A review of the introduced forest pests in Brazil

Special attention should be given to forest plantings in order to minimize the probability of exotic pest introduction and, consequently, of production losses. The objective of this review was to present, under a historic perspective, the main exotic insects that harm the Brazilian forest sector. Therefore, to better describe the phytosanitary context of introduced forest pests in Brazil, the main information regarding these insects was gathered here. Introduced species and species with a risk of introduction were listed. The following species were registered: 12 exotic introduced species related to eucalyptus, non-quarantine; 9 species related to pine, one quarantine; and 1 species related to teak, quarantine. Overall, the core problems for 57 pest species were addressed, followed by projections on current risks and priorities. Biological control programs and their respective agents were also mentioned. For eucalyptus plantations, the species belonging to the genera Ophelimus and Leptocybe are priorities and should be emphasized. Regarding pine species, the main current concerns are Bursaphelenchus xylophilus (transmitted by species of Monochamus), Rhyacionia frustrana, and Dendroctonus frontalis. Better risk management requires reinforcement of phytosanitary inspections and constant refinement of contingency plans, whose actions include monitoring by visual sampling, employment of sentinel plants, and preventive breeding programs aiming at pest resistance.

History, Distribution, Damage, and Life Cycle of a Pine Shoot Gall Sawfly, Xyela gallicaulis (Hymenoptera: Xyelidae)

Larvae of Xyela gallicaulis Smith cause shoot stem galls in young pines. Loblolly pine, Pinus taeda L., is the most seriously damaged, but galls have been observed on slash pine, P. elliottii var. elliottii Engelm., and shortleaf pine, P. echinata Mill. Studies in Virginia and Georgia confirm a 2-year life cycle. Larval development takes 4 - 6 wks. After feeding, larvae bore out of the galls and drop to the ground where they form a papery cocoon in the soil to pupate, and where they remain for 22 - 25 months. Adults emerge from cells constructed in the soil from early-December to mid-January of the second year. Eggs are inserted into the vegetative buds during odd-numbered years. Insect associates found feeding in or on gall tissues are the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Tortricidae), and the weevil Conotrachelus carolinensis Schoof (Curculionidae).

Variation in Developmental Synchrony of the Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) with Implications for Chemical Control

Regional variation in developmental phenology of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), was studied at four locations in southeastern Virginia and northeastern North Carolina. A companion study assessed the effects of developmental asynchronony on insecticide spray timing efficacy. Substantial variation in developmental synchrony was found within a relatively small area, with more synchronous development at Greensville and Isle of Wight Co., VA sites, and high levels of asynchrony at Sussex Co., VA, and Hertford Co., NC, sites. The Greensville Co. site showed a typical three generation developmental phenology, while the Isle of Wight Co. site had a more atypical two generation phenology. The Sussex and Hertford Co. sites appeared to have phenologies that were a combination of the other two sites. Spray timing evaluations with permethrin at the Sussex Co. site suggested that mid-April to early May and early to mid-July periods offer opportunities for effective chemical control of tip moths. These dates corresponded to the presence of high proportions of eggs and early-instar larvae in the field. Later season sprays were largely ineffective due to high developmental asynchrony, which resulted in the presence of high proportions of late-stage tip moths on virtually all collection and spray dates. Results suggest that multiple late-season treatments likely would be more effective. Overall, optimal spray dates at the Greensville Co. site, which had a typical three-generation tip moth developmental pattern, agreed most closely with published optimal spray period predictions which are based on historical temperature data.