Brazilian Collections and Laboratory Biology of the ThripsPseudophilothrips ichini(Thysanoptera: Phlaeothripidae): A Potential Biological Control Agent of the Invasive Weed Brazilian Peppertree (Sapindales: Anacardiaceae)

Salinity is one of the abiotic stressors affecting both upland and wetland ecosystems, yet its influence on invasive plant species and their herbivores in these environments remains poorly understood. Brazilian peppertree (Schinus terebinthifolia Raddi, BP) is a problematic tropical and subtropical shrub, widely invasive in parts of the United States (Florida, Texas, and Hawaii), Cuba, Australia, South Africa, and other subtropical regions of the world. The plant is known for its adaptability to various environments, including lower-lying and brackish areas. In 2019, Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae), commonly known as BP thrips, was introduced in Florida as a biological control agent for this invasive weed. The purpose of this study is to evaluate the impact of BP grown in brackish habitats on adult emergence, development time, fecundity, and adult longevity of the BP thrips. Brazilian peppertree plants were subjected to varying salinity conditions for two months (control: 0 ppt, low: 10 ppt, medium: 15 ppt, and high: 20 ppt). Twelve first-instar BP thrips were introduced to each BP plant treatment to complete their development into adults. Subsequently, adult thrips were transferred to new plants grown at the same salinity level to assess fecundity and adult longevity. Results indicate that different salinity levels had no significant effect on adult emergence, time of development, or longevity of P. ichini. A negative correlation was observed between increased salinity and average fecundity. A stochastic simulation model predicts, however, that BP thrips have a strong chance of surviving in brackish environments.

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), a perennial woody plant native to Brazil, Argentina, Uruguay and Paraguay, has become one of the most invasive weeds in Florida. A leaflet pit galling psyllid, Calophya terebinthifolii Burckhardt & Basset (Hemiptera: Calophyidae), has been identified as a potential biological control agent for Brazilian peppertree. However, biological information on the psyllid, including its life history, rearing procedures and potential distribution, is lacking. This type of information is essential when importing an insect for biological control purposes. From May–Aug 2009, field and laboratory research was conducted in Gaspar, Santa Catarina, Brazil with psyllids collected from the Atlantic coastal region of Santa Catarina. Laboratory studies on the psyllid in Brazil focused on: female fecundity (55.3 ± 8.9 eggs/female), the number and size of the immature stages, age-specific survivorship, and mean generation time (43.7 ± 1.2 days). Preliminary evidence from feeding trials suggests this psyllid from the Atlantic coastal region of Santa Catarina is locally adapted to Brazilian peppertree plants of haplotype A, which is one of the genetic types that invaded Florida. Ecological niche modelling with MaxEnt confirmed there was climatic overlap between Florida and the native range of the psyllid in South America. Using collection and survey locations of the psyllid in its native range and point locations for haplotype A plants in Florida, a map was created that predicted Volusia, coastal Pasco and Hernando counties, and a small section of southwestern Polk county as suitable locations for establishment of the psyllid if it is approved for release as a biocontrol agent.

Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), is an invasive tree in the Southeastern United States, Texas, California, and Hawaii. The Brazilian peppertree thrips, Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae), is a recently approved biological control agent for use within the US. The thrips have since been released in the field and are expected to reduce Brazilian peppertree performance. Pseudophilothrips ichini is likely to impact young trees but the impacts may vary based on thrips population size and tree age. To better understand the factors contributing to agent impact on young trees and P. ichini population growth, we measured the effect of P. ichini density (0, 4, 10, and 20 thrips) and tree age (3-, 4-, and 6-month-old plants), on tree performance and P. ichini productivity in the laboratory. Brazilian peppertree height and the number of growing tips were reduced across all age groups. However, the negative impact was more pronounced on the youngest trees, which had a reduction in the relative change in height of 171% and a 100% reduction in the number of growing tips. Pseudophilothrips ichini production was positively correlated with tree height (r = 0.44) and biomass (r = 0.56), but thrips relative production was similar across tree age. Results indicate that P. ichini have a great capacity for population increase regardless of starting density. Field studies are needed to corroborate these findings and identify barriers to agent success. This work aims to refine expectations of the impacts to Brazilian peppertree caused by P. ichini.

The impact and production of the Brazilian peppertree biological control agent Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae) is affected by the level of host-plant fertilization

Pseudophilothrips ichini (Hood) (Thysanoptera: Phlaeothripidae) is a classical biological control agent used to control Brazilian peppertree, Schinus terebinthifolia Raddi, in Florida, USA. Brazilian peppertree is an invasive weed that threatens natural and agricultural environments, including sensitive habitats such as mangrove swamps. As P. ichini generally pupates in the soil and its host plant can occur in wet areas, it is important to investigate the effects of soil type, moisture, salinity, and immersion survival time on adult emergence. Five moisture contents (0%, 25%, 50%, 75%, and 100%) were used in factorial combination with three soil types (fine sand, sand, and muck) using fresh or brackish water. To simulate sporadic flooding, we also assessed larval and pupal survival after being immersed in fresh and brackish water for 0, 1, 2, 3, 5, 8, 16, and 32 h. A generalised mixed model logistic regression was used to analyse the data in both experiments. As soil moisture content increased, the proportion of P. ichini emerging as adults decreased across all soil types and water types. The survival of larvae and pupae immersed in either brackish or fresh water declined over time, with no survival at 32 h. There was a significant difference between water types for the survival of pupae and adult emergence of pupae and larvae, with higher survival in brackish water. The outcome of this study contributes to our understanding of P. ichini ecology and the estimation of thrips establishment success in a variety of habitats infested by Brazilian peppertree.

