According to the website of Natural Resources Canada (NRC), the Forest Pest Management Forum (FPMF) is the largest and most significant gathering of forest pest management experts, managers and practitioners in Canada. The objective is to share information on current and future pest conditions, pest control operations, environmental issues and the development of alternatives to chemical insecticides, as well as to discuss new technology and the latest research findings. Proceedings of past meetings (the 57th annual meeting will be on December 2014) can be freely downloaded at http://www.nrcan.gc.ca/pestforum. In those proceedings the interested reader can follow the evolution of different pest problems that Canadian forests have experienced over the years.
Based on information from NRC and FPMF, below is a list of 119 species and 20 families of Lepidoptera caterpillars that have been considered at some point as pests of Canadian forests. Half of those species belong to just two families: Geometridae (27%) and Tortricidaae (26%), and seven families account for three quarters of the species (see figure below). While a few are considered major pests, most are of low significance and only cause minor affectations -either because the damage is too sporadic, or because they are only important at local level.
Families of Lepidoptera pests of Canadian Forests. Modified from the Proceedings of the Forest Pest Management Forum (http://www.nrcan.gc.ca/pestforum).
The proceedings of the FPMF last meetings (2005-present) mention at least 51 of those 119 species (43% of the total). Species are listed below in alphabetical order by their scientific names (with the common names and families of Lepidoptera they belong to, also provided). Species preceded by an asterisk (*) are those mentioned in the Pest Forum meetings from 2005 until present.
1 (*) Acleris gloverana (Walsingham) Western blackheaded budworm Tortricidae
2 (*) Acleris variana (Fernie) Eastern blackheaded budworm Tortricidae
3 Acossus centerensis [Lint.] Poplar carpenterworm Cossidae
4 (*) Acronicta americana (Harr.) American Dagger Moth Noctuidae
5 Acossus populi (Walker) Aspen carpenterworm Cossidae
6 (*) Alsophila pometaria [Harris] Fall cankerworm Geometridae
7 (*) Archips cerasivorana (Fitch) Uglynest caterpillar Tortricidae
8 Archips negundana (Dyar) Larger boxelder leafroller Tortricidae
9 (*) Argyresthia cupressella Walshingham Cypress tip moth Yponomeutidae
10 (*) Argyresthia thuiella (Packard) Arborvitae leafminer Yponomeutidae
11 Argyrotaenia citrana (Fernie) Orange tortrix Tortricidae
12 Argyrotaenia juglandana (Fern.) Hickory Leafroller Tortricidae
13 (*) Bucculatrix canadensisella Chambers Birch skeletonizer Bucculatrigidae
14 Callophrys eryphon (Boisduval) Western pine elfin Lycaenidae
15 Callophrys grynea barryi (Johnson) Barry’s hairstreak Lycaenidae
16 Callophrys grynea rosneri (Johnson) Rosner’s hairstreak Lycaenidae
17 (*) Caloptilia fraxinella (Ely) Ash leaf cone roller Gracillariidae
18 Caloptilia syringella (Fabricius) Lilac leafminer Gracillariidae
19 Cameraria aceriella (Clemens) Maple leafblotch miner Gracillariidae
20 (*) Caripeta divisata Walker Gray spruce looper Geometridae
21 Chionodes continuella (Zeller) Gelechiid moth Gelechiidae
22 (*) Choristoneura biennis Freeman Two-year-cycle budworm Tortricidae
23 (*) Choristoneura conflictana (Walker) Large aspen tortrix Tortricidae
24 (*) Choristoneura fumiferana (Clemens) Spruce budworm Tortricidae
25 (*) Choristoneura occidentalis (Freeman) Western spruce budworm Tortricidae
26 (*) Choristoneura pinus Freeman Jack pine budworm Tortricidae
27 (*) Choristoneura rosaceana (Harr.) Oblique banded leafroller Tortricidae
28 Cladara limitaria (Walker) Yellowlined forest looper Geometridae
29 Clepsis persicana (Fitch) Whitetriangle leafroller Tortricidae
30 (*) Coleophora laricella (Hubner) Larch casebearer Coleophoridae
31 (*) Coleophora serratella (Linnaeus) Birch casebearer Coleophoridae
32 Coleotechnites piceaella (Kearfott) Orange spruce needleminer Gelechiidae
33 Coleotechnites thujaella (Kft) Brown cedar leafminer Gelechiidae
34 (*) Croesia semipurpurana (Kraft) Oak leafshredder Tortricidae
