Band 107, Heft s1 - Special Issue: Invasive Species Records and Updates; Guest Editor: Muhammad Ahmed

The hibiscus bud weevil, Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), is an invasive pest of tropical hibiscus, Hibiscus rosa-sinensis L. (Malvaceae). While chemical and biological control alternatives have been identified, the viability of cultural control through sanitation (collecting and destroying dropped buds where larvae complete development) remains to be explored. The impact of adult hibiscus bud weevil infestation on flower bud abortion was studied in a greenhouse. Plants were infested with one mating pair of adult weevils, with non-infested plants as controls. Actively growing buds and dropped buds were counted weekly for four weeks. A subsequent shade house experiment evaluated the effect of sanitation on plant productivity. Groups of ten plants in a tunnel tent were infested with ten hibiscus bud weevil adult mating pairs per tent. Treatments included sanitation (weekly collection of dropped buds for eight weeks) and a no sanitation control. Five actively growing buds per tent were collected in search of eggs and larvae, while counts of actively growing buds and open flowers were recorded per plant. To identify efficient sanitation methods, the time required to remove fallen buds using three methods (manual, vacuum, and blower) was estimated. Hibiscus bud weevil infestation, using two adult weevils per plant, led to a 16-fold increase in bud abortion compared to non-infested plants. Sanitation reduced the proportion of dropped buds by 22 %, while no sanitation plants showed more actively growing buds, suggesting overcompensation in response to abortion. The vacuum method was the most efficient bud removal method tested. Sanitation can be an effective, practical, and complementary measure to reduce hibiscus bud weevil infestation in commercial nurseries.

Hibiscus mealybug Nipaecoccus viridis (Newstead; Hemiptera: Pseudococcidae) is a newly established pest in Florida citrus. In its native range, hibiscus mealybug is controlled by a suite of natural enemies. However, the potential predator population for this pest in Florida is currently unknown. Identifying and promoting natural enemies that prey on hibiscus mealybug in the newly established region are key to achieving sustainable management of this pest. We evaluated commercially available predators and field-collected predators for the ability to consume juvenile life stages of hibiscus mealybug. Additionally, we evaluated an augmentative release of Cryptolaemus montrouzieri (Mulsant; Coleoptera: Coccinelidae) inside of a citrus under protective screen (CUPS) production system to control a hibiscus mealybug infestation. In no-choice assays, we found that the commercially available predator Cr. montrouzieri consumed all juvenile stages of hibiscus mealybug, and another, Chrysoperla carnea (Stephens; Neuroptera: Chrysopidae), was able to consume eggs but showed a clear preference for nymphs. Other commercially available predators did not consume any juvenile life stage of hibiscus mealybug. Two field-collected predators consumed both nymphs and ovisacs at high rates in no-choice tests: Euborellia annulipes Lucas (Dermapter: Anisolabididae) and Ceraeochrysa sp. (Neuroptera: Chrysopidae). Moreover, ten species of natural enemies were identified from mealybug clusters sampled from the fields among which two predators, Fragosa sp. (Diptera: Syrphidae) and Anatrachyntis badia (Hodges; Lepidoptera: Cosmopterigidae), and two parasitoids, Anagyrus dactylopii (Howard; Hymenoptera: Encyrtidae) and Aprostocetus sp. (Hymenoptera: Eulophidae) were found in high abundance. In the augmentative release, we found a reduction in pest population after the release of Cr. montrouzieri . However, without additional resources to maintain the predator, hibiscus mealybug population increased once the beetle population died. Our results indicate that Cr. montrouzieri is an effective commercially available predator of hibiscus mealybug and that several naturally occurring predators and parasitoids prey on hibiscus mealybug in Florida citrus.

