The Seasonal Population Dynamics of Corythucha arcuata (Say, 1832) (Hemiptera: Tingidae) and the Relationship between Meteorological Factors and the Diurnal Flight Intensity of the Adults in Romanian Oak Forests

To control a forest pest, it is necessary to understand the biotic and/or abiotic factors that can lead to population regulation. Such knowledge is even more critical if the pest is an invasive alien species. This is the case for Corythucha arcuata (Say, 1832), commonly known as the oak lace bug (OLB), an alien insect species that has invaded oak forests on a large scale, both in Romania and other European countries. In this study, we set out to examine the relationship between adults of this species and meteorological factors, such as air temperature and humidity. The study lasted for two years (2019–2020) and was performed on three plots in Romania, in Ilfov, Giurgiu, and Călărași counties. In the first year, the seasonal dynamics of the OLB populations and the meteorological factors potentially influencing those were studied, whilst in the second year, the dynamics of the diurnal activity of the insect population were examined. We found that Corythucha arcuata experienced two population peaks—in July and August—and a diurnal population dynamic that reached a maximum at midday. Data analysis indicated that, for most of the time, the adult activity was influenced by both temperature and humidity. In addition, the population dynamics were not constant over the course of the day, preferring relatively high temperatures and low humidity but not exceeding certain thresholds of thermal discomfort.

EVALUATION OF CHRYSOPERLA CARNEA COMPLEX AND COCCINELLID PREDATORS AS BIOCONTROL AGENTS OF RICANIA SPECULUM (WALKER, 1851) (HEMIPTERA RICANIIDAE)

Ricania speculum is an alien insect feeding on several host plants belonging to several families, including important vegetables, crops, ornamental plants, wild plants as well as trees. For the first time, recently, Chrysoperla sp. and coccinellid beetles have been observed preying on this species in the field on Citrus sp. and Laurus nobilis plants. The main purposes of this work were to evaluate the possible predation capability of these groups of insects and determine their prey preference in laboratory trials. In the choice trials, R. speculum nymphs were paired in a confined space and exposed for 24h to single predators: Ch. carnea complex and to the coccinellids Cryptolaemus montrouzieri, Adalia bipunctata, Coccinella septempunctata, and Propylea quatuordecimpunctata. Specimens of Aphis rumicis, an aphid frequently found on her baceous plants, were used as a control prey. In the cage trials, a single Ch. carnea complex second-instar larva was placed into a jar containing a tomato plant with ten R. speculum nymphs. In the choice trials, a high mortality percentage of both preys was observed with the Ch. carnea complex, while in those with Coccinellids only high A. rumicis mortality was reported. In the cage trials, 13% mortality of R. speculm was recorded after 24h while after 72h and 168h prey mortalities reached 18% and 25%, respectively. The results of the study showed that larvae of the Ch. carnea complex could be potential predators of R. speculum, while coccinellids do not seem promising predators of this alien species.

First Record of Cacopsylla pulchella (Hemiptera, Psyllidae) in Albania

The aim of this study is to identify plant lice Cacopsylla pulchella as a new alien insect in the fauna of Albania. In order to assess the potential of this insect as a pest causing damages on trees, infestation level assessment was used. In the first decade of June 2020 samples were collected at three locations in Albania, where Cercis siliquastrum is grown. Samples were collected and brought to the laboratory for further analysis. Field research was performed to assess distribution and infestation intensity across various localities. The intensity of infestation was assessed by visual examination and was categorized according to previously determined categories. C. pulchella was confirmed on C. siliquastrum in three localities in Albania. Most of the infested trees had a moderate or high intensity of infestation. Compared to the results of other countries, it seems that the Judas trees are under heavy attack in Albania. Librazhd and Elbansn districts had the highest recorded infestation level. Infested trees found in this study should be inspected in the following years and this alien insect should be further monitored in order to estimate its potential of becoming an invasive pest in this country.