Aroeira ou pimenta rosa, Schinus terebinthifolia Raddi (Anacardaceae), planta nativa da Argentina, Brasil, Paraguai e Uruguai é uma das plantas daninhas mais invasivas na Flórida. Em sua região de origem, pelo menos 4 espécies de psilídeos do gênero Calophya (Hemiptera: Calophyidae) estão associados a esta planta. Todas as quatro espécies são monófagas e provavelmente constituem um grupo monofilético que induzem galhas lenticulares abertas, usualmente na face superior da folha. Aqui a taxonomia das 4 espécies é revisada, 2 das quais são descritas como novas, C. lutea sp. nov. e C. praestigiator sp. nov. Diferenças morfológicas entre as 4 espécies são detalhadas e estruturas relevantes são ilustradas. Fornecemos chave para identificação de adultos e imaturos de quinto instar para as 8 espécies conhecidas como indutoras de galhas em espécies de Schinus.

The Brazilian peppertree thrips, Pseudophilothrips ichini (Hood) (Thysanoptera: Phlaeothripidae), is an insect native to Brazil (Figure 1). This species has been studied for the last 20+ years as a potential biological control agent of Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), in Florida (Cuda et al. 2008; Cuda et al. 2008; Manrique at al. 2014; Wheeler et al. 2016a, b). Host specificity experiments demonstrated that Pseudophilothrips ichini has a limited host range (Cuda et al. 2008; Cuda et al. 2009; Wheeler et al. 2017) and can cause a severe reduction of Brazilian peppertree biomass (Manrique at al. 2014).https://edis.ifas.ufl.edu/in1270

Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), is an ornamental dioecious shrub introduced from South America that has become one of the major invasive weeds in Florida. Anecdotal evidence from the literature suggests that crushed leaves from female plants produce a more pungent aroma, indicating these plants may be better defended chemically than their male counterparts. To test this hypothesis, we compared the performance (adult feeding and survival) of the South American stem boring weevil Apocnemidophorus piptzi (Faust) (Coleoptera: Curculionidae) by caging insects on foliage collected from both male and female Brazilian peppertree plants. Results showed that weevils consumed significantly less leaf tissue from female plants compared to male plants. Furthermore, the LT50 (average time required to cause 50% mortality of the weevils) was significantly shorter when weevils fed exclusively on female leaf tissue. Our findings confirmed male-biased plant herbivory on Brazilian peppertree by one of its folivorous natural enemies.

Invasive plants are rapidly entering new ecosystems due to globalisation, increased trade, and frequent disturbances of natural habitats. Schinus terebinthifolia Raddi, known as the Brazilian peppertree, is a particularly aggressive invasive shrub in Florida, Hawaii, Texas, and California. Due to its aggressive growth and the damage it can cause to ecological systems, it is considered one of the worst upland invasive species in the state of Florida, prompting extensive biological control efforts. The classical biological control agent, Pseudophilothrips ichini, was approved for release in Florida in 2019, with over 6 million thrips released to date. However, the establishment and persistence of these thrips have been inconsistent, and little research has been conducted to understand these patterns. Here, we employ ecological niche modelling as a tool to predict suitable habitats for Brazilian peppertree and P. ichini. Ecological niche models were calibrated using location data of both organisms from their native ranges and bioclimatic data from WorldClim. These models accurately predicted the potential distribution of Brazilian peppertree (AUCtraining = 0.914, AUCvalidation = 0.913) and P. ichini (AUCtraining = 0.934, AUCvalidation = 0.918). The projections indicated that most of Florida is climatically suitable for the Brazilian peppertree, aligning with its known distribution. However, discrepancies were observed between the projected and actual distribution of P. ichini, suggesting that additional environmental or biotic factors may influence their establishment. Further research is necessary to refine these models and enhance the integration of P. ichini into pest management programmes to better conserve time, resources, and funds.

Summary The thrips Pseudophilothrips ichini (Hood) (Thysanoptera: Phlaeothripidae), which is native to Brazil, is a candidate for classical biological control of the invasive Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), in the USA. This paper corrects errors of omission about the history of the Brazilian peppertree biological control program in Florida and several misstatements about the identity of the thrips in previously published literature.

Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae) (hereafter Schinus), is one of the worst invasive species in Florida and Hawaii. The thrips Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae) is being considered as a potential biological control agent of Schinus. Two populations of this thrips were collected in the weed's native range; one from central-east Brazil (Ouro Preto thrips) and a second from north-east Brazil (Salvador thrips). Temperature requirements, adult fecundity and impact on different plant haplotypes by P. ichini were examined in the laboratory. Complete development of thrips from both populations occurred at temperatures ranging from 20 to 30°C. Two approaches were used to model the predicted distributions of the thrips populations in the USA: the physiological model (NAPPFAST) based on cold tolerance and the ecological niche model based on climatic variables (MaxEnt). The physiological model predicted that both populations of P. ichini may establish in similar areas of the USA, overlapping with the distribution of Schinus. However, the niche model predicted that only the Ouro Preto thrips could establish in the USA. The difference in model predictions suggests an apparent preadaptation of the Salvador thrips to lower temperatures than those experienced at the locations they were collected in Brazil. The Ouro Preto thrips had similar fecundity on two Florida Schinus haplotypes, whereas lower fecundity on haplotype A was found for the Salvador thrips. Based on these results, the Ouro Preto population may be better adapted to the climatic conditions and plant haplotypes found in Florida. Moreover, greenhouse studies indicated that Schinus growth was greatly reduced by thrips feeding, which may result in lower weed reproduction and densities in the field.

Regulation of hexamerin receptor phosphorylation by hemolymph protein HP19 and 20-hydroxyecdysone directs hexamerin uptake in the rice moth Corcyra cephalonica

Cophinforma spp. are gall-inducing fungi that can infect the highly invasive Brazilian peppertree (Schinus terebinthifolia Raddi), in its introduced range in southern Florida, USA. A classical biological control agent, the thrips Pseudophilothrips ichini, has been released to mitigate the invasive potential of S. terebinthifolia. We investigated the synergistic potential of thrips feeding damage and gall formation on S. terebinthifolia management program success. A group of potted S. terebinthifolia saplings were inoculated with Cophinforma. Galled, symptomatic and ungalled, asymptomatic saplings were then paired in laboratory cages for a two-choice test with 40 P. ichini adults. Galled and ungalled plants were assessed for dead stem tips and necrotic stem tissue, with and without thrips present. Larval F1 thrips were also counted on each plant. Thrips feeding damage significantly increased the number of dead tips and extent of stem necrosis. Regardless of thrips presence, stem tip mortality and extent of necrosis were not significantly different between galled and ungalled plant pairs. Additionally, the maximum number of F1 larvae counted on stems did not differ between those on galled versus ungalled plants. Gall growth on heavily thrips-damaged plants nearly stopped, while galls continued to grow on plants with little thrips damage. While our results suggest the Cophinforma galls do not impact damage potential or plant preference from P. ichini, more work is needed to understand other factors that may contribute to at least additive impacts on S. terebinthifolia in the field, such as more advanced stages of the fungal infection on mature plants and prolonged thrips feeding damage.

Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) is a non-native perennial woody plant that is one of the most invasive weeds in Florida, Hawaii, and more recently California and Texas. This plant was introduced into Florida from South America as a landscape ornamental in the late 19th century, eventually escaped cultivation, and now dominates entire ecosystems in south-central Florida. Recent DNA studies have confirmed two separate introductions of S. terebinthifolius in Florida, and there is evidence of hybridization. A thrips, Pseudophilothrips ichini s.l. (Hood) (Thysanoptera: Phlaeothripidae), is commonly found attacking shoots and flowers of S. terebinthifolius in Brazil. Immatures and occasionally adults form large aggregations on young terminal growth (stems and leaves) of the plant. Feeding damage by P. ichini s.l. frequently kills new shoots, which reduces vigor and restricts growth of S. terebinthifolius. Greenhouse and laboratory host range tests with 46 plant species in 18 families and 10 orders were conducted in Paraná, Brazil, and Florida. Results of no-choice, paired-choice, and multiple-choice tests indicated that P. ichini s.l. is capable of reproducing only on S. terebinthifolius and possibly Schinus molle L., an ornamental introduced into California from Peru that has escaped cultivation and is considered invasive. Our results showed that P. ichini s.l. posed minimal risk to mature S. molle plants or the Florida native Metopium toxiferum L. Krug and Urb. In May 2007, the federal interagency Technical Advisory Group for Biological Control Agents of Weeds (TAG) concluded P. ichini s.l. was sufficiently host specific to recommend its release from quarantine.

Background Aroeira or Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae: Rhoeae), is one of the worst invasive plants in California, Florida, and Hawaii, USA because of its wide distribution, adaptation to various habitats, toxicity, and demonstrated negative impacts on biodiversity. Chemical and mechanical methods provide only temporary control, are expensive, may damage native plants, and often create disturbance conducive to reinvasion by Brazilian peppertree and other invasive weeds. The leaflet galling psyllid Calophya terebinthifolii Burckhardt & Basset (Calophyidae: Calophyinae) is [...]