35 Cydia strobilella Linnaeus Spruce seed moth Tortricidae
36 Dasychira grisefacta (Dyar) Pine tussock moth Lymantriidae
37 Dichomeris marginella (Fabricius) Juniper webworm Gelechiidae
38 Dioryctria abietivorella (Grote) Fir coneworm Pyralidae
39 Dioryctria pseudotsugella Munroe Dioryctria moth Pyralidae
40 Dioryctria reniculelloides Mutuura and Munroe Spruce coneworm Pyralidae
41 Ditula angustiorana (Haworth) Red-barred tortrix Tortricidae
42 Dolichomia thymetusalis (Walker) Spruce needleworm, Paler dolichomia moth Pyralidae
43 (*) Dryocampa rubicunda (Fabricius) Greenstriped mapleworm Saturniidae
44 Ectropis crepuscularia (Denis and Schiffermuller) Saddleback looper Geometridae
45 (*) Enargia decolor (Walker) Aspen twoleaf tier Noctuidae
46 (*) Ennomos subsignaria (Hbn.) Elm Spanworm Geometridae
47 Enypia packardata (Taylor) Packard’s gridle moth Geometridae
48 Epinotia radicana (Heinr.) Spruce tip moth; redstriped needleworm Tortricidae
49 (*) Epinotia solandriana (Linnaeus) Birch-aspen leafroller Tortricidae
50 Epinotia subviridis Heinrich Cypress leaftier Tortricidae
51 Epirrita autumnata (Harrison) Green velvet looper Geometridae
52 Epirrita pulchraria (Taylor) Whitelined looper Geometridae
53 (*) Erranis tiliaria Harris Linden looper Geometridae
54 Eucosma gloriola Heinrich Eastern pine shoot borer Tortricidae
55 Eupithecia annulata (Hulst) Larch pug moth Geometridae
56 Eupithecia lariciata (Frey.) Fir needle inchworm Geometridae
57 Eupithecia palpata Pack. Small pine looper Geometridae
58 Eurois occulta (Linnaeus) Great brocade Noctuidae
59 (*) Exotelia pinifoliella (Cham.) Pine Needleminer Gelechiidae
60 Feralia jocosa (Gn.) Redlined conifer caterpillar Noctuidae
61 Hemithea aestivaria (Hubner) Common emerald Geometridae
62 Heterocampa guttivitta Walker Saddled prominent Notodontidae
63 Hyalophora euryalis (Walker) Ceanothus silk moth Saturniidae
64 (*) Hydria pruneverata (Ferguson) Cherryscallopshell moth Geometridae
65 Hypagyrtis piniata (Pack.) Pine measuringworm moth Geometridae
66 (*) Hyphantria cunea (Drury) Fall webworm Arctiidae
67 (*) Iridopsis ephyraria (Wlk.) Pale winged grey Geometridae
68 Itame pustularia (Guen.) Lesser maple spanworm Geometridae
69 (*) Lambdina fiscellaria fiscellaria (Guenée) Hemlock looper Geometridae
70 (*) Lambdina fiscellaria lugubrosa (Hulst) Western hemlock looper Geometridae
71 Lambdina fiscellaria somniaria (Hulst) Western oak looper Geometridae
72 (*) Leucoma salicis (L.) Satin moth Lymantriidae
73 Lophocampa argentata (Packard) Silverspotted tiger moth Arctiidae
74 (*) Lophocampa caryae Harris, 1841 Hickory tussock moth Arctiidae
75 (*) Lymantria dispar (Linnaeus) Gypsy moth Lymantriidae
76 Macaria signaria dispuncta (Walker) Spruce fir looper Geometridae
77 Malacosoma californicum pluviale (Dyar) Northern tent caterpillar Lasiocampidae
78 (*) Malacosoma disstria Hubner Forest tent caterpillar Lasiocampidae
79 Melanolophia imitata (Walker) Greenstriped forest looper Geometridae
80 (*) Micrurapteryx salcifoliella (Chambers) Willow Leaf Blotch Miner Gracillariidae
81 Nematocampa resistaria (Herrich-Schaffer) Filament bearer Geometridae
82 Neoalcis californiaria (Packard) Brownlined looper Geometridae
83 Neophasia menapia (C. & R. Felder) Pine white Pieridae
84 Nepytia freemani (Munroe) Western false hemlock looper Geometridae
85 Nepytia phantasmaria (Strecker) Phantom hemlock looper Geometridae
86 Nymphalis antiopa (Linnaeus) Mourningcloak butterfly or spiny elm caterpillar Nymphalidae
87 (*) Operophtera bruceata (Hulst) Bruce spanworm Geometridae
88 Operophtera brumata (L.) Winter moth Geometridae
89 (*) Orgyia antiqua (L.) Rusty tussock moth Noctuidae
90 (*) Orgyia leucostigma (J. E. Smith) Whitemarked tussock moth Lymantriidae
91 (*) Orgyia pseudotsugata (McDunnough) Douglas-fir tussock moth Lymantriidae
92 Orthosia hibisci (Guenée) Speckled green fruitworm Noctuidae
93 Paleacrita vernata (Peck) Spring cankerworm Geometridae
94 (*) Paraclemensia acerifoliella (Fitch) Maple leafcutter Incurvariidae
95 Pero morrisonaria (Hy. Edwards) Pero moth Geometridae
96 (*) Petrova albicapitana (Busck) Northern pitch twig moth/Pitch nodule maker Tortricidae
