Related by context. Frequent words. (Click for all words.) 74 Invasive species 68 purple loosestrife 67 invasive species 66 invasive weeds 65 invasives 64 Aphids 62 Japanese knotweed 62 Feral hogs 62 invasive weed 62 woody plants 61 leafy spurge 60 species 60 insect populations 60 hemlock trees 60 pests 59 Eurasian watermilfoil 59 cheatgrass 59 forbs 59 adelgid 59 Eurasian milfoil 58 buckthorn 58 whiteflies 58 insect pests 58 invasive pests 58 grasses 58 nonnative species 58 grassland birds 58 phragmites 58 conifers 58 vegetation 57 fungi 57 forest ecosystems 57 knotweed 57 aquatic weeds 57 knapweed 57 Herbicides 57 garlic mustard 57 insect infestations 57 noxious weeds 57 habitats 57 barberry 57 Poison ivy 57 ecosystems 56 weed seeds 56 insects 56 tamarisk 56 beetles 56 gypsy moth caterpillars 56 fireweed 56 understory 56 hemlocks 56 mountain pine beetles 55 Argentine ants 55 junipers 55 Pests 55 weeds 55 pine beetles 55 boreal forests 55 hemlock woolly adelgid 55 beneficial insects 55 feral pigs 55 Feral cats 54 monocultures 54 Phytophthora 54 aquatic ecosystems 54 spider mites 54 aquatic species 54 freshwater ecosystems 54 habitat fragmentation 54 herbaceous plants 54 Zebra mussels 54 invasive alien 54 prairie grasses 54 bark beetles 54 insect pest 54 eucalypts 54 ornamentals 54 flora 54 nonnative 54 noxious weed 54 invasive aquatic 54 shrubs 53 salt cedar 53 bark beetle 53 parasitic wasps 53 anthracnose 53 Honey bees 53 seagrasses 53 whitefly 53 hardwood trees 53 habitat 53 forests 53 Dandelions 53 invasive pest 53 hardwood forests 53 aquatic habitats 53 lodgepole pine 53 groundcovers 52 feral animals 52 fungal spores 52 Prescribed burns