance and possible damage in the current year. Methods. Field, accounting, analytical. Results. In 2020, sugar beet crops may be damaged by beetroot weevil, grey beetroot weevil, beet stalk borer, beet flea, beet leaf miner, beetroot aphids and other pests. According to the results of autumn field monitoring, 57% of beet areas was colonized by beetroot beetle with an average number per 1 m2 of 0.5–1.0 (beetles, pupae) with the maximum number of 2–9 in Volyn, Kyiv, Poltava, Cherkasy, Chernihiv, Zhytomyr, Sumy regions. During the autumn excavations, the beetles in the population were 75%, pupae 20% and larvae 5%. In respect to grey beetroot weevil, it made the greatest damage to sugar beet crops in Kyiv, Poltava, Kharkiv, Sumy, Volyn, Kirovohrad, Khmelnytsk, and other regions, where it colonized 24–100% of stands with an average number of 0.1–0.6 with a maximum of 0.6–1.0. It damaged, on average, 2–6% of stands with the maximum of 7–12%. Autumn monitoring of the pest found a significant number of the pest in all beetroot regions with an average number of 0.5–0.7 with the maximum of 1.0–4.0. In addition, autumn monitoring revealed a significant number of beet stalk borer (average 0.1–0.7, maximum 0.7–1.0 specimens) in farms of Poltava and Cherkasy regions. Beet tortoise beetles were detected on 10–100% of the monitored area with an average number of 0.1–0.4, which is lower than in long-term observations. In the majority of areas, goosefoot tortoise beetles dominated (33–100%). On average, the ratio was 54% of goosefoot and 46% of beet root tortoise beetles. The wintering stock of beet beetle was slightly lower than in the last year and amounted to an average of 14–54, with the maximum in Vinnytsia, Rivne, Khmelnytskyi regions (76–100). Autumn inspections of host plants (red bilberry, snowball tree, jasmine) revealed 12–36, maximum 150 wintering eggs of leaf aphids per 1 meter of a branch. The wintering stock of beet leaf miner was 0.8–1.8, somewhere 2.9 (in Ternopil, Vinnytsia Khmelnytsk regions), which is at the level of the last year’s numbers. Conclusions. The wintering stock of harmful sugar beet insects exceeds the generally accepted economic thresholds for harmfulness. The timely prognosis of the development and reproduction of sugar beet pests and the application of a complex of organizational, economic, biological and chemical measures to control their numbers will create conditions for the preservation of root harvest, improving root quality and reduce unreasonable pollution of the environment with chemicals.

Comprehensive Transcriptome of the Maize Stalk Borer, Busseola fusca, from Multiple Tissue Types, Developmental Stages, and Parasitoid Wasp Exposures

Busseola fusca (Fuller) (Lepidoptera: Noctuidae), the maize stalk borer, is a widespread crop pest in sub-Saharan Africa that has been the focus of biological research and intensive management strategies. Here, we present a comprehensive annotated transcriptome of B. fusca (originally collected in the Western Province of Kenya) based on ten pooled libraries including a wide array of developmental stages, tissue types, and exposures to parasitoid wasps. Parasitoid wasps have been used as a form of biocontrol to try and reduce crop losses with variable success, in part due to differential infectivities and immune responses among wasps and hosts. We identified a number of loci of interest for pest management, including genes potentially involved in chemoreception, immunity, and response to insecticides. The comprehensive sampling design used expands our current understanding of the transcriptome of this species and deepens the list of potential target genes for future crop loss mitigation, in addition to highlighting candidate loci for differential expression and functional genetic analyses in this important pest species.

Biocidal Activities of Seed Oils of Jatropha curcas and Moringa oleifera on Development of African Maize Stalk borer, Busseola fusca Fuller (Lepdoptera: Pyralidae)

Laboratory experiment was conducted at the Department of Crop Protection Laboratory, Faculty of Agriculture, Bayero University, Kano, in order to assess the effect of oils obtained from the seeds of Jatropha curcas and Moringa oleifera on African Maize Stalk Borer (Busseola fusca Fuller). The effects of the plant seed oils on larvae mortality, pupae and adult emergence were tested on freshly cut leaves/stem of maize 3-4 cm long) and treated with the prepared plant oils at various concentrations (10, 20, and 30%) and control (0%). The experiment was laid out in a completely randomized design and replicated four times. The results showed that both plant seeds oils were lethal to the developmental stages of B. fusca, causing mortality (21%) to the larvae, and subsequently preventing and/or suppressing pupae (2.08) and adult emergence (1.95). Treatment at 30% concentration was found to be more lethal to all the developmental stages of the test insect. Based on the findings of this study, it is recommended that any of the plant seed oils at 30 % concentration could be used to manage B. fusca.

Draft Genome of Busseola fusca, the Maize Stalk Borer, a Major Crop Pest in Sub-Saharan Africa

The maize stalk borer, Busseola fusca, is an important Lepidopteran pest of cereal crops in Central, East, and Southern Africa. Crop losses due to B. fusca feeding activity vary by region, but can result in total crop loss in areas with high levels of infestation. Genomic resources provide critical insight into the biology of pest species and can allow for the development of effective management tools and strategies to mitigate their impact on agriculture. To this end, we sequenced, assembled, and annotated the genome of B. fusca. The total assembled genome size was 492.9 Mb with 19,417 annotated protein-coding genes. Using a comparative approach, we identified a putative expansion in the Chorion gene family, which is involved in the formation of the egg shell structure. Our analysis revealed high repeat content within the B. fusca genome, with LTR sequences comprising the majority of the repetitive sequence. We hope genomic resources will provide a foundation for future work aimed at developing an integrated pest management strategy to reduce B. fusca’s impact on food security.