97 Petrova metallica (Busck) Metallic pitch blister moth Tortricidae
98 (*) Phyllocnistis populiella Chambers Common Aspen Leaf Miner or Aspen Serpentine Leafmine Gracillariidae
99 Podosesia syringae [Harr.] Lilac borer (Ash borer) Sesiidae
100 Prionoxystus robiniae (Peck) Carpenterworm Cossidae
101 (*) Pseudexentera oregonana (Wlsm.) Early Aspen Leafcurler/Leafroller Tortricidae
102 (*) Pseudosciaphila duplex (Walsingham) Spotted aspen leaf roller Tortricidae
103 (*) Rhyacionia buoliana (Denis and Schiffermuller) European pine shoot moth Tortricidae
104 Semiothisa sexmaculata (Packard) Green larch looper Geometridae
105 Sesia tibialis (Harris) Cottonwood crown borer Sesiidae
106 (*) Sparganothis acerivorana MacKay Maple leafroller Tortricidae
107 (*) Sparganothis pettitana (Rob.) Maple leafroller Tortricidae
108 (*) Symmerista canicosta Franc. Redhumped Oakworm Notodontidae
109 (*) Symmerista leucitys (Franclemont) Orangehumped Mapleworm Notodontidae
110 Synanthedon sequoiae (Hy. Edw.) Sequoia pitch moth Sesiidae
111 Syngrapha alias (Ottolengui) Spruce climbing cutworm Noctuidae
112 Tetracis cachexiata (Guenée) White slaut Geometridae
113 (*) Tetralopha aplastella (Hulst.) Aspen webworm Pyralidae
114 Zale duplicata (Bethune) Pine zale Noctuidae
115 (*) Zeiraphera canadensis Mutuura and Freeman Spruce bud moth Tortricidae
116 Zeiraphera hesperiana (Mutuura & Freeman) Douglas-fir bud moth Tortricidae
117 Zeiraphera improbana (Walker) Larch needleworm Tortricidae
118 Zeiraphera unfortunana Powell Purplestriped shootworm Tortricidae
119 Zelleria haimbachi Busck Pine needle sheathminer Yponomeutidae
Altogether, 299 species of Braconidae wasps have been found, worldwide, attacking those pest caterpillars. The world "worldwide" is stressed here in the sense that those records go beyond Canada to include ANY braconid wasp that has been cited in the scientific literature as a parasitoid of those lepidopterans. It is difficult and very time consuming to separate the sources of information for each individual species and pinpoint the country source (and it is even more difficult to be sure about the certainty of some of those records -some are likely to be wrong for a number of causes). Still, the information below gives an approximate estimate about the diversity of parasitoids of forest pest caterpillars.
For 40 (33.6%) of those caterpillar species there are none braconid wasps recorded as parasitoids. That means one third of the caterpillars where NOTHING is known about its parasitoid biology. And for another 31 species of lepidopterans (26%) only one or two species of braconid parasitoids.
On the other side of the spectrum, there are 30 or more braconid parasitoids recorded for 4 species of caterpillars. They represent important pests (such as the spruce budworm or the Gipsy moth) which at several times have been the focus of serious and intensive rearing efforts from biocontrol workers, resulting in hundreds of research papers.
Braconidae species (Total=299) recorded as parasitoids of 119 pests caterpillars of some relevance to Canadian forests. The numbers on top of each bar represent the actual number of braconids in each category. Modified from Taxapad (2012) and data from the Proceedings of the Forest Pest Management Forum (http://www.nrcan.gc.ca/pestforum).
It is obvious that more rearing studies are needed, and also more study of the specimens already available in collections that represent valuable information. Just one example: in the Canadian National Collection of Insects in Ottawa there are several thousand of braconid specimens reared from forest pest that have never been identified (http://www.biology.ualberta.ca/bsc/news26_2/microgastrinae.htm). Those records that await for study represent an unknown but rich source of biological information -which could be studied, hopefully soon.
Out of the 299 braconids, 120 species (or 40.1 %) were microgastrine wasps, reinforcing their importance as the main group of parasitoids wasps attacking caterpillars -not only in forestry but also in agriculture. At least 70% of those 120 species of microgastrines have been recorded in Canada, and over time we will be posting here more details on those species.