Trypanosomatids Detected in the Invasive Avian Parasite Philornis downsi (Diptera: Muscidae) in the Galapagos Islands

Alien insect species may present a multifaceted threat to ecosystems into which they are introduced. In addition to the direct damage they may cause, they may also bring novel diseases and parasites and/or have the capacity to vector microorganisms that are already established in the ecosystem and are causing harm. Damage caused by ectoparasitic larvae of the invasive fly, Philornis downsi (Dodge and Aitken) to nestlings of endemic birds in the Galapagos Islands is well documented, but nothing is known about whether this fly is itself associated with parasites or pathogens. In this study, diagnostic molecular methods indicated the presence of insect trypanosomatids in P. downsi; to our knowledge, this is the first record of insect trypanosomatids associated with Philornis species. Phylogenetic estimates and evolutionary distances indicate these species are most closely related to the Crithidia and Blastocrithidia genera, which are not currently reported in the Galapagos Islands. The prevalence of trypanosomatids indicates either P. downsi arrived with its own parasites or that it is a highly suitable host for trypanosomatids already found in the Galapagos Islands, or both. We recommend further studies to determine the origin of the trypanosomatid infections to better evaluate threats to endemic fauna of the Galapagos Islands.

First Record of Cacopsylla pulchella (Hemiptera, Psyllidae) in Croatia

The aim of this study is to identify plant lice Cacopsylla pulchella a new alien insect in the fauna of Croatia. We propose a new method of infestation level assessment in order to assess the potential of this insect as a pest. In May 2020 samples were collected from eleven locations in Croatia, where Cercis siliquastrum is grown in parks. Adults and nymphs of C. pulchella were collected together with a plant material and brought to entomological laboratory for further analysis. Field research was performed in order to assess the distribution and infestation intensity across various localities in Croatia. The intensity of infestation was assessed heuristically by visual examination and was categorized in four categories: 0) no infestation, 1) low, 2) moderate and 3) high infestation. C. pulchella was confirmed on C. siliquastrum in eleven localities in Croatia. Most of the infested trees had a low or moderate intensity of infestation. Damages caused by this insect are due to the emission of honey dew, a small spherical drop covered with waxy secretion causing necrotic areas which could lead to the premature fall of the leaves. It is not known what kind of progress in infestation intensity could be expected so infested trees found in this study should be checked closely in the coming years. It is strongly suggested to continue the monitoring of this alien insect on C. siliquastrum in Croatia and to estimate its potential of become an invasive pest which could endanger ornamental and other values of its hosts.

Biosecurity risks of invasive alien insect pest species pathways through shared borders with Nigeria

Understanding the biosecurity risks that invasive alien insect pest species currently ravaging forest trees pose is of great importance to forest ecosystems and health. This problem has posed significant challenges to researchers, relevant stakeholders, policy makers and national biosecurity agencies worldwide. This study gives an overview of the top 15 suspected insect pest species most likely to invade or have already invaded forested habitats in order to disrupt ecosystem services and biodiversity within the borders of Nigeria through borderline states (Gombe, Jigawa, Borno, Yobe, Sokoto, Cross River and Lagos). For Nigeria as a whole, all of these top 15 pest species have already established, with identified intra- border line states having no significant effect on severity of invasions ( F1,6=0.07, P=0.910) when compared to identified inter-border line states. This study concludes that the immediate biosecurity risks from already identified invasive insect pests are greater from outside country (inter) borders of Nigeria than within state-to-state (intra) borders of Nigeria. Our findings have potentially significant implications for immediate implementation of national biosecurity forest policy Acts in compliance with Cartagena and Nagoya protocols, emphasizing the need to initiate and implement biosecurity measures simultaneously with any ongoing trans-national border interventions. Keywords: Biosecurity, invasive alien pest species, forests, Nigeria

Invasive Aphid Strikes Sorghum in the U.S.

Invasions of alien insect pests often result in dramatic shifts in the entire ecosystems brought about by severe outbreaks of the pests exploiting new and frequently defenseless host plants. The explosive population dynamics of invasive insects often enable them to outcompete native pest species and alter both the abundance and diversity of communities of their natural enemies. These impacts are probably the most conspicuous and notorious when the invaded host plant is a key commodity crop and the invasive pest an aphid (Hemiptera: Aphididae). Aphids have a remarkable ability to overwhelm their plant hosts extremely rapidly owing to their parthenogenetic reproduction (i.e., daughters are clones of their mothers), live birth, and telescoping generations (i.e., the offspring of unborn aphids are already developing within their bodies). Aphids also attract exceptionally diverse communities of predators and parasitoids, which are strongly attracted to the volatiles emitted from plants attacked by aphids, albeit the natural enemies' attraction to invasive aphids often requires a period of adaption to recognize a new prey. Hence, when new species of aphids invade a new agroecosystem, their presence frequently creates an ?ecosystem earthquake' that can have profound implications for long-term stability of the system most directly affected by the invasive aphid as well as neighboring crops.