Bioecologia e predição de ocorrência do psilídeo-das-ponteiras do eucalipto, Blastopsylla occidentalis Taylor, 1985 (Hemiptera: Aphalaridae)

Abstract

The psilid Blastopsylla occidentalis Taylor, 1985 (Hemiptera: Aphalaridae) is an instrument that provides information about its bioecology, therefore, this study aimed to know the effect of temperature without development and reproduction in laboratory conditions, a population fluctuation in Sinop - MT, distribution and prediction of occurrence of the insect, in climatic changes and report of the first occurrence of Psyllaephagus blastopsyllae Tamesse, 2014 (Hymenoptera: Encyrtidae) parasitizing immature B. occidentalis in the State of Mato Grosso. The biological study was carried out at the Entomology Laboratory of the Federal University of Mato Grosso, using BOD air-conditioned chambers, at five temperatures between 15oC and 35oC with a variation of ± 2oC, 12/12-hour photoperiod and relative average> 70%. The psyllid completed the development at 20oC (32.78 days), 25oC (27.76 days) and 30oC (28.44 days). At 15 and 35oC there was no complete cycle, these being limitations. Observe fertility at temperatures of 20 oC and 25 o, respectively, according to the average of eggs / day of 19.04 and 26.40. The fluctuation was monitored at Fazenda Cunhatay, through collections carried out on fifteen trees (five for manual retirees of tips and ten for collection with entomological net), from December 2018 to January 2020. To collect eggs and immatures, five tips per plant were removed (twenty and belt tips per collection). For adults, ten net strikes were performed on each tree / collection and captured with an entomological aspirator. The collected material was screened and quantified at the Entomology Laboratory at UFMT. The population peak of the psyllid was observed in the months of drought (May to September) and reduction in the months of elevation (December to January). To model it was carried out or bibliographic survey and databases with world-class occurrence information, in which 219 occurrence points in the world were acquired and after removing outliers, totaling 133 points. We use the Arcgis, Maxent and Openmodeller programs in the process of modeling and climatological data related to the IPCC report, for the current period and for the most pessimistic scenario (A2) of the future (2030 and 2050). To generate models of altitude variables and biovariables of precipitation, temperature, radiation and humidity, they were used for their contribution to estimate the ecological niche of the insect. Result in maps plotted with projections from the Envelope Score algorithm, which do not result in a greater value of the area on a curve (0.91). The current distribution of the psyllid, corroborates with the related occurrence data, while for the future scenario, the increase in occurrence is deduced, including in countries where or within an unrelated state. During the flotation study, collections were made of 412 immature psilids with symptoms of parasitoidism, which were isolated in Petri dishes, to observe natural threats. No total of 31 emerging parasitoids, which after confirmation, are related to the first occurrence of P. blastopsyllae in Mato Grosso, parasitizing immatures of the psyllid. It concludes that the bioecology of B. occidentalis is influenced by climatic variability.