Canadian Forest Service Publications

Year: 2015

Available from: Atlantic Forestry Centre

Catalog ID: 36309

Language: English

CFS Availability: PDF (request by e-mail)

Available from the Journal's Web site. †
DOI: 10.4039/tce.2014.44

† This site may require a fee.

Abstract

Field studies were carried out to assess diel activity patterns of the balsam gall midge, Paradiplosis tumifex Gagné (Diptera: Cecidomyiidae) in 2012, and its inquiline, Dasineura balsamicola (Lintner) (Diptera: Cecidomyiidae) in 2013, in a young balsam fir (Abies balsamea (Linnaeus) Miller) stand in New Brunswick, Canada. Both gallmaker and inquiline are most active during the afternoon/evening hours (17:00-22:00 hours). Male gallmaker activity was largely confined to the space bleow the crown and typically involved short periods of light of <30 seconds. Calling and mating by the gallmaker occurred at ground level and were followed by dispersal of females to the vegetative crown. Female gallmakers were typically observed in the tree crown beginning in early afternoon, with peak oviposition occurring between 20:00 and 21:00 hours. Female inquilines displayed similar activity patterns, although no calling or mating were observed. Moreover, inquiline flight and foraging for oviposition sites were more active than the gallmaker, with shorter rest periods and more buds visited than the gallmaker. Our results indicate that population monitoring should focus on female gallmakers as they fly during the evening. Also, before beginning any treatment application, care should be taken to accurately identify the insects to ensure that the inquiline is not inadvertently killed.

Plain Language Summary

Accurate detection methods are essential to integrated pest management programs aimed at controlling insect pests. In particular, knowledge of where and when and insect pest is active, and what they are doing, can greatly improve our ability to both detect and treat an insect outbreak. Our study provides daily activity patterns for a major insect pest of Christmas tree crops in the Maritime region, the balsam gall midge, as well as a closely related competitor that often kills the midge through appropriating its feeding chamber. From this information we provide recommendations for increasing the precision and efficiency of field surveys for adult balsam gall midge.