Lygodium microphyllum (Cav.) R. Br. (Schizaeales: Lygodiaceae) is among the most damaging invasive plant species in Florida, USA. Following mechanical and herbicide treatment, the plant typically recovers to pre-treatment levels within 1–2 years through regrowth from the adult rhizome and recruitment of new sporelings. A classical biocontrol agent, the gall-inducing mite Floracarus perrepae Knihinicki & Boczek (Acariformes: Eriophyidae), could attack recovering L. microphyllum, thereby reducing the need for repeated treatments. Here, we investigated natural F. perrepae colonization of recovering L. microphyllum following treatment using two field experiments. First, we monitored F. perrepae colonization on adult regrowth and sporelings on tree islands that were clipped and treated with herbicide (glyphosate or triclopyr). At 24 months post-treatment, mite galls were most abundant on glyphosate treated islands where > 50% of adult rachises and > 80% of sporelings exhibited galls and were rare on untreated islands. Second, we investigated the separate effects of clipping and herbicide (triclopyr) treatment on F. perrepae colonization of regrowth within small-scale plots at four heavily invaded sites. Galls were most prevalent following cutting and least prevalent following herbicide seven months post-treatment, but, on a per pinna (i.e., leaflet) basis, were equivalent across treatments. Taken together, we report that both L. microphyllum regrowth and especially sporelings were highly susceptible to colonization by F. perrepae. Our findings suggest that biological control of L. microphyllum is compatible with herbicide treatment, and future research is needed to determine how best to integrate these management tactics.

Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is a zoophytophagous predator that feeds on plants as well as prey. Several non-crop host plant species have been used to maintain this mirid as a biological control agent in different crop systems. To evaluate the benefit of these non-crop host plants on biological control services, data on the life-history traits of N. tenuis on these plants are important as fundamental information. Herein, we studied the demographic growth parameters of N. tenuis reared on three alternative non-crop host plants (Cleome hassleriana Chod., Brassicales: Cleomaceae; Verbena × hybrida Voss, Lamiales: Verbenaceae; and Sesamum indicum L., Lamiales: Pedaliaceae) and one crop plant (tomato) in the absence of prey under laboratory conditions (25 ± 1 °C, 16:8 h L:D). The estimated intrinsic rate of increase in each plant was significantly greater in the following order: S. indicum (0.094) > C. hassleriana (0.074) > tomato (−0.002) > Verbena × hybrida (−0.060). The results indicated that C. hassleriana and S. indicum were able to fully support the development and reproduction of N. tenuis with nutrients derived from only its plant tissues, whereas Verbena × hybrida and tomato were not. Our findings revealed that C. hassleriana is a promising resource for the conservation or mass rearing of N. tenuis besides S. indicum.

Laricobius nigrinus Fender (Coleoptera: Derodontidae), a predatory beetle native to western North America, has been released since 2003 for management of hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), a non-native pest killing hemlocks in eastern North America. Over 420,000 L. nigrinus have been released in the eastern USA from field and lab-reared sources, 14,000 of which were deployed in the Commonwealth of Virginia, USA. In order to determine the establishment rates of L. nigrinus in Virginia, surveys were conducted in 2017 and 2018 at all release sites within this state. During the study, stand-level HWA densities were estimated, and hemlock tree health and predator–prey ratios were quantified. The identification of Laricobius spp. recoveries were made using microsatellite analysis. During the period of the study, L. nigrinus were found to have established at 82% of Virginia release sites and were the primary species recovered (80%). Both Laricobius rubidus (18%) and hybrids (2%) were also recovered. Stand-level HWA densities varied greatly over sites and years but showed a general decline in year two of the study. Establishment at such a high percentage of release sites suggests that the climate in Virginia is suitable for the predator and the insect is adaptable to the wide variety of site conditions where hemlocks typically grow.

Halyomorpha halys (Stal, 1855) is an invasive pest causing serious damage to agricultural crops in Europe and the USA. Very little is known about H. halys predators in Europe. This survey evaluated the potential of generalist predators/omnivorous species by means of predation bioassays in tri-dimensional arenas, where the predator had to locate H. halys prey items on the leaves of a bean plant. Eleven species of different taxa were tested and the prey items consisted in fresh eggmasses, 1st and 2nd instar nymphs. One species was also tested against adults. Some predators were species commercially available as biocontrol agents against plant pests, other predators were wild, captured in habitats shared with H. halys. All tested specimens were starved 24 h before starting the experiment. The survivorship of control prey items in predator-excluding cages was compared to that of predator treatment groups to determine the effect of predator presence. According to the results, the generalist species showed a quite low acceptance of H. halys prey items, since only two species caused 80% mortality on at least one item (Eupholidoptera chabrieri and Rhynocoris iracundus) and mortality due the other species never exceed 60%. Among commercially available species only Adalia bipunctata adults and Chrysoperla carnea larvae were effective, predating the eggs and 1st instar nymphs, respectively. Among the field collected specimens, the orthopteran E. chabrieri and the predatory hemipterans R. iracundus, Nagusta goedelii and Himacerus mirmicoides showed efficacy against 1st instar nymphs, E. chabrieri and R. iracundus showed efficacy against 2nd instar nymphs, whereas only E. chabrieri and N. goedelii predated the eggs. R. iracundus was also tested on the adults and successfully predated them. By identifying some of the species that can exploit H. halys as a suitable prey in southern Europe, the present investigation provides an important contribution for conservation biological control of this pest.