Hibiscus mealybug, Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae), is an invasive pest of citrus in Florida. It causes deformation and premature abortion of developing fruit. To date, hibiscus mealybug has been reported causing damage in commercial citrus groves in central and southern regions of Florida. As a recent invader, there is no information available on the phenology of this invasive pest on citrus in Florida. We sampled hibiscus mealybug population densities in six commercial citrus groves in central Florida throughout 2021 using absolute and relative sampling techniques. Results from absolute sampling showed that hibiscus mealybug completes multiple generations per year, with three of them being clearly defined. The first (March) and second (June) generations pose the greatest threat to citrus production in Florida. Results from relative sampling showed that a corrugated cardboard band trap is an effective tool for detecting and quantifying the population density of the pest in citrus in Florida. Our results also showed that the seasonal abundance of hibiscus mealybug was not influenced by new vegetative growth of citrus trees, nor by environmental factors measured at Florida Automated Weather Network stations close to the sampling sites. This description of the seasonal phenology of hibiscus mealybug will help improve the timing and effectiveness of management efforts for controlling this invasive pest in citrus groves in Florida.

The interstate highways I-10, I-75, and I-95 are key routes for long-distance truckers carrying agricultural products between states and countries. These products often carry pests. Inspectors from the Florida Department of Agriculture and Consumer Services, Division of Plant Industry (FDACS-DPI) work with Agricultural Law Enforcement officers at agricultural inspection stations along these interstate highways. Samples of suspect pests are collected by DPI inspectors and sent for identification. From 2009 to 2021, there were 5,408 samples submitted to entomologists at DPI from inspection stations. These samples resulted in 14,835 interception identifications, of which 1,466 (9.9 %) were pests of regulatory significance to Florida agriculture. Of the regulatorily significant pests, 61.3 % were hemipterans. Several regulated hemipterans, including the potato psyllid, Bactericera cockerelli (Šulc) (Triozidae) , are known to be vectors of plant pathogens that do not occur in Florida. Inspection station interceptions are an important tool for monitoring potentially invasive pests, as is demonstrated in the case of the Ligurian leafhopper, Eupteryx decemnotata (Rey) (Cicadellidae) , which was intercepted alive at the agricultural inspection stations several times and subsequently found to be established in Florida in 2021. Interceptions at Florida’s agricultural inspection stations can include pests that are not yet present in the United States, such as the armored scale Davidsonaspis aguacatae (Evans, Watson & Miller) (Diaspididae). This species is regularly intercepted alive on avocados and threatens domestically grown avocados. Our data illustrate the importance of interstate highways as a pathway for agricultural pests and of inspection stations as an early warning system for invasive insects.

An invasive mealybug (Hemiptera: Coccomorpha: Pseudococcidae) was first detected and identified in Florida in 2019 as Phenacoccus sisymbriifolium Granara de Willink. This species was described from Uruguay in 2007 on Solanum sisymbriifolium Lam. (Solanaceae) and Florida specimens largely matched the description. However, new morphological and molecular evidence supports that this species is Phenacoccus miruku Tanaka & Choi, recently described from Japan in 2022. P. miruku is presumed Neotropical or Nearctic in origin and invasive in Japan. We discuss the issues around the taxonomic identities of these species and for each give diagnoses. An available list of host plants, a current distribution map, notes on ecological associates, images of live specimens in the field, and a key to the species of Phenacoccus in Florida also are provided. Since its detection, this mealybug has been widely found throughout 20 Florida counties with a continuously expanding host list. It is currently most common on roadside weeds such as Bidens alba (L.) DC. and Ambrosia artemisiifolia L. (Asteraceae) but it has recently been identified on cultivated crops such as tomato ( Solanum lycopersicum L.), eggplant ( Solanum melongena L.), naranjilla ( Solanum quitoense Lam.), peppers ( Capsicum L.) (Solanaceae), and sweet potato ( Ipomoea batatas L.) (Convolvulaceae). This paper serves to provide information on this emerging mealybug pest, give resources for its identification, and facilitate detection and management.

