Species diversity, phenology, and temporal flight patterns of Hypothenemus pygmy borers (Coleoptera: Curculionidae: Scolytinae) in South Florida

Authors: JOHNSON, ANDREW - University Of Florida; Kendra, Paul; SKELTON, JAMES - University Of Florida; HULCR, JIRI - University Of Florida

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2016
Publication Date: 6/1/2016
Citation: Johnson, A. J., P. E. Kendra, J. Skelton, and J. Hulcr. 2016. Species diversity, phenology, and temporal flight patterns of Hypothenemus pygmy borers (Coleoptera: Curculionidae: Scolytinae) in South Florida. Environ. Entomol. 45 (3): 627-632.

Interpretive Summary: Bark beetles in the genus Hypothenemus are abundant in tropical and subtropical areas worldwide. However, they are often overlooked and have been rarely studied due to their minute size (most < 3 mm) and difficulties with taxonomic identification. Although most species are benign, boring into dead or dying branches, some species have become serious economic pests of seeds, including the coffee berry borer, H. hampei, which greatly impacts commercial production of coffee. To gain a better understanding of the Hypothenemus community in South Florida, and to survey for potential pest species that may have recently invaded the U.S., a 15-month study was initiated by a scientist from the USDA-ARS Subtropical Horticulture Research Station (Miami, FL) and the University of Florida (Gainesville). A total of 481 specimens were collected. during the survey. Most species were non-native, but no pest species were detected. This research comprised the first ecological study of an entire community of Hypothenemus beetles, documenting species diversity in subtropical Florida, seasonal patterns in abundance, and daily patterns in host-seeking flight. This information advances our understanding of the ecological habits of this poorly understood group of insects.

Technical Abstract: Hypothenemus are some of the most common and diverse bark beetles in natural as well as urban habitats, particularly in tropical and subtropical regions. Despite their ecological success and ubiquitous presence, very little is known about the habits of this genus. This study aimed to understand species diversity and daily and seasonal trends in host-seeking flight patterns of Hypothenemus in a suburban environment by systematic trapping over a 15-month period in South Florida. A total of 481 specimens were collected and identified as eight species, most of them non-native. Hypothenemus formed the overwhelming majority of bark beetles (Scolytinae) collected, confirming the dominance of the genus in urban environments. Hypothenemus brunneus (Hopkins) and H. seriatus (Eichhoff) were most abundant, comprising 74% of the capture. Rarefaction showed that the sample was sufficient to characterize the local diversity and composition. The seasonal pattern in Hypothenemus capture was positively correlated to day-time temperature, not to season as in most temperate Scolytinae. One other significant dynamics in the Hypothenemus community reflected synchronized occurrence of two common species, unrelated to season. Hypothenemus are predominantly diurnal with a broad flight window. Females fly as early as 11:00 hours (EDST), with peak flight occurring at 15:00 hours, significantly earlier than flight patterns of most other Scolytinae. Surprisingly, male Hypothenemus were frequently collected, despite their lack of functional wings. Several potential explanations are discussed. This is the first study into the ecology of an entire community of the twig-feeding Hypothenemus.