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), the oriental fruit fly, is a highly invasive species that has occasionally been detected in Florida, where conditions are highly favorable for the establishment of this pest. In 2015, a major infestation of B. dorsalis was detected in the Redland agricultural area of Miami-Dade county. Other detections of this pest have occurred in various locations in Florida, including the Redland area, before and after 2015. Questions arose whether any of these detections were related to the major infestation in Redland in 2015, possibly as one or more small, scattered populations that went undetected over time only to resurge as better conditions arose. To address this question, the genetic variation of the 2015 Redland outbreak was characterized using microsatellite DNA and by sequencing a portion of the mitochondrial cytochrome oxidase I (COI) gene. Population structure analyses and exclusion testing was performed on flies captured in years immediately preceding and after 2015 using microsatellites to determine (1) if flies were inconsistent with a shared source and (2) if the 2015 population could be excluded as source of subsequent captures. The COI sequences of the flies also were compared to determine if the 2015 outbreaks could explain variation in subsequent years. Results from this study found that flies captured before and after 2015 were not related to the population eradicated in Redland in 2015. Therefore, we concluded that flies captured in Florida between 2014 and 2021 were not part of any single, continuous breeding population that persisted over months.

Florida has become a worldwide hotspot for introduced and invasive ants (Hymenoptera: Formicidae). Furthermore, studies have shown that non-native ants support other invasive insects in Florida, such as the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), which is the vector of Candidatus Liberibacter asiaticus, the causal pathogen of citrus greening, the worst citrus disease in the world. The Asian citrus psyllid establishes beneficial interactions with invasive, introduced, and native ants. In this study, we described the ant diversity in a citrus grove in south Florida as a first step to assess ant-Asian citrus psyllid interactions for future studies. During the summer of 2018, 25 pitfall traps were set in a citrus grove. The red imported fire ant, Solenopsis invicta (Buren), was present in all the traps (100 %), and 19 traps (76 %) had Dorymyrmex bureni (Trager), the pyramid ant, which is native to the southeast United States. Two introduced ants, Cardiocondyla emeryi (Forel) and Brachymyrmex obscurior (Forel), were found in 15 (60 %) and 11 (44 %) traps, respectively. The South American big-headed ant, Pheidole obscurithorax (Naves), was found in 14 traps (56 %). This introduced ant has been found to co-exist with S. invicta , and to our knowledge, this is the first report of the species in this eastern part of peninsular Florida. Finally, Cardiocondyla venustula (Wheeler), an introduced ant from Africa, was found in one of the traps. Although, this ant is found in south Florida, it seems uncommon, and this is its first report in this county. Our study highlights the continued spread of introduced and invasive ants in Florida.

Chinese tallow tree ( Triadica sebifera [L.] Small) (Malpighiales: Euphorbiaceae) is one of the most invasive plants in the southeastern United States and is designated as a noxious weed in the state of Florida. Current management strategies for Chinese tallow are expensive and ineffective at the landscape scale, allowing for further spread. Here, we document the first records of four scale insect species, Ceroplastes rusci (Linnaeus) (Hemiptera: Coccidae), Coccus hesperidum Linnaeus (Hemiptera: Coccidae), Rhizoecus floridanus Hambleton (Hemiptera: Rhizoecidae), and Aonidiella orientalis (Newstead) (Hemiptera: Diaspididae), feeding on a small population of cultivated Chinese tallow and discuss the implications of invasive species interactions.

Floracarus perrepae Knihinicki & Boczek (Acariformes: Eriophyidae) is a gall-forming mite that is used as a biological control agent for the invasive weed Old World climbing fern, Lygodium microphyllum (Cav.) R.Br. (Lygodiaceae). The United States Department of Agriculture, Agricultural Research Service, Invasive Plant Research Laboratory in Fort Lauderdale, Florida, has mass reared and released over 49 million mites since 2014. Recently, a predatory mite has been observed in the mass-rearing and release colony. Preliminary field studies have revealed that the predatory mite is found within F . perrepae galls throughout south Florida. Molecular analysis was conducted and identified the predatory mite as Amblyseius tamatavensis Blommers (Acari: Phytoseiidae).